Merge branch 'jt/packmigrate'

Code movement to make it easier to hack later.

* jt/packmigrate: (23 commits)
  pack: move for_each_packed_object()
  pack: move has_pack_index()
  pack: move has_sha1_pack()
  pack: move find_pack_entry() and make it global
  pack: move find_sha1_pack()
  pack: move find_pack_entry_one(), is_pack_valid()
  pack: move check_pack_index_ptr(), nth_packed_object_offset()
  pack: move nth_packed_object_{sha1,oid}
  pack: move clear_delta_base_cache(), packed_object_info(), unpack_entry()
  pack: move unpack_object_header()
  pack: move get_size_from_delta()
  pack: move unpack_object_header_buffer()
  pack: move {,re}prepare_packed_git and approximate_object_count
  pack: move install_packed_git()
  pack: move add_packed_git()
  pack: move unuse_pack()
  pack: move use_pack()
  pack: move pack-closing functions
  pack: move release_pack_memory()
  pack: move open_pack_index(), parse_pack_index()
  ...

37 files changed, 2081 insertions, 2014 deletions

diff --git a/Makefile b/Makefile
index ffab6f4568..f2bb7f2f63 100644
--- a/Makefile
+++ b/Makefile
@@ -817,6 +817,7 @@ LIB_OBJS += notes-merge.o
 LIB_OBJS += notes-utils.o
 LIB_OBJS += object.o
 LIB_OBJS += oidset.o
+LIB_OBJS += packfile.o
 LIB_OBJS += pack-bitmap.o
 LIB_OBJS += pack-bitmap-write.o
 LIB_OBJS += pack-check.o
diff --git a/builtin/am.c b/builtin/am.c
index 81095dae02..c369dd1dce 100644
--- a/builtin/am.c
+++ b/builtin/am.c
@@ -31,6 +31,7 @@
 #include "mailinfo.h"
 #include "apply.h"
 #include "string-list.h"
+#include "packfile.h"
 
 /**
  * Returns 1 if the file is empty or does not exist, 0 otherwise.
diff --git a/builtin/cat-file.c b/builtin/cat-file.c
index 62c8cf0ebf..4ccbfaac31 100644
--- a/builtin/cat-file.c
+++ b/builtin/cat-file.c
@@ -12,6 +12,7 @@
 #include "streaming.h"
 #include "tree-walk.h"
 #include "sha1-array.h"
+#include "packfile.h"
 
 struct batch_options {
 	int enabled;
diff --git a/builtin/clone.c b/builtin/clone.c
index f7e17d2295..8d11b570a1 100644
--- a/builtin/clone.c
+++ b/builtin/clone.c
@@ -25,6 +25,7 @@
 #include "remote.h"
 #include "run-command.h"
 #include "connected.h"
+#include "packfile.h"
 
 /*
  * Overall FIXMEs:
diff --git a/builtin/count-objects.c b/builtin/count-objects.c
index 1d82e61f2a..33343818c8 100644
--- a/builtin/count-objects.c
+++ b/builtin/count-objects.c
@@ -10,6 +10,7 @@
 #include "builtin.h"
 #include "parse-options.h"
 #include "quote.h"
+#include "packfile.h"
 
 static unsigned long garbage;
 static off_t size_garbage;
diff --git a/builtin/fetch.c b/builtin/fetch.c
index 132e3224ed..225c734924 100644
--- a/builtin/fetch.c
+++ b/builtin/fetch.c
@@ -17,6 +17,7 @@
 #include "connected.h"
 #include "argv-array.h"
 #include "utf8.h"
+#include "packfile.h"
 
 static const char * const builtin_fetch_usage[] = {
 	N_("git fetch [<options>] [<repository> [<refspec>...]]"),
diff --git a/builtin/fsck.c b/builtin/fsck.c
index 0ab13848a4..1e4c471b41 100644
--- a/builtin/fsck.c
+++ b/builtin/fsck.c
@@ -15,6 +15,7 @@
 #include "progress.h"
 #include "streaming.h"
 #include "decorate.h"
+#include "packfile.h"
 
 #define REACHABLE 0x0001
 #define SEEN      0x0002
diff --git a/builtin/gc.c b/builtin/gc.c
index e6b84475ae..3c78fcb9b1 100644
--- a/builtin/gc.c
+++ b/builtin/gc.c
@@ -19,6 +19,7 @@
 #include "sigchain.h"
 #include "argv-array.h"
 #include "commit.h"
+#include "packfile.h"
 
 #define FAILED_RUN "failed to run %s"
 
diff --git a/builtin/index-pack.c b/builtin/index-pack.c
index 26828c1d82..f2be145e12 100644
--- a/builtin/index-pack.c
+++ b/builtin/index-pack.c
@@ -12,6 +12,7 @@
 #include "exec_cmd.h"
 #include "streaming.h"
 #include "thread-utils.h"
+#include "packfile.h"
 
 static const char index_pack_usage[] =
 "git index-pack [-v] [-o <index-file>] [--keep | --keep=<msg>] [--verify] [--strict] (<pack-file> | --stdin [--fix-thin] [<pack-file>])";
diff --git a/builtin/merge.c b/builtin/merge.c
index cc57052993..7b7320dede 100644
--- a/builtin/merge.c
+++ b/builtin/merge.c
@@ -32,6 +32,7 @@
 #include "gpg-interface.h"
 #include "sequencer.h"
 #include "string-list.h"
+#include "packfile.h"
 
 #define DEFAULT_TWOHEAD (1<<0)
 #define DEFAULT_OCTOPUS (1<<1)
diff --git a/builtin/pack-objects.c b/builtin/pack-objects.c
index c753e9237a..82ad6e0c81 100644
--- a/builtin/pack-objects.c
+++ b/builtin/pack-objects.c
@@ -25,6 +25,7 @@
 #include "sha1-array.h"
 #include "argv-array.h"
 #include "mru.h"
+#include "packfile.h"
 
 static const char *pack_usage[] = {
 	N_("git pack-objects --stdout [<options>...] [< <ref-list> | < <object-list>]"),
diff --git a/builtin/pack-redundant.c b/builtin/pack-redundant.c
index cb1df1c761..aaa8136322 100644
--- a/builtin/pack-redundant.c
+++ b/builtin/pack-redundant.c
@@ -7,6 +7,7 @@
 */
 
 #include "builtin.h"
+#include "packfile.h"
 
 #define BLKSIZE 512
 
diff --git a/builtin/prune-packed.c b/builtin/prune-packed.c
index 8f41f7c20e..419238171d 100644
--- a/builtin/prune-packed.c
+++ b/builtin/prune-packed.c
@@ -2,6 +2,7 @@
 #include "cache.h"
 #include "progress.h"
 #include "parse-options.h"
+#include "packfile.h"
 
 static const char * const prune_packed_usage[] = {
 	N_("git prune-packed [-n | --dry-run] [-q | --quiet]"),
diff --git a/builtin/receive-pack.c b/builtin/receive-pack.c
index 14b6e09b42..52c63ebfdc 100644
--- a/builtin/receive-pack.c
+++ b/builtin/receive-pack.c
@@ -23,6 +23,7 @@
 #include "fsck.h"
 #include "tmp-objdir.h"
 #include "oidset.h"
+#include "packfile.h"
 
 static const char * const receive_pack_usage[] = {
 	N_("git receive-pack <git-dir>"),
diff --git a/bulk-checkin.c b/bulk-checkin.c
index 5be7ce5c73..9a1f6c49ab 100644
--- a/bulk-checkin.c
+++ b/bulk-checkin.c
@@ -6,6 +6,7 @@
 #include "csum-file.h"
 #include "pack.h"
 #include "strbuf.h"
+#include "packfile.h"
 
 static struct bulk_checkin_state {
 	unsigned plugged:1;
diff --git a/cache.h b/cache.h
index bd8802af0e..a916bc79e3 100644
--- a/cache.h
+++ b/cache.h
@@ -903,20 +903,6 @@ extern void check_repository_format(void);
 extern const char *sha1_file_name(const unsigned char *sha1);
 
 /*
- * Return the name of the (local) packfile with the specified sha1 in
- * its name.  The return value is a pointer to memory that is
- * overwritten each time this function is called.
- */
-extern char *sha1_pack_name(const unsigned char *sha1);
-
-/*
- * Return the name of the (local) pack index file with the specified
- * sha1 in its name.  The return value is a pointer to memory that is
- * overwritten each time this function is called.
- */
-extern char *sha1_pack_index_name(const unsigned char *sha1);
-
-/*
  * Return an abbreviated sha1 unique within this repository's object database.
  * The result will be at least `len` characters long, and will be NUL
  * terminated.
@@ -1201,15 +1187,10 @@ extern void *map_sha1_file(const unsigned char *sha1, unsigned long *size);
 extern int unpack_sha1_header(git_zstream *stream, unsigned char *map, unsigned long mapsize, void *buffer, unsigned long bufsiz);
 extern int parse_sha1_header(const char *hdr, unsigned long *sizep);
 
-/* global flag to enable extra checks when accessing packed objects */
-extern int do_check_packed_object_crc;
-
 extern int check_sha1_signature(const unsigned char *sha1, void *buf, unsigned long size, const char *type);
 
 extern int finalize_object_file(const char *tmpfile, const char *filename);
 
-extern int has_sha1_pack(const unsigned char *sha1);
-
 /*
  * Open the loose object at path, check its sha1, and return the contents,
  * type, and size. If the object is a blob, then "contents" may return NULL,
@@ -1245,8 +1226,6 @@ extern int has_object_file_with_flags(const struct object_id *oid, int flags);
  */
 extern int has_loose_object_nonlocal(const unsigned char *sha1);
 
-extern int has_pack_index(const unsigned char *sha1);
-
 extern void assert_sha1_type(const unsigned char *sha1, enum object_type expect);
 
 /* Helper to check and "touch" a file */
@@ -1619,29 +1598,6 @@ struct pack_entry {
 	struct packed_git *p;
 };
 
-extern struct packed_git *parse_pack_index(unsigned char *sha1, const char *idx_path);
-
-/* A hook to report invalid files in pack directory */
-#define PACKDIR_FILE_PACK 1
-#define PACKDIR_FILE_IDX 2
-#define PACKDIR_FILE_GARBAGE 4
-extern void (*report_garbage)(unsigned seen_bits, const char *path);
-
-extern void prepare_packed_git(void);
-extern void reprepare_packed_git(void);
-extern void install_packed_git(struct packed_git *pack);
-
-/*
- * Give a rough count of objects in the repository. This sacrifices accuracy
- * for speed.
- */
-unsigned long approximate_object_count(void);
-
-extern struct packed_git *find_sha1_pack(const unsigned char *sha1,
-					 struct packed_git *packs);
-
-extern void pack_report(void);
-
 /*
  * Create a temporary file rooted in the object database directory, or
  * die on failure. The filename is taken from "pattern", which should have the
@@ -1651,15 +1607,6 @@ extern void pack_report(void);
 extern int odb_mkstemp(struct strbuf *template, const char *pattern);
 
 /*
- * Generate the filename to be used for a pack file with checksum "sha1" and
- * extension "ext". The result is written into the strbuf "buf", overwriting
- * any existing contents. A pointer to buf->buf is returned as a convenience.
- *
- * Example: odb_pack_name(out, sha1, "idx") => ".git/objects/pack/pack-1234..idx"
- */
-extern char *odb_pack_name(struct strbuf *buf, const unsigned char *sha1, const char *ext);
-
-/*
  * Create a pack .keep file named "name" (which should generally be the output
  * of odb_pack_name). Returns a file descriptor opened for writing, or -1 on
  * error.
@@ -1667,67 +1614,6 @@ extern char *odb_pack_name(struct strbuf *buf, const unsigned char *sha1, const
 extern int odb_pack_keep(const char *name);
 
 /*
- * mmap the index file for the specified packfile (if it is not
- * already mmapped).  Return 0 on success.
- */
-extern int open_pack_index(struct packed_git *);
-
-/*
- * munmap the index file for the specified packfile (if it is
- * currently mmapped).
- */
-extern void close_pack_index(struct packed_git *);
-
-extern unsigned char *use_pack(struct packed_git *, struct pack_window **, off_t, unsigned long *);
-extern void close_pack_windows(struct packed_git *);
-extern void close_all_packs(void);
-extern void unuse_pack(struct pack_window **);
-extern void clear_delta_base_cache(void);
-extern struct packed_git *add_packed_git(const char *path, size_t path_len, int local);
-
-/*
- * Make sure that a pointer access into an mmap'd index file is within bounds,
- * and can provide at least 8 bytes of data.
- *
- * Note that this is only necessary for variable-length segments of the file
- * (like the 64-bit extended offset table), as we compare the size to the
- * fixed-length parts when we open the file.
- */
-extern void check_pack_index_ptr(const struct packed_git *p, const void *ptr);
-
-/*
- * Return the SHA-1 of the nth object within the specified packfile.
- * Open the index if it is not already open.  The return value points
- * at the SHA-1 within the mmapped index.  Return NULL if there is an
- * error.
- */
-extern const unsigned char *nth_packed_object_sha1(struct packed_git *, uint32_t n);
-/*
- * Like nth_packed_object_sha1, but write the data into the object specified by
- * the the first argument.  Returns the first argument on success, and NULL on
- * error.
- */
-extern const struct object_id *nth_packed_object_oid(struct object_id *, struct packed_git *, uint32_t n);
-
-/*
- * Return the offset of the nth object within the specified packfile.
- * The index must already be opened.
- */
-extern off_t nth_packed_object_offset(const struct packed_git *, uint32_t n);
-
-/*
- * If the object named sha1 is present in the specified packfile,
- * return its offset within the packfile; otherwise, return 0.
- */
-extern off_t find_pack_entry_one(const unsigned char *sha1, struct packed_git *);
-
-extern int is_pack_valid(struct packed_git *);
-extern void *unpack_entry(struct packed_git *, off_t, enum object_type *, unsigned long *);
-extern unsigned long unpack_object_header_buffer(const unsigned char *buf, unsigned long len, enum object_type *type, unsigned long *sizep);
-extern unsigned long get_size_from_delta(struct packed_git *, struct pack_window **, off_t);
-extern int unpack_object_header(struct packed_git *, struct pack_window **, off_t *, unsigned long *);
-
-/*
  * Iterate over the files in the loose-object parts of the object
  * directory "path", triggering the following callbacks:
  *
@@ -1776,17 +1662,12 @@ int for_each_loose_file_in_objdir_buf(struct strbuf *path,
 				      void *data);
 
 /*
- * Iterate over loose and packed objects in both the local
+ * Iterate over loose objects in both the local
  * repository and any alternates repositories (unless the
  * LOCAL_ONLY flag is set).
  */
 #define FOR_EACH_OBJECT_LOCAL_ONLY 0x1
-typedef int each_packed_object_fn(const struct object_id *oid,
-				  struct packed_git *pack,
-				  uint32_t pos,
-				  void *data);
 extern int for_each_loose_object(each_loose_object_fn, void *, unsigned flags);
-extern int for_each_packed_object(each_packed_object_fn, void *, unsigned flags);
 
 struct object_info {
 	/* Request */
@@ -1836,7 +1717,6 @@ struct object_info {
 /* Do not retry packed storage after checking packed and loose storage */
 #define OBJECT_INFO_QUICK 8
 extern int sha1_object_info_extended(const unsigned char *, struct object_info *, unsigned flags);
-extern int packed_object_info(struct packed_git *pack, off_t offset, struct object_info *);
 
 /* Dumb servers support */
 extern int update_server_info(int);
diff --git a/connected.c b/connected.c
index 136c2ac168..f416b05051 100644
--- a/connected.c
+++ b/connected.c
@@ -3,6 +3,7 @@
 #include "sigchain.h"
 #include "connected.h"
 #include "transport.h"
+#include "packfile.h"
 
 /*
  * If we feed all the commits we want to verify to this command
diff --git a/diff.c b/diff.c
index a74cc08488..3d3e553a98 100644
--- a/diff.c
+++ b/diff.c
@@ -21,6 +21,7 @@
 #include "string-list.h"
 #include "argv-array.h"
 #include "graph.h"
+#include "packfile.h"
 
 #ifdef NO_FAST_WORKING_DIRECTORY
 #define FAST_WORKING_DIRECTORY 0
diff --git a/fast-import.c b/fast-import.c
index a959161b46..49516d60e6 100644
--- a/fast-import.c
+++ b/fast-import.c
@@ -167,6 +167,7 @@ Format of STDIN stream:
 #include "quote.h"
 #include "dir.h"
 #include "run-command.h"
+#include "packfile.h"
 
 #define PACK_ID_BITS 16
 #define MAX_PACK_ID ((1<<PACK_ID_BITS)-1)
diff --git a/fetch-pack.c b/fetch-pack.c
index fbbc99c888..105506e9aa 100644
--- a/fetch-pack.c
+++ b/fetch-pack.c
@@ -17,6 +17,7 @@
 #include "prio-queue.h"
 #include "sha1-array.h"
 #include "oidset.h"
+#include "packfile.h"
 
 static int transfer_unpack_limit = -1;
 static int fetch_unpack_limit = -1;
diff --git a/git-compat-util.h b/git-compat-util.h
index 7d2c0ca759..6678b488cc 100644
--- a/git-compat-util.h
+++ b/git-compat-util.h
@@ -749,8 +749,6 @@ const char *inet_ntop(int af, const void *src, char *dst, size_t size);
 extern int git_atexit(void (*handler)(void));
 #endif
 
-extern void release_pack_memory(size_t);
-
 typedef void (*try_to_free_t)(size_t);
 extern try_to_free_t set_try_to_free_routine(try_to_free_t);
 
diff --git a/http-backend.c b/http-backend.c
index 519025d2c3..8076b1d5e5 100644
--- a/http-backend.c
+++ b/http-backend.c
@@ -9,6 +9,7 @@
 #include "string-list.h"
 #include "url.h"
 #include "argv-array.h"
+#include "packfile.h"
 
 static const char content_type[] = "Content-Type";
 static const char content_length[] = "Content-Length";
diff --git a/http-push.c b/http-push.c
index c91f40a610..e4c9b065ce 100644
--- a/http-push.c
+++ b/http-push.c
@@ -11,6 +11,7 @@
 #include "list-objects.h"
 #include "sigchain.h"
 #include "argv-array.h"
+#include "packfile.h"
 
 #ifdef EXPAT_NEEDS_XMLPARSE_H
 #include <xmlparse.h>
diff --git a/http-walker.c b/http-walker.c
index ee049cb13d..1ae8363de2 100644
--- a/http-walker.c
+++ b/http-walker.c
@@ -4,6 +4,7 @@
 #include "http.h"
 #include "list.h"
 #include "transport.h"
+#include "packfile.h"
 
 struct alt_base {
 	char *base;
diff --git a/http.c b/http.c
index fa8666a21f..9e40a465fd 100644
--- a/http.c
+++ b/http.c
@@ -11,6 +11,7 @@
 #include "pkt-line.h"
 #include "gettext.h"
 #include "transport.h"
+#include "packfile.h"
 
 static struct trace_key trace_curl = TRACE_KEY_INIT(CURL);
 #if LIBCURL_VERSION_NUM >= 0x070a08
diff --git a/outgoing/packfile.h b/outgoing/packfile.h
new file mode 100644
index 0000000000..e69de29bb2
--- /dev/null
+++ b/outgoing/packfile.h
diff --git a/pack-bitmap.c b/pack-bitmap.c
index 327634cd71..cb3d14ba45 100644
--- a/pack-bitmap.c
+++ b/pack-bitmap.c
@@ -9,6 +9,7 @@
 #include "pack-bitmap.h"
 #include "pack-revindex.h"
 #include "pack-objects.h"
+#include "packfile.h"
 
 /*
  * An entry on the bitmap index, representing the bitmap for a given
diff --git a/pack-check.c b/pack-check.c
index e1fcb228fa..073c1fbd46 100644
--- a/pack-check.c
+++ b/pack-check.c
@@ -2,6 +2,7 @@
 #include "pack.h"
 #include "pack-revindex.h"
 #include "progress.h"
+#include "packfile.h"
 
 struct idx_entry {
 	off_t                offset;
diff --git a/packfile.c b/packfile.c
new file mode 100644
index 0000000000..f86fa051c9
--- /dev/null
+++ b/packfile.c
@@ -0,0 +1,1896 @@
+#include "cache.h"
+#include "mru.h"
+#include "pack.h"
+#include "dir.h"
+#include "mergesort.h"
+#include "packfile.h"
+#include "delta.h"
+#include "list.h"
+#include "streaming.h"
+#include "sha1-lookup.h"
+
+char *odb_pack_name(struct strbuf *buf,
+		    const unsigned char *sha1,
+		    const char *ext)
+{
+	strbuf_reset(buf);
+	strbuf_addf(buf, "%s/pack/pack-%s.%s", get_object_directory(),
+		    sha1_to_hex(sha1), ext);
+	return buf->buf;
+}
+
+char *sha1_pack_name(const unsigned char *sha1)
+{
+	static struct strbuf buf = STRBUF_INIT;
+	return odb_pack_name(&buf, sha1, "pack");
+}
+
+char *sha1_pack_index_name(const unsigned char *sha1)
+{
+	static struct strbuf buf = STRBUF_INIT;
+	return odb_pack_name(&buf, sha1, "idx");
+}
+
+static unsigned int pack_used_ctr;
+static unsigned int pack_mmap_calls;
+static unsigned int peak_pack_open_windows;
+static unsigned int pack_open_windows;
+static unsigned int pack_open_fds;
+static unsigned int pack_max_fds;
+static size_t peak_pack_mapped;
+static size_t pack_mapped;
+struct packed_git *packed_git;
+
+static struct mru packed_git_mru_storage;
+struct mru *packed_git_mru = &packed_git_mru_storage;
+
+#define SZ_FMT PRIuMAX
+static inline uintmax_t sz_fmt(size_t s) { return s; }
+
+void pack_report(void)
+{
+	fprintf(stderr,
+		"pack_report: getpagesize()            = %10" SZ_FMT "\n"
+		"pack_report: core.packedGitWindowSize = %10" SZ_FMT "\n"
+		"pack_report: core.packedGitLimit      = %10" SZ_FMT "\n",
+		sz_fmt(getpagesize()),
+		sz_fmt(packed_git_window_size),
+		sz_fmt(packed_git_limit));
+	fprintf(stderr,
+		"pack_report: pack_used_ctr            = %10u\n"
+		"pack_report: pack_mmap_calls          = %10u\n"
+		"pack_report: pack_open_windows        = %10u / %10u\n"
+		"pack_report: pack_mapped              = "
+			"%10" SZ_FMT " / %10" SZ_FMT "\n",
+		pack_used_ctr,
+		pack_mmap_calls,
+		pack_open_windows, peak_pack_open_windows,
+		sz_fmt(pack_mapped), sz_fmt(peak_pack_mapped));
+}
+
+/*
+ * Open and mmap the index file at path, perform a couple of
+ * consistency checks, then record its information to p.  Return 0 on
+ * success.
+ */
+static int check_packed_git_idx(const char *path, struct packed_git *p)
+{
+	void *idx_map;
+	struct pack_idx_header *hdr;
+	size_t idx_size;
+	uint32_t version, nr, i, *index;
+	int fd = git_open(path);
+	struct stat st;
+
+	if (fd < 0)
+		return -1;
+	if (fstat(fd, &st)) {
+		close(fd);
+		return -1;
+	}
+	idx_size = xsize_t(st.st_size);
+	if (idx_size < 4 * 256 + 20 + 20) {
+		close(fd);
+		return error("index file %s is too small", path);
+	}
+	idx_map = xmmap(NULL, idx_size, PROT_READ, MAP_PRIVATE, fd, 0);
+	close(fd);
+
+	hdr = idx_map;
+	if (hdr->idx_signature == htonl(PACK_IDX_SIGNATURE)) {
+		version = ntohl(hdr->idx_version);
+		if (version < 2 || version > 2) {
+			munmap(idx_map, idx_size);
+			return error("index file %s is version %"PRIu32
+				     " and is not supported by this binary"
+				     " (try upgrading GIT to a newer version)",
+				     path, version);
+		}
+	} else
+		version = 1;
+
+	nr = 0;
+	index = idx_map;
+	if (version > 1)
+		index += 2;  /* skip index header */
+	for (i = 0; i < 256; i++) {
+		uint32_t n = ntohl(index[i]);
+		if (n < nr) {
+			munmap(idx_map, idx_size);
+			return error("non-monotonic index %s", path);
+		}
+		nr = n;
+	}
+
+	if (version == 1) {
+		/*
+		 * Total size:
+		 *  - 256 index entries 4 bytes each
+		 *  - 24-byte entries * nr (20-byte sha1 + 4-byte offset)
+		 *  - 20-byte SHA1 of the packfile
+		 *  - 20-byte SHA1 file checksum
+		 */
+		if (idx_size != 4*256 + nr * 24 + 20 + 20) {
+			munmap(idx_map, idx_size);
+			return error("wrong index v1 file size in %s", path);
+		}
+	} else if (version == 2) {
+		/*
+		 * Minimum size:
+		 *  - 8 bytes of header
+		 *  - 256 index entries 4 bytes each
+		 *  - 20-byte sha1 entry * nr
+		 *  - 4-byte crc entry * nr
+		 *  - 4-byte offset entry * nr
+		 *  - 20-byte SHA1 of the packfile
+		 *  - 20-byte SHA1 file checksum
+		 * And after the 4-byte offset table might be a
+		 * variable sized table containing 8-byte entries
+		 * for offsets larger than 2^31.
+		 */
+		unsigned long min_size = 8 + 4*256 + nr*(20 + 4 + 4) + 20 + 20;
+		unsigned long max_size = min_size;
+		if (nr)
+			max_size += (nr - 1)*8;
+		if (idx_size < min_size || idx_size > max_size) {
+			munmap(idx_map, idx_size);
+			return error("wrong index v2 file size in %s", path);
+		}
+		if (idx_size != min_size &&
+		    /*
+		     * make sure we can deal with large pack offsets.
+		     * 31-bit signed offset won't be enough, neither
+		     * 32-bit unsigned one will be.
+		     */
+		    (sizeof(off_t) <= 4)) {
+			munmap(idx_map, idx_size);
+			return error("pack too large for current definition of off_t in %s", path);
+		}
+	}
+
+	p->index_version = version;
+	p->index_data = idx_map;
+	p->index_size = idx_size;
+	p->num_objects = nr;
+	return 0;
+}
+
+int open_pack_index(struct packed_git *p)
+{
+	char *idx_name;
+	size_t len;
+	int ret;
+
+	if (p->index_data)
+		return 0;
+
+	if (!strip_suffix(p->pack_name, ".pack", &len))
+		die("BUG: pack_name does not end in .pack");
+	idx_name = xstrfmt("%.*s.idx", (int)len, p->pack_name);
+	ret = check_packed_git_idx(idx_name, p);
+	free(idx_name);
+	return ret;
+}
+
+static struct packed_git *alloc_packed_git(int extra)
+{
+	struct packed_git *p = xmalloc(st_add(sizeof(*p), extra));
+	memset(p, 0, sizeof(*p));
+	p->pack_fd = -1;
+	return p;
+}
+
+struct packed_git *parse_pack_index(unsigned char *sha1, const char *idx_path)
+{
+	const char *path = sha1_pack_name(sha1);
+	size_t alloc = st_add(strlen(path), 1);
+	struct packed_git *p = alloc_packed_git(alloc);
+
+	memcpy(p->pack_name, path, alloc); /* includes NUL */
+	hashcpy(p->sha1, sha1);
+	if (check_packed_git_idx(idx_path, p)) {
+		free(p);
+		return NULL;
+	}
+
+	return p;
+}
+
+static void scan_windows(struct packed_git *p,
+	struct packed_git **lru_p,
+	struct pack_window **lru_w,
+	struct pack_window **lru_l)
+{
+	struct pack_window *w, *w_l;
+
+	for (w_l = NULL, w = p->windows; w; w = w->next) {
+		if (!w->inuse_cnt) {
+			if (!*lru_w || w->last_used < (*lru_w)->last_used) {
+				*lru_p = p;
+				*lru_w = w;
+				*lru_l = w_l;
+			}
+		}
+		w_l = w;
+	}
+}
+
+static int unuse_one_window(struct packed_git *current)
+{
+	struct packed_git *p, *lru_p = NULL;
+	struct pack_window *lru_w = NULL, *lru_l = NULL;
+
+	if (current)
+		scan_windows(current, &lru_p, &lru_w, &lru_l);
+	for (p = packed_git; p; p = p->next)
+		scan_windows(p, &lru_p, &lru_w, &lru_l);
+	if (lru_p) {
+		munmap(lru_w->base, lru_w->len);
+		pack_mapped -= lru_w->len;
+		if (lru_l)
+			lru_l->next = lru_w->next;
+		else
+			lru_p->windows = lru_w->next;
+		free(lru_w);
+		pack_open_windows--;
+		return 1;
+	}
+	return 0;
+}
+
+void release_pack_memory(size_t need)
+{
+	size_t cur = pack_mapped;
+	while (need >= (cur - pack_mapped) && unuse_one_window(NULL))
+		; /* nothing */
+}
+
+void close_pack_windows(struct packed_git *p)
+{
+	while (p->windows) {
+		struct pack_window *w = p->windows;
+
+		if (w->inuse_cnt)
+			die("pack '%s' still has open windows to it",
+			    p->pack_name);
+		munmap(w->base, w->len);
+		pack_mapped -= w->len;
+		pack_open_windows--;
+		p->windows = w->next;
+		free(w);
+	}
+}
+
+static int close_pack_fd(struct packed_git *p)
+{
+	if (p->pack_fd < 0)
+		return 0;
+
+	close(p->pack_fd);
+	pack_open_fds--;
+	p->pack_fd = -1;
+
+	return 1;
+}
+
+void close_pack_index(struct packed_git *p)
+{
+	if (p->index_data) {
+		munmap((void *)p->index_data, p->index_size);
+		p->index_data = NULL;
+	}
+}
+
+static void close_pack(struct packed_git *p)
+{
+	close_pack_windows(p);
+	close_pack_fd(p);
+	close_pack_index(p);
+}
+
+void close_all_packs(void)
+{
+	struct packed_git *p;
+
+	for (p = packed_git; p; p = p->next)
+		if (p->do_not_close)
+			die("BUG: want to close pack marked 'do-not-close'");
+		else
+			close_pack(p);
+}
+
+/*
+ * The LRU pack is the one with the oldest MRU window, preferring packs
+ * with no used windows, or the oldest mtime if it has no windows allocated.
+ */
+static void find_lru_pack(struct packed_git *p, struct packed_git **lru_p, struct pack_window **mru_w, int *accept_windows_inuse)
+{
+	struct pack_window *w, *this_mru_w;
+	int has_windows_inuse = 0;
+
+	/*
+	 * Reject this pack if it has windows and the previously selected
+	 * one does not.  If this pack does not have windows, reject
+	 * it if the pack file is newer than the previously selected one.
+	 */
+	if (*lru_p && !*mru_w && (p->windows || p->mtime > (*lru_p)->mtime))
+		return;
+
+	for (w = this_mru_w = p->windows; w; w = w->next) {
+		/*
+		 * Reject this pack if any of its windows are in use,
+		 * but the previously selected pack did not have any
+		 * inuse windows.  Otherwise, record that this pack
+		 * has windows in use.
+		 */
+		if (w->inuse_cnt) {
+			if (*accept_windows_inuse)
+				has_windows_inuse = 1;
+			else
+				return;
+		}
+
+		if (w->last_used > this_mru_w->last_used)
+			this_mru_w = w;
+
+		/*
+		 * Reject this pack if it has windows that have been
+		 * used more recently than the previously selected pack.
+		 * If the previously selected pack had windows inuse and
+		 * we have not encountered a window in this pack that is
+		 * inuse, skip this check since we prefer a pack with no
+		 * inuse windows to one that has inuse windows.
+		 */
+		if (*mru_w && *accept_windows_inuse == has_windows_inuse &&
+		    this_mru_w->last_used > (*mru_w)->last_used)
+			return;
+	}
+
+	/*
+	 * Select this pack.
+	 */
+	*mru_w = this_mru_w;
+	*lru_p = p;
+	*accept_windows_inuse = has_windows_inuse;
+}
+
+static int close_one_pack(void)
+{
+	struct packed_git *p, *lru_p = NULL;
+	struct pack_window *mru_w = NULL;
+	int accept_windows_inuse = 1;
+
+	for (p = packed_git; p; p = p->next) {
+		if (p->pack_fd == -1)
+			continue;
+		find_lru_pack(p, &lru_p, &mru_w, &accept_windows_inuse);
+	}
+
+	if (lru_p)
+		return close_pack_fd(lru_p);
+
+	return 0;
+}
+
+static unsigned int get_max_fd_limit(void)
+{
+#ifdef RLIMIT_NOFILE
+	{
+		struct rlimit lim;
+
+		if (!getrlimit(RLIMIT_NOFILE, &lim))
+			return lim.rlim_cur;
+	}
+#endif
+
+#ifdef _SC_OPEN_MAX
+	{
+		long open_max = sysconf(_SC_OPEN_MAX);
+		if (0 < open_max)
+			return open_max;
+		/*
+		 * Otherwise, we got -1 for one of the two
+		 * reasons:
+		 *
+		 * (1) sysconf() did not understand _SC_OPEN_MAX
+		 *     and signaled an error with -1; or
+		 * (2) sysconf() said there is no limit.
+		 *
+		 * We _could_ clear errno before calling sysconf() to
+		 * tell these two cases apart and return a huge number
+		 * in the latter case to let the caller cap it to a
+		 * value that is not so selfish, but letting the
+		 * fallback OPEN_MAX codepath take care of these cases
+		 * is a lot simpler.
+		 */
+	}
+#endif
+
+#ifdef OPEN_MAX
+	return OPEN_MAX;
+#else
+	return 1; /* see the caller ;-) */
+#endif
+}
+
+/*
+ * Do not call this directly as this leaks p->pack_fd on error return;
+ * call open_packed_git() instead.
+ */
+static int open_packed_git_1(struct packed_git *p)
+{
+	struct stat st;
+	struct pack_header hdr;
+	unsigned char sha1[20];
+	unsigned char *idx_sha1;
+	long fd_flag;
+
+	if (!p->index_data && open_pack_index(p))
+		return error("packfile %s index unavailable", p->pack_name);
+
+	if (!pack_max_fds) {
+		unsigned int max_fds = get_max_fd_limit();
+
+		/* Save 3 for stdin/stdout/stderr, 22 for work */
+		if (25 < max_fds)
+			pack_max_fds = max_fds - 25;
+		else
+			pack_max_fds = 1;
+	}
+
+	while (pack_max_fds <= pack_open_fds && close_one_pack())
+		; /* nothing */
+
+	p->pack_fd = git_open(p->pack_name);
+	if (p->pack_fd < 0 || fstat(p->pack_fd, &st))
+		return -1;
+	pack_open_fds++;
+
+	/* If we created the struct before we had the pack we lack size. */
+	if (!p->pack_size) {
+		if (!S_ISREG(st.st_mode))
+			return error("packfile %s not a regular file", p->pack_name);
+		p->pack_size = st.st_size;
+	} else if (p->pack_size != st.st_size)
+		return error("packfile %s size changed", p->pack_name);
+
+	/* We leave these file descriptors open with sliding mmap;
+	 * there is no point keeping them open across exec(), though.
+	 */
+	fd_flag = fcntl(p->pack_fd, F_GETFD, 0);
+	if (fd_flag < 0)
+		return error("cannot determine file descriptor flags");
+	fd_flag |= FD_CLOEXEC;
+	if (fcntl(p->pack_fd, F_SETFD, fd_flag) == -1)
+		return error("cannot set FD_CLOEXEC");
+
+	/* Verify we recognize this pack file format. */
+	if (read_in_full(p->pack_fd, &hdr, sizeof(hdr)) != sizeof(hdr))
+		return error("file %s is far too short to be a packfile", p->pack_name);
+	if (hdr.hdr_signature != htonl(PACK_SIGNATURE))
+		return error("file %s is not a GIT packfile", p->pack_name);
+	if (!pack_version_ok(hdr.hdr_version))
+		return error("packfile %s is version %"PRIu32" and not"
+			" supported (try upgrading GIT to a newer version)",
+			p->pack_name, ntohl(hdr.hdr_version));
+
+	/* Verify the pack matches its index. */
+	if (p->num_objects != ntohl(hdr.hdr_entries))
+		return error("packfile %s claims to have %"PRIu32" objects"
+			     " while index indicates %"PRIu32" objects",
+			     p->pack_name, ntohl(hdr.hdr_entries),
+			     p->num_objects);
+	if (lseek(p->pack_fd, p->pack_size - sizeof(sha1), SEEK_SET) == -1)
+		return error("end of packfile %s is unavailable", p->pack_name);
+	if (read_in_full(p->pack_fd, sha1, sizeof(sha1)) != sizeof(sha1))
+		return error("packfile %s signature is unavailable", p->pack_name);
+	idx_sha1 = ((unsigned char *)p->index_data) + p->index_size - 40;
+	if (hashcmp(sha1, idx_sha1))
+		return error("packfile %s does not match index", p->pack_name);
+	return 0;
+}
+
+static int open_packed_git(struct packed_git *p)
+{
+	if (!open_packed_git_1(p))
+		return 0;
+	close_pack_fd(p);
+	return -1;
+}
+
+static int in_window(struct pack_window *win, off_t offset)
+{
+	/* We must promise at least 20 bytes (one hash) after the
+	 * offset is available from this window, otherwise the offset
+	 * is not actually in this window and a different window (which
+	 * has that one hash excess) must be used.  This is to support
+	 * the object header and delta base parsing routines below.
+	 */
+	off_t win_off = win->offset;
+	return win_off <= offset
+		&& (offset + 20) <= (win_off + win->len);
+}
+
+unsigned char *use_pack(struct packed_git *p,
+		struct pack_window **w_cursor,
+		off_t offset,
+		unsigned long *left)
+{
+	struct pack_window *win = *w_cursor;
+
+	/* Since packfiles end in a hash of their content and it's
+	 * pointless to ask for an offset into the middle of that
+	 * hash, and the in_window function above wouldn't match
+	 * don't allow an offset too close to the end of the file.
+	 */
+	if (!p->pack_size && p->pack_fd == -1 && open_packed_git(p))
+		die("packfile %s cannot be accessed", p->pack_name);
+	if (offset > (p->pack_size - 20))
+		die("offset beyond end of packfile (truncated pack?)");
+	if (offset < 0)
+		die(_("offset before end of packfile (broken .idx?)"));
+
+	if (!win || !in_window(win, offset)) {
+		if (win)
+			win->inuse_cnt--;
+		for (win = p->windows; win; win = win->next) {
+			if (in_window(win, offset))
+				break;
+		}
+		if (!win) {
+			size_t window_align = packed_git_window_size / 2;
+			off_t len;
+
+			if (p->pack_fd == -1 && open_packed_git(p))
+				die("packfile %s cannot be accessed", p->pack_name);
+
+			win = xcalloc(1, sizeof(*win));
+			win->offset = (offset / window_align) * window_align;
+			len = p->pack_size - win->offset;
+			if (len > packed_git_window_size)
+				len = packed_git_window_size;
+			win->len = (size_t)len;
+			pack_mapped += win->len;
+			while (packed_git_limit < pack_mapped
+				&& unuse_one_window(p))
+				; /* nothing */
+			win->base = xmmap(NULL, win->len,
+				PROT_READ, MAP_PRIVATE,
+				p->pack_fd, win->offset);
+			if (win->base == MAP_FAILED)
+				die_errno("packfile %s cannot be mapped",
+					  p->pack_name);
+			if (!win->offset && win->len == p->pack_size
+				&& !p->do_not_close)
+				close_pack_fd(p);
+			pack_mmap_calls++;
+			pack_open_windows++;
+			if (pack_mapped > peak_pack_mapped)
+				peak_pack_mapped = pack_mapped;
+			if (pack_open_windows > peak_pack_open_windows)
+				peak_pack_open_windows = pack_open_windows;
+			win->next = p->windows;
+			p->windows = win;
+		}
+	}
+	if (win != *w_cursor) {
+		win->last_used = pack_used_ctr++;
+		win->inuse_cnt++;
+		*w_cursor = win;
+	}
+	offset -= win->offset;
+	if (left)
+		*left = win->len - xsize_t(offset);
+	return win->base + offset;
+}
+
+void unuse_pack(struct pack_window **w_cursor)
+{
+	struct pack_window *w = *w_cursor;
+	if (w) {
+		w->inuse_cnt--;
+		*w_cursor = NULL;
+	}
+}
+
+static void try_to_free_pack_memory(size_t size)
+{
+	release_pack_memory(size);
+}
+
+struct packed_git *add_packed_git(const char *path, size_t path_len, int local)
+{
+	static int have_set_try_to_free_routine;
+	struct stat st;
+	size_t alloc;
+	struct packed_git *p;
+
+	if (!have_set_try_to_free_routine) {
+		have_set_try_to_free_routine = 1;
+		set_try_to_free_routine(try_to_free_pack_memory);
+	}
+
+	/*
+	 * Make sure a corresponding .pack file exists and that
+	 * the index looks sane.
+	 */
+	if (!strip_suffix_mem(path, &path_len, ".idx"))
+		return NULL;
+
+	/*
+	 * ".pack" is long enough to hold any suffix we're adding (and
+	 * the use xsnprintf double-checks that)
+	 */
+	alloc = st_add3(path_len, strlen(".pack"), 1);
+	p = alloc_packed_git(alloc);
+	memcpy(p->pack_name, path, path_len);
+
+	xsnprintf(p->pack_name + path_len, alloc - path_len, ".keep");
+	if (!access(p->pack_name, F_OK))
+		p->pack_keep = 1;
+
+	xsnprintf(p->pack_name + path_len, alloc - path_len, ".pack");
+	if (stat(p->pack_name, &st) || !S_ISREG(st.st_mode)) {
+		free(p);
+		return NULL;
+	}
+
+	/* ok, it looks sane as far as we can check without
+	 * actually mapping the pack file.
+	 */
+	p->pack_size = st.st_size;
+	p->pack_local = local;
+	p->mtime = st.st_mtime;
+	if (path_len < 40 || get_sha1_hex(path + path_len - 40, p->sha1))
+		hashclr(p->sha1);
+	return p;
+}
+
+void install_packed_git(struct packed_git *pack)
+{
+	if (pack->pack_fd != -1)
+		pack_open_fds++;
+
+	pack->next = packed_git;
+	packed_git = pack;
+}
+
+void (*report_garbage)(unsigned seen_bits, const char *path);
+
+static void report_helper(const struct string_list *list,
+			  int seen_bits, int first, int last)
+{
+	if (seen_bits == (PACKDIR_FILE_PACK|PACKDIR_FILE_IDX))
+		return;
+
+	for (; first < last; first++)
+		report_garbage(seen_bits, list->items[first].string);
+}
+
+static void report_pack_garbage(struct string_list *list)
+{
+	int i, baselen = -1, first = 0, seen_bits = 0;
+
+	if (!report_garbage)
+		return;
+
+	string_list_sort(list);
+
+	for (i = 0; i < list->nr; i++) {
+		const char *path = list->items[i].string;
+		if (baselen != -1 &&
+		    strncmp(path, list->items[first].string, baselen)) {
+			report_helper(list, seen_bits, first, i);
+			baselen = -1;
+			seen_bits = 0;
+		}
+		if (baselen == -1) {
+			const char *dot = strrchr(path, '.');
+			if (!dot) {
+				report_garbage(PACKDIR_FILE_GARBAGE, path);
+				continue;
+			}
+			baselen = dot - path + 1;
+			first = i;
+		}
+		if (!strcmp(path + baselen, "pack"))
+			seen_bits |= 1;
+		else if (!strcmp(path + baselen, "idx"))
+			seen_bits |= 2;
+	}
+	report_helper(list, seen_bits, first, list->nr);
+}
+
+static void prepare_packed_git_one(char *objdir, int local)
+{
+	struct strbuf path = STRBUF_INIT;
+	size_t dirnamelen;
+	DIR *dir;
+	struct dirent *de;
+	struct string_list garbage = STRING_LIST_INIT_DUP;
+
+	strbuf_addstr(&path, objdir);
+	strbuf_addstr(&path, "/pack");
+	dir = opendir(path.buf);
+	if (!dir) {
+		if (errno != ENOENT)
+			error_errno("unable to open object pack directory: %s",
+				    path.buf);
+		strbuf_release(&path);
+		return;
+	}
+	strbuf_addch(&path, '/');
+	dirnamelen = path.len;
+	while ((de = readdir(dir)) != NULL) {
+		struct packed_git *p;
+		size_t base_len;
+
+		if (is_dot_or_dotdot(de->d_name))
+			continue;
+
+		strbuf_setlen(&path, dirnamelen);
+		strbuf_addstr(&path, de->d_name);
+
+		base_len = path.len;
+		if (strip_suffix_mem(path.buf, &base_len, ".idx")) {
+			/* Don't reopen a pack we already have. */
+			for (p = packed_git; p; p = p->next) {
+				size_t len;
+				if (strip_suffix(p->pack_name, ".pack", &len) &&
+				    len == base_len &&
+				    !memcmp(p->pack_name, path.buf, len))
+					break;
+			}
+			if (p == NULL &&
+			    /*
+			     * See if it really is a valid .idx file with
+			     * corresponding .pack file that we can map.
+			     */
+			    (p = add_packed_git(path.buf, path.len, local)) != NULL)
+				install_packed_git(p);
+		}
+
+		if (!report_garbage)
+			continue;
+
+		if (ends_with(de->d_name, ".idx") ||
+		    ends_with(de->d_name, ".pack") ||
+		    ends_with(de->d_name, ".bitmap") ||
+		    ends_with(de->d_name, ".keep"))
+			string_list_append(&garbage, path.buf);
+		else
+			report_garbage(PACKDIR_FILE_GARBAGE, path.buf);
+	}
+	closedir(dir);
+	report_pack_garbage(&garbage);
+	string_list_clear(&garbage, 0);
+	strbuf_release(&path);
+}
+
+static int approximate_object_count_valid;
+
+/*
+ * Give a fast, rough count of the number of objects in the repository. This
+ * ignores loose objects completely. If you have a lot of them, then either
+ * you should repack because your performance will be awful, or they are
+ * all unreachable objects about to be pruned, in which case they're not really
+ * interesting as a measure of repo size in the first place.
+ */
+unsigned long approximate_object_count(void)
+{
+	static unsigned long count;
+	if (!approximate_object_count_valid) {
+		struct packed_git *p;
+
+		prepare_packed_git();
+		count = 0;
+		for (p = packed_git; p; p = p->next) {
+			if (open_pack_index(p))
+				continue;
+			count += p->num_objects;
+		}
+	}
+	return count;
+}
+
+static void *get_next_packed_git(const void *p)
+{
+	return ((const struct packed_git *)p)->next;
+}
+
+static void set_next_packed_git(void *p, void *next)
+{
+	((struct packed_git *)p)->next = next;
+}
+
+static int sort_pack(const void *a_, const void *b_)
+{
+	const struct packed_git *a = a_;
+	const struct packed_git *b = b_;
+	int st;
+
+	/*
+	 * Local packs tend to contain objects specific to our
+	 * variant of the project than remote ones.  In addition,
+	 * remote ones could be on a network mounted filesystem.
+	 * Favor local ones for these reasons.
+	 */
+	st = a->pack_local - b->pack_local;
+	if (st)
+		return -st;
+
+	/*
+	 * Younger packs tend to contain more recent objects,
+	 * and more recent objects tend to get accessed more
+	 * often.
+	 */
+	if (a->mtime < b->mtime)
+		return 1;
+	else if (a->mtime == b->mtime)
+		return 0;
+	return -1;
+}
+
+static void rearrange_packed_git(void)
+{
+	packed_git = llist_mergesort(packed_git, get_next_packed_git,
+				     set_next_packed_git, sort_pack);
+}
+
+static void prepare_packed_git_mru(void)
+{
+	struct packed_git *p;
+
+	mru_clear(packed_git_mru);
+	for (p = packed_git; p; p = p->next)
+		mru_append(packed_git_mru, p);
+}
+
+static int prepare_packed_git_run_once = 0;
+void prepare_packed_git(void)
+{
+	struct alternate_object_database *alt;
+
+	if (prepare_packed_git_run_once)
+		return;
+	prepare_packed_git_one(get_object_directory(), 1);
+	prepare_alt_odb();
+	for (alt = alt_odb_list; alt; alt = alt->next)
+		prepare_packed_git_one(alt->path, 0);
+	rearrange_packed_git();
+	prepare_packed_git_mru();
+	prepare_packed_git_run_once = 1;
+}
+
+void reprepare_packed_git(void)
+{
+	approximate_object_count_valid = 0;
+	prepare_packed_git_run_once = 0;
+	prepare_packed_git();
+}
+
+unsigned long unpack_object_header_buffer(const unsigned char *buf,
+		unsigned long len, enum object_type *type, unsigned long *sizep)
+{
+	unsigned shift;
+	unsigned long size, c;
+	unsigned long used = 0;
+
+	c = buf[used++];
+	*type = (c >> 4) & 7;
+	size = c & 15;
+	shift = 4;
+	while (c & 0x80) {
+		if (len <= used || bitsizeof(long) <= shift) {
+			error("bad object header");
+			size = used = 0;
+			break;
+		}
+		c = buf[used++];
+		size += (c & 0x7f) << shift;
+		shift += 7;
+	}
+	*sizep = size;
+	return used;
+}
+
+unsigned long get_size_from_delta(struct packed_git *p,
+				  struct pack_window **w_curs,
+				  off_t curpos)
+{
+	const unsigned char *data;
+	unsigned char delta_head[20], *in;
+	git_zstream stream;
+	int st;
+
+	memset(&stream, 0, sizeof(stream));
+	stream.next_out = delta_head;
+	stream.avail_out = sizeof(delta_head);
+
+	git_inflate_init(&stream);
+	do {
+		in = use_pack(p, w_curs, curpos, &stream.avail_in);
+		stream.next_in = in;
+		st = git_inflate(&stream, Z_FINISH);
+		curpos += stream.next_in - in;
+	} while ((st == Z_OK || st == Z_BUF_ERROR) &&
+		 stream.total_out < sizeof(delta_head));
+	git_inflate_end(&stream);
+	if ((st != Z_STREAM_END) && stream.total_out != sizeof(delta_head)) {
+		error("delta data unpack-initial failed");
+		return 0;
+	}
+
+	/* Examine the initial part of the delta to figure out
+	 * the result size.
+	 */
+	data = delta_head;
+
+	/* ignore base size */
+	get_delta_hdr_size(&data, delta_head+sizeof(delta_head));
+
+	/* Read the result size */
+	return get_delta_hdr_size(&data, delta_head+sizeof(delta_head));
+}
+
+int unpack_object_header(struct packed_git *p,
+			 struct pack_window **w_curs,
+			 off_t *curpos,
+			 unsigned long *sizep)
+{
+	unsigned char *base;
+	unsigned long left;
+	unsigned long used;
+	enum object_type type;
+
+	/* use_pack() assures us we have [base, base + 20) available
+	 * as a range that we can look at.  (Its actually the hash
+	 * size that is assured.)  With our object header encoding
+	 * the maximum deflated object size is 2^137, which is just
+	 * insane, so we know won't exceed what we have been given.
+	 */
+	base = use_pack(p, w_curs, *curpos, &left);
+	used = unpack_object_header_buffer(base, left, &type, sizep);
+	if (!used) {
+		type = OBJ_BAD;
+	} else
+		*curpos += used;
+
+	return type;
+}
+
+void mark_bad_packed_object(struct packed_git *p, const unsigned char *sha1)
+{
+	unsigned i;
+	for (i = 0; i < p->num_bad_objects; i++)
+		if (!hashcmp(sha1, p->bad_object_sha1 + GIT_SHA1_RAWSZ * i))
+			return;
+	p->bad_object_sha1 = xrealloc(p->bad_object_sha1,
+				      st_mult(GIT_MAX_RAWSZ,
+					      st_add(p->num_bad_objects, 1)));
+	hashcpy(p->bad_object_sha1 + GIT_SHA1_RAWSZ * p->num_bad_objects, sha1);
+	p->num_bad_objects++;
+}
+
+const struct packed_git *has_packed_and_bad(const unsigned char *sha1)
+{
+	struct packed_git *p;
+	unsigned i;
+
+	for (p = packed_git; p; p = p->next)
+		for (i = 0; i < p->num_bad_objects; i++)
+			if (!hashcmp(sha1, p->bad_object_sha1 + 20 * i))
+				return p;
+	return NULL;
+}
+
+static off_t get_delta_base(struct packed_git *p,
+				    struct pack_window **w_curs,
+				    off_t *curpos,
+				    enum object_type type,
+				    off_t delta_obj_offset)
+{
+	unsigned char *base_info = use_pack(p, w_curs, *curpos, NULL);
+	off_t base_offset;
+
+	/* use_pack() assured us we have [base_info, base_info + 20)
+	 * as a range that we can look at without walking off the
+	 * end of the mapped window.  Its actually the hash size
+	 * that is assured.  An OFS_DELTA longer than the hash size
+	 * is stupid, as then a REF_DELTA would be smaller to store.
+	 */
+	if (type == OBJ_OFS_DELTA) {
+		unsigned used = 0;
+		unsigned char c = base_info[used++];
+		base_offset = c & 127;
+		while (c & 128) {
+			base_offset += 1;
+			if (!base_offset || MSB(base_offset, 7))
+				return 0;  /* overflow */
+			c = base_info[used++];
+			base_offset = (base_offset << 7) + (c & 127);
+		}
+		base_offset = delta_obj_offset - base_offset;
+		if (base_offset <= 0 || base_offset >= delta_obj_offset)
+			return 0;  /* out of bound */
+		*curpos += used;
+	} else if (type == OBJ_REF_DELTA) {
+		/* The base entry _must_ be in the same pack */
+		base_offset = find_pack_entry_one(base_info, p);
+		*curpos += 20;
+	} else
+		die("I am totally screwed");
+	return base_offset;
+}
+
+/*
+ * Like get_delta_base above, but we return the sha1 instead of the pack
+ * offset. This means it is cheaper for REF deltas (we do not have to do
+ * the final object lookup), but more expensive for OFS deltas (we
+ * have to load the revidx to convert the offset back into a sha1).
+ */
+static const unsigned char *get_delta_base_sha1(struct packed_git *p,
+						struct pack_window **w_curs,
+						off_t curpos,
+						enum object_type type,
+						off_t delta_obj_offset)
+{
+	if (type == OBJ_REF_DELTA) {
+		unsigned char *base = use_pack(p, w_curs, curpos, NULL);
+		return base;
+	} else if (type == OBJ_OFS_DELTA) {
+		struct revindex_entry *revidx;
+		off_t base_offset = get_delta_base(p, w_curs, &curpos,
+						   type, delta_obj_offset);
+
+		if (!base_offset)
+			return NULL;
+
+		revidx = find_pack_revindex(p, base_offset);
+		if (!revidx)
+			return NULL;
+
+		return nth_packed_object_sha1(p, revidx->nr);
+	} else
+		return NULL;
+}
+
+static int retry_bad_packed_offset(struct packed_git *p, off_t obj_offset)
+{
+	int type;
+	struct revindex_entry *revidx;
+	const unsigned char *sha1;
+	revidx = find_pack_revindex(p, obj_offset);
+	if (!revidx)
+		return OBJ_BAD;
+	sha1 = nth_packed_object_sha1(p, revidx->nr);
+	mark_bad_packed_object(p, sha1);
+	type = sha1_object_info(sha1, NULL);
+	if (type <= OBJ_NONE)
+		return OBJ_BAD;
+	return type;
+}
+
+#define POI_STACK_PREALLOC 64
+
+static enum object_type packed_to_object_type(struct packed_git *p,
+					      off_t obj_offset,
+					      enum object_type type,
+					      struct pack_window **w_curs,
+					      off_t curpos)
+{
+	off_t small_poi_stack[POI_STACK_PREALLOC];
+	off_t *poi_stack = small_poi_stack;
+	int poi_stack_nr = 0, poi_stack_alloc = POI_STACK_PREALLOC;
+
+	while (type == OBJ_OFS_DELTA || type == OBJ_REF_DELTA) {
+		off_t base_offset;
+		unsigned long size;
+		/* Push the object we're going to leave behind */
+		if (poi_stack_nr >= poi_stack_alloc && poi_stack == small_poi_stack) {
+			poi_stack_alloc = alloc_nr(poi_stack_nr);
+			ALLOC_ARRAY(poi_stack, poi_stack_alloc);
+			memcpy(poi_stack, small_poi_stack, sizeof(off_t)*poi_stack_nr);
+		} else {
+			ALLOC_GROW(poi_stack, poi_stack_nr+1, poi_stack_alloc);
+		}
+		poi_stack[poi_stack_nr++] = obj_offset;
+		/* If parsing the base offset fails, just unwind */
+		base_offset = get_delta_base(p, w_curs, &curpos, type, obj_offset);
+		if (!base_offset)
+			goto unwind;
+		curpos = obj_offset = base_offset;
+		type = unpack_object_header(p, w_curs, &curpos, &size);
+		if (type <= OBJ_NONE) {
+			/* If getting the base itself fails, we first
+			 * retry the base, otherwise unwind */
+			type = retry_bad_packed_offset(p, base_offset);
+			if (type > OBJ_NONE)
+				goto out;
+			goto unwind;
+		}
+	}
+
+	switch (type) {
+	case OBJ_BAD:
+	case OBJ_COMMIT:
+	case OBJ_TREE:
+	case OBJ_BLOB:
+	case OBJ_TAG:
+		break;
+	default:
+		error("unknown object type %i at offset %"PRIuMAX" in %s",
+		      type, (uintmax_t)obj_offset, p->pack_name);
+		type = OBJ_BAD;
+	}
+
+out:
+	if (poi_stack != small_poi_stack)
+		free(poi_stack);
+	return type;
+
+unwind:
+	while (poi_stack_nr) {
+		obj_offset = poi_stack[--poi_stack_nr];
+		type = retry_bad_packed_offset(p, obj_offset);
+		if (type > OBJ_NONE)
+			goto out;
+	}
+	type = OBJ_BAD;
+	goto out;
+}
+
+static struct hashmap delta_base_cache;
+static size_t delta_base_cached;
+
+static LIST_HEAD(delta_base_cache_lru);
+
+struct delta_base_cache_key {
+	struct packed_git *p;
+	off_t base_offset;
+};
+
+struct delta_base_cache_entry {
+	struct hashmap hash;
+	struct delta_base_cache_key key;
+	struct list_head lru;
+	void *data;
+	unsigned long size;
+	enum object_type type;
+};
+
+static unsigned int pack_entry_hash(struct packed_git *p, off_t base_offset)
+{
+	unsigned int hash;
+
+	hash = (unsigned int)(intptr_t)p + (unsigned int)base_offset;
+	hash += (hash >> 8) + (hash >> 16);
+	return hash;
+}
+
+static struct delta_base_cache_entry *
+get_delta_base_cache_entry(struct packed_git *p, off_t base_offset)
+{
+	struct hashmap_entry entry;
+	struct delta_base_cache_key key;
+
+	if (!delta_base_cache.cmpfn)
+		return NULL;
+
+	hashmap_entry_init(&entry, pack_entry_hash(p, base_offset));
+	key.p = p;
+	key.base_offset = base_offset;
+	return hashmap_get(&delta_base_cache, &entry, &key);
+}
+
+static int delta_base_cache_key_eq(const struct delta_base_cache_key *a,
+				   const struct delta_base_cache_key *b)
+{
+	return a->p == b->p && a->base_offset == b->base_offset;
+}
+
+static int delta_base_cache_hash_cmp(const void *unused_cmp_data,
+				     const void *va, const void *vb,
+				     const void *vkey)
+{
+	const struct delta_base_cache_entry *a = va, *b = vb;
+	const struct delta_base_cache_key *key = vkey;
+	if (key)
+		return !delta_base_cache_key_eq(&a->key, key);
+	else
+		return !delta_base_cache_key_eq(&a->key, &b->key);
+}
+
+static int in_delta_base_cache(struct packed_git *p, off_t base_offset)
+{
+	return !!get_delta_base_cache_entry(p, base_offset);
+}
+
+/*
+ * Remove the entry from the cache, but do _not_ free the associated
+ * entry data. The caller takes ownership of the "data" buffer, and
+ * should copy out any fields it wants before detaching.
+ */
+static void detach_delta_base_cache_entry(struct delta_base_cache_entry *ent)
+{
+	hashmap_remove(&delta_base_cache, ent, &ent->key);
+	list_del(&ent->lru);
+	delta_base_cached -= ent->size;
+	free(ent);
+}
+
+static void *cache_or_unpack_entry(struct packed_git *p, off_t base_offset,
+	unsigned long *base_size, enum object_type *type)
+{
+	struct delta_base_cache_entry *ent;
+
+	ent = get_delta_base_cache_entry(p, base_offset);
+	if (!ent)
+		return unpack_entry(p, base_offset, type, base_size);
+
+	if (type)
+		*type = ent->type;
+	if (base_size)
+		*base_size = ent->size;
+	return xmemdupz(ent->data, ent->size);
+}
+
+static inline void release_delta_base_cache(struct delta_base_cache_entry *ent)
+{
+	free(ent->data);
+	detach_delta_base_cache_entry(ent);
+}
+
+void clear_delta_base_cache(void)
+{
+	struct list_head *lru, *tmp;
+	list_for_each_safe(lru, tmp, &delta_base_cache_lru) {
+		struct delta_base_cache_entry *entry =
+			list_entry(lru, struct delta_base_cache_entry, lru);
+		release_delta_base_cache(entry);
+	}
+}
+
+static void add_delta_base_cache(struct packed_git *p, off_t base_offset,
+	void *base, unsigned long base_size, enum object_type type)
+{
+	struct delta_base_cache_entry *ent = xmalloc(sizeof(*ent));
+	struct list_head *lru, *tmp;
+
+	delta_base_cached += base_size;
+
+	list_for_each_safe(lru, tmp, &delta_base_cache_lru) {
+		struct delta_base_cache_entry *f =
+			list_entry(lru, struct delta_base_cache_entry, lru);
+		if (delta_base_cached <= delta_base_cache_limit)
+			break;
+		release_delta_base_cache(f);
+	}
+
+	ent->key.p = p;
+	ent->key.base_offset = base_offset;
+	ent->type = type;
+	ent->data = base;
+	ent->size = base_size;
+	list_add_tail(&ent->lru, &delta_base_cache_lru);
+
+	if (!delta_base_cache.cmpfn)
+		hashmap_init(&delta_base_cache, delta_base_cache_hash_cmp, NULL, 0);
+	hashmap_entry_init(ent, pack_entry_hash(p, base_offset));
+	hashmap_add(&delta_base_cache, ent);
+}
+
+int packed_object_info(struct packed_git *p, off_t obj_offset,
+		       struct object_info *oi)
+{
+	struct pack_window *w_curs = NULL;
+	unsigned long size;
+	off_t curpos = obj_offset;
+	enum object_type type;
+
+	/*
+	 * We always get the representation type, but only convert it to
+	 * a "real" type later if the caller is interested.
+	 */
+	if (oi->contentp) {
+		*oi->contentp = cache_or_unpack_entry(p, obj_offset, oi->sizep,
+						      &type);
+		if (!*oi->contentp)
+			type = OBJ_BAD;
+	} else {
+		type = unpack_object_header(p, &w_curs, &curpos, &size);
+	}
+
+	if (!oi->contentp && oi->sizep) {
+		if (type == OBJ_OFS_DELTA || type == OBJ_REF_DELTA) {
+			off_t tmp_pos = curpos;
+			off_t base_offset = get_delta_base(p, &w_curs, &tmp_pos,
+							   type, obj_offset);
+			if (!base_offset) {
+				type = OBJ_BAD;
+				goto out;
+			}
+			*oi->sizep = get_size_from_delta(p, &w_curs, tmp_pos);
+			if (*oi->sizep == 0) {
+				type = OBJ_BAD;
+				goto out;
+			}
+		} else {
+			*oi->sizep = size;
+		}
+	}
+
+	if (oi->disk_sizep) {
+		struct revindex_entry *revidx = find_pack_revindex(p, obj_offset);
+		*oi->disk_sizep = revidx[1].offset - obj_offset;
+	}
+
+	if (oi->typep || oi->typename) {
+		enum object_type ptot;
+		ptot = packed_to_object_type(p, obj_offset, type, &w_curs,
+					     curpos);
+		if (oi->typep)
+			*oi->typep = ptot;
+		if (oi->typename) {
+			const char *tn = typename(ptot);
+			if (tn)
+				strbuf_addstr(oi->typename, tn);
+		}
+		if (ptot < 0) {
+			type = OBJ_BAD;
+			goto out;
+		}
+	}
+
+	if (oi->delta_base_sha1) {
+		if (type == OBJ_OFS_DELTA || type == OBJ_REF_DELTA) {
+			const unsigned char *base;
+
+			base = get_delta_base_sha1(p, &w_curs, curpos,
+						   type, obj_offset);
+			if (!base) {
+				type = OBJ_BAD;
+				goto out;
+			}
+
+			hashcpy(oi->delta_base_sha1, base);
+		} else
+			hashclr(oi->delta_base_sha1);
+	}
+
+	oi->whence = in_delta_base_cache(p, obj_offset) ? OI_DBCACHED :
+							  OI_PACKED;
+
+out:
+	unuse_pack(&w_curs);
+	return type;
+}
+
+static void *unpack_compressed_entry(struct packed_git *p,
+				    struct pack_window **w_curs,
+				    off_t curpos,
+				    unsigned long size)
+{
+	int st;
+	git_zstream stream;
+	unsigned char *buffer, *in;
+
+	buffer = xmallocz_gently(size);
+	if (!buffer)
+		return NULL;
+	memset(&stream, 0, sizeof(stream));
+	stream.next_out = buffer;
+	stream.avail_out = size + 1;
+
+	git_inflate_init(&stream);
+	do {
+		in = use_pack(p, w_curs, curpos, &stream.avail_in);
+		stream.next_in = in;
+		st = git_inflate(&stream, Z_FINISH);
+		if (!stream.avail_out)
+			break; /* the payload is larger than it should be */
+		curpos += stream.next_in - in;
+	} while (st == Z_OK || st == Z_BUF_ERROR);
+	git_inflate_end(&stream);
+	if ((st != Z_STREAM_END) || stream.total_out != size) {
+		free(buffer);
+		return NULL;
+	}
+
+	return buffer;
+}
+
+static void write_pack_access_log(struct packed_git *p, off_t obj_offset)
+{
+	static struct trace_key pack_access = TRACE_KEY_INIT(PACK_ACCESS);
+	trace_printf_key(&pack_access, "%s %"PRIuMAX"\n",
+			 p->pack_name, (uintmax_t)obj_offset);
+}
+
+int do_check_packed_object_crc;
+
+#define UNPACK_ENTRY_STACK_PREALLOC 64
+struct unpack_entry_stack_ent {
+	off_t obj_offset;
+	off_t curpos;
+	unsigned long size;
+};
+
+static void *read_object(const unsigned char *sha1, enum object_type *type,
+			 unsigned long *size)
+{
+	struct object_info oi = OBJECT_INFO_INIT;
+	void *content;
+	oi.typep = type;
+	oi.sizep = size;
+	oi.contentp = &content;
+
+	if (sha1_object_info_extended(sha1, &oi, 0) < 0)
+		return NULL;
+	return content;
+}
+
+void *unpack_entry(struct packed_git *p, off_t obj_offset,
+		   enum object_type *final_type, unsigned long *final_size)
+{
+	struct pack_window *w_curs = NULL;
+	off_t curpos = obj_offset;
+	void *data = NULL;
+	unsigned long size;
+	enum object_type type;
+	struct unpack_entry_stack_ent small_delta_stack[UNPACK_ENTRY_STACK_PREALLOC];
+	struct unpack_entry_stack_ent *delta_stack = small_delta_stack;
+	int delta_stack_nr = 0, delta_stack_alloc = UNPACK_ENTRY_STACK_PREALLOC;
+	int base_from_cache = 0;
+
+	write_pack_access_log(p, obj_offset);
+
+	/* PHASE 1: drill down to the innermost base object */
+	for (;;) {
+		off_t base_offset;
+		int i;
+		struct delta_base_cache_entry *ent;
+
+		ent = get_delta_base_cache_entry(p, curpos);
+		if (ent) {
+			type = ent->type;
+			data = ent->data;
+			size = ent->size;
+			detach_delta_base_cache_entry(ent);
+			base_from_cache = 1;
+			break;
+		}
+
+		if (do_check_packed_object_crc && p->index_version > 1) {
+			struct revindex_entry *revidx = find_pack_revindex(p, obj_offset);
+			off_t len = revidx[1].offset - obj_offset;
+			if (check_pack_crc(p, &w_curs, obj_offset, len, revidx->nr)) {
+				const unsigned char *sha1 =
+					nth_packed_object_sha1(p, revidx->nr);
+				error("bad packed object CRC for %s",
+				      sha1_to_hex(sha1));
+				mark_bad_packed_object(p, sha1);
+				data = NULL;
+				goto out;
+			}
+		}
+
+		type = unpack_object_header(p, &w_curs, &curpos, &size);
+		if (type != OBJ_OFS_DELTA && type != OBJ_REF_DELTA)
+			break;
+
+		base_offset = get_delta_base(p, &w_curs, &curpos, type, obj_offset);
+		if (!base_offset) {
+			error("failed to validate delta base reference "
+			      "at offset %"PRIuMAX" from %s",
+			      (uintmax_t)curpos, p->pack_name);
+			/* bail to phase 2, in hopes of recovery */
+			data = NULL;
+			break;
+		}
+
+		/* push object, proceed to base */
+		if (delta_stack_nr >= delta_stack_alloc
+		    && delta_stack == small_delta_stack) {
+			delta_stack_alloc = alloc_nr(delta_stack_nr);
+			ALLOC_ARRAY(delta_stack, delta_stack_alloc);
+			memcpy(delta_stack, small_delta_stack,
+			       sizeof(*delta_stack)*delta_stack_nr);
+		} else {
+			ALLOC_GROW(delta_stack, delta_stack_nr+1, delta_stack_alloc);
+		}
+		i = delta_stack_nr++;
+		delta_stack[i].obj_offset = obj_offset;
+		delta_stack[i].curpos = curpos;
+		delta_stack[i].size = size;
+
+		curpos = obj_offset = base_offset;
+	}
+
+	/* PHASE 2: handle the base */
+	switch (type) {
+	case OBJ_OFS_DELTA:
+	case OBJ_REF_DELTA:
+		if (data)
+			die("BUG: unpack_entry: left loop at a valid delta");
+		break;
+	case OBJ_COMMIT:
+	case OBJ_TREE:
+	case OBJ_BLOB:
+	case OBJ_TAG:
+		if (!base_from_cache)
+			data = unpack_compressed_entry(p, &w_curs, curpos, size);
+		break;
+	default:
+		data = NULL;
+		error("unknown object type %i at offset %"PRIuMAX" in %s",
+		      type, (uintmax_t)obj_offset, p->pack_name);
+	}
+
+	/* PHASE 3: apply deltas in order */
+
+	/* invariants:
+	 *   'data' holds the base data, or NULL if there was corruption
+	 */
+	while (delta_stack_nr) {
+		void *delta_data;
+		void *base = data;
+		void *external_base = NULL;
+		unsigned long delta_size, base_size = size;
+		int i;
+
+		data = NULL;
+
+		if (base)
+			add_delta_base_cache(p, obj_offset, base, base_size, type);
+
+		if (!base) {
+			/*
+			 * We're probably in deep shit, but let's try to fetch
+			 * the required base anyway from another pack or loose.
+			 * This is costly but should happen only in the presence
+			 * of a corrupted pack, and is better than failing outright.
+			 */
+			struct revindex_entry *revidx;
+			const unsigned char *base_sha1;
+			revidx = find_pack_revindex(p, obj_offset);
+			if (revidx) {
+				base_sha1 = nth_packed_object_sha1(p, revidx->nr);
+				error("failed to read delta base object %s"
+				      " at offset %"PRIuMAX" from %s",
+				      sha1_to_hex(base_sha1), (uintmax_t)obj_offset,
+				      p->pack_name);
+				mark_bad_packed_object(p, base_sha1);
+				base = read_object(base_sha1, &type, &base_size);
+				external_base = base;
+			}
+		}
+
+		i = --delta_stack_nr;
+		obj_offset = delta_stack[i].obj_offset;
+		curpos = delta_stack[i].curpos;
+		delta_size = delta_stack[i].size;
+
+		if (!base)
+			continue;
+
+		delta_data = unpack_compressed_entry(p, &w_curs, curpos, delta_size);
+
+		if (!delta_data) {
+			error("failed to unpack compressed delta "
+			      "at offset %"PRIuMAX" from %s",
+			      (uintmax_t)curpos, p->pack_name);
+			data = NULL;
+			free(external_base);
+			continue;
+		}
+
+		data = patch_delta(base, base_size,
+				   delta_data, delta_size,
+				   &size);
+
+		/*
+		 * We could not apply the delta; warn the user, but keep going.
+		 * Our failure will be noticed either in the next iteration of
+		 * the loop, or if this is the final delta, in the caller when
+		 * we return NULL. Those code paths will take care of making
+		 * a more explicit warning and retrying with another copy of
+		 * the object.
+		 */
+		if (!data)
+			error("failed to apply delta");
+
+		free(delta_data);
+		free(external_base);
+	}
+
+	if (final_type)
+		*final_type = type;
+	if (final_size)
+		*final_size = size;
+
+out:
+	unuse_pack(&w_curs);
+
+	if (delta_stack != small_delta_stack)
+		free(delta_stack);
+
+	return data;
+}
+
+const unsigned char *nth_packed_object_sha1(struct packed_git *p,
+					    uint32_t n)
+{
+	const unsigned char *index = p->index_data;
+	if (!index) {
+		if (open_pack_index(p))
+			return NULL;
+		index = p->index_data;
+	}
+	if (n >= p->num_objects)
+		return NULL;
+	index += 4 * 256;
+	if (p->index_version == 1) {
+		return index + 24 * n + 4;
+	} else {
+		index += 8;
+		return index + 20 * n;
+	}
+}
+
+const struct object_id *nth_packed_object_oid(struct object_id *oid,
+					      struct packed_git *p,
+					      uint32_t n)
+{
+	const unsigned char *hash = nth_packed_object_sha1(p, n);
+	if (!hash)
+		return NULL;
+	hashcpy(oid->hash, hash);
+	return oid;
+}
+
+void check_pack_index_ptr(const struct packed_git *p, const void *vptr)
+{
+	const unsigned char *ptr = vptr;
+	const unsigned char *start = p->index_data;
+	const unsigned char *end = start + p->index_size;
+	if (ptr < start)
+		die(_("offset before start of pack index for %s (corrupt index?)"),
+		    p->pack_name);
+	/* No need to check for underflow; .idx files must be at least 8 bytes */
+	if (ptr >= end - 8)
+		die(_("offset beyond end of pack index for %s (truncated index?)"),
+		    p->pack_name);
+}
+
+off_t nth_packed_object_offset(const struct packed_git *p, uint32_t n)
+{
+	const unsigned char *index = p->index_data;
+	index += 4 * 256;
+	if (p->index_version == 1) {
+		return ntohl(*((uint32_t *)(index + 24 * n)));
+	} else {
+		uint32_t off;
+		index += 8 + p->num_objects * (20 + 4);
+		off = ntohl(*((uint32_t *)(index + 4 * n)));
+		if (!(off & 0x80000000))
+			return off;
+		index += p->num_objects * 4 + (off & 0x7fffffff) * 8;
+		check_pack_index_ptr(p, index);
+		return (((uint64_t)ntohl(*((uint32_t *)(index + 0)))) << 32) |
+				   ntohl(*((uint32_t *)(index + 4)));
+	}
+}
+
+off_t find_pack_entry_one(const unsigned char *sha1,
+				  struct packed_git *p)
+{
+	const uint32_t *level1_ofs = p->index_data;
+	const unsigned char *index = p->index_data;
+	unsigned hi, lo, stride;
+	static int debug_lookup = -1;
+
+	if (debug_lookup < 0)
+		debug_lookup = !!getenv("GIT_DEBUG_LOOKUP");
+
+	if (!index) {
+		if (open_pack_index(p))
+			return 0;
+		level1_ofs = p->index_data;
+		index = p->index_data;
+	}
+	if (p->index_version > 1) {
+		level1_ofs += 2;
+		index += 8;
+	}
+	index += 4 * 256;
+	hi = ntohl(level1_ofs[*sha1]);
+	lo = ((*sha1 == 0x0) ? 0 : ntohl(level1_ofs[*sha1 - 1]));
+	if (p->index_version > 1) {
+		stride = 20;
+	} else {
+		stride = 24;
+		index += 4;
+	}
+
+	if (debug_lookup)
+		printf("%02x%02x%02x... lo %u hi %u nr %"PRIu32"\n",
+		       sha1[0], sha1[1], sha1[2], lo, hi, p->num_objects);
+
+	while (lo < hi) {
+		unsigned mi = (lo + hi) / 2;
+		int cmp = hashcmp(index + mi * stride, sha1);
+
+		if (debug_lookup)
+			printf("lo %u hi %u rg %u mi %u\n",
+			       lo, hi, hi - lo, mi);
+		if (!cmp)
+			return nth_packed_object_offset(p, mi);
+		if (cmp > 0)
+			hi = mi;
+		else
+			lo = mi+1;
+	}
+	return 0;
+}
+
+int is_pack_valid(struct packed_git *p)
+{
+	/* An already open pack is known to be valid. */
+	if (p->pack_fd != -1)
+		return 1;
+
+	/* If the pack has one window completely covering the
+	 * file size, the pack is known to be valid even if
+	 * the descriptor is not currently open.
+	 */
+	if (p->windows) {
+		struct pack_window *w = p->windows;
+
+		if (!w->offset && w->len == p->pack_size)
+			return 1;
+	}
+
+	/* Force the pack to open to prove its valid. */
+	return !open_packed_git(p);
+}
+
+struct packed_git *find_sha1_pack(const unsigned char *sha1,
+				  struct packed_git *packs)
+{
+	struct packed_git *p;
+
+	for (p = packs; p; p = p->next) {
+		if (find_pack_entry_one(sha1, p))
+			return p;
+	}
+	return NULL;
+
+}
+
+static int fill_pack_entry(const unsigned char *sha1,
+			   struct pack_entry *e,
+			   struct packed_git *p)
+{
+	off_t offset;
+
+	if (p->num_bad_objects) {
+		unsigned i;
+		for (i = 0; i < p->num_bad_objects; i++)
+			if (!hashcmp(sha1, p->bad_object_sha1 + 20 * i))
+				return 0;
+	}
+
+	offset = find_pack_entry_one(sha1, p);
+	if (!offset)
+		return 0;
+
+	/*
+	 * We are about to tell the caller where they can locate the
+	 * requested object.  We better make sure the packfile is
+	 * still here and can be accessed before supplying that
+	 * answer, as it may have been deleted since the index was
+	 * loaded!
+	 */
+	if (!is_pack_valid(p))
+		return 0;
+	e->offset = offset;
+	e->p = p;
+	hashcpy(e->sha1, sha1);
+	return 1;
+}
+
+/*
+ * Iff a pack file contains the object named by sha1, return true and
+ * store its location to e.
+ */
+int find_pack_entry(const unsigned char *sha1, struct pack_entry *e)
+{
+	struct mru_entry *p;
+
+	prepare_packed_git();
+	if (!packed_git)
+		return 0;
+
+	for (p = packed_git_mru->head; p; p = p->next) {
+		if (fill_pack_entry(sha1, e, p->item)) {
+			mru_mark(packed_git_mru, p);
+			return 1;
+		}
+	}
+	return 0;
+}
+
+int has_sha1_pack(const unsigned char *sha1)
+{
+	struct pack_entry e;
+	return find_pack_entry(sha1, &e);
+}
+
+int has_pack_index(const unsigned char *sha1)
+{
+	struct stat st;
+	if (stat(sha1_pack_index_name(sha1), &st))
+		return 0;
+	return 1;
+}
+
+static int for_each_object_in_pack(struct packed_git *p, each_packed_object_fn cb, void *data)
+{
+	uint32_t i;
+	int r = 0;
+
+	for (i = 0; i < p->num_objects; i++) {
+		struct object_id oid;
+
+		if (!nth_packed_object_oid(&oid, p, i))
+			return error("unable to get sha1 of object %u in %s",
+				     i, p->pack_name);
+
+		r = cb(&oid, p, i, data);
+		if (r)
+			break;
+	}
+	return r;
+}
+
+int for_each_packed_object(each_packed_object_fn cb, void *data, unsigned flags)
+{
+	struct packed_git *p;
+	int r = 0;
+	int pack_errors = 0;
+
+	prepare_packed_git();
+	for (p = packed_git; p; p = p->next) {
+		if ((flags & FOR_EACH_OBJECT_LOCAL_ONLY) && !p->pack_local)
+			continue;
+		if (open_pack_index(p)) {
+			pack_errors = 1;
+			continue;
+		}
+		r = for_each_object_in_pack(p, cb, data);
+		if (r)
+			break;
+	}
+	return r ? r : pack_errors;
+}
diff --git a/packfile.h b/packfile.h
new file mode 100644
index 0000000000..0cdeb54dcd
--- /dev/null
+++ b/packfile.h
@@ -0,0 +1,138 @@
+#ifndef PACKFILE_H
+#define PACKFILE_H
+
+/*
+ * Generate the filename to be used for a pack file with checksum "sha1" and
+ * extension "ext". The result is written into the strbuf "buf", overwriting
+ * any existing contents. A pointer to buf->buf is returned as a convenience.
+ *
+ * Example: odb_pack_name(out, sha1, "idx") => ".git/objects/pack/pack-1234..idx"
+ */
+extern char *odb_pack_name(struct strbuf *buf, const unsigned char *sha1, const char *ext);
+
+/*
+ * Return the name of the (local) packfile with the specified sha1 in
+ * its name.  The return value is a pointer to memory that is
+ * overwritten each time this function is called.
+ */
+extern char *sha1_pack_name(const unsigned char *sha1);
+
+/*
+ * Return the name of the (local) pack index file with the specified
+ * sha1 in its name.  The return value is a pointer to memory that is
+ * overwritten each time this function is called.
+ */
+extern char *sha1_pack_index_name(const unsigned char *sha1);
+
+extern struct packed_git *parse_pack_index(unsigned char *sha1, const char *idx_path);
+
+/* A hook to report invalid files in pack directory */
+#define PACKDIR_FILE_PACK 1
+#define PACKDIR_FILE_IDX 2
+#define PACKDIR_FILE_GARBAGE 4
+extern void (*report_garbage)(unsigned seen_bits, const char *path);
+
+extern void prepare_packed_git(void);
+extern void reprepare_packed_git(void);
+extern void install_packed_git(struct packed_git *pack);
+
+/*
+ * Give a rough count of objects in the repository. This sacrifices accuracy
+ * for speed.
+ */
+unsigned long approximate_object_count(void);
+
+extern struct packed_git *find_sha1_pack(const unsigned char *sha1,
+					 struct packed_git *packs);
+
+extern void pack_report(void);
+
+/*
+ * mmap the index file for the specified packfile (if it is not
+ * already mmapped).  Return 0 on success.
+ */
+extern int open_pack_index(struct packed_git *);
+
+/*
+ * munmap the index file for the specified packfile (if it is
+ * currently mmapped).
+ */
+extern void close_pack_index(struct packed_git *);
+
+extern unsigned char *use_pack(struct packed_git *, struct pack_window **, off_t, unsigned long *);
+extern void close_pack_windows(struct packed_git *);
+extern void close_all_packs(void);
+extern void unuse_pack(struct pack_window **);
+extern void clear_delta_base_cache(void);
+extern struct packed_git *add_packed_git(const char *path, size_t path_len, int local);
+
+/*
+ * Make sure that a pointer access into an mmap'd index file is within bounds,
+ * and can provide at least 8 bytes of data.
+ *
+ * Note that this is only necessary for variable-length segments of the file
+ * (like the 64-bit extended offset table), as we compare the size to the
+ * fixed-length parts when we open the file.
+ */
+extern void check_pack_index_ptr(const struct packed_git *p, const void *ptr);
+
+/*
+ * Return the SHA-1 of the nth object within the specified packfile.
+ * Open the index if it is not already open.  The return value points
+ * at the SHA-1 within the mmapped index.  Return NULL if there is an
+ * error.
+ */
+extern const unsigned char *nth_packed_object_sha1(struct packed_git *, uint32_t n);
+/*
+ * Like nth_packed_object_sha1, but write the data into the object specified by
+ * the the first argument.  Returns the first argument on success, and NULL on
+ * error.
+ */
+extern const struct object_id *nth_packed_object_oid(struct object_id *, struct packed_git *, uint32_t n);
+
+/*
+ * Return the offset of the nth object within the specified packfile.
+ * The index must already be opened.
+ */
+extern off_t nth_packed_object_offset(const struct packed_git *, uint32_t n);
+
+/*
+ * If the object named sha1 is present in the specified packfile,
+ * return its offset within the packfile; otherwise, return 0.
+ */
+extern off_t find_pack_entry_one(const unsigned char *sha1, struct packed_git *);
+
+extern int is_pack_valid(struct packed_git *);
+extern void *unpack_entry(struct packed_git *, off_t, enum object_type *, unsigned long *);
+extern unsigned long unpack_object_header_buffer(const unsigned char *buf, unsigned long len, enum object_type *type, unsigned long *sizep);
+extern unsigned long get_size_from_delta(struct packed_git *, struct pack_window **, off_t);
+extern int unpack_object_header(struct packed_git *, struct pack_window **, off_t *, unsigned long *);
+
+extern void release_pack_memory(size_t);
+
+/* global flag to enable extra checks when accessing packed objects */
+extern int do_check_packed_object_crc;
+
+extern int packed_object_info(struct packed_git *pack, off_t offset, struct object_info *);
+
+extern void mark_bad_packed_object(struct packed_git *p, const unsigned char *sha1);
+extern const struct packed_git *has_packed_and_bad(const unsigned char *sha1);
+
+extern int find_pack_entry(const unsigned char *sha1, struct pack_entry *e);
+
+extern int has_sha1_pack(const unsigned char *sha1);
+
+extern int has_pack_index(const unsigned char *sha1);
+
+/*
+ * Iterate over packed objects in both the local
+ * repository and any alternates repositories (unless the
+ * FOR_EACH_OBJECT_LOCAL_ONLY flag, defined in cache.h, is set).
+ */
+typedef int each_packed_object_fn(const struct object_id *oid,
+				  struct packed_git *pack,
+				  uint32_t pos,
+				  void *data);
+extern int for_each_packed_object(each_packed_object_fn, void *, unsigned flags);
+
+#endif
diff --git a/path.c b/path.c
index e50d2befcf..b533ec938d 100644
--- a/path.c
+++ b/path.c
@@ -9,6 +9,7 @@
 #include "worktree.h"
 #include "submodule-config.h"
 #include "path.h"
+#include "packfile.h"
 
 static int get_st_mode_bits(const char *path, int *mode)
 {
diff --git a/reachable.c b/reachable.c
index c62efbfd43..d1ac5d97ef 100644
--- a/reachable.c
+++ b/reachable.c
@@ -9,6 +9,7 @@
 #include "cache-tree.h"
 #include "progress.h"
 #include "list-objects.h"
+#include "packfile.h"
 
 struct connectivity_progress {
 	struct progress *progress;
diff --git a/revision.c b/revision.c
index aa3b946a8d..94a5e98525 100644
--- a/revision.c
+++ b/revision.c
@@ -19,6 +19,7 @@
 #include "dir.h"
 #include "cache-tree.h"
 #include "bisect.h"
+#include "packfile.h"
 
 volatile show_early_output_fn_t show_early_output;
 
diff --git a/server-info.c b/server-info.c
index 5ec5b1d827..26a6c20b7d 100644
--- a/server-info.c
+++ b/server-info.c
@@ -3,6 +3,7 @@
 #include "object.h"
 #include "commit.h"
 #include "tag.h"
+#include "packfile.h"
 
 /*
  * Create the file "path" by writing to a temporary file and renaming
diff --git a/sha1_file.c b/sha1_file.c
index 73a4a0c98e..f56bb5cae7 100644
--- a/sha1_file.c
+++ b/sha1_file.c
@@ -28,9 +28,7 @@
 #include "list.h"
 #include "mergesort.h"
 #include "quote.h"
-
-#define SZ_FMT PRIuMAX
-static inline uintmax_t sz_fmt(size_t s) { return s; }
+#include "packfile.h"
 
 const unsigned char null_sha1[20];
 const struct object_id null_oid;
@@ -278,28 +276,6 @@ static const char *alt_sha1_path(struct alternate_object_database *alt,
 	return buf->buf;
 }
 
- char *odb_pack_name(struct strbuf *buf,
-		     const unsigned char *sha1,
-		     const char *ext)
-{
-	strbuf_reset(buf);
-	strbuf_addf(buf, "%s/pack/pack-%s.%s", get_object_directory(),
-		    sha1_to_hex(sha1), ext);
-	return buf->buf;
-}
-
-char *sha1_pack_name(const unsigned char *sha1)
-{
-	static struct strbuf buf = STRBUF_INIT;
-	return odb_pack_name(&buf, sha1, "pack");
-}
-
-char *sha1_pack_index_name(const unsigned char *sha1)
-{
-	static struct strbuf buf = STRBUF_INIT;
-	return odb_pack_name(&buf, sha1, "idx");
-}
-
 struct alternate_object_database *alt_odb_list;
 static struct alternate_object_database **alt_odb_tail;
 
@@ -705,213 +681,6 @@ static int has_loose_object(const unsigned char *sha1)
 	return check_and_freshen(sha1, 0);
 }
 
-static unsigned int pack_used_ctr;
-static unsigned int pack_mmap_calls;
-static unsigned int peak_pack_open_windows;
-static unsigned int pack_open_windows;
-static unsigned int pack_open_fds;
-static unsigned int pack_max_fds;
-static size_t peak_pack_mapped;
-static size_t pack_mapped;
-struct packed_git *packed_git;
-
-static struct mru packed_git_mru_storage;
-struct mru *packed_git_mru = &packed_git_mru_storage;
-
-void pack_report(void)
-{
-	fprintf(stderr,
-		"pack_report: getpagesize()            = %10" SZ_FMT "\n"
-		"pack_report: core.packedGitWindowSize = %10" SZ_FMT "\n"
-		"pack_report: core.packedGitLimit      = %10" SZ_FMT "\n",
-		sz_fmt(getpagesize()),
-		sz_fmt(packed_git_window_size),
-		sz_fmt(packed_git_limit));
-	fprintf(stderr,
-		"pack_report: pack_used_ctr            = %10u\n"
-		"pack_report: pack_mmap_calls          = %10u\n"
-		"pack_report: pack_open_windows        = %10u / %10u\n"
-		"pack_report: pack_mapped              = "
-			"%10" SZ_FMT " / %10" SZ_FMT "\n",
-		pack_used_ctr,
-		pack_mmap_calls,
-		pack_open_windows, peak_pack_open_windows,
-		sz_fmt(pack_mapped), sz_fmt(peak_pack_mapped));
-}
-
-/*
- * Open and mmap the index file at path, perform a couple of
- * consistency checks, then record its information to p.  Return 0 on
- * success.
- */
-static int check_packed_git_idx(const char *path, struct packed_git *p)
-{
-	void *idx_map;
-	struct pack_idx_header *hdr;
-	size_t idx_size;
-	uint32_t version, nr, i, *index;
-	int fd = git_open(path);
-	struct stat st;
-
-	if (fd < 0)
-		return -1;
-	if (fstat(fd, &st)) {
-		close(fd);
-		return -1;
-	}
-	idx_size = xsize_t(st.st_size);
-	if (idx_size < 4 * 256 + 20 + 20) {
-		close(fd);
-		return error("index file %s is too small", path);
-	}
-	idx_map = xmmap(NULL, idx_size, PROT_READ, MAP_PRIVATE, fd, 0);
-	close(fd);
-
-	hdr = idx_map;
-	if (hdr->idx_signature == htonl(PACK_IDX_SIGNATURE)) {
-		version = ntohl(hdr->idx_version);
-		if (version < 2 || version > 2) {
-			munmap(idx_map, idx_size);
-			return error("index file %s is version %"PRIu32
-				     " and is not supported by this binary"
-				     " (try upgrading GIT to a newer version)",
-				     path, version);
-		}
-	} else
-		version = 1;
-
-	nr = 0;
-	index = idx_map;
-	if (version > 1)
-		index += 2;  /* skip index header */
-	for (i = 0; i < 256; i++) {
-		uint32_t n = ntohl(index[i]);
-		if (n < nr) {
-			munmap(idx_map, idx_size);
-			return error("non-monotonic index %s", path);
-		}
-		nr = n;
-	}
-
-	if (version == 1) {
-		/*
-		 * Total size:
-		 *  - 256 index entries 4 bytes each
-		 *  - 24-byte entries * nr (20-byte sha1 + 4-byte offset)
-		 *  - 20-byte SHA1 of the packfile
-		 *  - 20-byte SHA1 file checksum
-		 */
-		if (idx_size != 4*256 + nr * 24 + 20 + 20) {
-			munmap(idx_map, idx_size);
-			return error("wrong index v1 file size in %s", path);
-		}
-	} else if (version == 2) {
-		/*
-		 * Minimum size:
-		 *  - 8 bytes of header
-		 *  - 256 index entries 4 bytes each
-		 *  - 20-byte sha1 entry * nr
-		 *  - 4-byte crc entry * nr
-		 *  - 4-byte offset entry * nr
-		 *  - 20-byte SHA1 of the packfile
-		 *  - 20-byte SHA1 file checksum
-		 * And after the 4-byte offset table might be a
-		 * variable sized table containing 8-byte entries
-		 * for offsets larger than 2^31.
-		 */
-		unsigned long min_size = 8 + 4*256 + nr*(20 + 4 + 4) + 20 + 20;
-		unsigned long max_size = min_size;
-		if (nr)
-			max_size += (nr - 1)*8;
-		if (idx_size < min_size || idx_size > max_size) {
-			munmap(idx_map, idx_size);
-			return error("wrong index v2 file size in %s", path);
-		}
-		if (idx_size != min_size &&
-		    /*
-		     * make sure we can deal with large pack offsets.
-		     * 31-bit signed offset won't be enough, neither
-		     * 32-bit unsigned one will be.
-		     */
-		    (sizeof(off_t) <= 4)) {
-			munmap(idx_map, idx_size);
-			return error("pack too large for current definition of off_t in %s", path);
-		}
-	}
-
-	p->index_version = version;
-	p->index_data = idx_map;
-	p->index_size = idx_size;
-	p->num_objects = nr;
-	return 0;
-}
-
-int open_pack_index(struct packed_git *p)
-{
-	char *idx_name;
-	size_t len;
-	int ret;
-
-	if (p->index_data)
-		return 0;
-
-	if (!strip_suffix(p->pack_name, ".pack", &len))
-		die("BUG: pack_name does not end in .pack");
-	idx_name = xstrfmt("%.*s.idx", (int)len, p->pack_name);
-	ret = check_packed_git_idx(idx_name, p);
-	free(idx_name);
-	return ret;
-}
-
-static void scan_windows(struct packed_git *p,
-	struct packed_git **lru_p,
-	struct pack_window **lru_w,
-	struct pack_window **lru_l)
-{
-	struct pack_window *w, *w_l;
-
-	for (w_l = NULL, w = p->windows; w; w = w->next) {
-		if (!w->inuse_cnt) {
-			if (!*lru_w || w->last_used < (*lru_w)->last_used) {
-				*lru_p = p;
-				*lru_w = w;
-				*lru_l = w_l;
-			}
-		}
-		w_l = w;
-	}
-}
-
-static int unuse_one_window(struct packed_git *current)
-{
-	struct packed_git *p, *lru_p = NULL;
-	struct pack_window *lru_w = NULL, *lru_l = NULL;
-
-	if (current)
-		scan_windows(current, &lru_p, &lru_w, &lru_l);
-	for (p = packed_git; p; p = p->next)
-		scan_windows(p, &lru_p, &lru_w, &lru_l);
-	if (lru_p) {
-		munmap(lru_w->base, lru_w->len);
-		pack_mapped -= lru_w->len;
-		if (lru_l)
-			lru_l->next = lru_w->next;
-		else
-			lru_p->windows = lru_w->next;
-		free(lru_w);
-		pack_open_windows--;
-		return 1;
-	}
-	return 0;
-}
-
-void release_pack_memory(size_t need)
-{
-	size_t cur = pack_mapped;
-	while (need >= (cur - pack_mapped) && unuse_one_window(NULL))
-		; /* nothing */
-}
-
 static void mmap_limit_check(size_t length)
 {
 	static size_t limit = 0;
@@ -950,681 +719,6 @@ void *xmmap(void *start, size_t length,
 	return ret;
 }
 
-void close_pack_windows(struct packed_git *p)
-{
-	while (p->windows) {
-		struct pack_window *w = p->windows;
-
-		if (w->inuse_cnt)
-			die("pack '%s' still has open windows to it",
-			    p->pack_name);
-		munmap(w->base, w->len);
-		pack_mapped -= w->len;
-		pack_open_windows--;
-		p->windows = w->next;
-		free(w);
-	}
-}
-
-static int close_pack_fd(struct packed_git *p)
-{
-	if (p->pack_fd < 0)
-		return 0;
-
-	close(p->pack_fd);
-	pack_open_fds--;
-	p->pack_fd = -1;
-
-	return 1;
-}
-
-static void close_pack(struct packed_git *p)
-{
-	close_pack_windows(p);
-	close_pack_fd(p);
-	close_pack_index(p);
-}
-
-void close_all_packs(void)
-{
-	struct packed_git *p;
-
-	for (p = packed_git; p; p = p->next)
-		if (p->do_not_close)
-			die("BUG: want to close pack marked 'do-not-close'");
-		else
-			close_pack(p);
-}
-
-
-/*
- * The LRU pack is the one with the oldest MRU window, preferring packs
- * with no used windows, or the oldest mtime if it has no windows allocated.
- */
-static void find_lru_pack(struct packed_git *p, struct packed_git **lru_p, struct pack_window **mru_w, int *accept_windows_inuse)
-{
-	struct pack_window *w, *this_mru_w;
-	int has_windows_inuse = 0;
-
-	/*
-	 * Reject this pack if it has windows and the previously selected
-	 * one does not.  If this pack does not have windows, reject
-	 * it if the pack file is newer than the previously selected one.
-	 */
-	if (*lru_p && !*mru_w && (p->windows || p->mtime > (*lru_p)->mtime))
-		return;
-
-	for (w = this_mru_w = p->windows; w; w = w->next) {
-		/*
-		 * Reject this pack if any of its windows are in use,
-		 * but the previously selected pack did not have any
-		 * inuse windows.  Otherwise, record that this pack
-		 * has windows in use.
-		 */
-		if (w->inuse_cnt) {
-			if (*accept_windows_inuse)
-				has_windows_inuse = 1;
-			else
-				return;
-		}
-
-		if (w->last_used > this_mru_w->last_used)
-			this_mru_w = w;
-
-		/*
-		 * Reject this pack if it has windows that have been
-		 * used more recently than the previously selected pack.
-		 * If the previously selected pack had windows inuse and
-		 * we have not encountered a window in this pack that is
-		 * inuse, skip this check since we prefer a pack with no
-		 * inuse windows to one that has inuse windows.
-		 */
-		if (*mru_w && *accept_windows_inuse == has_windows_inuse &&
-		    this_mru_w->last_used > (*mru_w)->last_used)
-			return;
-	}
-
-	/*
-	 * Select this pack.
-	 */
-	*mru_w = this_mru_w;
-	*lru_p = p;
-	*accept_windows_inuse = has_windows_inuse;
-}
-
-static int close_one_pack(void)
-{
-	struct packed_git *p, *lru_p = NULL;
-	struct pack_window *mru_w = NULL;
-	int accept_windows_inuse = 1;
-
-	for (p = packed_git; p; p = p->next) {
-		if (p->pack_fd == -1)
-			continue;
-		find_lru_pack(p, &lru_p, &mru_w, &accept_windows_inuse);
-	}
-
-	if (lru_p)
-		return close_pack_fd(lru_p);
-
-	return 0;
-}
-
-void unuse_pack(struct pack_window **w_cursor)
-{
-	struct pack_window *w = *w_cursor;
-	if (w) {
-		w->inuse_cnt--;
-		*w_cursor = NULL;
-	}
-}
-
-void close_pack_index(struct packed_git *p)
-{
-	if (p->index_data) {
-		munmap((void *)p->index_data, p->index_size);
-		p->index_data = NULL;
-	}
-}
-
-static unsigned int get_max_fd_limit(void)
-{
-#ifdef RLIMIT_NOFILE
-	{
-		struct rlimit lim;
-
-		if (!getrlimit(RLIMIT_NOFILE, &lim))
-			return lim.rlim_cur;
-	}
-#endif
-
-#ifdef _SC_OPEN_MAX
-	{
-		long open_max = sysconf(_SC_OPEN_MAX);
-		if (0 < open_max)
-			return open_max;
-		/*
-		 * Otherwise, we got -1 for one of the two
-		 * reasons:
-		 *
-		 * (1) sysconf() did not understand _SC_OPEN_MAX
-		 *     and signaled an error with -1; or
-		 * (2) sysconf() said there is no limit.
-		 *
-		 * We _could_ clear errno before calling sysconf() to
-		 * tell these two cases apart and return a huge number
-		 * in the latter case to let the caller cap it to a
-		 * value that is not so selfish, but letting the
-		 * fallback OPEN_MAX codepath take care of these cases
-		 * is a lot simpler.
-		 */
-	}
-#endif
-
-#ifdef OPEN_MAX
-	return OPEN_MAX;
-#else
-	return 1; /* see the caller ;-) */
-#endif
-}
-
-/*
- * Do not call this directly as this leaks p->pack_fd on error return;
- * call open_packed_git() instead.
- */
-static int open_packed_git_1(struct packed_git *p)
-{
-	struct stat st;
-	struct pack_header hdr;
-	unsigned char sha1[20];
-	unsigned char *idx_sha1;
-	long fd_flag;
-
-	if (!p->index_data && open_pack_index(p))
-		return error("packfile %s index unavailable", p->pack_name);
-
-	if (!pack_max_fds) {
-		unsigned int max_fds = get_max_fd_limit();
-
-		/* Save 3 for stdin/stdout/stderr, 22 for work */
-		if (25 < max_fds)
-			pack_max_fds = max_fds - 25;
-		else
-			pack_max_fds = 1;
-	}
-
-	while (pack_max_fds <= pack_open_fds && close_one_pack())
-		; /* nothing */
-
-	p->pack_fd = git_open(p->pack_name);
-	if (p->pack_fd < 0 || fstat(p->pack_fd, &st))
-		return -1;
-	pack_open_fds++;
-
-	/* If we created the struct before we had the pack we lack size. */
-	if (!p->pack_size) {
-		if (!S_ISREG(st.st_mode))
-			return error("packfile %s not a regular file", p->pack_name);
-		p->pack_size = st.st_size;
-	} else if (p->pack_size != st.st_size)
-		return error("packfile %s size changed", p->pack_name);
-
-	/* We leave these file descriptors open with sliding mmap;
-	 * there is no point keeping them open across exec(), though.
-	 */
-	fd_flag = fcntl(p->pack_fd, F_GETFD, 0);
-	if (fd_flag < 0)
-		return error("cannot determine file descriptor flags");
-	fd_flag |= FD_CLOEXEC;
-	if (fcntl(p->pack_fd, F_SETFD, fd_flag) == -1)
-		return error("cannot set FD_CLOEXEC");
-
-	/* Verify we recognize this pack file format. */
-	if (read_in_full(p->pack_fd, &hdr, sizeof(hdr)) != sizeof(hdr))
-		return error("file %s is far too short to be a packfile", p->pack_name);
-	if (hdr.hdr_signature != htonl(PACK_SIGNATURE))
-		return error("file %s is not a GIT packfile", p->pack_name);
-	if (!pack_version_ok(hdr.hdr_version))
-		return error("packfile %s is version %"PRIu32" and not"
-			" supported (try upgrading GIT to a newer version)",
-			p->pack_name, ntohl(hdr.hdr_version));
-
-	/* Verify the pack matches its index. */
-	if (p->num_objects != ntohl(hdr.hdr_entries))
-		return error("packfile %s claims to have %"PRIu32" objects"
-			     " while index indicates %"PRIu32" objects",
-			     p->pack_name, ntohl(hdr.hdr_entries),
-			     p->num_objects);
-	if (lseek(p->pack_fd, p->pack_size - sizeof(sha1), SEEK_SET) == -1)
-		return error("end of packfile %s is unavailable", p->pack_name);
-	if (read_in_full(p->pack_fd, sha1, sizeof(sha1)) != sizeof(sha1))
-		return error("packfile %s signature is unavailable", p->pack_name);
-	idx_sha1 = ((unsigned char *)p->index_data) + p->index_size - 40;
-	if (hashcmp(sha1, idx_sha1))
-		return error("packfile %s does not match index", p->pack_name);
-	return 0;
-}
-
-static int open_packed_git(struct packed_git *p)
-{
-	if (!open_packed_git_1(p))
-		return 0;
-	close_pack_fd(p);
-	return -1;
-}
-
-static int in_window(struct pack_window *win, off_t offset)
-{
-	/* We must promise at least 20 bytes (one hash) after the
-	 * offset is available from this window, otherwise the offset
-	 * is not actually in this window and a different window (which
-	 * has that one hash excess) must be used.  This is to support
-	 * the object header and delta base parsing routines below.
-	 */
-	off_t win_off = win->offset;
-	return win_off <= offset
-		&& (offset + 20) <= (win_off + win->len);
-}
-
-unsigned char *use_pack(struct packed_git *p,
-		struct pack_window **w_cursor,
-		off_t offset,
-		unsigned long *left)
-{
-	struct pack_window *win = *w_cursor;
-
-	/* Since packfiles end in a hash of their content and it's
-	 * pointless to ask for an offset into the middle of that
-	 * hash, and the in_window function above wouldn't match
-	 * don't allow an offset too close to the end of the file.
-	 */
-	if (!p->pack_size && p->pack_fd == -1 && open_packed_git(p))
-		die("packfile %s cannot be accessed", p->pack_name);
-	if (offset > (p->pack_size - 20))
-		die("offset beyond end of packfile (truncated pack?)");
-	if (offset < 0)
-		die(_("offset before end of packfile (broken .idx?)"));
-
-	if (!win || !in_window(win, offset)) {
-		if (win)
-			win->inuse_cnt--;
-		for (win = p->windows; win; win = win->next) {
-			if (in_window(win, offset))
-				break;
-		}
-		if (!win) {
-			size_t window_align = packed_git_window_size / 2;
-			off_t len;
-
-			if (p->pack_fd == -1 && open_packed_git(p))
-				die("packfile %s cannot be accessed", p->pack_name);
-
-			win = xcalloc(1, sizeof(*win));
-			win->offset = (offset / window_align) * window_align;
-			len = p->pack_size - win->offset;
-			if (len > packed_git_window_size)
-				len = packed_git_window_size;
-			win->len = (size_t)len;
-			pack_mapped += win->len;
-			while (packed_git_limit < pack_mapped
-				&& unuse_one_window(p))
-				; /* nothing */
-			win->base = xmmap(NULL, win->len,
-				PROT_READ, MAP_PRIVATE,
-				p->pack_fd, win->offset);
-			if (win->base == MAP_FAILED)
-				die_errno("packfile %s cannot be mapped",
-					  p->pack_name);
-			if (!win->offset && win->len == p->pack_size
-				&& !p->do_not_close)
-				close_pack_fd(p);
-			pack_mmap_calls++;
-			pack_open_windows++;
-			if (pack_mapped > peak_pack_mapped)
-				peak_pack_mapped = pack_mapped;
-			if (pack_open_windows > peak_pack_open_windows)
-				peak_pack_open_windows = pack_open_windows;
-			win->next = p->windows;
-			p->windows = win;
-		}
-	}
-	if (win != *w_cursor) {
-		win->last_used = pack_used_ctr++;
-		win->inuse_cnt++;
-		*w_cursor = win;
-	}
-	offset -= win->offset;
-	if (left)
-		*left = win->len - xsize_t(offset);
-	return win->base + offset;
-}
-
-static struct packed_git *alloc_packed_git(int extra)
-{
-	struct packed_git *p = xmalloc(st_add(sizeof(*p), extra));
-	memset(p, 0, sizeof(*p));
-	p->pack_fd = -1;
-	return p;
-}
-
-static void try_to_free_pack_memory(size_t size)
-{
-	release_pack_memory(size);
-}
-
-struct packed_git *add_packed_git(const char *path, size_t path_len, int local)
-{
-	static int have_set_try_to_free_routine;
-	struct stat st;
-	size_t alloc;
-	struct packed_git *p;
-
-	if (!have_set_try_to_free_routine) {
-		have_set_try_to_free_routine = 1;
-		set_try_to_free_routine(try_to_free_pack_memory);
-	}
-
-	/*
-	 * Make sure a corresponding .pack file exists and that
-	 * the index looks sane.
-	 */
-	if (!strip_suffix_mem(path, &path_len, ".idx"))
-		return NULL;
-
-	/*
-	 * ".pack" is long enough to hold any suffix we're adding (and
-	 * the use xsnprintf double-checks that)
-	 */
-	alloc = st_add3(path_len, strlen(".pack"), 1);
-	p = alloc_packed_git(alloc);
-	memcpy(p->pack_name, path, path_len);
-
-	xsnprintf(p->pack_name + path_len, alloc - path_len, ".keep");
-	if (!access(p->pack_name, F_OK))
-		p->pack_keep = 1;
-
-	xsnprintf(p->pack_name + path_len, alloc - path_len, ".pack");
-	if (stat(p->pack_name, &st) || !S_ISREG(st.st_mode)) {
-		free(p);
-		return NULL;
-	}
-
-	/* ok, it looks sane as far as we can check without
-	 * actually mapping the pack file.
-	 */
-	p->pack_size = st.st_size;
-	p->pack_local = local;
-	p->mtime = st.st_mtime;
-	if (path_len < 40 || get_sha1_hex(path + path_len - 40, p->sha1))
-		hashclr(p->sha1);
-	return p;
-}
-
-struct packed_git *parse_pack_index(unsigned char *sha1, const char *idx_path)
-{
-	const char *path = sha1_pack_name(sha1);
-	size_t alloc = st_add(strlen(path), 1);
-	struct packed_git *p = alloc_packed_git(alloc);
-
-	memcpy(p->pack_name, path, alloc); /* includes NUL */
-	hashcpy(p->sha1, sha1);
-	if (check_packed_git_idx(idx_path, p)) {
-		free(p);
-		return NULL;
-	}
-
-	return p;
-}
-
-void install_packed_git(struct packed_git *pack)
-{
-	if (pack->pack_fd != -1)
-		pack_open_fds++;
-
-	pack->next = packed_git;
-	packed_git = pack;
-}
-
-void (*report_garbage)(unsigned seen_bits, const char *path);
-
-static void report_helper(const struct string_list *list,
-			  int seen_bits, int first, int last)
-{
-	if (seen_bits == (PACKDIR_FILE_PACK|PACKDIR_FILE_IDX))
-		return;
-
-	for (; first < last; first++)
-		report_garbage(seen_bits, list->items[first].string);
-}
-
-static void report_pack_garbage(struct string_list *list)
-{
-	int i, baselen = -1, first = 0, seen_bits = 0;
-
-	if (!report_garbage)
-		return;
-
-	string_list_sort(list);
-
-	for (i = 0; i < list->nr; i++) {
-		const char *path = list->items[i].string;
-		if (baselen != -1 &&
-		    strncmp(path, list->items[first].string, baselen)) {
-			report_helper(list, seen_bits, first, i);
-			baselen = -1;
-			seen_bits = 0;
-		}
-		if (baselen == -1) {
-			const char *dot = strrchr(path, '.');
-			if (!dot) {
-				report_garbage(PACKDIR_FILE_GARBAGE, path);
-				continue;
-			}
-			baselen = dot - path + 1;
-			first = i;
-		}
-		if (!strcmp(path + baselen, "pack"))
-			seen_bits |= 1;
-		else if (!strcmp(path + baselen, "idx"))
-			seen_bits |= 2;
-	}
-	report_helper(list, seen_bits, first, list->nr);
-}
-
-static void prepare_packed_git_one(char *objdir, int local)
-{
-	struct strbuf path = STRBUF_INIT;
-	size_t dirnamelen;
-	DIR *dir;
-	struct dirent *de;
-	struct string_list garbage = STRING_LIST_INIT_DUP;
-
-	strbuf_addstr(&path, objdir);
-	strbuf_addstr(&path, "/pack");
-	dir = opendir(path.buf);
-	if (!dir) {
-		if (errno != ENOENT)
-			error_errno("unable to open object pack directory: %s",
-				    path.buf);
-		strbuf_release(&path);
-		return;
-	}
-	strbuf_addch(&path, '/');
-	dirnamelen = path.len;
-	while ((de = readdir(dir)) != NULL) {
-		struct packed_git *p;
-		size_t base_len;
-
-		if (is_dot_or_dotdot(de->d_name))
-			continue;
-
-		strbuf_setlen(&path, dirnamelen);
-		strbuf_addstr(&path, de->d_name);
-
-		base_len = path.len;
-		if (strip_suffix_mem(path.buf, &base_len, ".idx")) {
-			/* Don't reopen a pack we already have. */
-			for (p = packed_git; p; p = p->next) {
-				size_t len;
-				if (strip_suffix(p->pack_name, ".pack", &len) &&
-				    len == base_len &&
-				    !memcmp(p->pack_name, path.buf, len))
-					break;
-			}
-			if (p == NULL &&
-			    /*
-			     * See if it really is a valid .idx file with
-			     * corresponding .pack file that we can map.
-			     */
-			    (p = add_packed_git(path.buf, path.len, local)) != NULL)
-				install_packed_git(p);
-		}
-
-		if (!report_garbage)
-			continue;
-
-		if (ends_with(de->d_name, ".idx") ||
-		    ends_with(de->d_name, ".pack") ||
-		    ends_with(de->d_name, ".bitmap") ||
-		    ends_with(de->d_name, ".keep"))
-			string_list_append(&garbage, path.buf);
-		else
-			report_garbage(PACKDIR_FILE_GARBAGE, path.buf);
-	}
-	closedir(dir);
-	report_pack_garbage(&garbage);
-	string_list_clear(&garbage, 0);
-	strbuf_release(&path);
-}
-
-static int approximate_object_count_valid;
-
-/*
- * Give a fast, rough count of the number of objects in the repository. This
- * ignores loose objects completely. If you have a lot of them, then either
- * you should repack because your performance will be awful, or they are
- * all unreachable objects about to be pruned, in which case they're not really
- * interesting as a measure of repo size in the first place.
- */
-unsigned long approximate_object_count(void)
-{
-	static unsigned long count;
-	if (!approximate_object_count_valid) {
-		struct packed_git *p;
-
-		prepare_packed_git();
-		count = 0;
-		for (p = packed_git; p; p = p->next) {
-			if (open_pack_index(p))
-				continue;
-			count += p->num_objects;
-		}
-	}
-	return count;
-}
-
-static void *get_next_packed_git(const void *p)
-{
-	return ((const struct packed_git *)p)->next;
-}
-
-static void set_next_packed_git(void *p, void *next)
-{
-	((struct packed_git *)p)->next = next;
-}
-
-static int sort_pack(const void *a_, const void *b_)
-{
-	const struct packed_git *a = a_;
-	const struct packed_git *b = b_;
-	int st;
-
-	/*
-	 * Local packs tend to contain objects specific to our
-	 * variant of the project than remote ones.  In addition,
-	 * remote ones could be on a network mounted filesystem.
-	 * Favor local ones for these reasons.
-	 */
-	st = a->pack_local - b->pack_local;
-	if (st)
-		return -st;
-
-	/*
-	 * Younger packs tend to contain more recent objects,
-	 * and more recent objects tend to get accessed more
-	 * often.
-	 */
-	if (a->mtime < b->mtime)
-		return 1;
-	else if (a->mtime == b->mtime)
-		return 0;
-	return -1;
-}
-
-static void rearrange_packed_git(void)
-{
-	packed_git = llist_mergesort(packed_git, get_next_packed_git,
-				     set_next_packed_git, sort_pack);
-}
-
-static void prepare_packed_git_mru(void)
-{
-	struct packed_git *p;
-
-	mru_clear(packed_git_mru);
-	for (p = packed_git; p; p = p->next)
-		mru_append(packed_git_mru, p);
-}
-
-static int prepare_packed_git_run_once = 0;
-void prepare_packed_git(void)
-{
-	struct alternate_object_database *alt;
-
-	if (prepare_packed_git_run_once)
-		return;
-	prepare_packed_git_one(get_object_directory(), 1);
-	prepare_alt_odb();
-	for (alt = alt_odb_list; alt; alt = alt->next)
-		prepare_packed_git_one(alt->path, 0);
-	rearrange_packed_git();
-	prepare_packed_git_mru();
-	prepare_packed_git_run_once = 1;
-}
-
-void reprepare_packed_git(void)
-{
-	approximate_object_count_valid = 0;
-	prepare_packed_git_run_once = 0;
-	prepare_packed_git();
-}
-
-static void mark_bad_packed_object(struct packed_git *p,
-				   const unsigned char *sha1)
-{
-	unsigned i;
-	for (i = 0; i < p->num_bad_objects; i++)
-		if (!hashcmp(sha1, p->bad_object_sha1 + GIT_SHA1_RAWSZ * i))
-			return;
-	p->bad_object_sha1 = xrealloc(p->bad_object_sha1,
-				      st_mult(GIT_MAX_RAWSZ,
-					      st_add(p->num_bad_objects, 1)));
-	hashcpy(p->bad_object_sha1 + GIT_SHA1_RAWSZ * p->num_bad_objects, sha1);
-	p->num_bad_objects++;
-}
-
-static const struct packed_git *has_packed_and_bad(const unsigned char *sha1)
-{
-	struct packed_git *p;
-	unsigned i;
-
-	for (p = packed_git; p; p = p->next)
-		for (i = 0; i < p->num_bad_objects; i++)
-			if (!hashcmp(sha1, p->bad_object_sha1 + 20 * i))
-				return p;
-	return NULL;
-}
-
 /*
  * With an in-core object data in "map", rehash it to make sure the
  * object name actually matches "sha1" to detect object corruption.
@@ -1795,31 +889,6 @@ void *map_sha1_file(const unsigned char *sha1, unsigned long *size)
 	return map_sha1_file_1(NULL, sha1, size);
 }
 
-unsigned long unpack_object_header_buffer(const unsigned char *buf,
-		unsigned long len, enum object_type *type, unsigned long *sizep)
-{
-	unsigned shift;
-	unsigned long size, c;
-	unsigned long used = 0;
-
-	c = buf[used++];
-	*type = (c >> 4) & 7;
-	size = c & 15;
-	shift = 4;
-	while (c & 0x80) {
-		if (len <= used || bitsizeof(long) <= shift) {
-			error("bad object header");
-			size = used = 0;
-			break;
-		}
-		c = buf[used++];
-		size += (c & 0x7f) << shift;
-		shift += 7;
-	}
-	*sizep = size;
-	return used;
-}
-
 static int unpack_sha1_short_header(git_zstream *stream,
 				    unsigned char *map, unsigned long mapsize,
 				    void *buffer, unsigned long bufsiz)
@@ -2006,897 +1075,6 @@ int parse_sha1_header(const char *hdr, unsigned long *sizep)
 	return parse_sha1_header_extended(hdr, &oi, 0);
 }
 
-unsigned long get_size_from_delta(struct packed_git *p,
-				  struct pack_window **w_curs,
-			          off_t curpos)
-{
-	const unsigned char *data;
-	unsigned char delta_head[20], *in;
-	git_zstream stream;
-	int st;
-
-	memset(&stream, 0, sizeof(stream));
-	stream.next_out = delta_head;
-	stream.avail_out = sizeof(delta_head);
-
-	git_inflate_init(&stream);
-	do {
-		in = use_pack(p, w_curs, curpos, &stream.avail_in);
-		stream.next_in = in;
-		st = git_inflate(&stream, Z_FINISH);
-		curpos += stream.next_in - in;
-	} while ((st == Z_OK || st == Z_BUF_ERROR) &&
-		 stream.total_out < sizeof(delta_head));
-	git_inflate_end(&stream);
-	if ((st != Z_STREAM_END) && stream.total_out != sizeof(delta_head)) {
-		error("delta data unpack-initial failed");
-		return 0;
-	}
-
-	/* Examine the initial part of the delta to figure out
-	 * the result size.
-	 */
-	data = delta_head;
-
-	/* ignore base size */
-	get_delta_hdr_size(&data, delta_head+sizeof(delta_head));
-
-	/* Read the result size */
-	return get_delta_hdr_size(&data, delta_head+sizeof(delta_head));
-}
-
-static off_t get_delta_base(struct packed_git *p,
-				    struct pack_window **w_curs,
-				    off_t *curpos,
-				    enum object_type type,
-				    off_t delta_obj_offset)
-{
-	unsigned char *base_info = use_pack(p, w_curs, *curpos, NULL);
-	off_t base_offset;
-
-	/* use_pack() assured us we have [base_info, base_info + 20)
-	 * as a range that we can look at without walking off the
-	 * end of the mapped window.  Its actually the hash size
-	 * that is assured.  An OFS_DELTA longer than the hash size
-	 * is stupid, as then a REF_DELTA would be smaller to store.
-	 */
-	if (type == OBJ_OFS_DELTA) {
-		unsigned used = 0;
-		unsigned char c = base_info[used++];
-		base_offset = c & 127;
-		while (c & 128) {
-			base_offset += 1;
-			if (!base_offset || MSB(base_offset, 7))
-				return 0;  /* overflow */
-			c = base_info[used++];
-			base_offset = (base_offset << 7) + (c & 127);
-		}
-		base_offset = delta_obj_offset - base_offset;
-		if (base_offset <= 0 || base_offset >= delta_obj_offset)
-			return 0;  /* out of bound */
-		*curpos += used;
-	} else if (type == OBJ_REF_DELTA) {
-		/* The base entry _must_ be in the same pack */
-		base_offset = find_pack_entry_one(base_info, p);
-		*curpos += 20;
-	} else
-		die("I am totally screwed");
-	return base_offset;
-}
-
-/*
- * Like get_delta_base above, but we return the sha1 instead of the pack
- * offset. This means it is cheaper for REF deltas (we do not have to do
- * the final object lookup), but more expensive for OFS deltas (we
- * have to load the revidx to convert the offset back into a sha1).
- */
-static const unsigned char *get_delta_base_sha1(struct packed_git *p,
-						struct pack_window **w_curs,
-						off_t curpos,
-						enum object_type type,
-						off_t delta_obj_offset)
-{
-	if (type == OBJ_REF_DELTA) {
-		unsigned char *base = use_pack(p, w_curs, curpos, NULL);
-		return base;
-	} else if (type == OBJ_OFS_DELTA) {
-		struct revindex_entry *revidx;
-		off_t base_offset = get_delta_base(p, w_curs, &curpos,
-						   type, delta_obj_offset);
-
-		if (!base_offset)
-			return NULL;
-
-		revidx = find_pack_revindex(p, base_offset);
-		if (!revidx)
-			return NULL;
-
-		return nth_packed_object_sha1(p, revidx->nr);
-	} else
-		return NULL;
-}
-
-int unpack_object_header(struct packed_git *p,
-			 struct pack_window **w_curs,
-			 off_t *curpos,
-			 unsigned long *sizep)
-{
-	unsigned char *base;
-	unsigned long left;
-	unsigned long used;
-	enum object_type type;
-
-	/* use_pack() assures us we have [base, base + 20) available
-	 * as a range that we can look at.  (Its actually the hash
-	 * size that is assured.)  With our object header encoding
-	 * the maximum deflated object size is 2^137, which is just
-	 * insane, so we know won't exceed what we have been given.
-	 */
-	base = use_pack(p, w_curs, *curpos, &left);
-	used = unpack_object_header_buffer(base, left, &type, sizep);
-	if (!used) {
-		type = OBJ_BAD;
-	} else
-		*curpos += used;
-
-	return type;
-}
-
-static int retry_bad_packed_offset(struct packed_git *p, off_t obj_offset)
-{
-	int type;
-	struct revindex_entry *revidx;
-	const unsigned char *sha1;
-	revidx = find_pack_revindex(p, obj_offset);
-	if (!revidx)
-		return OBJ_BAD;
-	sha1 = nth_packed_object_sha1(p, revidx->nr);
-	mark_bad_packed_object(p, sha1);
-	type = sha1_object_info(sha1, NULL);
-	if (type <= OBJ_NONE)
-		return OBJ_BAD;
-	return type;
-}
-
-#define POI_STACK_PREALLOC 64
-
-static enum object_type packed_to_object_type(struct packed_git *p,
-					      off_t obj_offset,
-					      enum object_type type,
-					      struct pack_window **w_curs,
-					      off_t curpos)
-{
-	off_t small_poi_stack[POI_STACK_PREALLOC];
-	off_t *poi_stack = small_poi_stack;
-	int poi_stack_nr = 0, poi_stack_alloc = POI_STACK_PREALLOC;
-
-	while (type == OBJ_OFS_DELTA || type == OBJ_REF_DELTA) {
-		off_t base_offset;
-		unsigned long size;
-		/* Push the object we're going to leave behind */
-		if (poi_stack_nr >= poi_stack_alloc && poi_stack == small_poi_stack) {
-			poi_stack_alloc = alloc_nr(poi_stack_nr);
-			ALLOC_ARRAY(poi_stack, poi_stack_alloc);
-			memcpy(poi_stack, small_poi_stack, sizeof(off_t)*poi_stack_nr);
-		} else {
-			ALLOC_GROW(poi_stack, poi_stack_nr+1, poi_stack_alloc);
-		}
-		poi_stack[poi_stack_nr++] = obj_offset;
-		/* If parsing the base offset fails, just unwind */
-		base_offset = get_delta_base(p, w_curs, &curpos, type, obj_offset);
-		if (!base_offset)
-			goto unwind;
-		curpos = obj_offset = base_offset;
-		type = unpack_object_header(p, w_curs, &curpos, &size);
-		if (type <= OBJ_NONE) {
-			/* If getting the base itself fails, we first
-			 * retry the base, otherwise unwind */
-			type = retry_bad_packed_offset(p, base_offset);
-			if (type > OBJ_NONE)
-				goto out;
-			goto unwind;
-		}
-	}
-
-	switch (type) {
-	case OBJ_BAD:
-	case OBJ_COMMIT:
-	case OBJ_TREE:
-	case OBJ_BLOB:
-	case OBJ_TAG:
-		break;
-	default:
-		error("unknown object type %i at offset %"PRIuMAX" in %s",
-		      type, (uintmax_t)obj_offset, p->pack_name);
-		type = OBJ_BAD;
-	}
-
-out:
-	if (poi_stack != small_poi_stack)
-		free(poi_stack);
-	return type;
-
-unwind:
-	while (poi_stack_nr) {
-		obj_offset = poi_stack[--poi_stack_nr];
-		type = retry_bad_packed_offset(p, obj_offset);
-		if (type > OBJ_NONE)
-			goto out;
-	}
-	type = OBJ_BAD;
-	goto out;
-}
-
-static struct hashmap delta_base_cache;
-static size_t delta_base_cached;
-
-static LIST_HEAD(delta_base_cache_lru);
-
-struct delta_base_cache_key {
-	struct packed_git *p;
-	off_t base_offset;
-};
-
-struct delta_base_cache_entry {
-	struct hashmap hash;
-	struct delta_base_cache_key key;
-	struct list_head lru;
-	void *data;
-	unsigned long size;
-	enum object_type type;
-};
-
-static unsigned int pack_entry_hash(struct packed_git *p, off_t base_offset)
-{
-	unsigned int hash;
-
-	hash = (unsigned int)(intptr_t)p + (unsigned int)base_offset;
-	hash += (hash >> 8) + (hash >> 16);
-	return hash;
-}
-
-static struct delta_base_cache_entry *
-get_delta_base_cache_entry(struct packed_git *p, off_t base_offset)
-{
-	struct hashmap_entry entry;
-	struct delta_base_cache_key key;
-
-	if (!delta_base_cache.cmpfn)
-		return NULL;
-
-	hashmap_entry_init(&entry, pack_entry_hash(p, base_offset));
-	key.p = p;
-	key.base_offset = base_offset;
-	return hashmap_get(&delta_base_cache, &entry, &key);
-}
-
-static int delta_base_cache_key_eq(const struct delta_base_cache_key *a,
-				   const struct delta_base_cache_key *b)
-{
-	return a->p == b->p && a->base_offset == b->base_offset;
-}
-
-static int delta_base_cache_hash_cmp(const void *unused_cmp_data,
-				     const void *va, const void *vb,
-				     const void *vkey)
-{
-	const struct delta_base_cache_entry *a = va, *b = vb;
-	const struct delta_base_cache_key *key = vkey;
-	if (key)
-		return !delta_base_cache_key_eq(&a->key, key);
-	else
-		return !delta_base_cache_key_eq(&a->key, &b->key);
-}
-
-static int in_delta_base_cache(struct packed_git *p, off_t base_offset)
-{
-	return !!get_delta_base_cache_entry(p, base_offset);
-}
-
-/*
- * Remove the entry from the cache, but do _not_ free the associated
- * entry data. The caller takes ownership of the "data" buffer, and
- * should copy out any fields it wants before detaching.
- */
-static void detach_delta_base_cache_entry(struct delta_base_cache_entry *ent)
-{
-	hashmap_remove(&delta_base_cache, ent, &ent->key);
-	list_del(&ent->lru);
-	delta_base_cached -= ent->size;
-	free(ent);
-}
-
-static void *cache_or_unpack_entry(struct packed_git *p, off_t base_offset,
-	unsigned long *base_size, enum object_type *type)
-{
-	struct delta_base_cache_entry *ent;
-
-	ent = get_delta_base_cache_entry(p, base_offset);
-	if (!ent)
-		return unpack_entry(p, base_offset, type, base_size);
-
-	if (type)
-		*type = ent->type;
-	if (base_size)
-		*base_size = ent->size;
-	return xmemdupz(ent->data, ent->size);
-}
-
-static inline void release_delta_base_cache(struct delta_base_cache_entry *ent)
-{
-	free(ent->data);
-	detach_delta_base_cache_entry(ent);
-}
-
-void clear_delta_base_cache(void)
-{
-	struct list_head *lru, *tmp;
-	list_for_each_safe(lru, tmp, &delta_base_cache_lru) {
-		struct delta_base_cache_entry *entry =
-			list_entry(lru, struct delta_base_cache_entry, lru);
-		release_delta_base_cache(entry);
-	}
-}
-
-static void add_delta_base_cache(struct packed_git *p, off_t base_offset,
-	void *base, unsigned long base_size, enum object_type type)
-{
-	struct delta_base_cache_entry *ent = xmalloc(sizeof(*ent));
-	struct list_head *lru, *tmp;
-
-	delta_base_cached += base_size;
-
-	list_for_each_safe(lru, tmp, &delta_base_cache_lru) {
-		struct delta_base_cache_entry *f =
-			list_entry(lru, struct delta_base_cache_entry, lru);
-		if (delta_base_cached <= delta_base_cache_limit)
-			break;
-		release_delta_base_cache(f);
-	}
-
-	ent->key.p = p;
-	ent->key.base_offset = base_offset;
-	ent->type = type;
-	ent->data = base;
-	ent->size = base_size;
-	list_add_tail(&ent->lru, &delta_base_cache_lru);
-
-	if (!delta_base_cache.cmpfn)
-		hashmap_init(&delta_base_cache, delta_base_cache_hash_cmp, NULL, 0);
-	hashmap_entry_init(ent, pack_entry_hash(p, base_offset));
-	hashmap_add(&delta_base_cache, ent);
-}
-
-int packed_object_info(struct packed_git *p, off_t obj_offset,
-		       struct object_info *oi)
-{
-	struct pack_window *w_curs = NULL;
-	unsigned long size;
-	off_t curpos = obj_offset;
-	enum object_type type;
-
-	/*
-	 * We always get the representation type, but only convert it to
-	 * a "real" type later if the caller is interested.
-	 */
-	if (oi->contentp) {
-		*oi->contentp = cache_or_unpack_entry(p, obj_offset, oi->sizep,
-						      &type);
-		if (!*oi->contentp)
-			type = OBJ_BAD;
-	} else {
-		type = unpack_object_header(p, &w_curs, &curpos, &size);
-	}
-
-	if (!oi->contentp && oi->sizep) {
-		if (type == OBJ_OFS_DELTA || type == OBJ_REF_DELTA) {
-			off_t tmp_pos = curpos;
-			off_t base_offset = get_delta_base(p, &w_curs, &tmp_pos,
-							   type, obj_offset);
-			if (!base_offset) {
-				type = OBJ_BAD;
-				goto out;
-			}
-			*oi->sizep = get_size_from_delta(p, &w_curs, tmp_pos);
-			if (*oi->sizep == 0) {
-				type = OBJ_BAD;
-				goto out;
-			}
-		} else {
-			*oi->sizep = size;
-		}
-	}
-
-	if (oi->disk_sizep) {
-		struct revindex_entry *revidx = find_pack_revindex(p, obj_offset);
-		*oi->disk_sizep = revidx[1].offset - obj_offset;
-	}
-
-	if (oi->typep || oi->typename) {
-		enum object_type ptot;
-		ptot = packed_to_object_type(p, obj_offset, type, &w_curs,
-					     curpos);
-		if (oi->typep)
-			*oi->typep = ptot;
-		if (oi->typename) {
-			const char *tn = typename(ptot);
-			if (tn)
-				strbuf_addstr(oi->typename, tn);
-		}
-		if (ptot < 0) {
-			type = OBJ_BAD;
-			goto out;
-		}
-	}
-
-	if (oi->delta_base_sha1) {
-		if (type == OBJ_OFS_DELTA || type == OBJ_REF_DELTA) {
-			const unsigned char *base;
-
-			base = get_delta_base_sha1(p, &w_curs, curpos,
-						   type, obj_offset);
-			if (!base) {
-				type = OBJ_BAD;
-				goto out;
-			}
-
-			hashcpy(oi->delta_base_sha1, base);
-		} else
-			hashclr(oi->delta_base_sha1);
-	}
-
-	oi->whence = in_delta_base_cache(p, obj_offset) ? OI_DBCACHED :
-							  OI_PACKED;
-
-out:
-	unuse_pack(&w_curs);
-	return type;
-}
-
-static void *unpack_compressed_entry(struct packed_git *p,
-				    struct pack_window **w_curs,
-				    off_t curpos,
-				    unsigned long size)
-{
-	int st;
-	git_zstream stream;
-	unsigned char *buffer, *in;
-
-	buffer = xmallocz_gently(size);
-	if (!buffer)
-		return NULL;
-	memset(&stream, 0, sizeof(stream));
-	stream.next_out = buffer;
-	stream.avail_out = size + 1;
-
-	git_inflate_init(&stream);
-	do {
-		in = use_pack(p, w_curs, curpos, &stream.avail_in);
-		stream.next_in = in;
-		st = git_inflate(&stream, Z_FINISH);
-		if (!stream.avail_out)
-			break; /* the payload is larger than it should be */
-		curpos += stream.next_in - in;
-	} while (st == Z_OK || st == Z_BUF_ERROR);
-	git_inflate_end(&stream);
-	if ((st != Z_STREAM_END) || stream.total_out != size) {
-		free(buffer);
-		return NULL;
-	}
-
-	return buffer;
-}
-
-static void *read_object(const unsigned char *sha1, enum object_type *type,
-			 unsigned long *size);
-
-static void write_pack_access_log(struct packed_git *p, off_t obj_offset)
-{
-	static struct trace_key pack_access = TRACE_KEY_INIT(PACK_ACCESS);
-	trace_printf_key(&pack_access, "%s %"PRIuMAX"\n",
-			 p->pack_name, (uintmax_t)obj_offset);
-}
-
-int do_check_packed_object_crc;
-
-#define UNPACK_ENTRY_STACK_PREALLOC 64
-struct unpack_entry_stack_ent {
-	off_t obj_offset;
-	off_t curpos;
-	unsigned long size;
-};
-
-void *unpack_entry(struct packed_git *p, off_t obj_offset,
-		   enum object_type *final_type, unsigned long *final_size)
-{
-	struct pack_window *w_curs = NULL;
-	off_t curpos = obj_offset;
-	void *data = NULL;
-	unsigned long size;
-	enum object_type type;
-	struct unpack_entry_stack_ent small_delta_stack[UNPACK_ENTRY_STACK_PREALLOC];
-	struct unpack_entry_stack_ent *delta_stack = small_delta_stack;
-	int delta_stack_nr = 0, delta_stack_alloc = UNPACK_ENTRY_STACK_PREALLOC;
-	int base_from_cache = 0;
-
-	write_pack_access_log(p, obj_offset);
-
-	/* PHASE 1: drill down to the innermost base object */
-	for (;;) {
-		off_t base_offset;
-		int i;
-		struct delta_base_cache_entry *ent;
-
-		ent = get_delta_base_cache_entry(p, curpos);
-		if (ent) {
-			type = ent->type;
-			data = ent->data;
-			size = ent->size;
-			detach_delta_base_cache_entry(ent);
-			base_from_cache = 1;
-			break;
-		}
-
-		if (do_check_packed_object_crc && p->index_version > 1) {
-			struct revindex_entry *revidx = find_pack_revindex(p, obj_offset);
-			off_t len = revidx[1].offset - obj_offset;
-			if (check_pack_crc(p, &w_curs, obj_offset, len, revidx->nr)) {
-				const unsigned char *sha1 =
-					nth_packed_object_sha1(p, revidx->nr);
-				error("bad packed object CRC for %s",
-				      sha1_to_hex(sha1));
-				mark_bad_packed_object(p, sha1);
-				data = NULL;
-				goto out;
-			}
-		}
-
-		type = unpack_object_header(p, &w_curs, &curpos, &size);
-		if (type != OBJ_OFS_DELTA && type != OBJ_REF_DELTA)
-			break;
-
-		base_offset = get_delta_base(p, &w_curs, &curpos, type, obj_offset);
-		if (!base_offset) {
-			error("failed to validate delta base reference "
-			      "at offset %"PRIuMAX" from %s",
-			      (uintmax_t)curpos, p->pack_name);
-			/* bail to phase 2, in hopes of recovery */
-			data = NULL;
-			break;
-		}
-
-		/* push object, proceed to base */
-		if (delta_stack_nr >= delta_stack_alloc
-		    && delta_stack == small_delta_stack) {
-			delta_stack_alloc = alloc_nr(delta_stack_nr);
-			ALLOC_ARRAY(delta_stack, delta_stack_alloc);
-			memcpy(delta_stack, small_delta_stack,
-			       sizeof(*delta_stack)*delta_stack_nr);
-		} else {
-			ALLOC_GROW(delta_stack, delta_stack_nr+1, delta_stack_alloc);
-		}
-		i = delta_stack_nr++;
-		delta_stack[i].obj_offset = obj_offset;
-		delta_stack[i].curpos = curpos;
-		delta_stack[i].size = size;
-
-		curpos = obj_offset = base_offset;
-	}
-
-	/* PHASE 2: handle the base */
-	switch (type) {
-	case OBJ_OFS_DELTA:
-	case OBJ_REF_DELTA:
-		if (data)
-			die("BUG: unpack_entry: left loop at a valid delta");
-		break;
-	case OBJ_COMMIT:
-	case OBJ_TREE:
-	case OBJ_BLOB:
-	case OBJ_TAG:
-		if (!base_from_cache)
-			data = unpack_compressed_entry(p, &w_curs, curpos, size);
-		break;
-	default:
-		data = NULL;
-		error("unknown object type %i at offset %"PRIuMAX" in %s",
-		      type, (uintmax_t)obj_offset, p->pack_name);
-	}
-
-	/* PHASE 3: apply deltas in order */
-
-	/* invariants:
-	 *   'data' holds the base data, or NULL if there was corruption
-	 */
-	while (delta_stack_nr) {
-		void *delta_data;
-		void *base = data;
-		void *external_base = NULL;
-		unsigned long delta_size, base_size = size;
-		int i;
-
-		data = NULL;
-
-		if (base)
-			add_delta_base_cache(p, obj_offset, base, base_size, type);
-
-		if (!base) {
-			/*
-			 * We're probably in deep shit, but let's try to fetch
-			 * the required base anyway from another pack or loose.
-			 * This is costly but should happen only in the presence
-			 * of a corrupted pack, and is better than failing outright.
-			 */
-			struct revindex_entry *revidx;
-			const unsigned char *base_sha1;
-			revidx = find_pack_revindex(p, obj_offset);
-			if (revidx) {
-				base_sha1 = nth_packed_object_sha1(p, revidx->nr);
-				error("failed to read delta base object %s"
-				      " at offset %"PRIuMAX" from %s",
-				      sha1_to_hex(base_sha1), (uintmax_t)obj_offset,
-				      p->pack_name);
-				mark_bad_packed_object(p, base_sha1);
-				base = read_object(base_sha1, &type, &base_size);
-				external_base = base;
-			}
-		}
-
-		i = --delta_stack_nr;
-		obj_offset = delta_stack[i].obj_offset;
-		curpos = delta_stack[i].curpos;
-		delta_size = delta_stack[i].size;
-
-		if (!base)
-			continue;
-
-		delta_data = unpack_compressed_entry(p, &w_curs, curpos, delta_size);
-
-		if (!delta_data) {
-			error("failed to unpack compressed delta "
-			      "at offset %"PRIuMAX" from %s",
-			      (uintmax_t)curpos, p->pack_name);
-			data = NULL;
-			free(external_base);
-			continue;
-		}
-
-		data = patch_delta(base, base_size,
-				   delta_data, delta_size,
-				   &size);
-
-		/*
-		 * We could not apply the delta; warn the user, but keep going.
-		 * Our failure will be noticed either in the next iteration of
-		 * the loop, or if this is the final delta, in the caller when
-		 * we return NULL. Those code paths will take care of making
-		 * a more explicit warning and retrying with another copy of
-		 * the object.
-		 */
-		if (!data)
-			error("failed to apply delta");
-
-		free(delta_data);
-		free(external_base);
-	}
-
-	if (final_type)
-		*final_type = type;
-	if (final_size)
-		*final_size = size;
-
-out:
-	unuse_pack(&w_curs);
-
-	if (delta_stack != small_delta_stack)
-		free(delta_stack);
-
-	return data;
-}
-
-const unsigned char *nth_packed_object_sha1(struct packed_git *p,
-					    uint32_t n)
-{
-	const unsigned char *index = p->index_data;
-	if (!index) {
-		if (open_pack_index(p))
-			return NULL;
-		index = p->index_data;
-	}
-	if (n >= p->num_objects)
-		return NULL;
-	index += 4 * 256;
-	if (p->index_version == 1) {
-		return index + 24 * n + 4;
-	} else {
-		index += 8;
-		return index + 20 * n;
-	}
-}
-
-const struct object_id *nth_packed_object_oid(struct object_id *oid,
-					      struct packed_git *p,
-					      uint32_t n)
-{
-	const unsigned char *hash = nth_packed_object_sha1(p, n);
-	if (!hash)
-		return NULL;
-	hashcpy(oid->hash, hash);
-	return oid;
-}
-
-void check_pack_index_ptr(const struct packed_git *p, const void *vptr)
-{
-	const unsigned char *ptr = vptr;
-	const unsigned char *start = p->index_data;
-	const unsigned char *end = start + p->index_size;
-	if (ptr < start)
-		die(_("offset before start of pack index for %s (corrupt index?)"),
-		    p->pack_name);
-	/* No need to check for underflow; .idx files must be at least 8 bytes */
-	if (ptr >= end - 8)
-		die(_("offset beyond end of pack index for %s (truncated index?)"),
-		    p->pack_name);
-}
-
-off_t nth_packed_object_offset(const struct packed_git *p, uint32_t n)
-{
-	const unsigned char *index = p->index_data;
-	index += 4 * 256;
-	if (p->index_version == 1) {
-		return ntohl(*((uint32_t *)(index + 24 * n)));
-	} else {
-		uint32_t off;
-		index += 8 + p->num_objects * (20 + 4);
-		off = ntohl(*((uint32_t *)(index + 4 * n)));
-		if (!(off & 0x80000000))
-			return off;
-		index += p->num_objects * 4 + (off & 0x7fffffff) * 8;
-		check_pack_index_ptr(p, index);
-		return (((uint64_t)ntohl(*((uint32_t *)(index + 0)))) << 32) |
-				   ntohl(*((uint32_t *)(index + 4)));
-	}
-}
-
-off_t find_pack_entry_one(const unsigned char *sha1,
-				  struct packed_git *p)
-{
-	const uint32_t *level1_ofs = p->index_data;
-	const unsigned char *index = p->index_data;
-	unsigned hi, lo, stride;
-	static int debug_lookup = -1;
-
-	if (debug_lookup < 0)
-		debug_lookup = !!getenv("GIT_DEBUG_LOOKUP");
-
-	if (!index) {
-		if (open_pack_index(p))
-			return 0;
-		level1_ofs = p->index_data;
-		index = p->index_data;
-	}
-	if (p->index_version > 1) {
-		level1_ofs += 2;
-		index += 8;
-	}
-	index += 4 * 256;
-	hi = ntohl(level1_ofs[*sha1]);
-	lo = ((*sha1 == 0x0) ? 0 : ntohl(level1_ofs[*sha1 - 1]));
-	if (p->index_version > 1) {
-		stride = 20;
-	} else {
-		stride = 24;
-		index += 4;
-	}
-
-	if (debug_lookup)
-		printf("%02x%02x%02x... lo %u hi %u nr %"PRIu32"\n",
-		       sha1[0], sha1[1], sha1[2], lo, hi, p->num_objects);
-
-	while (lo < hi) {
-		unsigned mi = (lo + hi) / 2;
-		int cmp = hashcmp(index + mi * stride, sha1);
-
-		if (debug_lookup)
-			printf("lo %u hi %u rg %u mi %u\n",
-			       lo, hi, hi - lo, mi);
-		if (!cmp)
-			return nth_packed_object_offset(p, mi);
-		if (cmp > 0)
-			hi = mi;
-		else
-			lo = mi+1;
-	}
-	return 0;
-}
-
-int is_pack_valid(struct packed_git *p)
-{
-	/* An already open pack is known to be valid. */
-	if (p->pack_fd != -1)
-		return 1;
-
-	/* If the pack has one window completely covering the
-	 * file size, the pack is known to be valid even if
-	 * the descriptor is not currently open.
-	 */
-	if (p->windows) {
-		struct pack_window *w = p->windows;
-
-		if (!w->offset && w->len == p->pack_size)
-			return 1;
-	}
-
-	/* Force the pack to open to prove its valid. */
-	return !open_packed_git(p);
-}
-
-static int fill_pack_entry(const unsigned char *sha1,
-			   struct pack_entry *e,
-			   struct packed_git *p)
-{
-	off_t offset;
-
-	if (p->num_bad_objects) {
-		unsigned i;
-		for (i = 0; i < p->num_bad_objects; i++)
-			if (!hashcmp(sha1, p->bad_object_sha1 + 20 * i))
-				return 0;
-	}
-
-	offset = find_pack_entry_one(sha1, p);
-	if (!offset)
-		return 0;
-
-	/*
-	 * We are about to tell the caller where they can locate the
-	 * requested object.  We better make sure the packfile is
-	 * still here and can be accessed before supplying that
-	 * answer, as it may have been deleted since the index was
-	 * loaded!
-	 */
-	if (!is_pack_valid(p))
-		return 0;
-	e->offset = offset;
-	e->p = p;
-	hashcpy(e->sha1, sha1);
-	return 1;
-}
-
-/*
- * Iff a pack file contains the object named by sha1, return true and
- * store its location to e.
- */
-static int find_pack_entry(const unsigned char *sha1, struct pack_entry *e)
-{
-	struct mru_entry *p;
-
-	prepare_packed_git();
-	if (!packed_git)
-		return 0;
-
-	for (p = packed_git_mru->head; p; p = p->next) {
-		if (fill_pack_entry(sha1, e, p->item)) {
-			mru_mark(packed_git_mru, p);
-			return 1;
-		}
-	}
-	return 0;
-}
-
-struct packed_git *find_sha1_pack(const unsigned char *sha1,
-				  struct packed_git *packs)
-{
-	struct packed_git *p;
-
-	for (p = packs; p; p = p->next) {
-		if (find_pack_entry_one(sha1, p))
-			return p;
-	}
-	return NULL;
-
-}
-
 static int sha1_loose_object_info(const unsigned char *sha1,
 				  struct object_info *oi,
 				  int flags)
@@ -3053,6 +1231,20 @@ int sha1_object_info(const unsigned char *sha1, unsigned long *sizep)
 	return type;
 }
 
+static void *read_object(const unsigned char *sha1, enum object_type *type,
+			 unsigned long *size)
+{
+	struct object_info oi = OBJECT_INFO_INIT;
+	void *content;
+	oi.typep = type;
+	oi.sizep = size;
+	oi.contentp = &content;
+
+	if (sha1_object_info_extended(sha1, &oi, 0) < 0)
+		return NULL;
+	return content;
+}
+
 int pretend_sha1_file(void *buf, unsigned long len, enum object_type type,
 		      unsigned char *sha1)
 {
@@ -3071,20 +1263,6 @@ int pretend_sha1_file(void *buf, unsigned long len, enum object_type type,
 	return 0;
 }
 
-static void *read_object(const unsigned char *sha1, enum object_type *type,
-			 unsigned long *size)
-{
-	struct object_info oi = OBJECT_INFO_INIT;
-	void *content;
-	oi.typep = type;
-	oi.sizep = size;
-	oi.contentp = &content;
-
-	if (sha1_object_info_extended(sha1, &oi, 0) < 0)
-		return NULL;
-	return content;
-}
-
 /*
  * This function dies on corrupt objects; the callers who want to
  * deal with them should arrange to call read_object() and give error
@@ -3445,20 +1623,6 @@ int force_object_loose(const unsigned char *sha1, time_t mtime)
 	return ret;
 }
 
-int has_pack_index(const unsigned char *sha1)
-{
-	struct stat st;
-	if (stat(sha1_pack_index_name(sha1), &st))
-		return 0;
-	return 1;
-}
-
-int has_sha1_pack(const unsigned char *sha1)
-{
-	struct pack_entry e;
-	return find_pack_entry(sha1, &e);
-}
-
 int has_sha1_file_with_flags(const unsigned char *sha1, int flags)
 {
 	if (!startup_info->have_repository)
@@ -3851,46 +2015,6 @@ int for_each_loose_object(each_loose_object_fn cb, void *data, unsigned flags)
 	return foreach_alt_odb(loose_from_alt_odb, &alt);
 }
 
-static int for_each_object_in_pack(struct packed_git *p, each_packed_object_fn cb, void *data)
-{
-	uint32_t i;
-	int r = 0;
-
-	for (i = 0; i < p->num_objects; i++) {
-		struct object_id oid;
-
-		if (!nth_packed_object_oid(&oid, p, i))
-			return error("unable to get sha1 of object %u in %s",
-				     i, p->pack_name);
-
-		r = cb(&oid, p, i, data);
-		if (r)
-			break;
-	}
-	return r;
-}
-
-int for_each_packed_object(each_packed_object_fn cb, void *data, unsigned flags)
-{
-	struct packed_git *p;
-	int r = 0;
-	int pack_errors = 0;
-
-	prepare_packed_git();
-	for (p = packed_git; p; p = p->next) {
-		if ((flags & FOR_EACH_OBJECT_LOCAL_ONLY) && !p->pack_local)
-			continue;
-		if (open_pack_index(p)) {
-			pack_errors = 1;
-			continue;
-		}
-		r = for_each_object_in_pack(p, cb, data);
-		if (r)
-			break;
-	}
-	return r ? r : pack_errors;
-}
-
 static int check_stream_sha1(git_zstream *stream,
 			     const char *hdr,
 			     unsigned long size,
diff --git a/sha1_name.c b/sha1_name.c
index 862b6f1308..134ac9742f 100644
--- a/sha1_name.c
+++ b/sha1_name.c
@@ -9,6 +9,7 @@
 #include "remote.h"
 #include "dir.h"
 #include "sha1-array.h"
+#include "packfile.h"
 
 static int get_oid_oneline(const char *, struct object_id *, struct commit_list *);
 
diff --git a/streaming.c b/streaming.c
index 9afa66b8be..6f1c60f12b 100644
--- a/streaming.c
+++ b/streaming.c
@@ -3,6 +3,7 @@
  */
 #include "cache.h"
 #include "streaming.h"
+#include "packfile.h"
 
 enum input_source {
 	stream_error = -1,