teach config --blob option to parse config from database

This can be used to read configuration values directly from git's
database. For example it is useful for reading to be checked out
.gitmodules files directly from the database.

Signed-off-by: Heiko Voigt <hvoigt@hvoigt.net>
Acked-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

diff --git a/Documentation/git-config.txt b/Documentation/git-config.txt
index 9ae2508f3fb79b9da5fb4481a4fe2120f4a082b1..f0e179e38d8ea50f113e39ab97c430a572335d4e 100644 (file)
--- a/Documentation/git-config.txt
+++ b/Documentation/git-config.txt
@@ -118,6 +118,13 @@ See also <<FILES>>.
 --file config-file::
        Use the given config file instead of the one specified by GIT_CONFIG.
 
 --file config-file::
        Use the given config file instead of the one specified by GIT_CONFIG.
 

+--blob blob::
+       Similar to '--file' but use the given blob instead of a file. E.g.
+       you can use 'master:.gitmodules' to read values from the file
+       '.gitmodules' in the master branch. See "SPECIFYING REVISIONS"
+       section in linkgit:gitrevisions[7] for a more complete list of
+       ways to spell blob names.
+

 --remove-section::
        Remove the given section from the configuration file.
 
 --remove-section::
        Remove the given section from the configuration file.
 

diff --git a/builtin/config.c b/builtin/config.c
index 33c9bf9d84f514330f12de5cbd9dfb610a1b16de..8d01b7ab461b6db3a2e28499f9846739a133ed3b 100644 (file)
--- a/builtin/config.c
+++ b/builtin/config.c
@@ -21,6 +21,7 @@ static char term = '\n';
 
 static int use_global_config, use_system_config, use_local_config;
 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;
 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_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),
        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,
        }
 
        git_config_with_options(collect_config, &values,

-                               given_config_file, respect_includes);
+                               given_config_file, given_config_blob,
+                               respect_includes);

 
        ret = !values.nr;
 
 
        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,
        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);
 
        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,
        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"))
 
        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;
 }
 
                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;
 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);
 
                             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);
        }
                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,
                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'",
                                            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");
                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"),
                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;
        }
        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);
                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) {
                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_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, "^$", 0);
        }
        else if (actions == ACTION_REPLACE_ALL) {
                check_argc(argc, 2, 2);
                value = normalize_value(argv[0], argv[1]);
                return git_config_set_multivar_in_file(given_config_file,
                                                       argv[0], value, "^$", 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,
                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) {
                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,
                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) {
                                                      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_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]);
                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;
        }
        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);
                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 94ca1acf704bd2dfdc561b6b2d3d64740b975f61..be48c4bd217b22493f512c99e3c1b2ae65c5cb92 100644 (file)
--- a/cache.h
+++ b/cache.h
@@ -1142,11 +1142,15 @@ extern int update_server_info(int);
 typedef int (*config_fn_t)(const char *, const char *, void *);
 extern int git_default_config(const char *, const char *, void *);
 extern int git_config_from_file(config_fn_t fn, const char *, void *);
 typedef int (*config_fn_t)(const char *, const char *, void *);
 extern int git_default_config(const char *, const char *, void *);
 extern int git_config_from_file(config_fn_t fn, const char *, void *);

+extern int git_config_from_buf(config_fn_t fn, const char *name,
+                              const char *buf, size_t len, void *data);

 extern void git_config_push_parameter(const char *text);
 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 *,
 extern void git_config_push_parameter(const char *text);
 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 *);
 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 fc2796771b689e85daf0a400488eeae3f7a48cd9..10a015be4a7f5f10ac32f4a9aab0fba86b70fe0f 100644 (file)
--- a/config.c
+++ b/config.c
@@ -14,6 +14,11 @@ struct config_source {
        struct config_source *prev;
        union {
                FILE *file;
        struct config_source *prev;
        union {
                FILE *file;

+               struct config_buf {
+                       const char *buf;
+                       size_t len;
+                       size_t pos;
+               } buf;

        } u;
        const char *name;
        int linenr;
        } u;
        const char *name;
        int linenr;


@@ -45,6 +50,28 @@ static long config_file_ftell(struct config_source *conf)
        return ftell(conf->u.file);
 }
 
        return ftell(conf->u.file);
 }
 

+
+static int config_buf_fgetc(struct config_source *conf)
+{
+       if (conf->u.buf.pos < conf->u.buf.len)
+               return conf->u.buf.buf[conf->u.buf.pos++];
+
+       return EOF;
+}
+
+static int config_buf_ungetc(int c, struct config_source *conf)
+{
+       if (conf->u.buf.pos > 0)
+               return conf->u.buf.buf[--conf->u.buf.pos];
+
+       return EOF;
+}
+
+static long config_buf_ftell(struct config_source *conf)
+{
+       return conf->u.buf.pos;
+}
+

 #define MAX_INCLUDE_DEPTH 10
 static const char include_depth_advice[] =
 "exceeded maximum include depth (%d) while including\n"
 #define MAX_INCLUDE_DEPTH 10
 static const char include_depth_advice[] =
 "exceeded maximum include depth (%d) while including\n"


@@ -961,6 +988,57 @@ int git_config_from_file(config_fn_t fn, const char *filename, void *data)
        return ret;
 }
 
        return ret;
 }
 

+int git_config_from_buf(config_fn_t fn, const char *name, const char *buf,
+                       size_t len, void *data)
+{
+       struct config_source top;
+
+       top.u.buf.buf = buf;
+       top.u.buf.len = len;
+       top.u.buf.pos = 0;
+       top.name = name;
+       top.fgetc = config_buf_fgetc;
+       top.ungetc = config_buf_ungetc;
+       top.ftell = config_buf_ftell;
+
+       return do_config_from(&top, fn, data);
+}
+
+static int git_config_from_blob_sha1(config_fn_t fn,
+                                    const char *name,
+                                    const unsigned char *sha1,
+                                    void *data)
+{
+       enum object_type type;
+       char *buf;
+       unsigned long size;
+       int ret;
+
+       buf = read_sha1_file(sha1, &type, &size);
+       if (!buf)
+               return error("unable to load config blob object '%s'", name);
+       if (type != OBJ_BLOB) {
+               free(buf);
+               return error("reference '%s' does not point to a blob", name);
+       }
+
+       ret = git_config_from_buf(fn, name, buf, size, data);
+       free(buf);
+
+       return ret;
+}
+
+static int git_config_from_blob_ref(config_fn_t fn,
+                                   const char *name,
+                                   void *data)
+{
+       unsigned char sha1[20];
+
+       if (get_sha1(name, sha1) < 0)
+               return error("unable to resolve config blob '%s'", name);
+       return git_config_from_blob_sha1(fn, name, sha1, data);
+}
+

 const char *git_etc_gitconfig(void)
 {
        static const char *system_wide;
 const char *git_etc_gitconfig(void)
 {
        static const char *system_wide;


@@ -1026,7 +1104,9 @@ int git_config_early(config_fn_t fn, void *data, const char *repo_config)
 }
 
 int git_config_with_options(config_fn_t fn, void *data,
 }
 
 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;
 {
        char *repo_config = NULL;
        int ret;


@@ -1045,6 +1125,8 @@ int git_config_with_options(config_fn_t fn, void *data,
         */
        if (filename)
                return git_config_from_file(fn, filename, data);
         */
        if (filename)
                return git_config_from_file(fn, filename, data);

+       else if (blob_ref)
+               return git_config_from_blob_ref(fn, blob_ref, data);

 
        repo_config = git_pathdup("config");
        ret = git_config_early(fn, data, repo_config);
 
        repo_config = git_pathdup("config");
        ret = git_config_early(fn, data, repo_config);


@@ -1055,7 +1137,7 @@ int git_config_with_options(config_fn_t fn, void *data,
 
 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);

 }
 
 /*
 }
 
 /*

diff --git a/t/t1307-config-blob.sh b/t/t1307-config-blob.sh
new file mode 100755 (executable)
index 0000000..fdc257e
--- /dev/null
+++ b/t/t1307-config-blob.sh
@@ -0,0 +1,70 @@
+#!/bin/sh
+
+test_description='support for reading config from a blob'
+. ./test-lib.sh
+
+test_expect_success 'create config blob' '
+       cat >config <<-\EOF &&
+       [some]
+               value = 1
+       EOF
+       git add config &&
+       git commit -m foo
+'
+
+test_expect_success 'list config blob contents' '
+       echo some.value=1 >expect &&
+       git config --blob=HEAD:config --list >actual &&
+       test_cmp expect actual
+'
+
+test_expect_success 'fetch value from blob' '
+       echo true >expect &&
+       git config --blob=HEAD:config --bool some.value >actual &&
+       test_cmp expect actual
+'
+
+test_expect_success 'reading non-existing value from blob is an error' '
+       test_must_fail git config --blob=HEAD:config non.existing
+'
+
+test_expect_success 'reading from blob and file is an error' '
+       test_must_fail git config --blob=HEAD:config --system --list
+'
+
+test_expect_success 'reading from missing ref is an error' '
+       test_must_fail git config --blob=HEAD:doesnotexist --list
+'
+
+test_expect_success 'reading from non-blob is an error' '
+       test_must_fail git config --blob=HEAD --list
+'
+
+test_expect_success 'setting a value in a blob is an error' '
+       test_must_fail git config --blob=HEAD:config some.value foo
+'
+
+test_expect_success 'deleting a value in a blob is an error' '
+       test_must_fail git config --blob=HEAD:config --unset some.value
+'
+
+test_expect_success 'editing a blob is an error' '
+       test_must_fail git config --blob=HEAD:config --edit
+'
+
+test_expect_success 'parse errors in blobs are properly attributed' '
+       cat >config <<-\EOF &&
+       [some]
+               value = "
+       EOF
+       git add config &&
+       git commit -m broken &&
+
+       test_must_fail git config --blob=HEAD:config some.value 2>err &&
+
+       # just grep for our token as the exact error message is likely to
+       # change or be internationalized
+       grep "HEAD:config" err
+'
+
+test_done