Unify write_index_file functions

This patch unifies the write_index_file functions in
builtin-pack-objects.c and index-pack.c.  As the name
"index" is overloaded in git, move in the direction of
using "idx" and "pack idx" when refering to the pack index.
There should be no change in functionality.

Signed-off-by: Geert Bosch <bosch@gnat.com>
Acked-by: Nicolas Pitre <nico@cam.org>
Signed-off-by: Junio C Hamano <junkio@cox.net>

1 files changed, 37 insertions, 171 deletions

diff --git a/index-pack.c b/index-pack.c
index 58c4a9c41d..82c8da3683 100644
--- a/index-pack.c
+++ b/index-pack.c
@@ -13,13 +13,11 @@ static const char index_pack_usage[] =
 
 struct object_entry
 {
-	off_t offset;
+	struct pack_idx_entry idx;
 	unsigned long size;
 	unsigned int hdr_size;
-	uint32_t crc32;
 	enum object_type type;
 	enum object_type real_type;
-	unsigned char sha1[20];
 };
 
 union delta_base {
@@ -197,7 +195,7 @@ static void *unpack_raw_entry(struct object_entry *obj, union delta_base *delta_
 	unsigned shift;
 	void *data;
 
-	obj->offset = consumed_bytes;
+	obj->idx.offset = consumed_bytes;
 	input_crc32 = crc32(0, Z_NULL, 0);
 
 	p = fill(1);
@@ -229,15 +227,15 @@ static void *unpack_raw_entry(struct object_entry *obj, union delta_base *delta_
 		while (c & 128) {
 			base_offset += 1;
 			if (!base_offset || MSB(base_offset, 7))
-				bad_object(obj->offset, "offset value overflow for delta base object");
+				bad_object(obj->idx.offset, "offset value overflow for delta base object");
 			p = fill(1);
 			c = *p;
 			use(1);
 			base_offset = (base_offset << 7) + (c & 127);
 		}
-		delta_base->offset = obj->offset - base_offset;
-		if (delta_base->offset >= obj->offset)
-			bad_object(obj->offset, "delta base offset is out of bound");
+		delta_base->offset = obj->idx.offset - base_offset;
+		if (delta_base->offset >= obj->idx.offset)
+			bad_object(obj->idx.offset, "delta base offset is out of bound");
 		break;
 	case OBJ_COMMIT:
 	case OBJ_TREE:
@@ -245,19 +243,19 @@ static void *unpack_raw_entry(struct object_entry *obj, union delta_base *delta_
 	case OBJ_TAG:
 		break;
 	default:
-		bad_object(obj->offset, "unknown object type %d", obj->type);
+		bad_object(obj->idx.offset, "unknown object type %d", obj->type);
 	}
-	obj->hdr_size = consumed_bytes - obj->offset;
+	obj->hdr_size = consumed_bytes - obj->idx.offset;
 
-	data = unpack_entry_data(obj->offset, obj->size);
-	obj->crc32 = input_crc32;
+	data = unpack_entry_data(obj->idx.offset, obj->size);
+	obj->idx.crc32 = input_crc32;
 	return data;
 }
 
 static void *get_data_from_pack(struct object_entry *obj)
 {
-	unsigned long from = obj[0].offset + obj[0].hdr_size;
-	unsigned long len = obj[1].offset - from;
+	unsigned long from = obj[0].idx.offset + obj[0].hdr_size;
+	unsigned long len = obj[1].idx.offset - from;
 	unsigned long rdy = 0;
 	unsigned char *src, *data;
 	z_stream stream;
@@ -360,11 +358,11 @@ static void resolve_delta(struct object_entry *delta_obj, void *base_data,
 			     &result_size);
 	free(delta_data);
 	if (!result)
-		bad_object(delta_obj->offset, "failed to apply delta");
-	sha1_object(result, result_size, type, delta_obj->sha1);
+		bad_object(delta_obj->idx.offset, "failed to apply delta");
+	sha1_object(result, result_size, type, delta_obj->idx.sha1);
 	nr_resolved_deltas++;
 
-	hashcpy(delta_base.sha1, delta_obj->sha1);
+	hashcpy(delta_base.sha1, delta_obj->idx.sha1);
 	if (!find_delta_children(&delta_base, &first, &last)) {
 		for (j = first; j <= last; j++) {
 			struct object_entry *child = objects + deltas[j].obj_no;
@@ -374,7 +372,7 @@ static void resolve_delta(struct object_entry *delta_obj, void *base_data,
 	}
 
 	memset(&delta_base, 0, sizeof(delta_base));
-	delta_base.offset = delta_obj->offset;
+	delta_base.offset = delta_obj->idx.offset;
 	if (!find_delta_children(&delta_base, &first, &last)) {
 		for (j = first; j <= last; j++) {
 			struct object_entry *child = objects + deltas[j].obj_no;
@@ -418,12 +416,12 @@ static void parse_pack_objects(unsigned char *sha1)
 			delta->obj_no = i;
 			delta++;
 		} else
-			sha1_object(data, obj->size, obj->type, obj->sha1);
+			sha1_object(data, obj->size, obj->type, obj->idx.sha1);
 		free(data);
 		if (verbose)
 			display_progress(&progress, i+1);
 	}
-	objects[i].offset = consumed_bytes;
+	objects[i].idx.offset = consumed_bytes;
 	if (verbose)
 		stop_progress(&progress);
 
@@ -465,10 +463,10 @@ static void parse_pack_objects(unsigned char *sha1)
 
 		if (obj->type == OBJ_REF_DELTA || obj->type == OBJ_OFS_DELTA)
 			continue;
-		hashcpy(base.sha1, obj->sha1);
+		hashcpy(base.sha1, obj->idx.sha1);
 		ref = !find_delta_children(&base, &ref_first, &ref_last);
 		memset(&base, 0, sizeof(base));
-		base.offset = obj->offset;
+		base.offset = obj->idx.offset;
 		ofs = !find_delta_children(&base, &ofs_first, &ofs_last);
 		if (!ref && !ofs)
 			continue;
@@ -535,11 +533,11 @@ static void append_obj_to_pack(const unsigned char *sha1, void *buf,
 	}
 	header[n++] = c;
 	write_or_die(output_fd, header, n);
-	obj[0].crc32 = crc32(0, Z_NULL, 0);
-	obj[0].crc32 = crc32(obj[0].crc32, header, n);
-	obj[1].offset = obj[0].offset + n;
-	obj[1].offset += write_compressed(output_fd, buf, size, &obj[0].crc32);
-	hashcpy(obj->sha1, sha1);
+	obj[0].idx.crc32 = crc32(0, Z_NULL, 0);
+	obj[0].idx.crc32 = crc32(obj[0].idx.crc32, header, n);
+	obj[1].idx.offset = obj[0].idx.offset + n;
+	obj[1].idx.offset += write_compressed(output_fd, buf, size, &obj[0].idx.crc32);
+	hashcpy(obj->idx.sha1, sha1);
 }
 
 static int delta_pos_compare(const void *_a, const void *_b)
@@ -602,145 +600,6 @@ static void fix_unresolved_deltas(int nr_unresolved)
 	free(sorted_by_pos);
 }
 
-static uint32_t index_default_version = 1;
-static uint32_t index_off32_limit = 0x7fffffff;
-
-static int sha1_compare(const void *_a, const void *_b)
-{
-	struct object_entry *a = *(struct object_entry **)_a;
-	struct object_entry *b = *(struct object_entry **)_b;
-	return hashcmp(a->sha1, b->sha1);
-}
-
-/*
- * On entry *sha1 contains the pack content SHA1 hash, on exit it is
- * the SHA1 hash of sorted object names.
- */
-static const char *write_index_file(const char *index_name, unsigned char *sha1)
-{
-	struct sha1file *f;
-	struct object_entry **sorted_by_sha, **list, **last;
-	uint32_t array[256];
-	int i, fd;
-	SHA_CTX ctx;
-	uint32_t index_version;
-
-	if (nr_objects) {
-		sorted_by_sha =
-			xcalloc(nr_objects, sizeof(struct object_entry *));
-		list = sorted_by_sha;
-		last = sorted_by_sha + nr_objects;
-		for (i = 0; i < nr_objects; ++i)
-			sorted_by_sha[i] = &objects[i];
-		qsort(sorted_by_sha, nr_objects, sizeof(sorted_by_sha[0]),
-		      sha1_compare);
-	}
-	else
-		sorted_by_sha = list = last = NULL;
-
-	if (!index_name) {
-		static char tmpfile[PATH_MAX];
-		snprintf(tmpfile, sizeof(tmpfile),
-			 "%s/tmp_idx_XXXXXX", get_object_directory());
-		fd = mkstemp(tmpfile);
-		index_name = xstrdup(tmpfile);
-	} else {
-		unlink(index_name);
-		fd = open(index_name, O_CREAT|O_EXCL|O_WRONLY, 0600);
-	}
-	if (fd < 0)
-		die("unable to create %s: %s", index_name, strerror(errno));
-	f = sha1fd(fd, index_name);
-
-	/* if last object's offset is >= 2^31 we should use index V2 */
-	index_version = (objects[nr_objects-1].offset >> 31) ? 2 : index_default_version;
-
-	/* index versions 2 and above need a header */
-	if (index_version >= 2) {
-		struct pack_idx_header hdr;
-		hdr.idx_signature = htonl(PACK_IDX_SIGNATURE);
-		hdr.idx_version = htonl(index_version);
-		sha1write(f, &hdr, sizeof(hdr));
-	}
-
-	/*
-	 * Write the first-level table (the list is sorted,
-	 * but we use a 256-entry lookup to be able to avoid
-	 * having to do eight extra binary search iterations).
-	 */
-	for (i = 0; i < 256; i++) {
-		struct object_entry **next = list;
-		while (next < last) {
-			struct object_entry *obj = *next;
-			if (obj->sha1[0] != i)
-				break;
-			next++;
-		}
-		array[i] = htonl(next - sorted_by_sha);
-		list = next;
-	}
-	sha1write(f, array, 256 * 4);
-
-	/* compute the SHA1 hash of sorted object names. */
-	SHA1_Init(&ctx);
-
-	/*
-	 * Write the actual SHA1 entries..
-	 */
-	list = sorted_by_sha;
-	for (i = 0; i < nr_objects; i++) {
-		struct object_entry *obj = *list++;
-		if (index_version < 2) {
-			uint32_t offset = htonl(obj->offset);
-			sha1write(f, &offset, 4);
-		}
-		sha1write(f, obj->sha1, 20);
-		SHA1_Update(&ctx, obj->sha1, 20);
-	}
-
-	if (index_version >= 2) {
-		unsigned int nr_large_offset = 0;
-
-		/* write the crc32 table */
-		list = sorted_by_sha;
-		for (i = 0; i < nr_objects; i++) {
-			struct object_entry *obj = *list++;
-			uint32_t crc32_val = htonl(obj->crc32);
-			sha1write(f, &crc32_val, 4);
-		}
-
-		/* write the 32-bit offset table */
-		list = sorted_by_sha;
-		for (i = 0; i < nr_objects; i++) {
-			struct object_entry *obj = *list++;
-			uint32_t offset = (obj->offset <= index_off32_limit) ?
-				obj->offset : (0x80000000 | nr_large_offset++);
-			offset = htonl(offset);
-			sha1write(f, &offset, 4);
-		}
-
-		/* write the large offset table */
-		list = sorted_by_sha;
-		while (nr_large_offset) {
-			struct object_entry *obj = *list++;
-			uint64_t offset = obj->offset;
-			if (offset > index_off32_limit) {
-				uint32_t split[2];
-				split[0]	= htonl(offset >> 32);
-				split[1] = htonl(offset & 0xffffffff);
-				sha1write(f, split, 8);
-				nr_large_offset--;
-			}
-		}
-	}
-
-	sha1write(f, sha1, 20);
-	sha1close(f, NULL, 1);
-	free(sorted_by_sha);
-	SHA1_Final(sha1, &ctx);
-	return index_name;
-}
-
 static void final(const char *final_pack_name, const char *curr_pack_name,
 		  const char *final_index_name, const char *curr_index_name,
 		  const char *keep_name, const char *keep_msg,
@@ -830,6 +689,7 @@ int main(int argc, char **argv)
 	const char *curr_index, *index_name = NULL;
 	const char *keep_name = NULL, *keep_msg = NULL;
 	char *index_name_buf = NULL, *keep_name_buf = NULL;
+	struct pack_idx_entry **idx_objects;
 	unsigned char sha1[20];
 
 	for (i = 1; i < argc; i++) {
@@ -865,12 +725,12 @@ int main(int argc, char **argv)
 				index_name = argv[++i];
 			} else if (!prefixcmp(arg, "--index-version=")) {
 				char *c;
-				index_default_version = strtoul(arg + 16, &c, 10);
-				if (index_default_version > 2)
+				pack_idx_default_version = strtoul(arg + 16, &c, 10);
+				if (pack_idx_default_version > 2)
 					die("bad %s", arg);
 				if (*c == ',')
-					index_off32_limit = strtoul(c+1, &c, 0);
-				if (*c || index_off32_limit & 0x80000000)
+					pack_idx_off32_limit = strtoul(c+1, &c, 0);
+				if (*c || pack_idx_off32_limit & 0x80000000)
 					die("bad %s", arg);
 			} else
 				usage(index_pack_usage);
@@ -940,7 +800,13 @@ int main(int argc, char **argv)
 			    nr_deltas - nr_resolved_deltas);
 	}
 	free(deltas);
-	curr_index = write_index_file(index_name, sha1);
+
+	idx_objects = xmalloc((nr_objects) * sizeof(struct pack_idx_entry *));
+	for (i = 0; i < nr_objects; i++)
+		idx_objects[i] = &objects[i].idx;
+	curr_index = write_idx_file(index_name, idx_objects, nr_objects, sha1);
+	free(idx_objects);
+
 	final(pack_name, curr_pack,
 		index_name, curr_index,
 		keep_name, keep_msg,