X-Git-Url: https://git.verplant.org/?a=blobdiff_plain;f=update-cache.c;h=134ba7439891d698c4b82223a9e872d3a77e5edb;hb=9bd94cafdf104e613d7609401e60711cd08e209c;hp=942e309fe63f0eeffc0e24fa70027eaa39cc1a56;hpb=121481abf8d752ef871821d4ab9a3747595d86ae;p=git.git

diff --git a/update-cache.c b/update-cache.c
index 942e309f..134ba743 100644
--- a/update-cache.c
+++ b/update-cache.c
@@ -17,12 +17,16 @@ static int allow_add = 0, allow_remove = 0;
 static int index_fd(const char *path, int namelen, struct cache_entry *ce, int fd, struct stat *st)
 {
 	z_stream stream;
-	int max_out_bytes = namelen + st->st_size + 200;
+	unsigned long size = st->st_size;
+	int max_out_bytes = namelen + size + 200;
 	void *out = malloc(max_out_bytes);
 	void *metadata = malloc(namelen + 200);
-	void *in = mmap(NULL, st->st_size, PROT_READ, MAP_PRIVATE, fd, 0);
+	void *in;
 	SHA_CTX c;
 
+	in = "";
+	if (size)
+		in = mmap(NULL, size, PROT_READ, MAP_PRIVATE, fd, 0);
 	close(fd);
 	if (!out || (int)(long)in == -1)
 		return -1;
@@ -34,7 +38,7 @@ static int index_fd(const char *path, int namelen, struct cache_entry *ce, int f
 	 * ASCII size + nul byte
 	 */	
 	stream.next_in = metadata;
-	stream.avail_in = 1+sprintf(metadata, "blob %lu", (unsigned long) st->st_size);
+	stream.avail_in = 1+sprintf(metadata, "blob %lu", size);
 	stream.next_out = out;
 	stream.avail_out = max_out_bytes;
 	while (deflate(&stream, 0) == Z_OK)
@@ -44,7 +48,7 @@ static int index_fd(const char *path, int namelen, struct cache_entry *ce, int f
 	 * File content
 	 */
 	stream.next_in = in;
-	stream.avail_in = st->st_size;
+	stream.avail_in = size;
 	while (deflate(&stream, Z_FINISH) == Z_OK)
 		/*nothing */;
 
@@ -57,6 +61,26 @@ static int index_fd(const char *path, int namelen, struct cache_entry *ce, int f
 	return write_sha1_buffer(ce->sha1, out, stream.total_out);
 }
 
+/*
+ * This only updates the "non-critical" parts of the directory
+ * cache, ie the parts that aren't tracked by GIT, and only used
+ * to validate the cache.
+ */
+static void fill_stat_cache_info(struct cache_entry *ce, struct stat *st)
+{
+	ce->ce_ctime.sec = htonl(st->st_ctime);
+	ce->ce_mtime.sec = htonl(st->st_mtime);
+#ifdef NSEC
+	ce->ce_ctime.nsec = htonl(st->st_ctim.tv_nsec);
+	ce->ce_mtime.nsec = htonl(st->st_mtim.tv_nsec);
+#endif
+	ce->ce_dev = htonl(st->st_dev);
+	ce->ce_ino = htonl(st->st_ino);
+	ce->ce_uid = htonl(st->st_uid);
+	ce->ce_gid = htonl(st->st_gid);
+	ce->ce_size = htonl(st->st_size);
+}
+
 static int add_file_to_cache(char *path)
 {
 	int size, namelen;
@@ -81,17 +105,9 @@ static int add_file_to_cache(char *path)
 	ce = malloc(size);
 	memset(ce, 0, size);
 	memcpy(ce->name, path, namelen);
-	ce->ctime.sec = st.st_ctime;
-	ce->ctime.nsec = st.st_ctim.tv_nsec;
-	ce->mtime.sec = st.st_mtime;
-	ce->mtime.nsec = st.st_mtim.tv_nsec;
-	ce->st_dev = st.st_dev;
-	ce->st_ino = st.st_ino;
-	ce->st_mode = st.st_mode;
-	ce->st_uid = st.st_uid;
-	ce->st_gid = st.st_gid;
-	ce->st_size = st.st_size;
-	ce->namelen = namelen;
+	fill_stat_cache_info(ce, &st);
+	ce->ce_mode = htonl(st.st_mode);
+	ce->ce_flags = htons(namelen);
 
 	if (index_fd(path, namelen, ce, fd, &st) < 0)
 		return -1;
@@ -99,36 +115,106 @@ static int add_file_to_cache(char *path)
 	return add_cache_entry(ce, allow_add);
 }
 
-static void refresh_entry(struct cache_entry *ce)
+static int match_data(int fd, void *buffer, unsigned long size)
+{
+	while (size) {
+		char compare[1024];
+		int ret = read(fd, compare, sizeof(compare));
+
+		if (ret <= 0 || ret > size || memcmp(buffer, compare, ret))
+			return -1;
+		size -= ret;
+		buffer += ret;
+	}
+	return 0;
+}
+
+static int compare_data(struct cache_entry *ce, unsigned long expected_size)
+{
+	int match = -1;
+	int fd = open(ce->name, O_RDONLY);
+
+	if (fd >= 0) {
+		void *buffer;
+		unsigned long size;
+		char type[10];
+
+		buffer = read_sha1_file(ce->sha1, type, &size);
+		if (buffer) {
+			if (size == expected_size && !strcmp(type, "blob"))
+				match = match_data(fd, buffer, size);
+			free(buffer);
+		}
+		close(fd);
+	}
+	return match;
+}
+
+/*
+ * "refresh" does not calculate a new sha1 file or bring the
+ * cache up-to-date for mode/content changes. But what it
+ * _does_ do is to "re-match" the stat information of a file
+ * with the cache, so that you can refresh the cache for a
+ * file that hasn't been changed but where the stat entry is
+ * out of date.
+ *
+ * For example, you'd want to do this after doing a "read-tree",
+ * to link up the stat cache details with the proper files.
+ */
+static struct cache_entry *refresh_entry(struct cache_entry *ce)
 {
+	struct stat st;
+	struct cache_entry *updated;
+	int changed, size;
+
+	if (stat(ce->name, &st) < 0)
+		return NULL;
+
+	changed = cache_match_stat(ce, &st);
+	if (!changed)
+		return ce;
+
 	/*
-	 * This is really not the right way to do it, but
-	 * add_file_to_cache() does do the right thing.
-	 *
-	 * We should really just update the cache
-	 * entry in-place, I think. With this approach we
-	 * end up allocating a new one, searching for where
-	 * to insert it etc etc crud.
+	 * If the mode has changed, there's no point in trying
+	 * to refresh the entry - it's not going to match
 	 */
-	add_file_to_cache(ce->name);
+	if (changed & MODE_CHANGED)
+		return NULL;
+
+	if (compare_data(ce, st.st_size))
+		return NULL;
+
+	size = ce_size(ce);
+	updated = malloc(size);
+	memcpy(updated, ce, size);
+	fill_stat_cache_info(updated, &st);
+	return updated;
 }
 
 static void refresh_cache(void)
 {
 	int i;
 
-	for (i = 0; i < active_nr; i++)
-		refresh_entry(active_cache[i]);
+	for (i = 0; i < active_nr; i++) {
+		struct cache_entry *ce = active_cache[i];
+		struct cache_entry *new = refresh_entry(ce);
+
+		if (!new) {
+			printf("%s: needs update\n", ce->name);
+			continue;
+		}
+		active_cache[i] = new;
+	}
 }
 
 /*
  * We fundamentally don't like some paths: we don't want
  * dot or dot-dot anywhere, and in fact, we don't even want
- * any other dot-files (.dircache or anything else). They
+ * any other dot-files (.git or anything else). They
  * are hidden, for chist sake.
  *
  * Also, we don't want double slashes or slashes at the
- * end that can make pathnames ambiguous. 
+ * end that can make pathnames ambiguous.
  */
 static int verify_path(char *path)
 {
@@ -149,22 +235,59 @@ inside:
 	}
 }
 
+static int add_cacheinfo(char *arg1, char *arg2, char *arg3)
+{
+	int size, len;
+	unsigned int mode;
+	unsigned char sha1[20];
+	struct cache_entry *ce;
+
+	if (sscanf(arg1, "%o", &mode) != 1)
+		return -1;
+	printf("got mode %o\n", mode);
+	if (get_sha1_hex(arg2, sha1))
+		return -1;
+	printf("got sha1 %s\n", sha1_to_hex(sha1));
+	if (!verify_path(arg3))
+		return -1;
+	printf("got path %s\n", arg3);
+
+	len = strlen(arg3);
+	size = cache_entry_size(len);
+	ce = malloc(size);
+	memset(ce, 0, size);
+
+	memcpy(ce->sha1, sha1, 20);
+	memcpy(ce->name, arg3, len);
+	ce->ce_flags = htons(len);
+	ce->ce_mode = htonl(mode);
+	return add_cache_entry(ce, allow_add);
+}
+
+static int remove_lock = 0;
+
+static void remove_lock_file(void)
+{
+	if (remove_lock)
+		unlink(".git/index.lock");
+}
+
 int main(int argc, char **argv)
 {
 	int i, newfd, entries;
 	int allow_options = 1;
 
+	newfd = open(".git/index.lock", O_RDWR | O_CREAT | O_EXCL, 0600);
+	if (newfd < 0)
+		die("unable to create new cachefile");
+
+	atexit(remove_lock_file);
+	remove_lock = 1;
+
 	entries = read_cache();
-	if (entries < 0) {
-		perror("cache corrupted");
-		return -1;
-	}
+	if (entries < 0)
+		die("cache corrupted");
 
-	newfd = open(".dircache/index.lock", O_RDWR | O_CREAT | O_EXCL, 0600);
-	if (newfd < 0) {
-		perror("unable to create new cachefile");
-		return -1;
-	}
 	for (i = 1 ; i < argc; i++) {
 		char *path = argv[i];
 
@@ -185,20 +308,25 @@ int main(int argc, char **argv)
 				refresh_cache();
 				continue;
 			}
-			usage("unknown option %s", path);
+			if (!strcmp(path, "--cacheinfo")) {
+				if (i+3 >= argc || add_cacheinfo(argv[i+1], argv[i+2], argv[i+3]))
+					die("update-cache: --cacheinfo <mode> <sha1> <path>");
+				i += 3;
+				continue;
+			}
+			die("unknown option %s", path);
 		}
 		if (!verify_path(path)) {
 			fprintf(stderr, "Ignoring path %s\n", argv[i]);
 			continue;
 		}
-		if (add_file_to_cache(path)) {
-			fprintf(stderr, "Unable to add %s to database\n", path);
-			goto out;
-		}
+		if (add_file_to_cache(path))
+			die("Unable to add %s to database", path);
 	}
-	if (!write_cache(newfd, active_cache, active_nr) && !rename(".dircache/index.lock", ".dircache/index"))
-		return 0;
-out:
-	unlink(".dircache/index.lock");
+	if (write_cache(newfd, active_cache, active_nr) ||
+	    rename(".git/index.lock", ".git/index"))
+		die("Unable to write new cachefile");
+
+	remove_lock = 0;
 	return 0;
 }