X-Git-Url: https://git.tokkee.org/?a=blobdiff_plain;f=sha1_file.c;h=e6ce455ae90bd430f2128f454bdb6e0575412486;hb=a31c6d022e2435a514fcc8ca57f9995c4376a986;hp=d2f38f0cdc78d81ffb5a601eb603a81775586368;hpb=a44c9a5e2e6d4108452f2c64dbd11f74a83745af;p=git.git

diff --git a/sha1_file.c b/sha1_file.c
index d2f38f0cd..e6ce455ae 100644
--- a/sha1_file.c
+++ b/sha1_file.c
@@ -45,6 +45,48 @@ int get_sha1_hex(const char *hex, unsigned char *sha1)
 	return 0;
 }
 
+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);
+}
+
+int get_sha1(const char *str, unsigned char *sha1)
+{
+	static char pathname[PATH_MAX];
+	static const char *prefix[] = {
+		"",
+		"refs",
+		"refs/tags",
+		"refs/heads",
+		"refs/snap",
+		NULL
+	};
+	const char *gitdir;
+	const char **p;
+
+	if (!get_sha1_hex(str, sha1))
+		return 0;
+
+	gitdir = ".git";
+	for (p = prefix; *p; p++) {
+		snprintf(pathname, sizeof(pathname), "%s/%s/%s", gitdir, *p, str);
+		if (!get_sha1_file(pathname, sha1))
+			return 0;
+	}
+
+	return -1;
+}
+
 char * sha1_to_hex(const unsigned char *sha1)
 {
 	static char buffer[50];
@@ -73,7 +115,7 @@ char *sha1_file_name(const unsigned char *sha1)
 	if (!base) {
 		char *sha1_file_directory = getenv(DB_ENVIRONMENT) ? : DEFAULT_DB_ENVIRONMENT;
 		int len = strlen(sha1_file_directory);
-		base = malloc(len + 60);
+		base = xmalloc(len + 60);
 		memcpy(base, sha1_file_directory, len);
 		memset(base+len, 0, 60);
 		base[len] = '/';
@@ -161,9 +203,7 @@ void * unpack_sha1_file(void *map, unsigned long mapsize, char *type, unsigned l
 		return NULL;
 
 	bytes = strlen(buffer) + 1;
-	buf = malloc(*size);
-	if (!buf)
-		return NULL;
+	buf = xmalloc(*size);
 
 	memcpy(buf, buffer + bytes, stream.total_out - bytes);
 	bytes = stream.total_out - bytes;
@@ -191,47 +231,52 @@ void * read_sha1_file(const unsigned char *sha1, char *type, unsigned long *size
 	return NULL;
 }
 
-void *read_tree_with_tree_or_commit_sha1(const unsigned char *sha1,
-					 unsigned long *size,
-					 unsigned char *tree_sha1_return)
+void *read_object_with_reference(const unsigned char *sha1,
+				 const unsigned char *required_type,
+				 unsigned long *size,
+				 unsigned char *actual_sha1_return)
 {
 	char type[20];
 	void *buffer;
 	unsigned long isize;
-	int was_commit = 0;
-	unsigned char tree_sha1[20];
-
-	buffer = read_sha1_file(sha1, type, &isize);
-
-	/* 
-	 * We might have read a commit instead of a tree, in which case
-	 * we parse out the tree_sha1 and attempt to read from there.
-	 * (buffer + 5) is because the tree sha1 is always at offset 5
-	 * in a commit record ("tree ").
-	 */
-	if (buffer &&
-	    !strcmp(type, "commit") &&
-	    !get_sha1_hex(buffer + 5, tree_sha1)) {
-		free(buffer);
-		buffer = read_sha1_file(tree_sha1, type, &isize);
-		was_commit = 1;
-	}
+	unsigned char actual_sha1[20];
 
-	/*
-	 * Now do we have something and if so is it a tree?
-	 */
-	if (!buffer || strcmp(type, "tree")) {
-		free(buffer);
-		return NULL;
-	}
+	memcpy(actual_sha1, sha1, 20);
+	while (1) {
+		int ref_length = -1;
+		const char *ref_type = NULL;
 
-	*size = isize;
-	if (tree_sha1_return)
-		memcpy(tree_sha1_return, was_commit ? tree_sha1 : sha1, 20);
-	return buffer;
+		buffer = read_sha1_file(actual_sha1, type, &isize);
+		if (!buffer)
+			return NULL;
+		if (!strcmp(type, required_type)) {
+			*size = isize;
+			if (actual_sha1_return)
+				memcpy(actual_sha1_return, actual_sha1, 20);
+			return buffer;
+		}
+		/* Handle references */
+		else if (!strcmp(type, "commit"))
+			ref_type = "tree ";
+		else if (!strcmp(type, "tag"))
+			ref_type = "object ";
+		else {
+			free(buffer);
+			return NULL;
+		}
+		ref_length = strlen(ref_type);
+
+		if (memcmp(buffer, ref_type, ref_length) ||
+		    get_sha1_hex(buffer + ref_length, actual_sha1)) {
+			free(buffer);
+			return NULL;
+		}
+		/* Now we have the ID of the referred-to object in
+		 * actual_sha1.  Check again. */
+	}
 }
 
-int write_sha1_file(char *buf, unsigned len, const char *type, unsigned char *returnsha1)
+int write_sha1_file(char *buf, unsigned long len, const char *type, unsigned char *returnsha1)
 {
 	int size;
 	char *compressed;
@@ -239,11 +284,12 @@ int write_sha1_file(char *buf, unsigned len, const char *type, unsigned char *re
 	unsigned char sha1[20];
 	SHA_CTX c;
 	char *filename;
+	static char tmpfile[PATH_MAX];
 	char hdr[50];
-	int fd, hdrlen;
+	int fd, hdrlen, ret;
 
 	/* Generate the header */
-	hdrlen = sprintf(hdr, "%s %d", type, len)+1;
+	hdrlen = sprintf(hdr, "%s %lu", type, len)+1;
 
 	/* Sha1.. */
 	SHA1_Init(&c);
@@ -255,23 +301,33 @@ int write_sha1_file(char *buf, unsigned len, const char *type, unsigned char *re
 		memcpy(returnsha1, sha1, 20);
 
 	filename = sha1_file_name(sha1);
-	fd = open(filename, O_WRONLY | O_CREAT | O_EXCL, 0666);
-	if (fd < 0) {
-		if (errno != EEXIST)
-			return -1;
-
+	fd = open(filename, O_RDONLY);
+	if (fd >= 0) {
 		/*
-		 * We might do collision checking here, but we'd need to
-		 * uncompress the old file and check it. Later.
+		 * FIXME!!! We might do collision checking here, but we'd
+		 * need to uncompress the old file and check it. Later.
 		 */
+		close(fd);
 		return 0;
 	}
 
+	if (errno != ENOENT) {
+		fprintf(stderr, "sha1 file %s: %s", filename, strerror(errno));
+		return -1;
+	}
+
+	snprintf(tmpfile, sizeof(tmpfile), "%s/obj_XXXXXX", get_object_directory());
+	fd = mkstemp(tmpfile);
+	if (fd < 0) {
+		fprintf(stderr, "unable to create temporary sha1 filename %s: %s", tmpfile, strerror(errno));
+		return -1;
+	}
+
 	/* Set it up */
 	memset(&stream, 0, sizeof(stream));
 	deflateInit(&stream, Z_BEST_COMPRESSION);
 	size = deflateBound(&stream, len+hdrlen);
-	compressed = malloc(size);
+	compressed = xmalloc(size);
 
 	/* Compress it */
 	stream.next_out = compressed;
@@ -293,54 +349,34 @@ int write_sha1_file(char *buf, unsigned len, const char *type, unsigned char *re
 
 	if (write(fd, compressed, size) != size)
 		die("unable to write file");
+	fchmod(fd, 0444);
 	close(fd);
-		
-	return 0;
-}
-
-static inline int collision_check(char *filename, void *buf, unsigned int size)
-{
-#ifdef COLLISION_CHECK
-	void *map;
-	int fd = open(filename, O_RDONLY);
-	struct stat st;
-	int cmp;
-
-	/* Unreadable object, or object went away? Strange. */
-	if (fd < 0)
-		return -1;
-
-	if (fstat(fd, &st) < 0 || size != st.st_size)
-		return -1;
-
-	map = mmap(NULL, size, PROT_READ, MAP_PRIVATE, fd, 0);
-	close(fd);
-	if (map == MAP_FAILED)
-		return -1;
-	cmp = memcmp(buf, map, size);
-	munmap(map, size);
-	if (cmp)
-		return -1;
-#endif
-	return 0;
-}
 
-int write_sha1_buffer(const unsigned char *sha1, void *buf, unsigned int size)
-{
-	char *filename = sha1_file_name(sha1);
-	int fd;
+	ret = link(tmpfile, filename);
+	if (ret < 0) {
+		ret = errno;
 
-	fd = open(filename, O_WRONLY | O_CREAT | O_EXCL, 0666);
-	if (fd < 0) {
-		if (errno != EEXIST)
+		/*
+		 * Coda hack - coda doesn't like cross-directory links,
+		 * so we fall back to a rename, which will mean that it
+		 * won't be able to check collisions, but that's not a
+		 * big deal.
+		 *
+		 * When this succeeds, we just return 0. We have nothing
+		 * left to unlink.
+		 */
+		if (ret == EXDEV && !rename(tmpfile, filename))
+			return 0;
+	}
+	unlink(tmpfile);
+	if (ret) {
+		if (ret != EEXIST) {
+			fprintf(stderr, "unable to write sha1 filename %s: %s", filename, strerror(ret));
 			return -1;
-		if (collision_check(filename, buf, size))
-			return error("SHA1 collision detected!"
-					" This is bad, bad, BAD!\a\n");
-		return 0;
+		}
+		/* FIXME!!! Collision check here ? */
 	}
-	write(fd, buf, size);
-	close(fd);
+
 	return 0;
 }
 
@@ -415,3 +451,22 @@ int has_sha1_file(const unsigned char *sha1)
 		return 1;
 	return 0;
 }
+
+int index_fd(unsigned char *sha1, int fd, struct stat *st)
+{
+	unsigned long size = st->st_size;
+	void *buf;
+	int ret;
+
+	buf = "";
+	if (size)
+		buf = mmap(NULL, size, PROT_READ, MAP_PRIVATE, fd, 0);
+	close(fd);
+	if ((int)(long)buf == -1)
+		return -1;
+
+	ret = write_sha1_file(buf, size, "blob", sha1);
+	if (size)
+		munmap(buf, size);
+	return ret;
+}