[PATCH v6 4/8] convert: Separate generic structures and variables from the filter specific ones

[Ben Peart]

To enable future reuse of the filter.<driver>.process infrastructure,
split the cmd2process structure into two separate parts.

subprocess_entry will now contain the generic data required to manage
the creation and tracking of the child process in a hashmap. Also move
all knowledge of the hashmap into the generic functions.

cmd2process is a filter protocol specific structure that is used to
track the negotiated capabilities of the filter.

Signed-off-by: Ben Peart <benpe...@microsoft.com>
---
 convert.c | 35 ++++++++++++++++++++---------------
 1 file changed, 20 insertions(+), 15 deletions(-)

diff --git a/convert.c b/convert.c
index 36401fe087..bfb19beed5 100644
--- a/convert.c
+++ b/convert.c
@@ -496,26 +496,31 @@ static int apply_single_file_filter(const char *path, 
const char *src, size_t le
 #define CAP_CLEAN    (1u<<0)
 #define CAP_SMUDGE   (1u<<1)
 
-struct cmd2process {
+struct subprocess_entry {
        struct hashmap_entry ent; /* must be the first member! */
-       unsigned int supported_capabilities;
        const char *cmd;
        struct child_process process;
 };
 
+struct cmd2process {
+       struct subprocess_entry subprocess; /* must be the first member! */
+       unsigned int supported_capabilities;
+};
+
 static int cmd_process_map_initialized;
 static struct hashmap cmd_process_map;
 
-static int cmd2process_cmp(const struct cmd2process *e1,
-                          const struct cmd2process *e2,
+static int cmd2process_cmp(const struct subprocess_entry *e1,
+                          const struct subprocess_entry *e2,
                           const void *unused)
 {
        return strcmp(e1->cmd, e2->cmd);
 }
 
-static struct cmd2process *find_multi_file_filter_entry(struct hashmap 
*hashmap, const char *cmd)
+static struct subprocess_entry *find_multi_file_filter_entry(struct hashmap 
*hashmap, const char *cmd)
 {
-       struct cmd2process key;
+       struct subprocess_entry key;
+
        hashmap_entry_init(&key, strhash(cmd));
        key.cmd = cmd;
        return hashmap_get(hashmap, &key, NULL);
@@ -541,7 +546,7 @@ static void read_multi_file_filter_status(int fd, struct 
strbuf *status)
        }
 }
 
-static void kill_multi_file_filter(struct hashmap *hashmap, struct cmd2process 
*entry)
+static void kill_multi_file_filter(struct hashmap *hashmap, struct 
subprocess_entry *entry)
 {
        if (!entry)
                return;
@@ -571,8 +576,8 @@ static int start_multi_file_filter_fn(struct cmd2process 
*entry)
        struct string_list cap_list = STRING_LIST_INIT_NODUP;
        char *cap_buf;
        const char *cap_name;
-       struct child_process *process = &entry->process;
-       const char *cmd = entry->cmd;
+       struct child_process *process = &entry->subprocess.process;
+       const char *cmd = entry->subprocess.cmd;
 
        sigchain_push(SIGPIPE, SIG_IGN);
 
@@ -632,9 +637,9 @@ static struct cmd2process *start_multi_file_filter(struct 
hashmap *hashmap, cons
        const char *argv[] = { cmd, NULL };
 
        entry = xmalloc(sizeof(*entry));
-       entry->cmd = cmd;
+       entry->subprocess.cmd = cmd;
        entry->supported_capabilities = 0;
-       process = &entry->process;
+       process = &entry->subprocess.process;
 
        child_process_init(process);
        process->argv = argv;
@@ -654,7 +659,7 @@ static struct cmd2process *start_multi_file_filter(struct 
hashmap *hashmap, cons
        err = start_multi_file_filter_fn(entry);
        if (err) {
                error("initialization for external filter '%s' failed", cmd);
-               kill_multi_file_filter(hashmap, entry);
+               kill_multi_file_filter(hashmap, &entry->subprocess);
                return NULL;
        }
 
@@ -678,7 +683,7 @@ static int apply_multi_file_filter(const char *path, const 
char *src, size_t len
                hashmap_init(&cmd_process_map, (hashmap_cmp_fn) 
cmd2process_cmp, 0);
                entry = NULL;
        } else {
-               entry = find_multi_file_filter_entry(&cmd_process_map, cmd);
+               entry = (struct cmd2process 
*)find_multi_file_filter_entry(&cmd_process_map, cmd);
        }
 
        fflush(NULL);
@@ -688,7 +693,7 @@ static int apply_multi_file_filter(const char *path, const 
char *src, size_t len
                if (!entry)
                        return 0;
        }
-       process = &entry->process;
+       process = &entry->subprocess.process;
 
        if (!(wanted_capability & entry->supported_capabilities))
                return 0;
@@ -759,7 +764,7 @@ 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(&cmd_process_map, entry);
+                       kill_multi_file_filter(&cmd_process_map, 
&entry->subprocess);
                }
        } else {
                strbuf_swap(dst, &nbuf);
-- 
2.12.0.windows.1.33.g243d9b384c