It is possible to have multiple packed graph files in a pack directory,
but only one is important at a time. Use a 'graph_head' file to point
to the important file. Teach git-graph to write 'graph_head' upon
writing a new packed graph file.
Signed-off-by: Derrick Stolee <dsto...@microsoft.com>
---
Documentation/git-graph.txt | 38 ++++++++++++++++++++++++++++++++++++--
builtin/graph.c | 38 +++++++++++++++++++++++++++++++++++---
packed-graph.c | 25 +++++++++++++++++++++++++
packed-graph.h | 1 +
t/t5319-graph.sh | 12 ++++++++++--
5 files changed, 107 insertions(+), 7 deletions(-)
diff --git a/Documentation/git-graph.txt b/Documentation/git-graph.txt
index 0939c3f1be..ac20aa67a9 100644
--- a/Documentation/git-graph.txt
+++ b/Documentation/git-graph.txt
@@ -12,19 +12,53 @@ SYNOPSIS
'git graph' --write <options> [--pack-dir <pack_dir>]
'git graph' --read <options> [--pack-dir <pack_dir>]
+OPTIONS
+-------
+--pack-dir::
+ Use given directory for the location of packfiles, graph-head,
+ and graph files.
+
+--read::
+ Read a graph file given by the graph-head file and output basic
+ details about the graph file. (Cannot be combined with --write.)
+
+--graph-id::
+ When used with --read, consider the graph file graph-<oid>.graph.
+
+--write::
+ Write a new graph file to the pack directory. (Cannot be combined
+ with --read.)
+
+--update-head::
+ When used with --write, update the graph-head file to point to
+ the written graph file.
+
EXAMPLES
--------
+* Output the OID of the graph file pointed to by <dir>/graph-head.
++
+------------------------------------------------
+$ git graph --pack-dir=<dir>
+------------------------------------------------
+
* Write a graph file for the packed commits in your local .git folder.
+
------------------------------------------------
-$ git midx --write
+$ git graph --write
+------------------------------------------------
+
+* Write a graph file for the packed commits in your local .git folder,
+* and update graph-head.
++
+------------------------------------------------
+$ git graph --write --update-head
------------------------------------------------
* Read basic information from a graph file.
+
------------------------------------------------
-$ git midx --read --graph-id=<oid>
+$ git graph --read --graph-id=<oid>
------------------------------------------------
CONFIGURATION
diff --git a/builtin/graph.c b/builtin/graph.c
index bc66722924..0760d99f43 100644
--- a/builtin/graph.c
+++ b/builtin/graph.c
@@ -11,7 +11,7 @@
static char const * const builtin_graph_usage[] ={
N_("git graph [--pack-dir <packdir>]"),
N_("git graph --read [--graph-id=<oid>]"),
- N_("git graph --write [--pack-dir <packdir>]"),
+ N_("git graph --write [--pack-dir <packdir>] [--update-head]"),
NULL
};
@@ -20,6 +20,9 @@ static struct opts_graph {
int read;
const char *graph_id;
int write;
+ int update_head;
+ int has_existing;
+ struct object_id old_graph_oid;
} opts;
static int graph_read(void)
@@ -30,8 +33,8 @@ static int graph_read(void)
if (opts.graph_id && strlen(opts.graph_id) == GIT_MAX_HEXSZ)
get_oid_hex(opts.graph_id, &graph_oid);
- else
- die("no graph id specified");
+ else if (!get_graph_head_oid(opts.pack_dir, &graph_oid))
+ die("no graph-head exists.");
graph_file = get_graph_filename_oid(opts.pack_dir, &graph_oid);
graph = load_packed_graph_one(graph_file, opts.pack_dir);
@@ -62,10 +65,33 @@ static int graph_read(void)
return 0;
}
+static void update_head_file(const char *pack_dir, const struct object_id
*graph_id)
+{
+ struct strbuf head_path = STRBUF_INIT;
+ int fd;
+ struct lock_file lk = LOCK_INIT;
+
+ strbuf_addstr(&head_path, pack_dir);
+ strbuf_addstr(&head_path, "/");
+ strbuf_addstr(&head_path, "graph-head");
+
+ fd = hold_lock_file_for_update(&lk, head_path.buf, LOCK_DIE_ON_ERROR);
+ strbuf_release(&head_path);
+
+ if (fd < 0)
+ die_errno("unable to open graph-head");
+
+ write_in_full(fd, oid_to_hex(graph_id), GIT_MAX_HEXSZ);
+ commit_lock_file(&lk);
+}
+
static int graph_write(void)
{
struct object_id *graph_id = construct_graph(opts.pack_dir);
+ if (opts.update_head)
+ update_head_file(opts.pack_dir, graph_id);
+
if (graph_id)
printf("%s\n", oid_to_hex(graph_id));
@@ -83,6 +109,8 @@ int cmd_graph(int argc, const char **argv, const char
*prefix)
N_("read graph file")),
OPT_BOOL('w', "write", &opts.write,
N_("write graph file")),
+ OPT_BOOL('u', "update-head", &opts.update_head,
+ N_("update graph-head to written graph file")),
{ OPTION_STRING, 'M', "graph-id", &opts.graph_id,
N_("oid"),
N_("An OID for a specific graph file in the pack-dir."),
@@ -111,11 +139,15 @@ int cmd_graph(int argc, const char **argv, const char
*prefix)
opts.pack_dir = strbuf_detach(&path, NULL);
}
+ opts.has_existing = !!get_graph_head_oid(opts.pack_dir,
&opts.old_graph_oid);
+
if (opts.read)
return graph_read();
if (opts.write)
return graph_write();
+ if (opts.has_existing)
+ printf("%s\n", oid_to_hex(&opts.old_graph_oid));
return 0;
}
diff --git a/packed-graph.c b/packed-graph.c
index eaa656becb..5723f163ae 100644
--- a/packed-graph.c
+++ b/packed-graph.c
@@ -35,6 +35,31 @@
#define GRAPH_MIN_SIZE (GRAPH_CHUNKLOOKUP_SIZE + GRAPH_FANOUT_SIZE + \
GRAPH_OID_LEN + sizeof(struct packed_graph_header))
+struct object_id *get_graph_head_oid(const char *pack_dir, struct object_id
*oid)
+{
+ struct strbuf head_filename = STRBUF_INIT;
+ char oid_hex[GIT_MAX_HEXSZ + 1];
+ FILE *f;
+
+ strbuf_addstr(&head_filename, pack_dir);
+ strbuf_addstr(&head_filename, "/graph-head");
+
+ f = fopen(head_filename.buf, "r");
+ strbuf_release(&head_filename);
+
+ if (!f)
+ return 0;
+
+ if (!fgets(oid_hex, sizeof(oid_hex), f))
+ die("failed to read graph-head");
+
+ fclose(f);
+
+ if (get_oid_hex(oid_hex, oid))
+ return 0;
+ return oid;
+}
+
char* get_graph_filename_oid(const char *pack_dir,
struct object_id *oid)
{
diff --git a/packed-graph.h b/packed-graph.h
index 1a7eaa2a46..ad561863c8 100644
--- a/packed-graph.h
+++ b/packed-graph.h
@@ -4,6 +4,7 @@
#include "git-compat-util.h"
#include "commit.h"
+extern struct object_id *get_graph_head_oid(const char *pack_dir, struct
object_id *oid);
extern char* get_graph_filename_oid(const char *pack_dir,
struct object_id *oid);
diff --git a/t/t5319-graph.sh b/t/t5319-graph.sh
index 4975f65dee..3919a3ad73 100755
--- a/t/t5319-graph.sh
+++ b/t/t5319-graph.sh
@@ -13,7 +13,8 @@ test_expect_success 'setup full repo' \
packdir=".git/objects/pack"'
test_expect_success 'write graph with no packs' \
- 'git graph --write --pack-dir .'
+ 'git graph --write --pack-dir . &&
+ test_path_is_missing graph-head'
test_expect_success 'create commits and repack' \
'for i in $(test_seq 5)
@@ -37,6 +38,7 @@ EOF
test_expect_success 'write graph' \
'graph1=$(git graph --write) &&
test_path_is_file ${packdir}/graph-${graph1}.graph &&
+ test_path_is_missing ${packdir}/graph-head &&
git graph --read --graph-id=${graph1} >output &&
_graph_read_expect "5" "${packdir}" &&
cmp expect output'
@@ -69,8 +71,11 @@ test_expect_success 'Add more commits' \
git repack'
test_expect_success 'write graph with merges' \
- 'graph2=$(git graph --write) &&
+ 'graph2=$(git graph --write --update-head) &&
test_path_is_file ${packdir}/graph-${graph2}.graph &&
+ test_path_is_file ${packdir}/graph-head &&
+ echo ${graph2} >expect &&
+ cmp -n 40 expect ${packdir}/graph-head &&
git graph --read --graph-id=${graph2} >output &&
_graph_read_expect "18" "${packdir}" &&
cmp expect output'
@@ -86,6 +91,9 @@ test_expect_success 'setup bare repo' \
test_expect_success 'write graph in bare repo' \
'graphbare=$(git graph --write) &&
test_path_is_file ${baredir}/graph-${graphbare}.graph &&
+ test_path_is_file ${baredir}/graph-head &&
+ echo ${graphbare} >expect &&
+ cmp -n 40 expect ${baredir}/graph-head &&
git graph --read --graph-id=${graphbare} >output &&
_graph_read_expect "18" "${baredir}" &&
cmp expect output'
--
2.16.0
