Currently `git_config()` uses a callback mechanism and file rereads for
config values. Due to this approach, it is not uncommon for the config
files to be parsed several times during the run of a git program, with
different callbacks picking out different variables useful to themselves.
Add a `config_set`, that can be used to construct an in-memory cache for
config-like files that the caller specifies (i.e., files like `.gitmodules`,
`~/.gitconfig` etc.). Add two external functions `git_configset_get_value`
and `git_configset_get_value_multi` for querying from the config sets.
`git_configset_get_value` follows `last one wins` semantic (i.e. if there
are multiple matches for the queried key in the files of the configset the
value returned will be the last entry in `value_list`).
`git_configset_get_value_multi` returns a list of values sorted in order of
increasing priority (i.e. last match will be at the end of the list). Add
type specific query functions like `git_configset_get_bool` and similar.
Add a default `config_set`, `the_config_set` to cache all key-value pairs
read from usual config files (repo specific .git/config, user wide
~/.gitconfig, XDG config and the global /etc/gitconfig). `the_config_set`
is populated using `git_config()`.
Add two external functions `git_config_get_value` and
`git_config_get_value_multi` for querying in a non-callback manner from
`the_config_set`. Also, add type specific query functions that are
implemented as a thin wrapper around the `config_set` API.
Signed-off-by: Tanay Abhra <tanayabh@xxxxxxxxx>
---
Documentation/technical/api-config.txt | 134 +++++++++++++++
Makefile | 1 +
cache.h | 34 ++++
config-hash.c | 295 +++++++++++++++++++++++++++++++++
config.c | 3 +
5 files changed, 467 insertions(+)
create mode 100644 config-hash.c
diff --git a/Documentation/technical/api-config.txt b/Documentation/technical/api-config.txt
index 230b3a0..65a6717 100644
--- a/Documentation/technical/api-config.txt
+++ b/Documentation/technical/api-config.txt
@@ -77,6 +77,81 @@ To read a specific file in git-config format, use
`git_config_from_file`. This takes the same callback and data parameters
as `git_config`.
+Querying For Specific Variables
+-------------------------------
+
+For programs wanting to query for specific variables in a non-callback
+manner, the config API provides two functions `git_config_get_value`
+and `git_config_get_value_multi`. They both read values from an internal
+cache generated previously from reading the config files.
+
+`int git_config_get_value(const char *key, const char **value)`::
+
+ Finds the highest-priority value for the configuration variable `key`,
+ stores the pointer to it in `value` and returns 0. When the
+ configuration variable `key` is not found, returns 1 without touching
+ `value`. The caller should not free or modify `value`, as it is owned
+ by the cache.
+
+`const struct string_list *git_config_get_value_multi(const char *key)`::
+
+ Finds and returns the value list, sorted in order of increasing priority
+ for the configuration variable `key`. When the configuration variable
+ `key` is not found, returns NULL. The caller should not free or modify
+ the returned pointer, as it is owned by the cache.
+
+`void git_config_clear(void)`::
+
+ Resets and invalidates the config cache.
+
+The config API also provides type specific API functions which do conversion
+as well as retrieval for the queried variable, including:
+
+`int git_config_get_int(const char *key, int *dest)`::
+
+ Finds and parses the value to an integer for the configuration variable
+ `key`. Dies on error; otherwise, stores the value of the parsed integer in
+ `dest` and returns 0. When the configuration variable `key` is not found,
+ returns 1 without touching `dest`.
+
+`int git_config_get_ulong(const char *key, unsigned long *dest)`::
+
+ Similar to `git_config_get_int` but for unsigned longs.
+
+`int git_config_get_bool(const char *key, int *dest)`::
+
+ Finds and parses the value into a boolean value, for the configuration
+ variable `key`respecting keywords like "true" and "false". Integer
+ values are converted into true/false values (when they are non-zero or
+ zero, respectively). Other values cause a die(). If parsing is successful,
+ stores the value of the parsed result in `dest` and returns 0. When the
+ configuration variable `key` is not found, returns 1 without touching
+ `dest`.
+
+`int git_config_get_bool_or_int(const char *key, int *is_bool, int *dest)`::
+
+ Similar to `git_config_get_bool`, except that integers are copied as-is,
+ and `is_bool` flag is unset.
+
+`int git_config_get_maybe_bool(const char *key, int *dest)`::
+
+ Similar to `git_config_get_bool`, except that it returns -1 on error
+ rather than dying.
+
+`int git_config_get_string(const char *key, const char **dest)`::
+
+ Allocates and copies the retrieved string into the `dest` parameter for
+ the configuration variable `key`; if NULL string is given, prints an
+ error message and returns -1. When the configuration variable `key` is
+ not found, returns 1 without touching `dest`.
+
+`int git_config_get_pathname(const char *key, const char **dest)`::
+
+ Similar to `git_config_get_string`, but expands `~` or `~user` into
+ the user's home directory when found at the beginning of the path.
+
+See test-config.c for usage examples.
+
Value Parsing Helpers
---------------------
@@ -134,6 +209,65 @@ int read_file_with_include(const char *file, config_fn_t fn, void *data)
`git_config` respects includes automatically. The lower-level
`git_config_from_file` does not.
+Custom Configsets
+-----------------
+
+A `config_set` can be used to construct an in-memory cache for
+config-like files that the caller specifies (i.e., files like `.gitmodules`,
+`~/.gitconfig` etc.). For example,
+
+---------------------------------------
+struct config_set gm_config;
+git_configset_init(&gm_config);
+int b;
+/* we add config files to the config_set */
+git_configset_add_file(&gm_config, ".gitmodules");
+git_configset_add_file(&gm_config, ".gitmodules_alt");
+
+if (!git_configset_get_bool(gm_config, "submodule.frotz.ignore", &b)) {
+ /* hack hack hack */
+}
+
+/* when we are done with the configset */
+git_configset_clear(&gm_config);
+----------------------------------------
+
+Configset API provides functions for the above mentioned work flow, including:
+
+`void git_configset_init(struct config_set *cs)`::
+
+ Initializes the config_set `cs`.
+
+`int git_configset_add_file(struct config_set *cs, const char *filename)`::
+
+ Parses the file and adds the variable-value pairs to the `config_set`,
+ dies if there is an error in parsing the file.
+
+`int git_configset_get_value(struct config_set *cs, const char *key, const char **value)`::
+
+ Finds the highest-priority value for the configuration variable `key`
+ and config set `cs`, stores the pointer to it in `value` and returns 0.
+ When the configuration variable `key` is not found, returns 1 without
+ touching `value`. The caller should not free or modify `value`, as it
+ is owned by the cache.
+
+`const struct string_list *git_configset_get_value_multi(struct config_set *cs, const char *key)`::
+
+ Finds and returns the value list, sorted in order of increasing priority
+ for the configuration variable `key` and config set `cs`. When the
+ configuration variable `key` is not found, returns NULL. The caller
+ should not free or modify the returned pointer, as it is owned by the cache.
+
+`void git_configset_clear(struct config_set *cs)`::
+
+ Clears `config_set` structure, removes all saved variable-value pairs.
+
+In addition to above functions, the `config_set` API provides type specific
+functions in the vein of `git_config_get_int` and family but with an extra
+parameter, pointer to struct `config_set`.
+They all behave similarly to the `git_config_get*()` family described in
+"Querying For Specific Variables" above.
+
Writing Config Files
--------------------
diff --git a/Makefile b/Makefile
index 07ea105..d503f78 100644
--- a/Makefile
+++ b/Makefile
@@ -777,6 +777,7 @@ LIB_OBJS += commit.o
LIB_OBJS += compat/obstack.o
LIB_OBJS += compat/terminal.o
LIB_OBJS += config.o
+LIB_OBJS += config-hash.o
LIB_OBJS += connect.o
LIB_OBJS += connected.o
LIB_OBJS += convert.o
diff --git a/cache.h b/cache.h
index df65231..35bd71e 100644
--- a/cache.h
+++ b/cache.h
@@ -1325,6 +1325,40 @@ extern int parse_config_key(const char *var,
const char **subsection, int *subsection_len,
const char **key);
+/* config-hash.c */
+
+struct config_set {
+ struct hashmap config_hash;
+ int hash_initialized;
+};
+
+extern void git_configset_init(struct config_set *cs);
+extern int git_configset_add_file(struct config_set *cs, const char *filename);
+extern int git_configset_get_value(struct config_set *cs, const char *key, const char **value);
+extern const struct string_list *git_configset_get_value_multi(struct config_set *cs, const char *key);
+extern void git_configset_clear(struct config_set *cs);
+extern void git_configset_iter(struct config_set *cs, config_fn_t fn, void *data);
+extern int git_configset_get_string(struct config_set *cs, const char *key, const char **dest);
+extern int git_configset_get_int(struct config_set *cs, const char *key, int *dest);
+extern int git_configset_get_ulong(struct config_set *cs, const char *key, unsigned long *dest);
+extern int git_configset_get_bool(struct config_set *cs, const char *key, int *dest);
+extern int git_configset_get_bool_or_int(struct config_set *cs, const char *key, int *is_bool, int *dest);
+extern int git_configset_get_maybe_bool(struct config_set *cs, const char *key, int *dest);
+extern int git_configset_get_pathname(struct config_set *cs, const char *key, const char **dest);
+
+extern int git_config_get_value(const char *key, const char **value);
+extern const struct string_list *git_config_get_value_multi(const char *key);
+extern void git_config_clear(void);
+extern void git_config_iter(config_fn_t fn, void *data);
+extern int git_config_get_string(const char *key, const char **dest);
+extern int git_config_get_int(const char *key, int *dest);
+extern int git_config_get_ulong(const char *key, unsigned long *dest);
+extern int git_config_get_bool(const char *key, int *dest);
+extern int git_config_get_bool_or_int(const char *key, int *is_bool, int *dest);
+extern int git_config_get_maybe_bool(const char *key, int *dest);
+extern int git_config_get_pathname(const char *key, const char **dest);
+
+
extern int committer_ident_sufficiently_given(void);
extern int author_ident_sufficiently_given(void);
diff --git a/config-hash.c b/config-hash.c
new file mode 100644
index 0000000..7cf6a96
--- /dev/null
+++ b/config-hash.c
@@ -0,0 +1,295 @@
+#include "cache.h"
+#include "hashmap.h"
+#include "string-list.h"
+
+
+/*
+ * Default config_set that contains key-value pairs from the usual set of config
+ * config files (i.e repo specific .git/config, user wide ~/.gitconfig, XDG
+ * config file and the global /etc/gitconfig)
+ */
+static struct config_set the_config_set;
+
+struct config_hash_entry {
+ struct hashmap_entry ent;
+ char *key;
+ struct string_list value_list;
+};
+
+static int config_hash_add_value(const char *, const char *, struct hashmap *);
+
+static int config_hash_entry_cmp(const struct config_hash_entry *e1,
+ const struct config_hash_entry *e2, const void *unused)
+{
+ return strcmp(e1->key, e2->key);
+}
+
+static void configset_init(struct config_set *cs)
+{
+ if (!cs->hash_initialized) {
+ hashmap_init(&cs->config_hash, (hashmap_cmp_fn)config_hash_entry_cmp, 0);
+ cs->hash_initialized = 1;
+ }
+}
+
+static int config_hash_callback(const char *key, const char *value, void *cb)
+{
+ struct config_set *cs = cb;
+ config_hash_add_value(key, value, &cs->config_hash);
+ return 0;
+}
+
+int git_configset_add_file(struct config_set *cs, const char *filename)
+{
+ int ret = 0;
+ configset_init(cs);
+ ret = git_config_from_file(config_hash_callback, filename, cs);
+ if (!ret)
+ return 0;
+ else {
+ hashmap_free(&cs->config_hash, 1);
+ cs->hash_initialized = 0;
+ return -1;
+ }
+}
+
+static struct config_hash_entry *config_hash_find_entry(const char *key,
+ struct hashmap *config_hash)
+{
+ struct config_hash_entry k;
+ struct config_hash_entry *found_entry;
+ char *normalized_key;
+ int ret;
+ /*
+ * `key` may come from the user, so normalize it before using it
+ * for querying entries from the hashmap.
+ */
+ ret = git_config_parse_key(key, &normalized_key, NULL);
+
+ if (ret)
+ return NULL;
+
+ hashmap_entry_init(&k, strhash(normalized_key));
+ k.key = normalized_key;
+ found_entry = hashmap_get(config_hash, &k, NULL);
+ free(normalized_key);
+ return found_entry;
+}
+
+static struct string_list *configset_get_list(const char *key, struct config_set *cs)
+{
+ struct config_hash_entry *e = config_hash_find_entry(key, &cs->config_hash);
+ return e ? &e->value_list : NULL;
+}
+
+static int config_hash_add_value(const char *key, const char *value, struct hashmap *config_hash)
+{
+ struct config_hash_entry *e;
+ e = config_hash_find_entry(key, config_hash);
+ /*
+ * Since the keys are being fed by git_config*() callback mechanism, they
+ * are already normalized. So simply add them without any further munging.
+ */
+ if (!e) {
+ e = xmalloc(sizeof(*e));
+ hashmap_entry_init(e, strhash(key));
+ e->key = xstrdup(key);
+ memset(&e->value_list, 0, sizeof(e->value_list));
+ e->value_list.strdup_strings = 1;
+ hashmap_add(config_hash, e);
+ }
+ string_list_append_nodup(&e->value_list, value ? xstrdup(value) : NULL);
+
+ return 0;
+}
+
+void git_configset_init(struct config_set *cs)
+{
+ cs->hash_initialized = 0;
+}
+
+int git_configset_get_value(struct config_set *cs, const char *key, const char **value)
+{
+ struct string_list *values = NULL;
+ /*
+ * Follows "last one wins" semantic, i.e., if there are multiple matches for the
+ * queried key in the files of the configset, the value returned will be the last
+ * value in the value list for that key.
+ */
+ values = configset_get_list(key, cs);
+
+ if (!values)
+ return 1;
+ assert(values->nr > 0);
+ *value = values->items[values->nr - 1].string;
+ return 0;
+}
+
+const struct string_list *git_configset_get_value_multi(struct config_set *cs, const char *key)
+{
+ return configset_get_list(key, cs);
+}
+
+void git_configset_clear(struct config_set *cs)
+{
+ struct config_hash_entry *entry;
+ struct hashmap_iter iter;
+ if (!cs->hash_initialized)
+ return;
+
+ hashmap_iter_init(&cs->config_hash, &iter);
+ while ((entry = hashmap_iter_next(&iter))) {
+ free(entry->key);
+ string_list_clear(&entry->value_list, 0);
+ }
+ hashmap_free(&cs->config_hash, 1);
+}
+
+int git_configset_get_string(struct config_set *cs, const char *key, const char **dest)
+{
+ const char *value;
+ if (!git_configset_get_value(cs, key, &value))
+ return git_config_string(dest, key, value);
+ else
+ return 1;
+}
+
+int git_configset_get_int(struct config_set *cs, const char *key, int *dest)
+{
+ const char *value;
+ if (!git_configset_get_value(cs, key, &value)) {
+ *dest = git_config_int(key, value);
+ return 0;
+ } else
+ return 1;
+}
+
+int git_configset_get_ulong(struct config_set *cs, const char *key, unsigned long *dest)
+{
+ const char *value;
+ if (!git_configset_get_value(cs, key, &value)) {
+ *dest = git_config_ulong(key, value);
+ return 0;
+ } else
+ return 1;
+}
+
+int git_configset_get_bool(struct config_set *cs, const char *key, int *dest)
+{
+ const char *value;
+ if (!git_configset_get_value(cs, key, &value)) {
+ *dest = git_config_bool(key, value);
+ return 0;
+ } else
+ return 1;
+}
+
+int git_configset_get_bool_or_int(struct config_set *cs, const char *key,
+ int *is_bool, int *dest)
+{
+ const char *value;
+ if (!git_configset_get_value(cs, key, &value)) {
+ *dest = git_config_bool_or_int(key, value, is_bool);
+ return 0;
+ } else
+ return 1;
+}
+
+int git_configset_get_maybe_bool(struct config_set *cs, const char *key, int *dest)
+{
+ const char *value;
+ if (!git_configset_get_value(cs, key, &value)) {
+ *dest = git_config_maybe_bool(key, value);
+ if (*dest == -1)
+ return -1;
+ return 0;
+ } else
+ return 1;
+}
+
+int git_configset_get_pathname(struct config_set *cs, const char *key, const char **dest)
+{
+ const char *value;
+ if (!git_configset_get_value(cs, key, &value))
+ return git_config_pathname(dest, key, value);
+ else
+ return 1;
+}
+
+static int git_config_check_init(void)
+{
+ int ret = 0;
+ if (the_config_set.hash_initialized)
+ return 0;
+ configset_init(&the_config_set);
+ ret = git_config(config_hash_callback, &the_config_set);
+ if (ret >= 0)
+ return 0;
+ else {
+ hashmap_free(&the_config_set.config_hash, 1);
+ the_config_set.hash_initialized = 0;
+ return -1;
+ }
+}
+
+int git_config_get_value(const char *key, const char **value)
+{
+ git_config_check_init();
+ return git_configset_get_value(&the_config_set, key, value);
+}
+
+const struct string_list *git_config_get_value_multi(const char *key)
+{
+ git_config_check_init();
+ return git_configset_get_value_multi(&the_config_set, key);
+}
+
+void git_config_clear(void)
+{
+ if (!the_config_set.hash_initialized)
+ return;
+ git_configset_clear(&the_config_set);
+ the_config_set.hash_initialized = 0;
+}
+
+int git_config_get_string(const char *key, const char **dest)
+{
+ git_config_check_init();
+ return git_configset_get_string(&the_config_set, key, dest);
+}
+
+int git_config_get_int(const char *key, int *dest)
+{
+ git_config_check_init();
+ return git_configset_get_int(&the_config_set, key, dest);
+}
+
+int git_config_get_ulong(const char *key, unsigned long *dest)
+{
+ git_config_check_init();
+ return git_configset_get_ulong(&the_config_set, key, dest);
+}
+
+int git_config_get_bool(const char *key, int *dest)
+{
+ git_config_check_init();
+ return git_configset_get_bool(&the_config_set, key, dest);
+}
+
+int git_config_get_bool_or_int(const char *key, int *is_bool, int *dest)
+{
+ git_config_check_init();
+ return git_configset_get_bool_or_int(&the_config_set, key, is_bool, dest);
+}
+
+int git_config_get_maybe_bool(const char *key, int *dest)
+{
+ git_config_check_init();
+ return git_configset_get_maybe_bool(&the_config_set, key, dest);
+}
+
+int git_config_get_pathname(const char *key, const char **dest)
+{
+ git_config_check_init();
+ return git_configset_get_pathname(&the_config_set, key, dest);
+}
diff --git a/config.c b/config.c
index a1aef1c..6cffec7 100644
--- a/config.c
+++ b/config.c
@@ -1708,6 +1708,9 @@ int git_config_set_multivar_in_file(const char *config_filename,
lock = NULL;
ret = 0;
+ /* Invalidate the config cache */
+ git_config_clear();
+
out_free:
if (lock)
rollback_lock_file(lock);
--
1.9.0.GIT
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