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authorJunio C Hamano <junkio@cox.net>2006-05-20 00:56:11 -0700
committerJunio C Hamano <junkio@cox.net>2006-05-20 00:56:11 -0700
commit283c8eef6c9a4e379c73904d2bc22b19341b15c8 (patch)
tree80eb9553f23256e1f1cbb6ba022b330a8a6a4422 /read-cache.c
parent288c0384505e6c25cc1a162242919a0485d50a74 (diff)
parentb6c4a480b3161effaa3578df91d8cdc83044d7b6 (diff)
downloadgit-283c8eef6c9a4e379c73904d2bc22b19341b15c8.tar.gz
Merge branch 'jc/cache-tree' into jc/dirwalk-n-cache-tree
* jc/cache-tree: (24 commits) Fix crash when reading the empty tree fsck-objects: do not segfault on missing tree in cache-tree cache-tree: a bit more debugging support. read-tree: invalidate cache-tree entry when a new index entry is added. Fix test-dump-cache-tree in one-tree disappeared case. fsck-objects: mark objects reachable from cache-tree cache-tree: replace a sscanf() by two strtol() calls cache-tree.c: typefix test-dump-cache-tree: validate the cached data as well. cache_tree_update: give an option to update cache-tree only. read-tree: teach 1-way merege and plain read to prime cache-tree. read-tree: teach 1 and 2 way merges about cache-tree. update-index: when --unresolve, smudge the relevant cache-tree entries. test-dump-cache-tree: report number of subtrees. cache-tree: sort the subtree entries. Teach fsck-objects about cache-tree. index: make the index file format extensible. cache-tree: protect against "git prune". Add test-dump-cache-tree Use cache-tree in update-index. ...
Diffstat (limited to 'read-cache.c')
-rw-r--r--read-cache.c72
1 files changed, 72 insertions, 0 deletions
diff --git a/read-cache.c b/read-cache.c
index b95edcc14c..2512565260 100644
--- a/read-cache.c
+++ b/read-cache.c
@@ -4,11 +4,26 @@
* Copyright (C) Linus Torvalds, 2005
*/
#include "cache.h"
+#include "cache-tree.h"
+
+/* Index extensions.
+ *
+ * The first letter should be 'A'..'Z' for extensions that are not
+ * necessary for a correct operation (i.e. optimization data).
+ * When new extensions are added that _needs_ to be understood in
+ * order to correctly interpret the index file, pick character that
+ * is outside the range, to cause the reader to abort.
+ */
+
+#define CACHE_EXT(s) ( (s[0]<<24)|(s[1]<<16)|(s[2]<<8)|(s[3]) )
+#define CACHE_EXT_TREE 0x54524545 /* "TREE" */
struct cache_entry **active_cache = NULL;
static time_t index_file_timestamp;
unsigned int active_nr = 0, active_alloc = 0, active_cache_changed = 0;
+struct cache_tree *active_cache_tree = NULL;
+
/*
* This only updates the "non-critical" parts of the directory
* cache, ie the parts that aren't tracked by GIT, and only used
@@ -630,6 +645,22 @@ static int verify_hdr(struct cache_header *hdr, unsigned long size)
return 0;
}
+static int read_index_extension(const char *ext, void *data, unsigned long sz)
+{
+ switch (CACHE_EXT(ext)) {
+ case CACHE_EXT_TREE:
+ active_cache_tree = cache_tree_read(data, sz);
+ break;
+ default:
+ if (*ext < 'A' || 'Z' < *ext)
+ return error("index uses %.4s extension, which we do not understand",
+ ext);
+ fprintf(stderr, "ignoring %.4s extension\n", ext);
+ break;
+ }
+ return 0;
+}
+
int read_cache(void)
{
int fd, i;
@@ -678,6 +709,22 @@ int read_cache(void)
active_cache[i] = ce;
}
index_file_timestamp = st.st_mtime;
+ while (offset <= size - 20 - 8) {
+ /* After an array of active_nr index entries,
+ * there can be arbitrary number of extended
+ * sections, each of which is prefixed with
+ * extension name (4-byte) and section length
+ * in 4-byte network byte order.
+ */
+ unsigned long extsize;
+ memcpy(&extsize, map + offset + 4, 4);
+ extsize = ntohl(extsize);
+ if (read_index_extension(map + offset,
+ map + offset + 8, extsize) < 0)
+ goto unmap;
+ offset += 8;
+ offset += extsize;
+ }
return active_nr;
unmap:
@@ -712,6 +759,17 @@ static int ce_write(SHA_CTX *context, int fd, void *data, unsigned int len)
return 0;
}
+static int write_index_ext_header(SHA_CTX *context, int fd,
+ unsigned long ext, unsigned long sz)
+{
+ ext = htonl(ext);
+ sz = htonl(sz);
+ if ((ce_write(context, fd, &ext, 4) < 0) ||
+ (ce_write(context, fd, &sz, 4) < 0))
+ return -1;
+ return 0;
+}
+
static int ce_flush(SHA_CTX *context, int fd)
{
unsigned int left = write_buffer_len;
@@ -808,5 +866,19 @@ int write_cache(int newfd, struct cache_entry **cache, int entries)
if (ce_write(&c, newfd, ce, ce_size(ce)) < 0)
return -1;
}
+
+ /* Write extension data here */
+ if (active_cache_tree) {
+ unsigned long sz;
+ void *data = cache_tree_write(active_cache_tree, &sz);
+ if (data &&
+ !write_index_ext_header(&c, newfd, CACHE_EXT_TREE, sz) &&
+ !ce_write(&c, newfd, data, sz))
+ ;
+ else {
+ free(data);
+ return -1;
+ }
+ }
return ce_flush(&c, newfd);
}