Of all the functions in `git_config*()` family, `git_config()` has the
most invocations in the whole code base. Each `git_config()` invocation
causes config file rereads which can be avoided using the config-set API.
Use the config-set API to rewrite `git_config()` to use the config caching
layer to avoid config file rereads on each invocation during a git process
lifetime. First invocation constructs the cache, and after that for each
successive invocation, `git_config()` feeds values from the config cache
instead of rereading the configuration files.
Signed-off-by: Tanay Abhra <tanayabh@xxxxxxxxx>
---
cache.h | 24 +++++++++++++++++++++
config.c | 57 ++++++++++++++++++++++++++++++++++++++++++-------
t/t4055-diff-context.sh | 2 +-
3 files changed, 74 insertions(+), 9 deletions(-)
diff --git a/cache.h b/cache.h
index c61919d..4d3c6bd 100644
--- a/cache.h
+++ b/cache.h
@@ -8,6 +8,7 @@
#include "gettext.h"
#include "convert.h"
#include "trace.h"
+#include "string-list.h"
#include SHA1_HEADER
#ifndef git_SHA_CTX
@@ -1351,9 +1352,32 @@ extern int parse_config_key(const char *var,
const char **subsection, int *subsection_len,
const char **key);
+struct config_set_element {
+ struct hashmap_entry ent;
+ char *key;
+ struct string_list value_list;
+};
+
+struct configset_list_item {
+ struct config_set_element *e;
+ int value_index;
+};
+
+/*
+ * the contents of the list are ordered according to their
+ * position in the config files and order of parsing the files.
+ * (i.e. key-value pair at the last position of .git/config will
+ * be at the last item of the list)
+ */
+struct configset_list {
+ struct configset_list_item *items;
+ unsigned int nr, alloc;
+};
+
struct config_set {
struct hashmap config_hash;
int hash_initialized;
+ struct configset_list list;
};
extern void git_configset_init(struct config_set *cs);
diff --git a/config.c b/config.c
index c0faaca..4937515 100644
--- a/config.c
+++ b/config.c
@@ -35,12 +35,6 @@ struct config_source {
long (*do_ftell)(struct config_source *c);
};
-struct config_set_element {
- struct hashmap_entry ent;
- char *key;
- struct string_list value_list;
-};
-
static struct config_source *cf;
static int zlib_compression_seen;
@@ -1235,7 +1229,7 @@ struct key_value_info {
int linenr;
};
-void git_config(config_fn_t fn, void *data)
+static void git_config_raw(config_fn_t fn, void *data)
{
if (git_config_with_options(fn, data, NULL, 1) < 0)
/*
@@ -1252,6 +1246,39 @@ void git_config(config_fn_t fn, void *data)
die("Unknown error occured while reading the configuration files");
}
+static void configset_iter(struct config_set *cs, config_fn_t fn, void *data)
+{
+ int i, value_index;
+ struct string_list *values;
+ struct config_set_element *entry;
+ struct configset_list *list = &cs->list;
+ struct key_value_info *kv_info;
+
+ for (i = 0; i < list->nr; i++) {
+ entry = list->items[i].e;
+ value_index = list->items[i].value_index;
+ values = &entry->value_list;
+ if (fn(entry->key, values->items[value_index].string, data) < 0) {
+ kv_info = values->items[value_index].util;
+ if (!kv_info->linenr)
+ die("unable to parse '%s' from command-line config", entry->key);
+ else
+ die("bad config variable '%s' at file line %d in %s",
+ entry->key,
+ kv_info->linenr,
+ kv_info->filename);
+ }
+ }
+}
+
+static void git_config_check_init(void);
+
+void git_config(config_fn_t fn, void *data)
+{
+ git_config_check_init();
+ configset_iter(&the_config_set, fn, data);
+}
+
static struct config_set_element *configset_find_element(struct config_set *cs, const char *key)
{
struct config_set_element k;
@@ -1278,6 +1305,7 @@ static int configset_add_value(struct config_set *cs, const char *key, const cha
{
struct config_set_element *e;
struct string_list_item *si;
+ struct configset_list_item *l_item;
struct key_value_info *kv_info = xmalloc(sizeof(*kv_info));
e = configset_find_element(cs, key);
@@ -1293,6 +1321,12 @@ static int configset_add_value(struct config_set *cs, const char *key, const cha
hashmap_add(&cs->config_hash, e);
}
si = string_list_append_nodup(&e->value_list, value ? xstrdup(value) : NULL);
+
+ ALLOC_GROW(cs->list.items, cs->list.nr + 1, cs->list.alloc);
+ l_item = &cs->list.items[cs->list.nr++];
+ l_item->e = e;
+ l_item->value_index = e->value_list.nr - 1;
+
if (cf) {
kv_info->filename = strintern(cf->name);
kv_info->linenr = cf->linenr;
@@ -1316,6 +1350,9 @@ void git_configset_init(struct config_set *cs)
{
hashmap_init(&cs->config_hash, (hashmap_cmp_fn)config_set_element_cmp, 0);
cs->hash_initialized = 1;
+ cs->list.nr = 0;
+ cs->list.alloc = 0;
+ cs->list.items = NULL;
}
void git_configset_clear(struct config_set *cs)
@@ -1332,6 +1369,10 @@ void git_configset_clear(struct config_set *cs)
}
hashmap_free(&cs->config_hash, 1);
cs->hash_initialized = 0;
+ free(cs->list.items);
+ cs->list.nr = 0;
+ cs->list.alloc = 0;
+ cs->list.items = NULL;
}
static int config_set_callback(const char *key, const char *value, void *cb)
@@ -1450,7 +1491,7 @@ static void git_config_check_init(void)
if (the_config_set.hash_initialized)
return;
git_configset_init(&the_config_set);
- git_config(config_set_callback, &the_config_set);
+ git_config_raw(config_set_callback, &the_config_set);
}
void git_config_clear(void)
diff --git a/t/t4055-diff-context.sh b/t/t4055-diff-context.sh
index cd04543..741e080 100755
--- a/t/t4055-diff-context.sh
+++ b/t/t4055-diff-context.sh
@@ -79,7 +79,7 @@ test_expect_success 'non-integer config parsing' '
test_expect_success 'negative integer config parsing' '
git config diff.context -1 &&
test_must_fail git diff 2>output &&
- test_i18ngrep "bad config file" output
+ test_i18ngrep "bad config variable" output
'
test_expect_success '-U0 is valid, so is diff.context=0' '
--
1.9.0.GIT
--
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