In cases where a hook requires only a small amount of information via
stdin, it should be simple for users to provide a string_list alone. But
in more complicated cases where the stdin is too large to hold in
memory, let's provide a callback the users can populate line after line
with instead.
Signed-off-by: Emily Shaffer <emilyshaffer@xxxxxxxxxx>
---
hook.c | 38 ++++++++++++++++++++++++++++++++++++--
hook.h | 28 ++++++++++++++++++++++++++++
2 files changed, 64 insertions(+), 2 deletions(-)
diff --git a/hook.c b/hook.c
index 1fa7976583..8aa0d4fdf2 100644
--- a/hook.c
+++ b/hook.c
@@ -7,8 +7,10 @@
void free_hook(struct hook *ptr)
{
- if (ptr)
+ if (ptr) {
strbuf_release(&ptr->command);
+ free(ptr->feed_pipe_cb_data);
+ }
free(ptr);
}
@@ -38,6 +40,7 @@ static void append_or_move_hook(struct list_head *head, const char *command)
strbuf_init(&to_add->command, 0);
strbuf_addstr(&to_add->command, command);
to_add->from_hookdir = 0;
+ to_add->feed_pipe_cb_data = NULL;
}
/* re-set the scope so we show where an override was specified */
@@ -257,6 +260,8 @@ void run_hooks_opt_init_sync(struct run_hooks_opt *o)
o->run_hookdir = configured_hookdir_opt();
o->jobs = 1;
o->dir = NULL;
+ o->feed_pipe = NULL;
+ o->feed_pipe_ctx = NULL;
}
void run_hooks_opt_init_async(struct run_hooks_opt *o)
@@ -290,6 +295,28 @@ void run_hooks_opt_clear(struct run_hooks_opt *o)
strvec_clear(&o->args);
}
+int pipe_from_string_list(struct strbuf *pipe, void *pp_cb, void *pp_task_cb)
+{
+ int *item_idx;
+ struct hook *ctx = pp_task_cb;
+ struct string_list *to_pipe = ((struct hook_cb_data*)pp_cb)->options->feed_pipe_ctx;
+
+ /* Bootstrap the state manager if necessary. */
+ if (!ctx->feed_pipe_cb_data) {
+ ctx->feed_pipe_cb_data = xmalloc(sizeof(unsigned int));
+ *(int*)ctx->feed_pipe_cb_data = 0;
+ }
+
+ item_idx = ctx->feed_pipe_cb_data;
+
+ if (*item_idx < to_pipe->nr) {
+ strbuf_addf(pipe, "%s\n", to_pipe->items[*item_idx].string);
+ (*item_idx)++;
+ return 0;
+ }
+ return 1;
+}
+
static int pick_next_hook(struct child_process *cp,
struct strbuf *out,
void *pp_cb,
@@ -305,6 +332,10 @@ static int pick_next_hook(struct child_process *cp,
if (hook_cb->options->path_to_stdin) {
cp->no_stdin = 0;
cp->in = xopen(hook_cb->options->path_to_stdin, O_RDONLY);
+ } else if (hook_cb->options->feed_pipe) {
+ /* ask for start_command() to make a pipe for us */
+ cp->in = -1;
+ cp->no_stdin = 0;
} else {
cp->no_stdin = 1;
}
@@ -383,6 +414,9 @@ int run_hooks(const char *hookname, struct run_hooks_opt *options)
if (!options)
BUG("a struct run_hooks_opt must be provided to run_hooks");
+ if (options->path_to_stdin && options->feed_pipe)
+ BUG("choose only one method to populate stdin");
+
to_run = hook_list(hookname);
list_for_each_safe(pos, tmp, to_run) {
@@ -402,7 +436,7 @@ int run_hooks(const char *hookname, struct run_hooks_opt *options)
run_processes_parallel_tr2(options->jobs,
pick_next_hook,
notify_start_failure,
- NULL,
+ options->feed_pipe,
notify_hook_finished,
&cb_data,
"hook",
diff --git a/hook.h b/hook.h
index 218b9e1721..aba62d4112 100644
--- a/hook.h
+++ b/hook.h
@@ -2,6 +2,7 @@
#include "list.h"
#include "strbuf.h"
#include "strvec.h"
+#include "run-command.h"
struct hook {
struct list_head list;
@@ -13,6 +14,12 @@ struct hook {
/* The literal command to run. */
struct strbuf command;
unsigned from_hookdir : 1;
+
+ /*
+ * Use this to keep state for your feed_pipe_fn if you are using
+ * run_hooks_opt.feed_pipe. Otherwise, do not touch it.
+ */
+ void *feed_pipe_cb_data;
};
/*
@@ -58,14 +65,35 @@ struct run_hooks_opt
/* Path to file which should be piped to stdin for each hook */
const char *path_to_stdin;
+ /*
+ * Callback and state pointer to ask for more content to pipe to stdin.
+ * Will be called repeatedly, for each hook. See
+ * hook.c:pipe_from_stdin() for an example. Keep per-hook state in
+ * hook.feed_pipe_cb_data (per process). Keep initialization context in
+ * feed_pipe_ctx (shared by all processes).
+ *
+ * See 'pipe_from_string_list()' for info about how to specify a
+ * string_list as the stdin input instead of writing your own handler.
+ */
+ feed_pipe_fn feed_pipe;
+ void *feed_pipe_ctx;
/* Number of threads to parallelize across */
int jobs;
/* Path to initial working directory for subprocess */
const char *dir;
+
};
+/*
+ * To specify a 'struct string_list', set 'run_hooks_opt.feed_pipe_ctx' to the
+ * string_list and set 'run_hooks_opt.feed_pipe' to 'pipe_from_string_list()'.
+ * This will pipe each string in the list to stdin, separated by newlines. (Do
+ * not inject your own newlines.)
+ */
+int pipe_from_string_list(struct strbuf *pipe, void *pp_cb, void *pp_task_cb);
+
/*
* Callback provided to feed_pipe_fn and consume_sideband_fn.
*/
--
2.31.1.818.g46aad6cb9e-goog
