Make "read-tree" read the tree into the current directory cache.

It will no longer update the actual working directory, just the
cache. To update the working directory, you need to use "checkout-cache".

checkout-cache.c

@@ -36,6 +36,34 @@
 
 static int force = 0, quiet = 0;
 
+static void create_directories(const char *path)
+{
+	int len = strlen(path);
+	char *buf = malloc(len + 1);
+	const char *slash = path;
+
+	while ((slash = strchr(slash+1, '/')) != NULL) {
+		len = slash - path;
+		memcpy(buf, path, len);
+		buf[len] = 0;
+		mkdir(buf, 0700);
+	}
+}
+
+static int create_file(const char *path, unsigned int mode)
+{
+	int fd = open(path, O_WRONLY | O_TRUNC | O_CREAT, 0600);
+	if (fd < 0) {
+		if (errno == ENOENT) {
+			create_directories(path);
+			fd = open(path, O_WRONLY | O_TRUNC | O_CREAT, 0600);
+		}
+	}
+	if (fd >= 0)
+		fchmod(fd, mode);
+	return fd;
+}
+
 static int write_entry(struct cache_entry *ce)
 {
 	int fd;
@@ -50,7 +78,7 @@ static int write_entry(struct cache_entry *ce)
 			ce->name, sha1_to_hex(ce->sha1));
 		return -1;
 	}
-	fd = open(ce->name, O_WRONLY | O_CREAT | O_TRUNC, 0600);
+	fd = create_file(ce->name, ce->st_mode);
 	if (fd < 0) {
 		fprintf(stderr, "checkout-cache: unable to create %s (%s)\n",
 			ce->name, strerror(errno));

read-tree.c

@@ -5,83 +5,87 @@
  */
 #include "cache.h"
 
-static void create_directories(const char *path)
+static int read_one_entry(unsigned char *sha1, const char *pathname, unsigned mode)
 {
-	int len = strlen(path);
-	char *buf = malloc(len + 1);
-	const char *slash = path;
+	int len = strlen(pathname);
+	unsigned int size = cache_entry_size(len);
+	struct cache_entry *ce = malloc(size);
 
-	while ((slash = strchr(slash+1, '/')) != NULL) {
-		len = slash - path;
-		memcpy(buf, path, len);
-		buf[len] = 0;
-		mkdir(buf, 0700);
-	}
-}
+	memset(ce, 0, size);
 
-static int create_file(const char *path)
-{
-	int fd = open(path, O_WRONLY | O_TRUNC | O_CREAT, 0600);
-	if (fd < 0) {
-		if (errno == ENOENT) {
-			create_directories(path);
-			fd = open(path, O_WRONLY | O_TRUNC | O_CREAT, 0600);
-		}
-	}
-	return fd;
+	ce->st_mode = mode;
+	ce->namelen = len;
+	memcpy(ce->name, pathname, len+1);
+	memcpy(ce->sha1, sha1, 20);
+	return add_cache_entry(ce);
 }
 
-static int unpack(unsigned char *sha1)
+static int read_tree(unsigned char *sha1)
 {
 	void *buffer;
 	unsigned long size;
 	char type[20];
 
 	buffer = read_sha1_file(sha1, type, &size);
 	if (!buffer)
-		usage("unable to read sha1 file");
+		return -1;
 	if (strcmp(type, "tree"))
-		usage("expected a 'tree' node");
+		return -1;
 	while (size) {
 		int len = strlen(buffer)+1;
 		unsigned char *sha1 = buffer + len;
 		char *path = strchr(buffer, ' ')+1;
-		char *data;
-		unsigned long filesize;
 		unsigned int mode;
-		int fd;
 
 		if (size < len + 20 || sscanf(buffer, "%o", &mode) != 1)
-			usage("corrupt 'tree' file");
+			return -1;
+
 		buffer = sha1 + 20;
 		size -= len + 20;
-		data = read_sha1_file(sha1, type, &filesize);
-		if (!data || strcmp(type, "blob"))
-			usage("tree file refers to bad file data");
-		fd = create_file(path);
-		if (fd < 0)
-			usage("unable to create file");
-		if (write(fd, data, filesize) != filesize)
-			usage("unable to write file");
-		fchmod(fd, mode);
-		close(fd);
-		free(data);
+
+		if (read_one_entry(sha1, path, mode) < 0)
+			return -1;
 	}
 	return 0;
 }
 
 int main(int argc, char **argv)
 {
+	int i, newfd;
 	unsigned char sha1[20];
 
-	if (argc != 2)
-		usage("read-tree <key>");
-	if (get_sha1_hex(argv[1], sha1) < 0)
-		usage("read-tree <key>");
-	sha1_file_directory = getenv(DB_ENVIRONMENT);
-	if (!sha1_file_directory)
-		sha1_file_directory = DEFAULT_DB_ENVIRONMENT;
-	if (unpack(sha1) < 0)
-		usage("unpack failed");
-	return 0;
+	newfd = open(".dircache/index.lock", O_RDWR | O_CREAT | O_EXCL, 0600);
+	if (newfd < 0)
+		usage("unable to create new cachefile");
+
+	for (i = 1; i < argc; i++) {
+		const char *arg = argv[i];
+
+		/* "-m" stands for "merge" current directory cache */
+		if (!strcmp(arg, "-m")) {
+			if (active_cache) {
+				fprintf(stderr, "read-tree: cannot merge old cache on top of new\n");
+				goto out;
+			}
+			if (read_cache() < 0) {
+				fprintf(stderr, "read-tree: corrupt directory cache\n");
+				goto out;
+			}
+			continue;
+		}
+		if (get_sha1_hex(arg, sha1) < 0) {
+			fprintf(stderr, "read-tree [-m] <sha1>\n");
+			goto out;
+		}
+		if (read_tree(sha1) < 0) {
+			fprintf(stderr, "failed to unpack tree object %s\n", arg);
+			goto out;
+		}
+	}
+	if (!write_cache(newfd, active_cache, active_nr) && !rename(".dircache/index.lock", ".dircache/index"))
+		return 0;
+
+out:
+	unlink(".dircache/index.lock");
+	exit(1);
 }