[PATCH 04/17] index: make narrow index incompatible with older git

From

Nguyễn Thái Ngọc Duy <pclouds@gmail.com>

Date

Sep 5, 2010, 06:47 UTC

Message-ID

<1283669264-15759-5-git-send-email-pclouds@gmail.com>

In-Reply-To

<1283669264-15759-1-git-send-email-pclouds@gmail.com>

Signed-off-by: Nguyễn Thái Ngọc Duy <pclouds@gmail.com>
---
 cache.h                |    1 +
 read-cache.c           |   32 ++++++++++++++++++++++++++++++--
 t/t0063-narrow-repo.sh |   28 ++++++++++++++++++++++++++++
 3 files changed, 59 insertions(+), 2 deletions(-)

diff --git a/cache.h b/cache.h
index d09c4fc..88a2ec6 100644
--- a/cache.h
+++ b/cache.h
@@ -292,6 +292,7 @@ struct index_state {
 	struct string_list *resolve_undo;
 	struct cache_tree *cache_tree;
 	struct cache_time timestamp;
+	char *narrow_prefix;
 	void *alloc;
 	unsigned name_hash_initialized : 1,
 		 initialized : 1;
diff --git a/read-cache.c b/read-cache.c
index 1f42473..250013c 100644
--- a/read-cache.c
+++ b/read-cache.c
@@ -12,6 +12,7 @@
 #include "commit.h"
 #include "blob.h"
 #include "resolve-undo.h"
+#include "narrow-tree.h"
 
 static struct cache_entry *refresh_cache_entry(struct cache_entry *ce, int really);
 
@@ -25,8 +26,9 @@ static struct cache_entry *refresh_cache_entry(struct cache_entry *ce, int reall
  */
 
 #define CACHE_EXT(s) ( (s[0]<<24)|(s[1]<<16)|(s[2]<<8)|(s[3]) )
-#define CACHE_EXT_TREE 0x54524545	/* "TREE" */
-#define CACHE_EXT_RESOLVE_UNDO 0x52455543 /* "REUC" */
+#define CACHE_EXT_TREE		0x54524545	/* "TREE" */
+#define CACHE_EXT_RESOLVE_UNDO	0x52455543	/* "REUC" */
+#define CACHE_EXT_NARROW	0x6e617277	/* "narw" */
 
 struct index_state the_index;
 
@@ -1188,6 +1190,9 @@ static int read_index_extension(struct index_state *istate,
 	case CACHE_EXT_RESOLVE_UNDO:
 		istate->resolve_undo = resolve_undo_read(data, sz);
 		break;
+	case CACHE_EXT_NARROW:
+		istate->narrow_prefix = xstrdup(data);
+		break;
 	default:
 		if (*ext < 'A' || 'Z' < *ext)
 			return error("index uses %.4s extension, which we do not understand",
@@ -1352,6 +1357,18 @@ int read_index_from(struct index_state *istate, const char *path)
 		src_offset += extsize;
 	}
 	munmap(mmap, mmap_size);
+
+	if ((!get_narrow_prefix() && !istate->narrow_prefix))
+		;		/* good */
+	else if (get_narrow_prefix() && istate->narrow_prefix) {
+		char *buf = get_narrow_string();
+		if (strcmp(buf, istate->narrow_prefix))
+			die("Invalid index, narrow prefix does not match $GIT_DIR/narrow");
+		free(buf);
+	}
+	else
+		die("Invalid index, not suitable for narrow repository");
+
 	return istate->cache_nr;
 
 unmap:
@@ -1378,6 +1395,8 @@ int discard_index(struct index_state *istate)
 	free(istate->alloc);
 	istate->alloc = NULL;
 	istate->initialized = 0;
+	free(istate->narrow_prefix);
+	istate->narrow_prefix = NULL;
 
 	/* no need to throw away allocated active_cache */
 	return 0;
@@ -1607,6 +1626,15 @@ int write_index(struct index_state *istate, int newfd)
 		if (err)
 			return -1;
 	}
+	if (get_narrow_prefix()) {
+		char *buf = get_narrow_string();
+		int len = strlen(buf)+1;
+		err = write_index_ext_header(&c, newfd, CACHE_EXT_NARROW, len) < 0 ||
+			ce_write(&c, newfd, buf, len) < 0;
+		free(buf);
+		if (err)
+			return -1;
+	}
 
 	if (ce_flush(&c, newfd) || fstat(newfd, &st))
 		return -1;
diff --git a/t/t0063-narrow-repo.sh b/t/t0063-narrow-repo.sh
index 51b753d..926802c 100755
--- a/t/t0063-narrow-repo.sh
+++ b/t/t0063-narrow-repo.sh
@@ -43,4 +43,32 @@ test_expect_success 'unsorted multiple prefix' '
 	test_must_fail git rev-parse --narrow-prefix
 '
 
+test_expect_success 'create narrow index' '
+	echo a >.git/narrow &&
+	: >foo
+	git add foo &&
+	test -f .git/index
+'
+
+test_expect_success '$GIT_DIR/narrow and index do not match' '
+	echo b >.git/narrow &&
+	test_must_fail git add foo
+'
+
+test_expect_success 'narrow index and normal repo' '
+	rm .git/narrow &&
+	test_must_fail git add foo
+'
+
+test_expect_success 'turn to normal index again' '
+	rm .git/index &&
+	git add foo &&
+	test -f .git/index
+'
+
+test_expect_success 'normal index and narrow repo' '
+	echo a >.git/narrow &&
+	test_must_fail git add foo
+'
+
 test_done

-- 
1.7.1.rc1.69.g24c2f7