There may be multiple MIDX files in a single pack directory. The primary
file is pointed to by a pointer file "midx-head" that contains an OID.
The MIDX file to load is then given by "midx-<OID>.midx".
This head file will be especially important when the MIDX files are
extended to be incremental and we expect multiple MIDX files at any
point.
Signed-off-by: Derrick Stolee <dsto...@microsoft.com>
---
Documentation/git-midx.txt | 19 ++++++++++++++++++-
builtin/midx.c | 32 ++++++++++++++++++++++++++++++--
midx.c | 31 +++++++++++++++++++++++++++++++
midx.h | 3 +++
t/t5318-midx.sh | 33 ++++++++++++++++++++++-----------
5 files changed, 104 insertions(+), 14 deletions(-)
diff --git a/Documentation/git-midx.txt b/Documentation/git-midx.txt
index 17464222c1..01f79cbba5 100644
--- a/Documentation/git-midx.txt
+++ b/Documentation/git-midx.txt
@@ -9,7 +9,7 @@ git-midx - Write and verify multi-pack-indexes (MIDX files).
SYNOPSIS
--------
[verse]
-'git midx' --write [--pack-dir <pack_dir>]
+'git midx' --write <options> [--pack-dir <pack_dir>]
DESCRIPTION
-----------
@@ -26,15 +26,32 @@ OPTIONS
If specified, write a new midx file to the pack directory using
the packfiles present. Outputs the hash of the result midx file.
+--update-head::
+ If specified with --write, update the midx-head file to point to
+ the written midx file.
+
EXAMPLES
--------
+* Read the midx-head file and output the OID of the head MIDX file.
++
+------------------------------------------------
+$ git midx
+------------------------------------------------
+
* Write a MIDX file for the packfiles in your local .git folder.
+
------------------------------------------------
$ git midx --write
------------------------------------------------
+* Write a MIDX file for the packfiles in your local .git folder and
+* update the midx-head file.
++
+------------------------------------------------
+$ git midx --write --update-head
+------------------------------------------------
+
* Write a MIDX file for the packfiles in a different folder
+
---------------------------------------------------------
diff --git a/builtin/midx.c b/builtin/midx.c
index 4aae14cf8e..84ce6588a2 100644
--- a/builtin/midx.c
+++ b/builtin/midx.c
@@ -9,13 +9,17 @@
#include "midx.h"
static char const * const builtin_midx_usage[] = {
- N_("git midx --write [--pack-dir <packdir>]"),
+ N_("git midx [--pack-dir <packdir>]"),
+ N_("git midx --write [--update-head] [--pack-dir <packdir>]"),
NULL
};
static struct opts_midx {
const char *pack_dir;
int write;
+ int update_head;
+ int has_existing;
+ struct object_id old_midx_oid;
} opts;
static int build_midx_from_packs(
@@ -109,6 +113,22 @@ static int build_midx_from_packs(
return 0;
}
+static void update_head_file(const char *pack_dir, const char *midx_id)
+{
+ int fd;
+ struct lock_file lk = LOCK_INIT;
+ char *head_path = get_midx_head_filename(pack_dir);
+
+ fd = hold_lock_file_for_update(&lk, head_path, LOCK_DIE_ON_ERROR);
+ FREE_AND_NULL(head_path);
+
+ if (fd < 0)
+ die_errno("unable to open midx-head");
+
+ write_in_full(fd, midx_id, GIT_MAX_HEXSZ);
+ commit_lock_file(&lk);
+}
+
static int midx_write(void)
{
const char **pack_names = NULL;
@@ -152,6 +172,9 @@ static int midx_write(void)
printf("%s\n", midx_id);
+ if (opts.update_head)
+ update_head_file(opts.pack_dir, midx_id);
+
cleanup:
if (pack_names)
FREE_AND_NULL(pack_names);
@@ -166,6 +189,8 @@ int cmd_midx(int argc, const char **argv, const char
*prefix)
N_("The pack directory containing set of packfile and
pack-index pairs.") },
OPT_BOOL('w', "write", &opts.write,
N_("write midx file")),
+ OPT_BOOL('u', "update-head", &opts.update_head,
+ N_("update midx-head to written midx file")),
OPT_END(),
};
@@ -187,9 +212,12 @@ int cmd_midx(int argc, const char **argv, const char
*prefix)
opts.pack_dir = strbuf_detach(&path, NULL);
}
+ opts.has_existing = !!get_midx_head_oid(opts.pack_dir,
&opts.old_midx_oid);
+
if (opts.write)
return midx_write();
- usage_with_options(builtin_midx_usage, builtin_midx_options);
+ if (opts.has_existing)
+ printf("%s\n", oid_to_hex(&opts.old_midx_oid));
return 0;
}
diff --git a/midx.c b/midx.c
index 5c320726ed..f4178c1b81 100644
--- a/midx.c
+++ b/midx.c
@@ -34,6 +34,37 @@ char* get_midx_filename_oid(const char *pack_dir,
return strbuf_detach(&head_path, NULL);
}
+char *get_midx_head_filename(const char *pack_dir)
+{
+ struct strbuf head_filename = STRBUF_INIT;
+ strbuf_addstr(&head_filename, pack_dir);
+ strbuf_addstr(&head_filename, "/midx-head");
+ return strbuf_detach(&head_filename, NULL);
+}
+
+struct object_id *get_midx_head_oid(const char *pack_dir,
+ struct object_id *oid)
+{
+ char oid_hex[GIT_MAX_HEXSZ + 1];
+ FILE *f;
+ char *head_filename = get_midx_head_filename(pack_dir);
+
+ f = fopen(head_filename, "r");
+ FREE_AND_NULL(head_filename);
+
+ if (!f)
+ return 0;
+
+ if (!fgets(oid_hex, sizeof(oid_hex), f))
+ die("failed to read midx-head");
+
+ fclose(f);
+
+ if (get_oid_hex(oid_hex, oid))
+ return 0;
+ return oid;
+}
+
struct pack_midx_details_internal {
uint32_t pack_int_id;
uint32_t internal_offset;
diff --git a/midx.h b/midx.h
index 4b00463651..9d9ab85261 100644
--- a/midx.h
+++ b/midx.h
@@ -7,6 +7,9 @@
extern char *get_midx_filename_oid(const char *pack_dir,
struct object_id *oid);
+extern char *get_midx_head_filename(const char *pack_dir);
+
+extern struct object_id *get_midx_head_oid(const char *pack_dir, struct
object_id *oid);
struct pack_midx_entry {
struct object_id oid;
diff --git a/t/t5318-midx.sh b/t/t5318-midx.sh
index 869bbea29c..b66efcdce9 100755
--- a/t/t5318-midx.sh
+++ b/t/t5318-midx.sh
@@ -29,13 +29,16 @@ test_expect_success 'create objects' \
test_expect_success 'write-midx from index version 1' \
'pack1=$(git rev-list --all --objects | git pack-objects --index-version=1
${packdir}/test-1) &&
midx1=$(git midx --write) &&
- test_path_is_file ${packdir}/midx-${midx1}.midx'
+ test_path_is_file ${packdir}/midx-${midx1}.midx &&
+ test_path_is_missing ${packdir}/midx-head'
test_expect_success 'write-midx from index version 2' \
'rm "${packdir}/test-1-${pack1}.pack" &&
pack2=$(git rev-list --all --objects | git pack-objects --index-version=2
${packdir}/test-2) &&
- midx2=$(git midx --write) &&
- test_path_is_file ${packdir}/midx-${midx2}.midx'
+ midx2=$(git midx --write --update-head) &&
+ test_path_is_file ${packdir}/midx-${midx2}.midx &&
+ test_path_is_file ${packdir}/midx-head &&
+ test $(cat ${packdir}/midx-head) = "$midx2"'
test_expect_success 'Create more objects' \
'for i in $(test_seq 100)
@@ -49,8 +52,10 @@ test_expect_success 'Create more objects' \
test_expect_success 'write-midx with two packs' \
'pack3=$(git rev-list --objects commit2 ^commit1 | git pack-objects
--index-version=2 ${packdir}/test-3) &&
- midx3=$(git midx --write) &&
- test_path_is_file ${packdir}/midx-${midx3}.midx'
+ midx3=$(git midx --write --update-head) &&
+ test_path_is_file ${packdir}/midx-${midx3}.midx &&
+ test_path_is_file ${packdir}/midx-head &&
+ test $(cat ${packdir}/midx-head) = "$midx3"'
test_expect_success 'Add more packs' \
'for j in $(test_seq 10)
@@ -77,13 +82,17 @@ test_expect_success 'Add more packs' \
done'
test_expect_success 'write-midx with twelve packs' \
- 'midx4=$(git midx --write) &&
- test_path_is_file ${packdir}/midx-${midx4}.midx'
+ 'midx4=$(git midx --write --update-head) &&
+ test_path_is_file ${packdir}/midx-${midx4}.midx &&
+ test_path_is_file ${packdir}/midx-head &&
+ test $(cat ${packdir}/midx-head) = "$midx4"'
test_expect_success 'write-midx with no new packs' \
- 'midx5=$(git midx --write) &&
+ 'midx5=$(git midx --write --update-head) &&
test_path_is_file ${packdir}/midx-${midx5}.midx &&
- test "a$midx4" = "a$midx5"'
+ test "a$midx4" = "a$midx5" &&
+ test_path_is_file ${packdir}/midx-head &&
+ test $(cat ${packdir}/midx-head) = "$midx4"'
test_expect_success 'create bare repo' \
'cd .. &&
@@ -94,7 +103,9 @@ test_expect_success 'create bare repo' \
baredir=objects/pack'
test_expect_success 'write-midx in bare repo' \
- 'midxbare=$(git midx --write) &&
- test_path_is_file ${baredir}/midx-${midxbare}.midx'
+ 'midxbare=$(git midx --write --update-head) &&
+ test_path_is_file ${baredir}/midx-${midxbare}.midx &&
+ test_path_is_file ${baredir}/midx-head &&
+ test $(cat ${baredir}/midx-head) = "$midxbare"'
test_done
--
2.15.0
