X-Git-Url: https://git.octo.it/?a=blobdiff_plain;f=sha1_file.c;h=e648c068b558fbdbbdc866c8829af3641e2c5b60;hb=17ebe977d72290dcdc848b78ae2e65b59d4e1b4c;hp=942b673dc3c7fa9f057c5c452e3a1b73eaeb8707;hpb=f1a7eb36b017c62d9a007b6b8660bdeec3f94f97;p=git.git

diff --git a/sha1_file.c b/sha1_file.c
index 942b673d..e648c068 100644
--- a/sha1_file.c
+++ b/sha1_file.c
@@ -6,9 +6,8 @@
  * This handles basic git sha1 object files - packing, unpacking,
  * creation etc.
  */
-#include <stdarg.h>
-#include <limits.h>
 #include "cache.h"
+#include "delta.h"
 
 #ifndef O_NOATIME
 #if defined(__linux__) && (defined(__i386__) || defined(__PPC__))
@@ -44,7 +43,7 @@ int get_sha1_hex(const char *hex, unsigned char *sha1)
 	return 0;
 }
 
-int get_sha1_file(const char *path, unsigned char *result)
+static int get_sha1_file(const char *path, unsigned char *result)
 {
 	char buffer[60];
 	int fd = open(path, O_RDONLY);
@@ -59,7 +58,7 @@ int get_sha1_file(const char *path, unsigned char *result)
 	return get_sha1_hex(buffer, result);
 }
 
-static char *git_dir, *git_object_dir, *git_index_file;
+static char *git_dir, *git_object_dir, *git_index_file, *git_refs_dir;
 static void setup_git_env(void)
 {
 	git_dir = gitenv(GIT_DIR_ENVIRONMENT);
@@ -70,6 +69,8 @@ static void setup_git_env(void)
 		git_object_dir = xmalloc(strlen(git_dir) + 9);
 		sprintf(git_object_dir, "%s/objects", git_dir);
 	}
+	git_refs_dir = xmalloc(strlen(git_dir) + 6);
+	sprintf(git_refs_dir, "%s/refs", git_dir);
 	git_index_file = gitenv(INDEX_ENVIRONMENT);
 	if (!git_index_file) {
 		git_index_file = xmalloc(strlen(git_dir) + 7);
@@ -84,6 +85,13 @@ char *get_object_directory(void)
 	return git_object_dir;
 }
 
+char *get_refs_directory(void)
+{
+	if (!git_refs_dir)
+		setup_git_env();
+	return git_refs_dir;
+}
+
 char *get_index_file(void)
 {
 	if (!git_index_file)
@@ -199,7 +207,7 @@ static void prepare_alt_odb(void)
 {
 	int pass, totlen, i;
 	const char *cp, *last;
-	char *op = 0;
+	char *op = NULL;
 	const char *alt = gitenv(ALTERNATE_DB_ENVIRONMENT) ? : "";
 
 	/* The first pass counts how large an area to allocate to
@@ -236,7 +244,7 @@ static void prepare_alt_odb(void)
 		if (pass)
 			break;
 		alt_odb = xmalloc(sizeof(*alt_odb) * (i + 1) + totlen);
-		alt_odb[i].base = alt_odb[i].name = 0;
+		alt_odb[i].base = alt_odb[i].name = NULL;
 		op = (char*)(&alt_odb[i+1]);
 	}
 }
@@ -258,7 +266,7 @@ static char *find_sha1_file(const unsigned char *sha1, struct stat *st)
 	return NULL;
 }
 
-int check_sha1_signature(unsigned char *sha1, void *map, unsigned long size, const char *type)
+int check_sha1_signature(const unsigned char *sha1, void *map, unsigned long size, const char *type)
 {
 	char header[100];
 	unsigned char real_sha1[20];
@@ -308,40 +316,189 @@ void *map_sha1_file(const unsigned char *sha1, unsigned long *size)
 	return map;
 }
 
+int unpack_sha1_header(z_stream *stream, void *map, unsigned long mapsize, void *buffer, unsigned long size)
+{
+	/* Get the data stream */
+	memset(stream, 0, sizeof(*stream));
+	stream->next_in = map;
+	stream->avail_in = mapsize;
+	stream->next_out = buffer;
+	stream->avail_out = size;
+
+	inflateInit(stream);
+	return inflate(stream, 0);
+}
+
+void *unpack_sha1_rest(z_stream *stream, void *buffer, unsigned long size)
+{
+	int bytes = strlen(buffer) + 1;
+	char *buf = xmalloc(1+size);
+
+	memcpy(buf, buffer + bytes, stream->total_out - bytes);
+	bytes = stream->total_out - bytes;
+	if (bytes < size) {
+		stream->next_out = buf + bytes;
+		stream->avail_out = size - bytes;
+		while (inflate(stream, Z_FINISH) == Z_OK)
+			/* nothing */;
+	}
+	buf[size] = 0;
+	inflateEnd(stream);
+	return buf;
+}
+
+/*
+ * We used to just use "sscanf()", but that's actually way
+ * too permissive for what we want to check. So do an anal
+ * object header parse by hand.
+ */
+int parse_sha1_header(char *hdr, char *type, unsigned long *sizep)
+{
+	int i;
+	unsigned long size;
+
+	/*
+	 * The type can be at most ten bytes (including the 
+	 * terminating '\0' that we add), and is followed by
+	 * a space. 
+	 */
+	i = 10;
+	for (;;) {
+		char c = *hdr++;
+		if (c == ' ')
+			break;
+		if (!--i)
+			return -1;
+		*type++ = c;
+	}
+	*type = 0;
+
+	/*
+	 * The length must follow immediately, and be in canonical
+	 * decimal format (ie "010" is not valid).
+	 */
+	size = *hdr++ - '0';
+	if (size > 9)
+		return -1;
+	if (size) {
+		for (;;) {
+			unsigned long c = *hdr - '0';
+			if (c > 9)
+				break;
+			hdr++;
+			size = size * 10 + c;
+		}
+	}
+	*sizep = size;
+
+	/*
+	 * The length must be followed by a zero byte
+	 */
+	return *hdr ? -1 : 0;
+}
+
 void * unpack_sha1_file(void *map, unsigned long mapsize, char *type, unsigned long *size)
 {
-	int ret, bytes;
+	int ret;
 	z_stream stream;
-	char buffer[8192];
-	char *buf;
-
-	/* Get the data stream */
-	memset(&stream, 0, sizeof(stream));
-	stream.next_in = map;
-	stream.avail_in = mapsize;
-	stream.next_out = buffer;
-	stream.avail_out = sizeof(buffer);
+	char hdr[8192];
 
-	inflateInit(&stream);
-	ret = inflate(&stream, 0);
-	if (ret < Z_OK)
-		return NULL;
-	if (sscanf(buffer, "%10s %lu", type, size) != 2)
+	ret = unpack_sha1_header(&stream, map, mapsize, hdr, sizeof(hdr));
+	if (ret < Z_OK || parse_sha1_header(hdr, type, size) < 0)
 		return NULL;
 
-	bytes = strlen(buffer) + 1;
-	buf = xmalloc(*size);
+	return unpack_sha1_rest(&stream, hdr, *size);
+}
 
-	memcpy(buf, buffer + bytes, stream.total_out - bytes);
-	bytes = stream.total_out - bytes;
-	if (bytes < *size && ret == Z_OK) {
-		stream.next_out = buf + bytes;
-		stream.avail_out = *size - bytes;
-		while (inflate(&stream, Z_FINISH) == Z_OK)
-			/* nothing */;
+int sha1_delta_base(const unsigned char *sha1, unsigned char *base_sha1)
+{
+	int ret;
+	unsigned long mapsize, size;
+	void *map;
+	z_stream stream;
+	char hdr[64], type[20];
+	void *delta_data_head;
+
+	map = map_sha1_file(sha1, &mapsize);
+	if (!map)
+		return -1;
+	ret = unpack_sha1_header(&stream, map, mapsize, hdr, sizeof(hdr));
+	if (ret < Z_OK || parse_sha1_header(hdr, type, &size) < 0) {
+		ret = -1;
+		goto out;
+	}
+	if (strcmp(type, "delta")) {
+		ret = 0;
+		goto out;
 	}
+
+	delta_data_head = hdr + strlen(hdr) + 1;
+	ret = 1;
+	memcpy(base_sha1, delta_data_head, 20);
+ out:
 	inflateEnd(&stream);
-	return buf;
+	munmap(map, mapsize);
+	return ret;
+}
+
+int sha1_file_size(const unsigned char *sha1, unsigned long *sizep)
+{
+	int ret, status;
+	unsigned long mapsize, size;
+	void *map;
+	z_stream stream;
+	char hdr[64], type[20];
+	const unsigned char *data;
+	unsigned char cmd;
+	int i;
+
+	map = map_sha1_file(sha1, &mapsize);
+	if (!map)
+		return -1;
+	ret = unpack_sha1_header(&stream, map, mapsize, hdr, sizeof(hdr));
+	status = -1;
+	if (ret < Z_OK || parse_sha1_header(hdr, type, &size) < 0)
+		goto out;
+	if (strcmp(type, "delta")) {
+		*sizep = size;
+		status = 0;
+		goto out;
+	}
+
+	/* We are dealing with a delta object.  Inflated, the first
+	 * 20 bytes hold the base object SHA1, and delta data follows
+	 * immediately after it.
+	 *
+	 * The initial part of the delta starts at delta_data_head +
+	 * 20.  Borrow code from patch-delta to read the result size.
+	 */
+	data = hdr + strlen(hdr) + 1 + 20;
+
+	/* Skip over the source size; we are not interested in
+	 * it and we cannot verify it because we do not want
+	 * to read the base object.
+	 */
+	cmd = *data++;
+	while (cmd) {
+		if (cmd & 1)
+			data++;
+		cmd >>= 1;
+	}
+	/* Read the result size */
+	size = i = 0;
+	cmd = *data++;
+	while (cmd) {
+		if (cmd & 1)
+			size |= *data++ << i;
+		i += 8;
+		cmd >>= 1;
+	}
+	*sizep = size;
+	status = 0;
+ out:
+	inflateEnd(&stream);
+	munmap(map, mapsize);
+	return status;
 }
 
 void * read_sha1_file(const unsigned char *sha1, char *type, unsigned long *size)
@@ -353,13 +510,26 @@ void * read_sha1_file(const unsigned char *sha1, char *type, unsigned long *size
 	if (map) {
 		buf = unpack_sha1_file(map, mapsize, type, size);
 		munmap(map, mapsize);
+		if (buf && !strcmp(type, "delta")) {
+			void *ref = NULL, *delta = buf;
+			unsigned long ref_size, delta_size = *size;
+			buf = NULL;
+			if (delta_size > 20)
+				ref = read_sha1_file(delta, type, &ref_size);
+			if (ref)
+				buf = patch_delta(ref, ref_size,
+						  delta+20, delta_size-20, 
+						  size);
+			free(delta);
+			free(ref);
+		}
 		return buf;
 	}
 	return NULL;
 }
 
 void *read_object_with_reference(const unsigned char *sha1,
-				 const unsigned char *required_type,
+				 const char *required_type,
 				 unsigned long *size,
 				 unsigned char *actual_sha1_return)
 {
@@ -403,20 +573,20 @@ void *read_object_with_reference(const unsigned char *sha1,
 	}
 }
 
-int write_sha1_file(char *buf, unsigned long len, const char *type, unsigned char *returnsha1)
+int write_sha1_file(void *buf, unsigned long len, const char *type, unsigned char *returnsha1)
 {
 	int size;
-	char *compressed;
+	unsigned char *compressed;
 	z_stream stream;
 	unsigned char sha1[20];
 	SHA_CTX c;
 	char *filename;
 	static char tmpfile[PATH_MAX];
-	char hdr[50];
+	unsigned char hdr[50];
 	int fd, hdrlen, ret;
 
 	/* Generate the header */
-	hdrlen = sprintf(hdr, "%s %lu", type, len)+1;
+	hdrlen = sprintf((char *)hdr, "%s %lu", type, len)+1;
 
 	/* Sha1.. */
 	SHA1_Init(&c);
@@ -516,8 +686,8 @@ int write_sha1_from_fd(const unsigned char *sha1, int fd)
 	int local;
 	z_stream stream;
 	unsigned char real_sha1[20];
-	char buf[4096];
-	char discard[4096];
+	unsigned char buf[4096];
+	unsigned char discard[4096];
 	int ret;
 	SHA_CTX c;