Move config to a backend structure

Configuration options can come from different sources. Currently,
there is only support for reading them from a flat file, but it might
make sense to read it from a database at some point.

Move the parsing code into src/config_file.c and create an include
file include/git2/config_backend.h to allow for other backends to be
developed.

Signed-off-by: Carlos Martín Nieto <cmn@elego.de>

include/git2/config.h

@@ -37,13 +37,23 @@
  */
 GIT_BEGIN_DECL
 
+/**
+ * Allocate a new configuration
+ */
+GIT_EXTERN(int) git_config_new(git_config **out);
+
 /**
  * Open a configuration file
  *
  * @param cfg_out pointer to the configuration data
  * @param path where to load the confiration from
  */
-GIT_EXTERN(int) git_config_open(git_config **cfg_out, const char *path);
+GIT_EXTERN(int) git_config_open_bare(git_config **cfg_out, const char *path);
+
+/**
+ *
+ */
+GIT_EXTERN(int) git_config_add_backend(git_config *cfg, git_config_backend *backend, int priority);
 
 /**
  * Free the configuration and its associated memory

include/git2/config_backend.h

@@ -0,0 +1,57 @@
+/*
+ * This file is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License, version 2,
+ * as published by the Free Software Foundation.
+ *
+ * In addition to the permissions in the GNU General Public License,
+ * the authors give you unlimited permission to link the compiled
+ * version of this file into combinations with other programs,
+ * and to distribute those combinations without any restriction
+ * coming from the use of this file.  (The General Public License
+ * restrictions do apply in other respects; for example, they cover
+ * modification of the file, and distribution when not linked into
+ * a combined executable.)
+ *
+ * This file is distributed in the hope that it will be useful, but
+ * WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+ * General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; see the file COPYING.  If not, write to
+ * the Free Software Foundation, 51 Franklin Street, Fifth Floor,
+ * Boston, MA 02110-1301, USA.
+ */
+
+#ifndef INCLUDE_git_config_backend_h__
+#define INCLUDE_git_config_backend_h__
+
+#include "common.h"
+#include "types.h"
+#include "config.h"
+
+GIT_BEGIN_DECL
+
+struct git_config;
+
+struct git_config_backend {
+	struct git_config *cfg;
+	/* Open means open the file/database and parse if necessary */
+	int (*open)(struct git_config_backend *);
+	int (* get)(struct git_config_backend *, const char *key, const char **value);
+	int (* set)(struct git_config_backend *, const char *key, const char *value);
+	int (*foreach)(struct git_config_backend *, int (*fn)(const char *, void *), void *data);
+	void (*free)(struct git_config_backend *);
+};
+
+/**
+ * Create a file-backed configuration backend
+ *
+ * @param out the new backend
+ * @path where the config file is located
+ */
+GIT_EXTERN(int) git_config_backend_file(struct git_config_backend **out, const char *path);
+
+GIT_END_DECL
+
+#endif

include/git2/types.h

@@ -133,6 +133,9 @@ typedef struct git_index git_index;
 /** Memory representation of a config file */
 typedef struct git_config git_config;
 
+/** A specific implementation of a config backend */
+typedef struct git_config_backend git_config_backend;
+
 /** Memory representation of a config variable */
 typedef struct git_cvar git_cvar;
 

src/config.h

@@ -1,72 +1,14 @@
 #ifndef INCLUDE_config_h__
 #define INCLUDE_config_h__
 
+#include "git2.h"
 #include "git2/config.h"
-
-typedef struct {
-	git_cvar *head;
-	git_cvar *tail;
-} git_cvar_list;
+#include "vector.h"
 
 struct git_config {
-	git_cvar_list var_list;
-
-	struct {
-		gitfo_buf buffer;
-		char *read_ptr;
-		int line_number;
-		int eof;
-	} reader;
-
-	char *file_path;
+	git_vector backends;
 };
 
-struct git_cvar {
-	git_cvar *next;
-	char *section;
-	char *name;
-	char *value;
-};
-
-#define CVAR_LIST_HEAD(list) ((list)->head)
-
-#define CVAR_LIST_TAIL(list) ((list)->tail)
-
-#define CVAR_LIST_NEXT(var) ((var)->next)
-
-#define CVAR_LIST_EMPTY(list) ((list)->head == NULL)
-
-#define CVAR_LIST_APPEND(list, var) do {\
-	if (CVAR_LIST_EMPTY(list)) {\
-		CVAR_LIST_HEAD(list) = CVAR_LIST_TAIL(list) = var;\
-	} else {\
-		CVAR_LIST_NEXT(CVAR_LIST_TAIL(list)) = var;\
-		CVAR_LIST_TAIL(list) = var;\
-	}\
-} while(0)
-
-#define CVAR_LIST_REMOVE_HEAD(list) do {\
-	CVAR_LIST_HEAD(list) = CVAR_LIST_NEXT(CVAR_LIST_HEAD(list));\
-} while(0)
-
-#define CVAR_LIST_REMOVE_AFTER(var) do {\
-	CVAR_LIST_NEXT(var) = CVAR_LIST_NEXT(CVAR_LIST_NEXT(var));\
-} while(0)
-
-#define CVAR_LIST_FOREACH(list, iter)\
-	for ((iter) = CVAR_LIST_HEAD(list);\
-		 (iter) != NULL;\
-		 (iter) = CVAR_LIST_NEXT(iter))
-
-/*
- * Inspired by the FreeBSD functions
- */
-#define CVAR_LIST_FOREACH_SAFE(start, iter, tmp)\
-	for ((iter) = CVAR_LIST_HEAD(vars);\
-		 (iter) && (((tmp) = CVAR_LIST_NEXT(iter) || 1));\
-		 (iter) = (tmp))
-
-
 void git__strtolower(char *str);
 void git__strntolower(char *str, int len);
 

tests/t15-config.c

@@ -36,7 +36,7 @@ BEGIN_TEST(config0, "read a simple configuration")
 	git_config *cfg;
 	int i;
 
-	must_pass(git_config_open(&cfg, CONFIG_BASE "/config0"));
+	must_pass(git_config_open_bare(&cfg, CONFIG_BASE "/config0"));
 	must_pass(git_config_get_int(cfg, "core.repositoryformatversion", &i));
 	must_be_true(i == 0);
 	must_pass(git_config_get_bool(cfg, "core.filemode", &i));
@@ -58,7 +58,7 @@ BEGIN_TEST(config1, "case sensitivity")
 	int i;
 	const char *str;
 
-	must_pass(git_config_open(&cfg, CONFIG_BASE "/config1"));
+	must_pass(git_config_open_bare(&cfg, CONFIG_BASE "/config1"));
 
 	must_pass(git_config_get_string(cfg, "this.that.other", &str));
 	must_be_true(!strcmp(str, "true"));
@@ -84,7 +84,7 @@ BEGIN_TEST(config2, "parse a multiline value")
 	git_config *cfg;
 	const char *str;
 
-	must_pass(git_config_open(&cfg, CONFIG_BASE "/config2"));
+	must_pass(git_config_open_bare(&cfg, CONFIG_BASE "/config2"));
 
 	must_pass(git_config_get_string(cfg, "this.That.and", &str));
 	must_be_true(!strcmp(str, "one one one two two three three"));
@@ -99,7 +99,7 @@ BEGIN_TEST(config3, "parse a [section.subsection] header")
 	git_config *cfg;
 	const char *str;
 
-	must_pass(git_config_open(&cfg, CONFIG_BASE "/config3"));
+	must_pass(git_config_open_bare(&cfg, CONFIG_BASE "/config3"));
 
 	must_pass(git_config_get_string(cfg, "section.subsection.var", &str));
 	must_be_true(!strcmp(str, "hello"));
@@ -117,7 +117,7 @@ BEGIN_TEST(config4, "a variable name on its own is valid")
 const char *str;
 int i;
 
-	must_pass(git_config_open(&cfg, CONFIG_BASE "/config4"));
+	must_pass(git_config_open_bare(&cfg, CONFIG_BASE "/config4"));
 
 	must_pass(git_config_get_string(cfg, "some.section.variable", &str));
 	must_be_true(str == NULL);
@@ -134,7 +134,7 @@ BEGIN_TEST(config5, "test number suffixes")
 	const char *str;
 	long int i;
 
-	must_pass(git_config_open(&cfg, CONFIG_BASE "/config5"));
+	must_pass(git_config_open_bare(&cfg, CONFIG_BASE "/config5"));
 
 	must_pass(git_config_get_long(cfg, "number.simple", &i));
 	must_be_true(i == 1);