Re: [PATCH v6 3/8] convert: Split start_multi_file_filter into two separate functions

[Ben Peart <peartben@gmail.com>]

On 4/24/2017 12:31 AM, Junio C Hamano wrote:
> Ben Peart <peartben@gmail.com> writes:
>
>> Subject: [PATCH v6 3/8] convert: Split start_multi_file_filter into two separate functions
> Two minor nits, because the capital after "<area>:" looks ugly in shortlog
> output, and having () there makes it easier to notice that a
> function name is being discussed.  I.e.
>
>      convert: split start_multi_file_filter() into two separate functions

I'll make it so in the next version of the patch series.

>> 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.
> The above fails to describe a lot more important/significant change
> this patch makes.  Two mistaken check "errno == EPIPE" have been
> removed as a preliminary bugfix.  I think the bugfix deserves to be
> split into a separate patch by itself and hoisted much earlier in
> the series.  It alone is a very good change, with or without the
> remainder of the changes in this patch.

OK, I'll pull that bugfix out into a separate patch.

> Thanks.
>
>> Signed-off-by: Ben Peart <benpeart@microsoft.com>
>> ---
>>   convert.c | 62 ++++++++++++++++++++++++++++++++++++--------------------------
>>   1 file changed, 36 insertions(+), 26 deletions(-)
>>
>> diff --git a/convert.c b/convert.c
>> index 793c29ebfd..36401fe087 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 +621,38 @@ static struct cmd2process *start_multi_file_filter(struct hashmap *hashmap, cons
>>   done:
>>   	sigchain_pop(SIGPIPE);
>>   
>> -	if (err || errno == EPIPE) {
>> +	return err;
>> +}
>> +
>> +static struct cmd2process *start_multi_file_filter(struct hashmap *hashmap, const char *cmd)
>> +{
>> +	int err;
>> +	struct cmd2process *entry;
>> +	struct child_process *process;
>> +	const char *argv[] = { cmd, NULL };
>> +
>> +	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));
>> +
>> +	err = start_multi_file_filter_fn(entry);
>> +	if (err) {
>>   		error("initialization for external filter '%s' failed", cmd);
>>   		kill_multi_file_filter(hashmap, entry);
>>   		return NULL;
>> @@ -733,7 +743,7 @@ static int apply_multi_file_filter(const char *path, const char *src, size_t len
>>   done:
>>   	sigchain_pop(SIGPIPE);
>>   
>> -	if (err || errno == EPIPE) {
>> +	if (err) {
>>   		if (!strcmp(filter_status.buf, "error")) {
>>   			/* The filter signaled a problem with the file. */
>>   		} else if (!strcmp(filter_status.buf, "abort")) {