X-Git-Url: https://git.octo.it/?a=blobdiff_plain;ds=sidebyside;f=sha1_file.c;h=2d109f928bef6fe74f2a27af1419d9e82a7b9b33;hb=da27f4f3f4c23d0276a372726ed050ed13e45168;hp=df5eb2ac670e2969fcb611148929fef68e3747cc;hpb=70b9829ea73931f7e2f23fbe5f1853e0dca5ca12;p=git.git

diff --git a/sha1_file.c b/sha1_file.c
index df5eb2ac..2d109f92 100644
--- a/sha1_file.c
+++ b/sha1_file.c
@@ -46,21 +46,6 @@ int get_sha1_hex(const char *hex, unsigned char *sha1)
 	return 0;
 }
 
-static int get_sha1_file(const char *path, unsigned char *result)
-{
-	char buffer[60];
-	int fd = open(path, O_RDONLY);
-	int len;
-
-	if (fd < 0)
-		return -1;
-	len = read(fd, buffer, sizeof(buffer));
-	close(fd);
-	if (len < 40)
-		return -1;
-	return get_sha1_hex(buffer, result);
-}
-
 static char *git_dir, *git_object_dir, *git_index_file, *git_refs_dir,
 	*git_graft_file;
 static void setup_git_env(void)
@@ -132,30 +117,6 @@ int safe_create_leading_directories(char *path)
 	return 0;
 }
 
-int get_sha1(const char *str, unsigned char *sha1)
-{
-	static const char *prefix[] = {
-		"",
-		"refs",
-		"refs/tags",
-		"refs/heads",
-		"refs/snap",
-		NULL
-	};
-	const char **p;
-
-	if (!get_sha1_hex(str, sha1))
-		return 0;
-
-	for (p = prefix; *p; p++) {
-		char * pathname = git_path("%s/%s", *p, str);
-		if (!get_sha1_file(pathname, sha1))
-			return 0;
-	}
-
-	return -1;
-}
-
 char * sha1_to_hex(const unsigned char *sha1)
 {
 	static char buffer[50];
@@ -261,84 +222,100 @@ char *sha1_pack_index_name(const unsigned char *sha1)
 	return base;
 }
 
-struct alternate_object_database *alt_odb;
+struct alternate_object_database *alt_odb_list;
+static struct alternate_object_database **alt_odb_tail;
 
 /*
  * Prepare alternate object database registry.
- * alt_odb points at an array of struct alternate_object_database.
- * This array is terminated with an element that has both its base
- * and name set to NULL.  alt_odb[n] comes from n'th non-empty
- * element from colon separated ALTERNATE_DB_ENVIRONMENT environment
- * variable, and its base points at a statically allocated buffer
- * that contains "/the/directory/corresponding/to/.git/objects/...",
- * while its name points just after the slash at the end of
- * ".git/objects/" in the example above, and has enough space to hold
- * 40-byte hex SHA1, an extra slash for the first level indirection,
- * and the terminating NUL.
- * This function allocates the alt_odb array and all the strings
- * pointed by base fields of the array elements with one xmalloc();
- * the string pool immediately follows the array.
+ *
+ * The variable alt_odb_list points at the list of struct
+ * alternate_object_database.  The elements on this list come from
+ * non-empty elements from colon separated ALTERNATE_DB_ENVIRONMENT
+ * environment variable, and $GIT_OBJECT_DIRECTORY/info/alternates,
+ * whose contents is exactly in the same format as that environment
+ * variable.  Its base points at a statically allocated buffer that
+ * contains "/the/directory/corresponding/to/.git/objects/...", while
+ * its name points just after the slash at the end of ".git/objects/"
+ * in the example above, and has enough space to hold 40-byte hex
+ * SHA1, an extra slash for the first level indirection, and the
+ * terminating NUL.
  */
-void prepare_alt_odb(void)
+static void link_alt_odb_entries(const char *alt, const char *ep)
 {
-	int pass, totlen, i;
 	const char *cp, *last;
-	char *op = NULL;
-	const char *alt = gitenv(ALTERNATE_DB_ENVIRONMENT) ? : "";
+	struct alternate_object_database *ent;
 
-	if (alt_odb)
+	last = alt;
+	do {
+		for (cp = last; cp < ep && *cp != ':'; cp++)
+			;
+		if (last != cp) {
+			/* 43 = 40-byte + 2 '/' + terminating NUL */
+			int pfxlen = cp - last;
+			int entlen = pfxlen + 43;
+
+			ent = xmalloc(sizeof(*ent) + entlen);
+			*alt_odb_tail = ent;
+			alt_odb_tail = &(ent->next);
+			ent->next = NULL;
+
+			memcpy(ent->base, last, pfxlen);
+			ent->name = ent->base + pfxlen + 1;
+			ent->base[pfxlen] = ent->base[pfxlen + 3] = '/';
+			ent->base[entlen-1] = 0;
+		}
+		while (cp < ep && *cp == ':')
+			cp++;
+		last = cp;
+	} while (cp < ep);
+}
+
+void prepare_alt_odb(void)
+{
+	char path[PATH_MAX];
+	char *map, *ep;
+	int fd;
+	struct stat st;
+	char *alt = gitenv(ALTERNATE_DB_ENVIRONMENT) ? : "";
+
+	sprintf(path, "%s/info/alternates", get_object_directory());
+	if (alt_odb_tail)
+		return;
+	alt_odb_tail = &alt_odb_list;
+	link_alt_odb_entries(alt, alt + strlen(alt));
+
+	fd = open(path, O_RDONLY);
+	if (fd < 0)
+		return;
+	if (fstat(fd, &st) || (st.st_size == 0)) {
+		close(fd);
 		return;
-	/* The first pass counts how large an area to allocate to
-	 * hold the entire alt_odb structure, including array of
-	 * structs and path buffers for them.  The second pass fills
-	 * the structure and prepares the path buffers for use by
-	 * fill_sha1_path().
-	 */
-	for (totlen = pass = 0; pass < 2; pass++) {
-		last = alt;
-		i = 0;
-		do {
-			cp = strchr(last, ':') ? : last + strlen(last);
-			if (last != cp) {
-				/* 43 = 40-byte + 2 '/' + terminating NUL */
-				int pfxlen = cp - last;
-				int entlen = pfxlen + 43;
-				if (pass == 0)
-					totlen += entlen;
-				else {
-					alt_odb[i].base = op;
-					alt_odb[i].name = op + pfxlen + 1;
-					memcpy(op, last, pfxlen);
-					op[pfxlen] = op[pfxlen + 3] = '/';
-					op[entlen-1] = 0;
-					op += entlen;
-				}
-				i++;
-			}
-			while (*cp && *cp == ':')
-				cp++;
-			last = cp;
-		} while (*cp);
-		if (pass)
-			break;
-		alt_odb = xmalloc(sizeof(*alt_odb) * (i + 1) + totlen);
-		alt_odb[i].base = alt_odb[i].name = NULL;
-		op = (char*)(&alt_odb[i+1]);
 	}
+	map = mmap(NULL, st.st_size, PROT_READ, MAP_PRIVATE, fd, 0);
+	close(fd);
+	if (map == MAP_FAILED)
+		return;
+
+	/* Remove the trailing newline */
+	for (ep = map + st.st_size - 1; map < ep && ep[-1] == '\n'; ep--)
+		;
+	link_alt_odb_entries(map, ep);
+	munmap(map, st.st_size);
 }
 
 static char *find_sha1_file(const unsigned char *sha1, struct stat *st)
 {
-	int i;
 	char *name = sha1_file_name(sha1);
+	struct alternate_object_database *alt;
 
 	if (!stat(name, st))
 		return name;
 	prepare_alt_odb();
-	for (i = 0; (name = alt_odb[i].name) != NULL; i++) {
+	for (alt = alt_odb_list; alt; alt = alt->next) {
+		name = alt->name;
 		fill_sha1_path(name, sha1);
-		if (!stat(alt_odb[i].base, st))
-			return alt_odb[i].base;
+		if (!stat(alt->base, st))
+			return alt->base;
 	}
 	return NULL;
 }
@@ -561,18 +538,18 @@ static void prepare_packed_git_one(char *objdir)
 
 void prepare_packed_git(void)
 {
-	int i;
 	static int run_once = 0;
+	struct alternate_object_database *alt;
 
-	if (run_once++)
+	if (run_once)
 		return;
-
 	prepare_packed_git_one(get_object_directory());
 	prepare_alt_odb();
-	for (i = 0; alt_odb[i].base != NULL; i++) {
-		alt_odb[i].name[0] = 0;
-		prepare_packed_git_one(alt_odb[i].base);
+	for (alt = alt_odb_list; alt; alt = alt->next) {
+		alt->name[0] = 0;
+		prepare_packed_git_one(alt->base);
 	}
+	run_once = 1;
 }
 
 int check_sha1_signature(const unsigned char *sha1, void *map, unsigned long size, const char *type)
@@ -1204,6 +1181,7 @@ void *read_object_with_reference(const unsigned char *sha1,
 			free(buffer);
 			return NULL;
 		}
+		free(buffer);
 		/* Now we have the ID of the referred-to object in
 		 * actual_sha1.  Check again. */
 	}
@@ -1335,8 +1313,11 @@ int write_sha1_to_fd(int fd, const unsigned char *sha1)
 	ssize_t size;
 	unsigned long objsize;
 	int posn = 0;
-	void *buf = map_sha1_file_internal(sha1, &objsize);
+	void *map = map_sha1_file_internal(sha1, &objsize);
+	void *buf = map;
+	void *temp_obj = NULL;
 	z_stream stream;
+
 	if (!buf) {
 		unsigned char *unpacked;
 		unsigned long len;
@@ -1352,7 +1333,7 @@ int write_sha1_to_fd(int fd, const unsigned char *sha1)
 		memset(&stream, 0, sizeof(stream));
 		deflateInit(&stream, Z_BEST_COMPRESSION);
 		size = deflateBound(&stream, len + hdrlen);
-		buf = xmalloc(size);
+		temp_obj = buf = xmalloc(size);
 
 		/* Compress it */
 		stream.next_out = buf;
@@ -1370,6 +1351,7 @@ int write_sha1_to_fd(int fd, const unsigned char *sha1)
 		while (deflate(&stream, Z_FINISH) == Z_OK)
 			/* nothing */;
 		deflateEnd(&stream);
+		free(unpacked);
 		
 		objsize = stream.total_out;
 	}
@@ -1386,6 +1368,12 @@ int write_sha1_to_fd(int fd, const unsigned char *sha1)
 		}
 		posn += size;
 	} while (posn < objsize);
+
+	if (map)
+		munmap(map, objsize);
+	if (temp_obj)
+		free(temp_obj);
+
 	return 0;
 }
 
@@ -1416,7 +1404,7 @@ int write_sha1_from_fd(const unsigned char *sha1, int fd, char *buffer,
 		ssize_t size;
 		if (*bufposn) {
 			stream.avail_in = *bufposn;
-			stream.next_in = buffer;
+			stream.next_in = (unsigned char *) buffer;
 			do {
 				stream.next_out = discard;
 				stream.avail_out = sizeof(discard);