[PATCH v6 5/8] convert: Update generic functions to only use generic data structures

[Ben Peart]

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 <benpe...@microsoft.com>
---
 convert.c | 41 +++++++++++++++++++++++------------------
 1 file changed, 23 insertions(+), 18 deletions(-)

diff --git a/convert.c b/convert.c
index bfb19beed5..d15b10a3c5 100644
--- a/convert.c
+++ b/convert.c
@@ -556,7 +556,6 @@ static void kill_multi_file_filter(struct hashmap *hashmap, 
struct subprocess_en
        finish_command(&entry->process);
 
        hashmap_remove(hashmap, entry, NULL);
-       free(entry);
 }
 
 static void stop_multi_file_filter(struct child_process *process)
@@ -570,14 +569,15 @@ 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);
 
@@ -629,17 +629,16 @@ static int start_multi_file_filter_fn(struct cmd2process 
*entry)
        return err;
 }
 
-static struct cmd2process *start_multi_file_filter(struct hashmap *hashmap, 
const char *cmd)
+typedef int(*subprocess_start_fn)(struct subprocess_entry *entry);
+int start_multi_file_filter(struct hashmap *hashmap, 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;
+       entry->cmd = cmd;
+       process = &entry->process;
 
        child_process_init(process);
        process->argv = argv;
@@ -649,22 +648,23 @@ static struct cmd2process *start_multi_file_filter(struct 
hashmap *hashmap, cons
        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(hashmap, &entry->subprocess);
-               return NULL;
+               kill_multi_file_filter(hashmap, entry);
+               return err;
        }
 
        hashmap_add(hashmap, entry);
-       return entry;
+       return 0;
 }
 
 static int apply_multi_file_filter(const char *path, const char *src, size_t 
len,
@@ -689,9 +689,13 @@ 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_process_map, cmd);
-               if (!entry)
+               entry = xmalloc(sizeof(*entry));
+               entry->supported_capabilities = 0;
+
+               if (start_multi_file_filter(&cmd_process_map, 
&entry->subprocess, cmd, start_multi_file_filter_fn)) {
+                       free(entry);
                        return 0;
+               }
        }
        process = &entry->subprocess.process;
 
@@ -765,6 +769,7 @@ static int apply_multi_file_filter(const char *path, const 
char *src, size_t len
                         */
                        error("external filter '%s' failed", cmd);
                        kill_multi_file_filter(&cmd_process_map, 
&entry->subprocess);
+                       free(entry);
                }
        } else {
                strbuf_swap(dst, &nbuf);
-- 
2.12.0.windows.1.33.g243d9b384c