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[PATCH 6/6] submodule: simplify memory handling in config parsing

From
Jeff King <peff@peff.net>
Date
Jan 14, 2013, 15:07 UTC
Message-ID
<20130114150741.GF16828@sigill.intra.peff.net>
In-Reply-To
<20130114145845.GA16497@sigill.intra.peff.net>

We keep a strbuf for the name of the submodule, even though we only ever add one buffer (which we know the length of) to it. Let's just use xmemdupz instead, which is slightly more efficient and makes it easier to follow what is going on.

Unfortunately, we still end up having to deal with some memory ownership issues in some code branches, as we have to allocate the string in order to do a string list lookup, and then only sometimes want to hand ownership of that string over to the string_list. Still, making that explicit in the code (as opposed to sometimes detaching the strbuf, and then always releasing it) makes it a little more obvious what is going on.

Signed-off-by: Jeff King <peff@peff.net>
---
I'm undecided on this one. I think the result is easier to follow, but
others might find the original easier. This would be a lot more
readable if the config parser gave us a broken-out representation with
real C strings. Then we could pass the subsection straight to the
string_list functions for lookup, and using the "dup" flag of string
list, avoid even having to deal with memory duplication at all.
 submodule.c | 30 ++++++++++++++----------------
 1 file changed, 14 insertions(+), 16 deletions(-)
diff --git a/submodule.c b/submodule.c
index 4361207..23a8490 100644
--- a/submodule.c
+++ b/submodule.c
@@ -127,7 +127,6 @@ int parse_submodule_config_option(const char *var, const char *value)
 int parse_submodule_config_option(const char *var, const char *value)
 {
 	struct string_list_item *config;
-	struct strbuf submodname = STRBUF_INIT;
 	const char *name, *key;
 	int namelen;
 
@@ -136,37 +135,36 @@ int parse_submodule_config_option(const char *var, const char *value)
 		return 0;
 
 	if (!strcmp(key, "path")) {
-		strbuf_add(&submodname, name, namelen);
 		config = unsorted_string_list_lookup(&config_name_for_path, value);
 		if (config)
 			free(config->util);
 		else
 			config = string_list_append(&config_name_for_path, xstrdup(value));
-		config->util = strbuf_detach(&submodname, NULL);
-		strbuf_release(&submodname);
+		config->util = xmemdupz(name, namelen);
 	} else if (!strcmp(key, "fetchrecursesubmodules")) {
-		strbuf_add(&submodname, name, namelen);
-		config = unsorted_string_list_lookup(&config_fetch_recurse_submodules_for_name, submodname.buf);
+		char *name_cstr = xmemdupz(name, namelen);
+		config = unsorted_string_list_lookup(&config_fetch_recurse_submodules_for_name, name_cstr);
 		if (!config)
-			config = string_list_append(&config_fetch_recurse_submodules_for_name,
-						    strbuf_detach(&submodname, NULL));
+			config = string_list_append(&config_fetch_recurse_submodules_for_name, name_cstr);
+		else
+			free(name_cstr);
 		config->util = (void *)(intptr_t)parse_fetch_recurse_submodules_arg(var, value);
-		strbuf_release(&submodname);
 	} else if (!strcmp(key, "ignore")) {
+		char *name_cstr;
+
 		if (strcmp(value, "untracked") && strcmp(value, "dirty") &&
 		    strcmp(value, "all") && strcmp(value, "none")) {
 			warning("Invalid parameter \"%s\" for config option \"submodule.%s.ignore\"", value, var);
 			return 0;
 		}
 
-		strbuf_add(&submodname, name, namelen);
-		config = unsorted_string_list_lookup(&config_ignore_for_name, submodname.buf);
-		if (config)
+		name_cstr = xmemdupz(name, namelen);
+		config = unsorted_string_list_lookup(&config_ignore_for_name, name_cstr);
+		if (config) {
 			free(config->util);
-		else
-			config = string_list_append(&config_ignore_for_name,
-						    strbuf_detach(&submodname, NULL));
-		strbuf_release(&submodname);
+			free(name_cstr);
+		} else
+			config = string_list_append(&config_ignore_for_name, name_cstr);
 		config->util = xstrdup(value);
 		return 0;
 	}
-- 
1.8.1.rc1.10.g7d71f7b
Previous: Jeff King
Message 31 of 31 in “archive-tar: fix sanity check in config parsing”
  1. archive-tar: fix sanity check in config parsingRené Scharfe, Jan 13, 2013
  2. Jeff KingJan 13, 2013
  3. Joachim SchmitzJan 14, 2013
  4. Jeff KingJan 14, 2013
  5. Jeff KingJan 14, 2013
  6. 1/6 config: add helper function for parsing key namesJeff King, Jan 14, 2013
  7. Junio C HamanoJan 14, 2013
  8. Jeff KingJan 15, 2013
  9. Junio C HamanoJan 15, 2013
  10. Junio C HamanoJan 18, 2013
  11. 0/8 config key-parsing cleanupsJeff King, Jan 23, 2013
  12. 1/8 config: add helper function for parsing key namesJeff King, Jan 23, 2013
  13. 2/8 archive-tar: use parse_config_key when parsing configJeff King, Jan 23, 2013
  14. 3/8 convert some config callbacks to parse_config_keyJeff King, Jan 23, 2013
  15. 4/8 userdiff: drop parse_driver functionJeff King, Jan 23, 2013
  16. 5/8 submodule: use parse_config_key when parsing configJeff King, Jan 23, 2013
  17. Jens LehmannJan 23, 2013
  18. 6/8 submodule: simplify memory handling in config parsingJeff King, Jan 23, 2013
  19. Jens LehmannJan 23, 2013
  20. 7/8 help: use parse_config_key for man configJeff King, Jan 23, 2013
  21. 8/8 reflog: use parse_config_key in config callbackJeff King, Jan 23, 2013
  22. Junio C HamanoJan 23, 2013
  23. Jonathan NiederJan 23, 2013
  24. 2/6 archive-tar: use match_config_key when parsing configJeff King, Jan 14, 2013
  25. 3/6 convert some config callbacks to match_config_keyJeff King, Jan 14, 2013
  26. Jonathan NiederJan 14, 2013
  27. Jeff KingJan 14, 2013
  28. Jeff KingJan 14, 2013
  29. 4/6 userdiff: drop parse_driver functionJeff King, Jan 14, 2013
  30. 5/6 submodule: use match_config_key when parsing configJeff King, Jan 14, 2013
  31. 6/6 submodule: simplify memory handling in config parsingJeff King, Jan 14, 2013

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