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Re: [PATCH v2 4/4] teach config parsing to read from strbuf

From
Jeff King <peff@peff.net>
Date
Mar 14, 2013, 07:10 UTC
Message-ID
<20130314071046.GB6103@sigill.intra.peff.net>
In-Reply-To
<20130314063933.GB4062@sandbox-ub.fritz.box>
On Thu, Mar 14, 2013 at 07:39:33AM +0100, Heiko Voigt wrote:
Show 7 quoted lines
> > I am on the fence. I do not want to create more work for you, but I do
> > think it may come in handy, if only for doing submodule things from
> > shell. And it is hopefully not a very large patch. I'd say try it, and
> > if starts looking like it will be very ugly, the right thing may be to
> > leave it until somebody really wants it.
> 
> Thats what I will do: Try it and see where I get.

I looked into this a little. The first sticking point is that git_config_with_options needs to support the alternate source. Here's a sketch of what I think the solution should look like, on top of your patches.

diff --git a/builtin/config.c b/builtin/config.c
index 33c9bf9..8d01b7a 100644
--- a/builtin/config.c
+++ b/builtin/config.c
@@ -21,6 +21,7 @@ static const char *given_config_file;
 
 static int use_global_config, use_system_config, use_local_config;
 static const char *given_config_file;
+static const char *given_config_blob;
 static int actions, types;
 static const char *get_color_slot, *get_colorbool_slot;
 static int end_null;
@@ -53,6 +54,7 @@ static struct option builtin_config_options[] = {
 	OPT_BOOLEAN(0, "system", &use_system_config, N_("use system config file")),
 	OPT_BOOLEAN(0, "local", &use_local_config, N_("use repository config file")),
 	OPT_STRING('f', "file", &given_config_file, N_("file"), N_("use given config file")),
+	OPT_STRING(0, "blob", &given_config_blob, N_("blob-id"), N_("read config from given blob object")),
 	OPT_GROUP(N_("Action")),
 	OPT_BIT(0, "get", &actions, N_("get value: name [value-regex]"), ACTION_GET),
 	OPT_BIT(0, "get-all", &actions, N_("get all values: key [value-regex]"), ACTION_GET_ALL),
@@ -218,7 +220,8 @@ static int get_value(const char *key_, const char *regex_)
 	}
 
 	git_config_with_options(collect_config, &values,
-				given_config_file, respect_includes);
+				given_config_file, given_config_blob,
+				respect_includes);
 
 	ret = !values.nr;
 
@@ -302,7 +305,8 @@ static void get_color(const char *def_color)
 	get_color_found = 0;
 	parsed_color[0] = '\0';
 	git_config_with_options(git_get_color_config, NULL,
-				given_config_file, respect_includes);
+				given_config_file, given_config_blob,
+				respect_includes);
 
 	if (!get_color_found && def_color)
 		color_parse(def_color, "command line", parsed_color);
@@ -330,7 +334,8 @@ static int get_colorbool(int print)
 	get_colorbool_found = -1;
 	get_diff_color_found = -1;
 	git_config_with_options(git_get_colorbool_config, NULL,
-				given_config_file, respect_includes);
+				given_config_file, given_config_blob,
+				respect_includes);
 
 	if (get_colorbool_found < 0) {
 		if (!strcmp(get_colorbool_slot, "color.diff"))
@@ -348,6 +353,12 @@ static int get_colorbool(int print)
 		return get_colorbool_found ? 0 : 1;
 }
 
+static void check_blob_write(void)
+{
+	if (given_config_blob)
+		die("writing config blobs is not supported");
+}
+
 int cmd_config(int argc, const char **argv, const char *prefix)
 {
 	int nongit = !startup_info->have_repository;
@@ -359,7 +370,8 @@ int cmd_config(int argc, const char **argv, const char *prefix)
 			     builtin_config_usage,
 			     PARSE_OPT_STOP_AT_NON_OPTION);
 
-	if (use_global_config + use_system_config + use_local_config + !!given_config_file > 1) {
+	if (use_global_config + use_system_config + use_local_config +
+	    !!given_config_file + !!given_config_blob > 1) {
 		error("only one config file at a time.");
 		usage_with_options(builtin_config_usage, builtin_config_options);
 	}
@@ -438,6 +450,7 @@ int cmd_config(int argc, const char **argv, const char *prefix)
 		check_argc(argc, 0, 0);
 		if (git_config_with_options(show_all_config, NULL,
 					    given_config_file,
+					    given_config_blob,
 					    respect_includes) < 0) {
 			if (given_config_file)
 				die_errno("unable to read config file '%s'",
@@ -450,6 +463,8 @@ int cmd_config(int argc, const char **argv, const char *prefix)
 		check_argc(argc, 0, 0);
 		if (!given_config_file && nongit)
 			die("not in a git directory");
+		if (given_config_blob)
+			die("editing blobs is not supported");
 		git_config(git_default_config, NULL);
 		launch_editor(given_config_file ?
 			      given_config_file : git_path("config"),
@@ -457,6 +472,7 @@ int cmd_config(int argc, const char **argv, const char *prefix)
 	}
 	else if (actions == ACTION_SET) {
 		int ret;
+		check_blob_write();
 		check_argc(argc, 2, 2);
 		value = normalize_value(argv[0], argv[1]);
 		ret = git_config_set_in_file(given_config_file, argv[0], value);
@@ -466,18 +482,21 @@ int cmd_config(int argc, const char **argv, const char *prefix)
 		return ret;
 	}
 	else if (actions == ACTION_SET_ALL) {
+		check_blob_write();
 		check_argc(argc, 2, 3);
 		value = normalize_value(argv[0], argv[1]);
 		return git_config_set_multivar_in_file(given_config_file,
 						       argv[0], value, argv[2], 0);
 	}
 	else if (actions == ACTION_ADD) {
+		check_blob_write();
 		check_argc(argc, 2, 2);
 		value = normalize_value(argv[0], argv[1]);
 		return git_config_set_multivar_in_file(given_config_file,
 						       argv[0], value, "^$", 0);
 	}
 	else if (actions == ACTION_REPLACE_ALL) {
+		check_blob_write();
 		check_argc(argc, 2, 3);
 		value = normalize_value(argv[0], argv[1]);
 		return git_config_set_multivar_in_file(given_config_file,
@@ -500,6 +519,7 @@ int cmd_config(int argc, const char **argv, const char *prefix)
 		return get_value(argv[0], argv[1]);
 	}
 	else if (actions == ACTION_UNSET) {
+		check_blob_write();
 		check_argc(argc, 1, 2);
 		if (argc == 2)
 			return git_config_set_multivar_in_file(given_config_file,
@@ -509,12 +529,14 @@ int cmd_config(int argc, const char **argv, const char *prefix)
 						      argv[0], NULL);
 	}
 	else if (actions == ACTION_UNSET_ALL) {
+		check_blob_write();
 		check_argc(argc, 1, 2);
 		return git_config_set_multivar_in_file(given_config_file,
 						       argv[0], NULL, argv[1], 1);
 	}
 	else if (actions == ACTION_RENAME_SECTION) {
 		int ret;
+		check_blob_write();
 		check_argc(argc, 2, 2);
 		ret = git_config_rename_section_in_file(given_config_file,
 							argv[0], argv[1]);
@@ -525,6 +547,7 @@ int cmd_config(int argc, const char **argv, const char *prefix)
 	}
 	else if (actions == ACTION_REMOVE_SECTION) {
 		int ret;
+		check_blob_write();
 		check_argc(argc, 1, 1);
 		ret = git_config_rename_section_in_file(given_config_file,
 							argv[0], NULL);
diff --git a/cache.h b/cache.h
index a2621fa..9db5f74 100644
--- a/cache.h
+++ b/cache.h
@@ -1134,7 +1134,9 @@ extern int git_config_with_options(config_fn_t fn, void *,
 extern int git_config_from_parameters(config_fn_t fn, void *data);
 extern int git_config(config_fn_t fn, void *);
 extern int git_config_with_options(config_fn_t fn, void *,
-				   const char *filename, int respect_includes);
+				   const char *filename,
+				   const char *blob_ref,
+				   int respect_includes);
 extern int git_config_early(config_fn_t fn, void *, const char *repo_config);
 extern int git_parse_ulong(const char *, unsigned long *);
 extern int git_config_int(const char *, const char *);
diff --git a/config.c b/config.c
index b8c8640..35aa8e2 100644
--- a/config.c
+++ b/config.c
@@ -1073,8 +1073,34 @@ int git_config_with_options(config_fn_t fn, void *data,
 	return ret == 0 ? found : ret;
 }
 
+static int read_blob_reference(const char *ref,
+			       struct strbuf *sb)
+{
+	unsigned char sha1[20];
+	enum object_type type;
+	void *buf;
+	unsigned long size;
+
+	if (get_sha1(ref, sha1) < 0)
+		return error("unable to resolve config blob '%s'", ref);
+
+	buf = read_sha1_file(sha1, &type, &size);
+	if (!buf)
+		return error("unable to load config blob object '%s'", ref);
+	if (type != OBJ_BLOB) {
+		free(buf);
+		return error("reference '%s' does not point to a blob", ref);
+	}
+
+	/* read_sha1_file always NUL-terminates for us, so size+1 is OK */
+	strbuf_attach(sb, buf, size, size+1);
+	return 0;
+}
+
 int git_config_with_options(config_fn_t fn, void *data,
-			    const char *filename, int respect_includes)
+			    const char *filename,
+			    const char *blob_ref,
+			    int respect_includes)
 {
 	char *repo_config = NULL;
 	int ret;
@@ -1093,6 +1119,15 @@ int git_config_with_options(config_fn_t fn, void *data,
 	 */
 	if (filename)
 		return git_config_from_file(fn, filename, data);
+	else if (blob_ref) {
+		struct strbuf buf = STRBUF_INIT;
+		if (read_blob_reference(blob_ref, &buf) < 0)
+			return -1;
+
+		ret = git_config_from_strbuf(fn, blob_ref, &buf, data);
+		strbuf_release(&buf);
+		return ret;
+	}
 
 	repo_config = git_pathdup("config");
 	ret = git_config_early(fn, data, repo_config);
@@ -1103,7 +1138,7 @@ int git_config(config_fn_t fn, void *data)
 
 int git_config(config_fn_t fn, void *data)
 {
-	return git_config_with_options(fn, data, NULL, 1);
+	return git_config_with_options(fn, data, NULL, NULL, 1);
 }
 
 /*
Previous: Heiko VoigtNext: Jeff King
Message 22 of 24 in “allow more sources for config values”
  1. 0/4 allow more sources for config valuesHeiko Voigt, Mar 10, 2013
  2. 1/4 config: factor out config file stack managementHeiko Voigt, Mar 10, 2013
  3. Jeff KingMar 12, 2013
  4. Heiko VoigtMar 12, 2013
  5. Jeff KingMar 12, 2013
  6. Heiko VoigtMar 14, 2013
  7. 2/4 config: drop file pointer validity check in get_next_char()Heiko Voigt, Mar 10, 2013
  8. Jeff KingMar 12, 2013
  9. Heiko VoigtMar 12, 2013
  10. Heiko VoigtMar 12, 2013
  11. Jeff KingMar 12, 2013
  12. Jeff KingMar 12, 2013
  13. 3/4 config: make parsing stack struct independent from actual data sourceHeiko Voigt, Mar 10, 2013
  14. Jeff KingMar 12, 2013
  15. Heiko VoigtMar 12, 2013
  16. Jeff KingMar 12, 2013
  17. 4/4 teach config parsing to read from strbufHeiko Voigt, Mar 10, 2013
  18. Jeff KingMar 12, 2013
  19. Heiko VoigtMar 12, 2013
  20. Jeff KingMar 12, 2013
  21. Heiko VoigtMar 14, 2013
  22. Jeff KingMar 14, 2013
  23. Jeff KingMar 14, 2013
  24. Heiko VoigtMar 18, 2013

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