index: make the index file format extensible.

... and move the cache-tree data into it.

Signed-off-by: Junio C Hamano <[email protected]>

apply.c

@@ -12,10 +12,6 @@
 #include "quote.h"
 #include "blob.h"
 
-static unsigned char active_cache_sha1[20];
-static struct cache_tree *active_cache_tree;
-
-
 //  --check turns on checking that the working tree matches the
 //    files that are being modified, but doesn't apply the patch
 //  --stat does just a diffstat, and doesn't actually apply
@@ -1919,9 +1915,8 @@ static int apply_patch(int fd, const char *filename)
 	if (write_index)
 		newfd = hold_index_file_for_update(&cache_file, get_index_file());
 	if (check_index) {
-		if (read_cache_1(active_cache_sha1) < 0)
+		if (read_cache() < 0)
 			die("unable to read index file");
-		active_cache_tree = read_cache_tree(active_cache_sha1);
 	}
 
 	if ((check || apply) && check_patch_list(list) < 0)
@@ -1931,11 +1926,9 @@ static int apply_patch(int fd, const char *filename)
 		write_out_results(list, skipped_patch);
 
 	if (write_index) {
-		if (write_cache_1(newfd, active_cache, active_nr,
-				  active_cache_sha1) ||
+		if (write_cache(newfd, active_cache, active_nr) ||
 		    commit_index_file(&cache_file))
 			die("Unable to write new cachefile");
-		write_cache_tree(active_cache_sha1, active_cache_tree);
 	}
 
 	if (show_index_info)

cache-tree.c

@@ -11,16 +11,18 @@ struct cache_tree *cache_tree(void)
 	return it;
 }
 
-void cache_tree_free(struct cache_tree *it)
+void cache_tree_free(struct cache_tree **it_p)
 {
 	int i;
+	struct cache_tree *it = *it_p;
 
 	if (!it)
 		return;
 	for (i = 0; i < it->subtree_nr; i++)
-		cache_tree_free(it->down[i]->cache_tree);
+		cache_tree_free(&it->down[i]->cache_tree);
 	free(it->down);
 	free(it);
+	*it_p = NULL;
 }
 
 static struct cache_tree_sub *find_subtree(struct cache_tree *it,
@@ -78,7 +80,7 @@ void cache_tree_invalidate_path(struct cache_tree *it, const char *path)
 				break;
 		}
 		if (i < it->subtree_nr) {
-			cache_tree_free(it->down[i]->cache_tree);
+			cache_tree_free(&it->down[i]->cache_tree);
 			free(it->down[i]);
 			/* 0 1 2 3 4 5
 			 *       ^     ^subtree_nr = 6
@@ -159,13 +161,27 @@ static void discard_unused_subtrees(struct cache_tree *it)
 		if (s->used)
 			down[dst++] = s;
 		else {
-			cache_tree_free(s->cache_tree);
+			cache_tree_free(&s->cache_tree);
 			free(s);
 			it->subtree_nr--;
 		}
 	}
 }
 
+int cache_tree_fully_valid(struct cache_tree *it)
+{
+	int i;
+	if (!it)
+		return 0;
+	if (it->entry_count < 0 || !has_sha1_file(it->sha1))
+		return 0;
+	for (i = 0; i < it->subtree_nr; i++) {
+		if (!cache_tree_fully_valid(it->down[i]->cache_tree))
+			return 0;
+	}
+	return 1;
+}
+
 static int update_one(struct cache_tree *it,
 		      struct cache_entry **cache,
 		      int entries,
@@ -354,19 +370,15 @@ static void *write_one(struct cache_tree *it,
 	return buffer;
 }
 
-static void *cache_tree_write(const unsigned char *cache_sha1,
-			      struct cache_tree *root,
-			      unsigned long *offset_p)
+void *cache_tree_write(struct cache_tree *root, unsigned long *size_p)
 {
 	char path[PATH_MAX];
 	unsigned long size = 8192;
 	char *buffer = xmalloc(size);
 
-	/* the cache checksum of the corresponding index file. */
-	memcpy(buffer, cache_sha1, 20);
-	*offset_p = 20;
+	*size_p = 0;
 	path[0] = 0;
-	return write_one(root, path, 0, buffer, &size, offset_p);
+	return write_one(root, path, 0, buffer, &size, size_p);
 }
 
 static struct cache_tree *read_one(const char **buffer, unsigned long *size_p)
@@ -439,81 +451,13 @@ static struct cache_tree *read_one(const char **buffer, unsigned long *size_p)
 	return it;
 
  free_return:
-	cache_tree_free(it);
+	cache_tree_free(&it);
 	return NULL;
 }
 
-static struct cache_tree *cache_tree_read(unsigned char *sha1,
-					  const char *buffer,
-					  unsigned long size)
+struct cache_tree *cache_tree_read(const char *buffer, unsigned long size)
 {
-	/* check the cache-tree matches the index */
-	if (memcmp(buffer, sha1, 20))
-		return NULL; /* checksum mismatch */
-	if (buffer[20])
+	if (buffer[0])
 		return NULL; /* not the whole tree */
-	buffer += 20;
-	size -= 20;
 	return read_one(&buffer, &size);
 }
-
-struct cache_tree *read_cache_tree(unsigned char *sha1)
-{
-	int fd;
-	struct stat st;
-	char path[PATH_MAX];
-	unsigned long size = 0;
-	void *map;
-	struct cache_tree *it;
-
-	sprintf(path, "%s.aux", get_index_file());
-	fd = open(path, O_RDONLY);
-	if (fd < 0)
-		return cache_tree();
-
-	if (fstat(fd, &st))
-		return cache_tree();
-	size = st.st_size;
-	map = mmap(NULL, size, PROT_READ, MAP_PRIVATE, fd, 0);
-	close(fd);
-	if (map == MAP_FAILED)
-		return cache_tree();
-	it = cache_tree_read(sha1, map, size);
-	munmap(map, size);
-	if (!it)
-		return cache_tree();
-	return it;
-}
-
-int write_cache_tree(const unsigned char *sha1, struct cache_tree *root)
-{
-	char path[PATH_MAX];
-	unsigned long size = 0;
-	void *buf, *buffer;
-	int fd, ret = -1;
-
-	sprintf(path, "%s.aux", get_index_file());
-	if (!root) {
-		unlink(path);
-		return -1;
-	}
-	fd = open(path, O_WRONLY|O_CREAT, 0666);
-	if (fd < 0)
-		return -1;
-	buffer = buf = cache_tree_write(sha1, root, &size);
-	while (size) {
-		int written = xwrite(fd, buf, size);
-		if (written <= 0)
-			goto fail;
-		buf += written;
-		size -= written;
-	}
-	ret = 0;
-
- fail:
-	close(fd);
-	free(buffer);
-	if (ret)
-		unlink(path);
-	return ret;
-}

cache-tree.h

@@ -18,12 +18,13 @@ struct cache_tree {
 };
 
 struct cache_tree *cache_tree(void);
-void cache_tree_free(struct cache_tree *);
+void cache_tree_free(struct cache_tree **);
 void cache_tree_invalidate_path(struct cache_tree *, const char *);
 
-int write_cache_tree(const unsigned char *, struct cache_tree *);
-struct cache_tree *read_cache_tree(unsigned char *);
-int cache_tree_update(struct cache_tree *, struct cache_entry **, int, int);
+void *cache_tree_write(struct cache_tree *root, unsigned long *size_p);
+struct cache_tree *cache_tree_read(const char *buffer, unsigned long size);
 
+int cache_tree_fully_valid(struct cache_tree *);
+int cache_tree_update(struct cache_tree *, struct cache_entry **, int, int);
 
 #endif

cache.h

@@ -114,6 +114,7 @@ static inline unsigned int create_ce_mode(unsigned int mode)
 
 extern struct cache_entry **active_cache;
 extern unsigned int active_nr, active_alloc, active_cache_changed;
+extern struct cache_tree *active_cache_tree;
 
 #define GIT_DIR_ENVIRONMENT "GIT_DIR"
 #define DEFAULT_GIT_DIR_ENVIRONMENT ".git"
@@ -138,11 +139,8 @@ extern const char *prefix_filename(const char *prefix, int len, const char *path
 #define alloc_nr(x) (((x)+16)*3/2)
 
 /* Initialize and use the cache information */
-extern int read_cache_1(unsigned char *);
-extern int write_cache_1(int, struct cache_entry **, int, unsigned char *);
 extern int read_cache(void);
-extern int write_cache(int, struct cache_entry **, int);
-
+extern int write_cache(int newfd, struct cache_entry **cache, int entries);
 extern int cache_name_pos(const char *name, int namelen);
 #define ADD_CACHE_OK_TO_ADD 1		/* Ok to add */
 #define ADD_CACHE_OK_TO_REPLACE 2	/* Ok to replace file/directory */

checkout-index.c

@@ -39,6 +39,7 @@
 #include "cache.h"
 #include "strbuf.h"
 #include "quote.h"
+#include "cache-tree.h"
 
 #define CHECKOUT_ALL 4
 static const char *prefix;

dump-cache-tree.c

@@ -2,12 +2,11 @@
 #include "tree.h"
 #include "cache-tree.h"
 
-static unsigned char active_cache_sha1[20];
-static struct cache_tree *active_cache_tree;
-
 static void dump_cache_tree(struct cache_tree *it, const char *pfx)
 {
 	int i;
+	if (!it)
+		return;
 	if (it->entry_count < 0)
 		printf("%-40s %s\n", "invalid", pfx);
 	else
@@ -24,9 +23,8 @@ static void dump_cache_tree(struct cache_tree *it, const char *pfx)
 
 int main(int ac, char **av)
 {
-	if (read_cache_1(active_cache_sha1) < 0)
+	if (read_cache() < 0)
 		die("unable to read index file");
-	active_cache_tree = read_cache_tree(active_cache_sha1);
 	dump_cache_tree(active_cache_tree, "");
 	return 0;
 }