X-Git-Url: https://git.octo.it/?a=blobdiff_plain;f=pack-objects.c;h=3d622787cc554eb2936995441e4591ec1986bded;hb=031260064840e6e8c6bc36d7856a091ba80330c2;hp=d1e62dc019b46afb4eab076be430381d8fe07c64;hpb=a733cb606fed08130317d803956e946f73b0b88e;p=git.git

diff --git a/pack-objects.c b/pack-objects.c
index d1e62dc0..3d622787 100644
--- a/pack-objects.c
+++ b/pack-objects.c
@@ -5,7 +5,7 @@
 #include "pack.h"
 #include "csum-file.h"
 
-static const char pack_usage[] = "git-pack-objects [--window=N] [--depth=N] {--stdout | base-name} < object-list";
+static const char pack_usage[] = "git-pack-objects [--incremental] [--window=N] [--depth=N] {--stdout | base-name} < object-list";
 
 struct object_entry {
 	unsigned char sha1[20];
@@ -18,6 +18,9 @@ struct object_entry {
 	struct object_entry *delta;
 };
 
+static unsigned char object_list_sha1[20];
+static int non_empty = 0;
+static int incremental = 0;
 static struct object_entry **sorted_by_sha, **sorted_by_type;
 static struct object_entry *objects = NULL;
 static int nr_objects = 0, nr_alloc = 0;
@@ -34,7 +37,7 @@ static void *delta_against(void *buf, unsigned long size, struct object_entry *e
 	if (!otherbuf)
 		die("unable to read %s", sha1_to_hex(entry->delta->sha1));
         delta_buf = diff_delta(otherbuf, othersize,
-			       buf, size, &delta_size, ~0UL);
+			       buf, size, &delta_size, 0);
         if (!delta_buf || delta_size != entry->delta_size)
         	die("delta size changed");
         free(buf);
@@ -51,32 +54,19 @@ static void *delta_against(void *buf, unsigned long size, struct object_entry *e
  */
 static int encode_header(enum object_type type, unsigned long size, unsigned char *hdr)
 {
-	int n = 1, i;
+	int n = 1;
 	unsigned char c;
 
 	if (type < OBJ_COMMIT || type > OBJ_DELTA)
 		die("bad type %d", type);
 
-	/*
-	 * Shift the size up by 7 bits at a time,
-	 * until you get bits in the "high four".
-	 * That will be our beginning. We'll have
-	 * four size bits in 28..31, then groups
-	 * of seven in 21..27, 14..20, 7..13 and
-	 * finally 0..6.
-	 */
-	if (size) {
-		n = 5;
-		while (!(size & 0xfe000000)) {
-			size <<= 7;
-			n--;
-		}
-	}
-	c = (type << 4) | (size >> 28);
-	for (i = 1; i < n; i++) {
+	c = (type << 4) | (size & 15);
+	size >>= 4;
+	while (size) {
 		*hdr++ = c | 0x80;
-		c = (size >> 21) & 0x7f;
-		size <<= 7;
+		c = size & 0x7f;
+		size >>= 7;
+		n++;
 	}
 	*hdr = c;
 	return n;
@@ -97,9 +87,9 @@ static unsigned long write_object(struct sha1file *f, struct object_entry *entry
 		die("object %s size inconsistency (%lu vs %lu)", sha1_to_hex(entry->sha1), size, entry->size);
 
 	/*
-	 * The object header is a byte of 'type' followed by four bytes of
-	 * length, except for deltas that has the 20 bytes of delta sha
-	 * instead.
+	 * The object header is a byte of 'type' followed by zero or
+	 * more bytes of length.  For deltas, the 20 bytes of delta sha1
+	 * follows that.
 	 */
 	obj_type = entry->type;
 	if (entry->delta) {
@@ -118,6 +108,23 @@ static unsigned long write_object(struct sha1file *f, struct object_entry *entry
 	return hdrlen + datalen;
 }
 
+static unsigned long write_one(struct sha1file *f,
+			       struct object_entry *e,
+			       unsigned long offset)
+{
+	if (e->offset)
+		/* offset starts from header size and cannot be zero
+		 * if it is written already.
+		 */
+		return offset;
+	e->offset = offset;
+	offset += write_object(f, e);
+	/* if we are delitified, write out its base object. */
+	if (e->delta)
+		offset = write_one(f, e->delta, offset);
+	return offset;
+}
+
 static void write_pack_file(void)
 {
 	int i;
@@ -129,17 +136,15 @@ static void write_pack_file(void)
 	if (!base_name)
 		f = sha1fd(1, "<stdout>");
 	else
-		f = sha1create("%s.%s", base_name, "pack");
+		f = sha1create("%s-%s.%s", base_name, sha1_to_hex(object_list_sha1), "pack");
 	hdr.hdr_signature = htonl(PACK_SIGNATURE);
-	hdr.hdr_version = htonl(1);
+	hdr.hdr_version = htonl(PACK_VERSION);
 	hdr.hdr_entries = htonl(nr_objects);
 	sha1write(f, &hdr, sizeof(hdr));
 	offset = sizeof(hdr);
-	for (i = 0; i < nr_objects; i++) {
-		struct object_entry *entry = objects + i;
-		entry->offset = offset;
-		offset += write_object(f, entry);
-	}
+	for (i = 0; i < nr_objects; i++)
+		offset = write_one(f, objects + i, offset);
+
 	sha1close(f, pack_file_sha1, 1);
 	mb = offset >> 20;
 	offset &= 0xfffff;
@@ -148,7 +153,7 @@ static void write_pack_file(void)
 static void write_index_file(void)
 {
 	int i;
-	struct sha1file *f = sha1create("%s.%s", base_name, "idx");
+	struct sha1file *f = sha1create("%s-%s.%s", base_name, sha1_to_hex(object_list_sha1), "idx");
 	struct object_entry **list = sorted_by_sha;
 	struct object_entry **last = list + nr_objects;
 	unsigned int array[256];
@@ -185,11 +190,14 @@ static void write_index_file(void)
 	sha1close(f, NULL, 1);
 }
 
-static void add_object_entry(unsigned char *sha1, unsigned int hash)
+static int add_object_entry(unsigned char *sha1, unsigned int hash)
 {
 	unsigned int idx = nr_objects;
 	struct object_entry *entry;
 
+	if (incremental && has_sha1_pack(sha1))
+		return 0;
+
 	if (idx >= nr_alloc) {
 		unsigned int needed = (idx + 1024) * 3 / 2;
 		objects = xrealloc(objects, needed * sizeof(*entry));
@@ -200,6 +208,7 @@ static void add_object_entry(unsigned char *sha1, unsigned int hash)
 	memcpy(entry->sha1, sha1, 20);
 	entry->hash = hash;
 	nr_objects = idx+1;
+	return 1;
 }
 
 static void check_object(struct object_entry *entry)
@@ -373,10 +382,15 @@ static void find_deltas(struct object_entry **list, int window, int depth)
 		if (idx >= window)
 			idx = 0;
 	}
+
+	for (i = 0; i < window; ++i)
+		free(array[i].data);
+	free(array);
 }
 
 int main(int argc, char **argv)
 {
+	SHA_CTX ctx;
 	char line[PATH_MAX + 20];
 	int window = 10, depth = 10, pack_to_stdout = 0;
 	int i;
@@ -385,6 +399,14 @@ int main(int argc, char **argv)
 		const char *arg = argv[i];
 
 		if (*arg == '-') {
+			if (!strcmp("--non-empty", arg)) {
+				non_empty = 1;
+				continue;
+			}
+			if (!strcmp("--incremental", arg)) {
+				incremental = 1;
+				continue;
+			}
 			if (!strncmp("--window=", arg, 9)) {
 				char *end;
 				window = strtoul(arg+9, &end, 0);
@@ -413,6 +435,7 @@ int main(int argc, char **argv)
 	if (pack_to_stdout != !base_name)
 		usage(pack_usage);
 
+	SHA1_Init(&ctx);
 	while (fgets(line, sizeof(line), stdin) != NULL) {
 		unsigned int hash;
 		char *p;
@@ -428,8 +451,12 @@ int main(int argc, char **argv)
 				continue;
 			hash = hash * 11 + c;
 		}
-		add_object_entry(sha1, hash);
+		if (add_object_entry(sha1, hash))
+			SHA1_Update(&ctx, sha1, 20);
 	}
+	SHA1_Final(object_list_sha1, &ctx);
+	if (non_empty && !nr_objects)
+		return 0;
 	get_object_details();
 
 	fprintf(stderr, "Packing %d objects\n", nr_objects);
@@ -440,7 +467,9 @@ int main(int argc, char **argv)
 		find_deltas(sorted_by_type, window+1, depth);
 
 	write_pack_file();
-	if (!pack_to_stdout)
+	if (!pack_to_stdout) {
 		write_index_file();
+		puts(sha1_to_hex(object_list_sha1));
+	}
 	return 0;
 }