[PATCH v4 5/8] convert: Update generic functions to only use generic data structures

[Ben Peart <peartben@xxxxxxxxx>]

Update all functions that are going to be moved into a reusable module
so that they only work with the reusable data structures.  Move code
that is specific to the filter out into the filter specific functions.

Signed-off-by: Ben Peart <benpeart@xxxxxxxxxxxxx>
---
 convert.c | 46 ++++++++++++++++++++++++++++------------------
 1 file changed, 28 insertions(+), 18 deletions(-)

diff --git a/convert.c b/convert.c
index f569026511..747c0c363b 100644
--- a/convert.c
+++ b/convert.c
@@ -576,14 +576,15 @@ static void stop_multi_file_filter(struct child_process *process)
 	finish_command(process);
 }
 
-static int start_multi_file_filter_fn(struct cmd2process *entry)
+static int start_multi_file_filter_fn(struct subprocess_entry *subprocess)
 {
 	int err;
+	struct cmd2process *entry = (struct cmd2process *)subprocess;
 	struct string_list cap_list = STRING_LIST_INIT_NODUP;
 	char *cap_buf;
 	const char *cap_name;
-	struct child_process *process = &entry->subprocess.process;
-	const char *cmd = entry->subprocess.cmd;
+	struct child_process *process = &subprocess->process;
+	const char *cmd = subprocess->cmd;
 
 	sigchain_push(SIGPIPE, SIG_IGN);
 
@@ -638,17 +639,21 @@ static int start_multi_file_filter_fn(struct cmd2process *entry)
 	return err;
 }
 
-static struct cmd2process *start_multi_file_filter(const char *cmd)
+typedef int(*subprocess_start_fn)(struct subprocess_entry *entry);
+int start_multi_file_filter(struct subprocess_entry *entry, const char *cmd,
+	subprocess_start_fn startfn)
 {
 	int err;
-	struct cmd2process *entry;
 	struct child_process *process;
 	const char *argv[] = { cmd, NULL };
 
-	entry = xmalloc(sizeof(*entry));
-	entry->subprocess.cmd = cmd;
-	entry->supported_capabilities = 0;
-	process = &entry->subprocess.process;
+	if (!cmd_process_map_initialized) {
+		cmd_process_map_initialized = 1;
+		hashmap_init(&cmd_process_map, (hashmap_cmp_fn)cmd2process_cmp, 0);
+	}
+
+	entry->cmd = cmd;
+	process = &entry->process;
 
 	child_process_init(process);
 	process->argv = argv;
@@ -658,22 +663,23 @@ static struct cmd2process *start_multi_file_filter(const char *cmd)
 	process->clean_on_exit = 1;
 	process->clean_on_exit_handler = stop_multi_file_filter;
 
-	if (start_command(process)) {
+	err = start_command(process);
+	if (err) {
 		error("cannot fork to run external filter '%s'", cmd);
-		return NULL;
+		return err;
 	}
 
 	hashmap_entry_init(entry, strhash(cmd));
 
-	err = start_multi_file_filter_fn(entry);
+	err = startfn(entry);
 	if (err) {
 		error("initialization for external filter '%s' failed", cmd);
-		kill_multi_file_filter(&entry->subprocess);
-		return NULL;
+		kill_multi_file_filter(entry);
+		return err;
 	}
 
 	hashmap_add(&cmd_process_map, entry);
-	return entry;
+	return 0;
 }
 
 static int apply_multi_file_filter(const char *path, const char *src, size_t len,
@@ -692,9 +698,13 @@ static int apply_multi_file_filter(const char *path, const char *src, size_t len
 	fflush(NULL);
 
 	if (!entry) {
-		entry = start_multi_file_filter(cmd);
-		if (!entry)
+		entry = xmalloc(sizeof(*entry));
+		entry->supported_capabilities = 0;
+
+		if (start_multi_file_filter(&entry->subprocess, cmd, start_multi_file_filter_fn)) {
+			free(entry);
 			return 0;
+		}
 	}
 	process = &entry->subprocess.process;
 
@@ -767,7 +777,7 @@ static int apply_multi_file_filter(const char *path, const char *src, size_t len
 			 * Force shutdown and restart if another blob requires filtering.
 			 */
 			error("external filter '%s' failed", cmd);
-			kill_multi_file_filter(&entry->subprocess);
+			kill_multi_file_filter((struct subprocess_entry *)entry);
 		}
 	} else {
 		strbuf_swap(dst, &nbuf);
-- 
2.12.1.gvfs.1.18.ge47db72