Re: [PATCH v5 3/8] convert: Split start_multi_file_filter into two separate functions

On 07 Apr 2017, at 14:03, Ben Peart [off-list ref] wrote:

To enable future reuse of the filter.<driver>.process infrastructure,
split start_multi_file_filter into two separate parts.

start_multi_file_filter will now only contain the generic logic to
manage the creation and tracking of the child process in a hashmap.

start_multi_file_filter_fn is a protocol specific initialization
function that will negotiate the multi-file-filter interface version
and capabilities.

Signed-off-by: Ben Peart <redacted>
---
convert.c | 63 ++++++++++++++++++++++++++++++++++++++-------------------------
1 file changed, 38 insertions(+), 25 deletions(-)

diff --git a/convert.c b/convert.c
index 793c29ebfd..404757eac9 100644
--- a/convert.c
+++ b/convert.c

@@ -565,35 +565,14 @@ static void stop_multi_file_filter(struct child_process *process)

	finish_command(process);
}

-static struct cmd2process *start_multi_file_filter(struct hashmap *hashmap, const char *cmd)
+static int start_multi_file_filter_fn(struct cmd2process *entry)
{
	int err;
-	struct cmd2process *entry;
-	struct child_process *process;
-	const char *argv[] = { cmd, NULL };
	struct string_list cap_list = STRING_LIST_INIT_NODUP;
	char *cap_buf;
	const char *cap_name;
-
-	entry = xmalloc(sizeof(*entry));
-	entry->cmd = cmd;
-	entry->supported_capabilities = 0;
-	process = &entry->process;
-
-	child_process_init(process);
-	process->argv = argv;
-	process->use_shell = 1;
-	process->in = -1;
-	process->out = -1;
-	process->clean_on_exit = 1;
-	process->clean_on_exit_handler = stop_multi_file_filter;
-
-	if (start_command(process)) {
-		error("cannot fork to run external filter '%s'", cmd);
-		return NULL;
-	}
-
-	hashmap_entry_init(entry, strhash(cmd));
+	struct child_process *process = &entry->process;
+	const char *cmd = entry->cmd;

	sigchain_push(SIGPIPE, SIG_IGN);

@@ -642,7 +621,41 @@ static struct cmd2process *start_multi_file_filter(struct hashmap *hashmap, cons

done:
	sigchain_pop(SIGPIPE);

-	if (err || errno == EPIPE) {
+	if (err || errno == EPIPE)
+		err = err ? err : errno;