Create a new multi_pack_index struct for loading multi-pack-indexes into
memory. Create a test-tool builtin for reading basic information about
that multi-pack-index to verify the correct data is written.
Signed-off-by: Derrick Stolee <dsto...@microsoft.com>
---
Makefile | 1 +
midx.c | 82 +++++++++++++++++++++++++++++++++++++
midx.h | 4 ++
object-store.h | 16 ++++++++
t/helper/test-read-midx.c | 34 +++++++++++++++
t/helper/test-tool.c | 1 +
t/helper/test-tool.h | 1 +
t/t5319-multi-pack-index.sh | 12 +++++-
8 files changed, 150 insertions(+), 1 deletion(-)
create mode 100644 t/helper/test-read-midx.c
diff --git a/Makefile b/Makefile
index f5636c711d..0b801d1b16 100644
--- a/Makefile
+++ b/Makefile
@@ -717,6 +717,7 @@ TEST_BUILTINS_OBJS += test-online-cpus.o
TEST_BUILTINS_OBJS += test-path-utils.o
TEST_BUILTINS_OBJS += test-prio-queue.o
TEST_BUILTINS_OBJS += test-read-cache.o
+TEST_BUILTINS_OBJS += test-read-midx.o
TEST_BUILTINS_OBJS += test-ref-store.o
TEST_BUILTINS_OBJS += test-regex.o
TEST_BUILTINS_OBJS += test-revision-walking.o
diff --git a/midx.c b/midx.c
index f85f2d334d..fb388f5858 100644
--- a/midx.c
+++ b/midx.c
@@ -1,18 +1,100 @@
#include "cache.h"
#include "csum-file.h"
#include "lockfile.h"
+#include "object-store.h"
#include "midx.h"
#define MIDX_SIGNATURE 0x4d494458 /* "MIDX" */
#define MIDX_VERSION 1
+#define MIDX_BYTE_FILE_VERSION 4
+#define MIDX_BYTE_HASH_VERSION 5
+#define MIDX_BYTE_NUM_CHUNKS 6
+#define MIDX_BYTE_NUM_PACKS 8
#define MIDX_HASH_VERSION 1
#define MIDX_HEADER_SIZE 12
+#define MIDX_HASH_LEN 20
+#define MIDX_MIN_SIZE (MIDX_HEADER_SIZE + MIDX_HASH_LEN)
static char *get_midx_filename(const char *object_dir)
{
return xstrfmt("%s/pack/multi-pack-index", object_dir);
}
+struct multi_pack_index *load_multi_pack_index(const char *object_dir)
+{
+ struct multi_pack_index *m = NULL;
+ int fd;
+ struct stat st;
+ size_t midx_size;
+ void *midx_map = NULL;
+ uint32_t hash_version;
+ char *midx_name = get_midx_filename(object_dir);
+
+ fd = git_open(midx_name);
+
+ if (fd < 0)
+ goto cleanup_fail;
+ if (fstat(fd, &st)) {
+ error_errno(_("failed to read %s"), midx_name);
+ goto cleanup_fail;
+ }
+
+ midx_size = xsize_t(st.st_size);
+
+ if (midx_size < MIDX_MIN_SIZE) {
+ close(fd);
+ error(_("multi-pack-index file %s is too small"), midx_name);
+ goto cleanup_fail;
+ }
+
+ FREE_AND_NULL(midx_name);
+
+ midx_map = xmmap(NULL, midx_size, PROT_READ, MAP_PRIVATE, fd, 0);
+
+ m = xcalloc(1, sizeof(*m) + strlen(object_dir) + 1);
+ strcpy(m->object_dir, object_dir);
+ m->fd = fd;
+ m->data = midx_map;
+ m->data_len = midx_size;
+
+ m->signature = get_be32(m->data);
+ if (m->signature != MIDX_SIGNATURE) {
+ error(_("multi-pack-index signature 0x%08x does not match
signature 0x%08x"),
+ m->signature, MIDX_SIGNATURE);
+ goto cleanup_fail;
+ }
+
+ m->version = m->data[MIDX_BYTE_FILE_VERSION];
+ if (m->version != MIDX_VERSION) {
+ error(_("multi-pack-index version %d not recognized"),
+ m->version);
+ goto cleanup_fail;
+ }
+
+ hash_version = m->data[MIDX_BYTE_HASH_VERSION];
+ if (hash_version != MIDX_HASH_VERSION) {
+ error(_("hash version %u does not match"), hash_version);
+ goto cleanup_fail;
+ }
+ m->hash_len = MIDX_HASH_LEN;
+
+ m->num_chunks = m->data[MIDX_BYTE_NUM_CHUNKS];
+
+ m->num_packs = get_be32(m->data + MIDX_BYTE_NUM_PACKS);
+
+ return m;
+
+cleanup_fail:
+ /* no need to check for NULL when freeing */
+ free(m);
+ free(midx_name);
+ if (midx_map)
+ munmap(midx_map, midx_size);
+ if (0 <= fd)
+ close(fd);
+ return NULL;
+}
+
static size_t write_midx_header(struct hashfile *f,
unsigned char num_chunks,
uint32_t num_packs)
diff --git a/midx.h b/midx.h
index dbdbe9f873..2d83dd9ec1 100644
--- a/midx.h
+++ b/midx.h
@@ -1,6 +1,10 @@
#ifndef __MIDX_H__
#define __MIDX_H__
+struct multi_pack_index;
+
+struct multi_pack_index *load_multi_pack_index(const char *object_dir);
+
int write_midx_file(const char *object_dir);
#endif
diff --git a/object-store.h b/object-store.h
index d683112fd7..4f410841cc 100644
--- a/object-store.h
+++ b/object-store.h
@@ -84,6 +84,22 @@ struct packed_git {
char pack_name[FLEX_ARRAY]; /* more */
};
+struct multi_pack_index {
+ int fd;
+
+ const unsigned char *data;
+ size_t data_len;
+
+ uint32_t signature;
+ unsigned char version;
+ unsigned char hash_len;
+ unsigned char num_chunks;
+ uint32_t num_packs;
+ uint32_t num_objects;
+
+ char object_dir[FLEX_ARRAY];
+};
+
struct raw_object_store {
/*
* Path to the repository's object store.
diff --git a/t/helper/test-read-midx.c b/t/helper/test-read-midx.c
new file mode 100644
index 0000000000..5abf969175
--- /dev/null
+++ b/t/helper/test-read-midx.c
@@ -0,0 +1,34 @@
+/*
+ * test-mktemp.c: code to exercise the creation of temporary files
+ */
+#include "test-tool.h"
+#include "cache.h"
+#include "midx.h"
+#include "repository.h"
+#include "object-store.h"
+
+static int read_midx_file(const char *object_dir)
+{
+ struct multi_pack_index *m = load_multi_pack_index(object_dir);
+
+ if (!m)
+ return 0;
+
+ printf("header: %08x %d %d %d\n",
+ m->signature,
+ m->version,
+ m->num_chunks,
+ m->num_packs);
+
+ printf("object_dir: %s\n", m->object_dir);
+
+ return 0;
+}
+
+int cmd__read_midx(int argc, const char **argv)
+{
+ if (argc != 2)
+ usage("read-midx <object_dir>");
+
+ return read_midx_file(argv[1]);
+}
diff --git a/t/helper/test-tool.c b/t/helper/test-tool.c
index 805a45de9c..1c3ab36e6c 100644
--- a/t/helper/test-tool.c
+++ b/t/helper/test-tool.c
@@ -27,6 +27,7 @@ static struct test_cmd cmds[] = {
{ "path-utils", cmd__path_utils },
{ "prio-queue", cmd__prio_queue },
{ "read-cache", cmd__read_cache },
+ { "read-midx", cmd__read_midx },
{ "ref-store", cmd__ref_store },
{ "regex", cmd__regex },
{ "revision-walking", cmd__revision_walking },
diff --git a/t/helper/test-tool.h b/t/helper/test-tool.h
index 7116ddfb94..6af8c08a66 100644
--- a/t/helper/test-tool.h
+++ b/t/helper/test-tool.h
@@ -21,6 +21,7 @@ int cmd__online_cpus(int argc, const char **argv);
int cmd__path_utils(int argc, const char **argv);
int cmd__prio_queue(int argc, const char **argv);
int cmd__read_cache(int argc, const char **argv);
+int cmd__read_midx(int argc, const char **argv);
int cmd__ref_store(int argc, const char **argv);
int cmd__regex(int argc, const char **argv);
int cmd__revision_walking(int argc, const char **argv);
diff --git a/t/t5319-multi-pack-index.sh b/t/t5319-multi-pack-index.sh
index 8622a7cdce..2ecc369529 100755
--- a/t/t5319-multi-pack-index.sh
+++ b/t/t5319-multi-pack-index.sh
@@ -3,9 +3,19 @@
test_description='multi-pack-indexes'
. ./test-lib.sh
+midx_read_expect () {
+ cat >expect <<-EOF
+ header: 4d494458 1 0 0
+ object_dir: .
+ EOF
+ test-tool read-midx . >actual &&
+ test_cmp expect actual
+}
+
test_expect_success 'write midx with no packs' '
git multi-pack-index --object-dir=. write &&
- test_path_is_file pack/multi-pack-index
+ test_path_is_file pack/multi-pack-index &&
+ midx_read_expect
'
test_done
--
2.18.0.118.gd4f65b8d14
