Re: [PATCH v7 08/14] commit-graph: implement git commit-graph read

[Jakub Narebski]

Derrick Stolee  writes:

[...]
>  EXAMPLES
>  
> @@ -45,6 +51,12 @@ EXAMPLES
>  $ git commit-graph write
>  
>  
> +* Read basic information from the commit-graph file.
> ++
> +
> +$ git commit-graph read
> +

It would be better to have example output of this command here, perhaps
together with ASCII-art diagram of the code graph.

[...]
> + if (!graph)
> + die("graph file %s does not exist", graph_name);
> + FREE_AND_NULL(graph_name);

Shouldn't the error message be marked up for translation, too?

Regards,
-- 
Jakub Narębski

Re: [PATCH v7 08/14] commit-graph: implement git commit-graph read

[Derrick Stolee]

On 4/2/2018 5:33 PM, Junio C Hamano wrote:

Derrick Stolee  writes:


From: Derrick Stolee 
...
+static int graph_read(int argc, const char **argv)
+{
+   struct commit_graph *graph = 0;

The previous round said NULL above, not 0, and NULL is the better
way to spell it, I would think.


Sorry about that. Hopefully it is easy to squash.

Re: [PATCH v7 08/14] commit-graph: implement git commit-graph read

[Junio C Hamano]

Derrick Stolee  writes:

> From: Derrick Stolee 
> ...
> +static int graph_read(int argc, const char **argv)
> +{
> + struct commit_graph *graph = 0;

The previous round said NULL above, not 0, and NULL is the better
way to spell it, I would think.

[PATCH v7 08/14] commit-graph: implement git commit-graph read

[Derrick Stolee]

From: Derrick Stolee 

Teach git-commit-graph to read commit graph files and summarize their contents.

Use the read subcommand to verify the contents of a commit graph file in the
tests.

Signed-off-by: Derrick Stolee 
---
 Documentation/git-commit-graph.txt |  12 +++
 builtin/commit-graph.c |  56 
 commit-graph.c | 137 -
 commit-graph.h |  23 +
 t/t5318-commit-graph.sh|  32 +--
 5 files changed, 254 insertions(+), 6 deletions(-)

diff --git a/Documentation/git-commit-graph.txt 
b/Documentation/git-commit-graph.txt
index 47996e8f89..8aad8303f5 100644
--- a/Documentation/git-commit-graph.txt
+++ b/Documentation/git-commit-graph.txt
@@ -9,6 +9,7 @@ git-commit-graph - Write and verify Git commit graph files
 SYNOPSIS
 
 [verse]
+'git commit-graph read' [--object-dir ]
 'git commit-graph write'  [--object-dir ]
 
 
@@ -35,6 +36,11 @@ COMMANDS
 Write a commit graph file based on the commits found in packfiles.
 Includes all commits from the existing commit graph file.
 
+'read'::
+
+Read a graph file given by the commit-graph file and output basic
+details about the graph file. Used for debugging purposes.
+
 
 EXAMPLES
 
@@ -45,6 +51,12 @@ EXAMPLES
 $ git commit-graph write
 
 
+* Read basic information from the commit-graph file.
++
+
+$ git commit-graph read
+
+
 
 GIT
 ---
diff --git a/builtin/commit-graph.c b/builtin/commit-graph.c
index 26b6360289..e3f67401fb 100644
--- a/builtin/commit-graph.c
+++ b/builtin/commit-graph.c
@@ -7,10 +7,16 @@
 
 static char const * const builtin_commit_graph_usage[] = {
N_("git commit-graph [--object-dir ]"),
+   N_("git commit-graph read [--object-dir ]"),
N_("git commit-graph write [--object-dir ]"),
NULL
 };
 
+static const char * const builtin_commit_graph_read_usage[] = {
+   N_("git commit-graph read [--object-dir ]"),
+   NULL
+};
+
 static const char * const builtin_commit_graph_write_usage[] = {
N_("git commit-graph write [--object-dir ]"),
NULL
@@ -20,6 +26,54 @@ static struct opts_commit_graph {
const char *obj_dir;
 } opts;
 
+static int graph_read(int argc, const char **argv)
+{
+   struct commit_graph *graph = 0;
+   char *graph_name;
+
+   static struct option builtin_commit_graph_read_options[] = {
+   OPT_STRING(0, "object-dir", _dir,
+   N_("dir"),
+   N_("The object directory to store the graph")),
+   OPT_END(),
+   };
+
+   argc = parse_options(argc, argv, NULL,
+builtin_commit_graph_read_options,
+builtin_commit_graph_read_usage, 0);
+
+   if (!opts.obj_dir)
+   opts.obj_dir = get_object_directory();
+
+   graph_name = get_commit_graph_filename(opts.obj_dir);
+   graph = load_commit_graph_one(graph_name);
+
+   if (!graph)
+   die("graph file %s does not exist", graph_name);
+   FREE_AND_NULL(graph_name);
+
+   printf("header: %08x %d %d %d %d\n",
+   ntohl(*(uint32_t*)graph->data),
+   *(unsigned char*)(graph->data + 4),
+   *(unsigned char*)(graph->data + 5),
+   *(unsigned char*)(graph->data + 6),
+   *(unsigned char*)(graph->data + 7));
+   printf("num_commits: %u\n", graph->num_commits);
+   printf("chunks:");
+
+   if (graph->chunk_oid_fanout)
+   printf(" oid_fanout");
+   if (graph->chunk_oid_lookup)
+   printf(" oid_lookup");
+   if (graph->chunk_commit_data)
+   printf(" commit_metadata");
+   if (graph->chunk_large_edges)
+   printf(" large_edges");
+   printf("\n");
+
+   return 0;
+}
+
 static int graph_write(int argc, const char **argv)
 {
static struct option builtin_commit_graph_write_options[] = {
@@ -60,6 +114,8 @@ int cmd_commit_graph(int argc, const char **argv, const char 
*prefix)
 PARSE_OPT_STOP_AT_NON_OPTION);
 
if (argc > 0) {
+   if (!strcmp(argv[0], "read"))
+   return graph_read(argc, argv);
if (!strcmp(argv[0], "write"))
return graph_write(argc, argv);
}
diff --git a/commit-graph.c b/commit-graph.c
index f3f7c4f189..b1bd3a892d 100644
--- a/commit-graph.c
+++ b/commit-graph.c
@@ -39,11 +39,146 @@
GRAPH_OID_LEN + 8)
 
 
-static char *get_commit_graph_filename(const char *obj_dir)
+char *get_commit_graph_filename(const char *obj_dir)
 {
return xstrfmt("%s/info/commit-graph", obj_dir);
 }
 
+static struct commit_graph *alloc_commit_graph(void)
+{
+   struct commit_graph *g =