From: Felix Fietkau <nbd@openwrt.org>
Date: Wed, 23 Jan 2008 07:10:45 +0000 (+0100)
Subject: major code refactoring for more code reuse and smaller code size
X-Git-Url: https://git.archive.openwrt.org/?p=project%2Fuci.git;a=commitdiff_plain;h=8f5a6c07caaaf5bd692623d1ed8ffbfa20f564d8

major code refactoring for more code reuse and smaller code size
---

diff --git a/cli.c b/cli.c
index 2252e5e..3a19b36 100644
--- a/cli.c
+++ b/cli.c
@@ -33,14 +33,14 @@ static void uci_usage(int argc, char **argv)
 
 static void uci_show_section(struct uci_section *p)
 {
-	struct uci_option *o;
+	struct uci_element *e;
 	const char *cname, *sname;
 
-	cname = p->package->name;
-	sname = p->name;
+	cname = p->package->e.name;
+	sname = p->e.name;
 	printf("%s.%s=%s\n", cname, sname, p->type);
-	uci_foreach_entry(option, &p->options, o) {
-		printf("%s.%s.%s=%s\n", cname, sname, o->name, o->value);
+	uci_foreach_element(&p->options, e) {
+		printf("%s.%s.%s=%s\n", cname, sname, e->name, uci_to_option(e)->value);
 	}
 }
 
@@ -48,7 +48,7 @@ static int uci_show(int argc, char **argv)
 {
 	char *section = (argc > 2 ? argv[2] : NULL);
 	struct uci_package *package;
-	struct uci_section *s;
+	struct uci_element *e;
 	char **configs;
 	char **p;
 
@@ -62,9 +62,9 @@ static int uci_show(int argc, char **argv)
 				uci_perror(ctx, "uci_load");
 				return 255;
 			}
-			uci_foreach_entry(section, &package->sections, s) {
-				if (!section || !strcmp(s->name, section))
-					uci_show_section(s);
+			uci_foreach_element( &package->sections, e) {
+				if (!section || !strcmp(e->name, section))
+					uci_show_section(uci_to_section(e));
 			}
 			uci_unload(ctx, *p);
 		}
diff --git a/file.c b/file.c
index 3ccffb7..2ca7fce 100644
--- a/file.c
+++ b/file.c
@@ -84,10 +84,9 @@ static void uci_file_cleanup(struct uci_context *ctx)
 		return;
 
 	ctx->pctx = NULL;
-	if (pctx->package) {
-		uci_list_del(&pctx->package->list);
-		uci_drop_config(pctx->package);
-	}
+	if (pctx->package)
+		uci_free_package(pctx->package);
+
 	if (pctx->buf)
 		free(pctx->buf);
 	if (pctx->file)
@@ -249,7 +248,7 @@ static char *next_arg(struct uci_context *ctx, char **str, bool required)
 		UCI_THROW(ctx, UCI_ERR_PARSE);
 	}
 
-	return uci_strdup(ctx, val);
+	return val;
 }
 
 /*
@@ -282,7 +281,7 @@ static void uci_switch_config(struct uci_context *ctx)
 
 	/* add the last config to main config file list */
 	if (pctx->package) {
-		uci_list_add(&ctx->root, &pctx->package->list);
+		uci_list_add(&ctx->root, &pctx->package->e.list);
 
 		pctx->package = NULL;
 		pctx->section = NULL;
@@ -301,7 +300,7 @@ static void uci_switch_config(struct uci_context *ctx)
 ignore:
 	ctx->errno = 0;
 
-	pctx->package = uci_alloc_config(ctx, name);
+	pctx->package = uci_alloc_package(ctx, name);
 }
 
 /*
@@ -314,18 +313,10 @@ static void uci_parse_package(struct uci_context *ctx, char **str)
 	/* command string null-terminated by strtok */
 	*str += strlen(*str) + 1;
 
-	UCI_TRAP_SAVE(ctx, error);
 	name = next_arg(ctx, str, true);
 	assert_eol(ctx, str);
 	ctx->pctx->name = name;
 	uci_switch_config(ctx);
-	UCI_TRAP_RESTORE(ctx);
-	return;
-
-error:
-	if (name)
-		free(name);
-	UCI_THROW(ctx, ctx->errno);
 }
 
 /*
@@ -348,20 +339,10 @@ static void uci_parse_config(struct uci_context *ctx, char **str)
 	/* command string null-terminated by strtok */
 	*str += strlen(*str) + 1;
 
-	UCI_TRAP_SAVE(ctx, error);
 	type = next_arg(ctx, str, true);
 	name = next_arg(ctx, str, false);
 	assert_eol(ctx, str);
-	ctx->pctx->section = uci_add_section(ctx->pctx->package, type, name);
-	UCI_TRAP_RESTORE(ctx);
-	return;
-
-error:
-	if (name)
-		free(name);
-	if (type)
-		free(type);
-	UCI_THROW(ctx, ctx->errno);
+	ctx->pctx->section = uci_alloc_section(ctx->pctx->package, type, name);
 }
 
 /*
@@ -380,20 +361,10 @@ static void uci_parse_option(struct uci_context *ctx, char **str)
 	/* command string null-terminated by strtok */
 	*str += strlen(*str) + 1;
 
-	UCI_TRAP_SAVE(ctx, error);
 	name = next_arg(ctx, str, true);
 	value = next_arg(ctx, str, true);
 	assert_eol(ctx, str);
-	uci_add_option(ctx->pctx->section, name, value);
-	UCI_TRAP_RESTORE(ctx);
-	return;
-
-error:
-	if (name)
-		free(name);
-	if (value)
-		free(value);
-	UCI_THROW(ctx, ctx->errno);
+	uci_alloc_option(ctx->pctx->section, name, value);
 }
 
 
@@ -479,19 +450,20 @@ static char *uci_escape(struct uci_context *ctx, char *str)
 /*
  * export a single config package to a file stream
  */
-static void uci_export_config(struct uci_package *package, FILE *stream)
+static void uci_export_package(struct uci_package *p, FILE *stream)
 {
-	struct uci_context *ctx = package->ctx;
-	struct uci_section *s;
-	struct uci_option *o;
-
-	fprintf(stream, "package '%s'\n", uci_escape(ctx, package->name));
-	uci_foreach_entry(section, &package->sections, s) {
-		fprintf(stream, "\nconfig '%s'", uci_escape(ctx, s->type));
-		fprintf(stream, " '%s'\n", uci_escape(ctx, s->name));
-		uci_foreach_entry(option, &s->options, o) {
-			fprintf(stream, "\toption '%s'", uci_escape(ctx, o->name));
-			fprintf(stream, " '%s'\n", uci_escape(ctx, o->value));
+	struct uci_context *ctx = p->ctx;
+	struct uci_element *s, *o;
+
+	fprintf(stream, "package '%s'\n", uci_escape(ctx, p->e.name));
+	uci_foreach_element(&p->sections, s) {
+		struct uci_section *sec = uci_to_section(s);
+		fprintf(stream, "\nconfig '%s'", uci_escape(ctx, sec->type));
+		fprintf(stream, " '%s'\n", uci_escape(ctx, sec->e.name));
+		uci_foreach_element(&sec->options, o) {
+			struct uci_option *opt = uci_to_option(o);
+			fprintf(stream, "\toption '%s'", uci_escape(ctx, opt->e.name));
+			fprintf(stream, " '%s'\n", uci_escape(ctx, opt->value));
 		}
 	}
 	fprintf(stream, "\n");
@@ -499,16 +471,18 @@ static void uci_export_config(struct uci_package *package, FILE *stream)
 
 int uci_export(struct uci_context *ctx, FILE *stream, struct uci_package *package)
 {
+	struct uci_element *e;
+
 	UCI_HANDLE_ERR(ctx);
 	UCI_ASSERT(ctx, stream != NULL);
 
 	if (package) {
-		uci_export_config(package, stream);
+		uci_export_package(package, stream);
 		goto done;
 	}
 
-	uci_foreach_entry(package, &ctx->root, package) {
-		uci_export_config(package, stream);
+	uci_foreach_element(&ctx->root, e) {
+		uci_export_package(uci_to_package(e), stream);
 	}
 done:
 	return 0;
diff --git a/libuci.c b/libuci.c
index c6335d5..92205e8 100644
--- a/libuci.c
+++ b/libuci.c
@@ -96,11 +96,11 @@ struct uci_context *uci_alloc(void)
 
 void uci_free(struct uci_context *ctx)
 {
-	struct uci_package *package;
+	struct uci_element *e, *tmp;
 
 	uci_cleanup(ctx);
-	uci_foreach_entry(package, &ctx->root, package) {
-		uci_drop_config(package);
+	uci_foreach_element_safe(&ctx->root, tmp, e) {
+		uci_free_package(uci_to_package(e));
 	}
 	free(ctx);
 	return;
diff --git a/list.c b/list.c
index ba5a9f0..357b2e4 100644
--- a/list.c
+++ b/list.c
@@ -46,138 +46,132 @@ static inline void uci_list_del(struct uci_list *ptr)
 
 	prev->next = next;
 	next->prev = prev;
+
+	uci_list_init(ptr);
 }
 
-static void uci_drop_option(struct uci_option *option)
+static struct uci_element *
+uci_alloc_generic(struct uci_context *ctx, const char *name, int size)
 {
-	if (!option)
-		return;
-	if (option->name)
-		free(option->name);
-	if (option->value)
-		free(option->value);
-	free(option);
+	struct uci_element *e;
+	void *ptr;
+
+	ptr = uci_malloc(ctx, size + strlen(name) + 1);
+	e = (struct uci_element *) ptr;
+	e->name = (char *) ptr + size;
+	strcpy(e->name, name);
+	uci_list_init(&e->list);
+
+	return e;
 }
 
-static struct uci_option *uci_add_option(struct uci_section *section, const char *name, const char *value)
+static void
+uci_free_element(struct uci_element *e)
 {
-	struct uci_package *package = section->package;
-	struct uci_context *ctx = package->ctx;
-	struct uci_option *option = NULL;
-
-	UCI_TRAP_SAVE(ctx, error);
-	option = (struct uci_option *) uci_malloc(ctx, sizeof(struct uci_option));
-	option->name = uci_strdup(ctx, name);
-	option->value = uci_strdup(ctx, value);
-	uci_list_add(&section->options, &option->list);
-	UCI_TRAP_RESTORE(ctx);
-	return option;
-
-error:
-	uci_drop_option(option);
-	UCI_THROW(ctx, ctx->errno);
-	return NULL;
+	if (!e)
+		return;
+
+	if (!uci_list_empty(&e->list))
+		uci_list_del(&e->list);
+	free(e);
 }
 
-static void uci_drop_section(struct uci_section *section)
+static struct uci_option *
+uci_alloc_option(struct uci_section *s, const char *name, const char *value)
 {
-	struct uci_option *opt;
-
-	if (!section)
-		return;
+	struct uci_package *p = s->package;
+	struct uci_context *ctx = p->ctx;
+	struct uci_option *o;
 
-	uci_foreach_entry(option, &section->options, opt) {
-		uci_list_del(&opt->list);
-		uci_drop_option(opt);
-	}
+	o = uci_alloc_element(ctx, option, name, strlen(value) + 1);
+	o->value = uci_dataptr(o);
+	o->section = s;
+	strcpy(o->value, value);
+	uci_list_add(&s->options, &o->e.list);
 
-	if (section->name)
-		free(section->name);
-	if (section->type)
-		free(section->type);
-	free(section);
+	return o;
 }
 
-static struct uci_section *uci_add_section(struct uci_package *package, const char *type, const char *name)
+static inline void
+uci_free_option(struct uci_option *o)
 {
-	struct uci_section *section = NULL;
-	struct uci_context *ctx = package->ctx;
-
-	UCI_TRAP_SAVE(ctx, error);
-	package->n_section++;
-	section = (struct uci_section *) uci_malloc(ctx, sizeof(struct uci_section));
-	section->package = package;
-	uci_list_init(&section->list);
-	uci_list_init(&section->options);
-	section->type = uci_strdup(ctx, type);
-	if (name && name[0])
-		section->name = uci_strdup(ctx, name);
-	else
-		asprintf(&section->name, "cfg%d", package->n_section);
-	uci_list_add(&package->sections, &section->list);
-	UCI_TRAP_RESTORE(ctx);
-
-	return section;
-
-error:
-	uci_drop_section(section);
-	UCI_THROW(ctx, ctx->errno);
-	return NULL;
+	uci_free_element(&o->e);
 }
 
-static void uci_drop_config(struct uci_package *package)
+static struct uci_section *
+uci_alloc_section(struct uci_package *p, const char *type, const char *name)
 {
+	struct uci_context *ctx = p->ctx;
 	struct uci_section *s;
+	char buf[16];
 
-	if(!package)
-		return;
-
-	uci_foreach_entry(section, &package->sections, s) {
-		uci_list_del(&s->list);
-		uci_drop_section(s);
+	if (!name || !name[0]) {
+		snprintf(buf, 16, "cfg%d", p->n_section);
+		name = buf;
 	}
 
-	if (package->name)
-		free(package->name);
-	free(package);
+	s = uci_alloc_element(ctx, section, name, strlen(type) + 1);
+	s->type = uci_dataptr(s);
+	s->package = p;
+	strcpy(s->type, type);
+	uci_list_init(&s->options);
+	uci_list_add(&p->sections, &s->e.list);
+
+	return s;
 }
 
+static void
+uci_free_section(struct uci_section *s)
+{
+	struct uci_element *o, *tmp;
 
-static struct uci_package *uci_alloc_config(struct uci_context *ctx, const char *name)
+	uci_foreach_element_safe(&s->options, tmp, o) {
+		uci_free_option(uci_to_option(o));
+	}
+	uci_free_element(&s->e);
+}
+
+static struct uci_package *
+uci_alloc_package(struct uci_context *ctx, const char *name)
 {
-	struct uci_package *package = NULL;
-
-	UCI_TRAP_SAVE(ctx, error);
-	package = (struct uci_package *) uci_malloc(ctx, sizeof(struct uci_package));
-	uci_list_init(&package->list);
-	uci_list_init(&package->sections);
-	package->name = uci_strdup(ctx, name);
-	package->ctx = ctx;
-	UCI_TRAP_RESTORE(ctx);
-	return package;
-
-error:
-	uci_drop_config(package);
-	UCI_THROW(ctx, ctx->errno);
-	return NULL;
+	struct uci_package *p;
+
+	p = uci_alloc_element(ctx, package, name, 0);
+	p->ctx = ctx;
+	uci_list_init(&p->sections);
+	return p;
 }
 
+static void
+uci_free_package(struct uci_package *p)
+{
+	struct uci_element *e, *tmp;
+
+	if(!p)
+		return;
+
+	uci_foreach_element_safe(&p->sections, tmp, e) {
+		uci_free_section(uci_to_section(e));
+	}
+	uci_free_element(&p->e);
+}
+
+
 int uci_unload(struct uci_context *ctx, const char *name)
 {
-	struct uci_package *package;
+	struct uci_element *e;
 
 	UCI_HANDLE_ERR(ctx);
 	UCI_ASSERT(ctx, name != NULL);
 
-	uci_foreach_entry(package, &ctx->root, package) {
-		if (!strcmp(package->name, name))
+	uci_foreach_element(&ctx->root, e) {
+		if (!strcmp(e->name, name))
 			goto found;
 	}
 	UCI_THROW(ctx, UCI_ERR_NOTFOUND);
 
 found:
-	uci_list_del(&package->list);
-	uci_drop_config(package);
+	uci_free_package(uci_to_package(e));
 
 	return 0;
 }
@@ -234,3 +228,4 @@ char **uci_list_configs(struct uci_context *ctx)
 	return configs;
 }
 
+
diff --git a/uci.h b/uci.h
index 687454f..96bebf5 100644
--- a/uci.h
+++ b/uci.h
@@ -15,6 +15,16 @@
 #ifndef __LIBUCI_H
 #define __LIBUCI_H
 
+/*
+ * you can use these defines to enable debugging behavior for
+ * apps compiled against libuci:
+ *
+ * #define UCI_DEBUG_TYPECAST:
+ *   enable uci_element typecast checking at run time
+ *
+ */
+
+
 #include <setjmp.h>
 #include <stdio.h>
 
@@ -113,6 +123,18 @@ extern int uci_cleanup(struct uci_context *ctx);
 extern char **uci_list_configs(struct uci_context *ctx);
 
 /* UCI data structures */
+enum uci_type {
+	UCI_TYPE_PACKAGE,
+	UCI_TYPE_SECTION,
+	UCI_TYPE_OPTION
+};
+
+struct uci_element
+{
+	struct uci_list list;
+	enum uci_type type;
+	char *name;
+};
 
 struct uci_context
 {
@@ -147,37 +169,28 @@ struct uci_parse_context
 
 struct uci_package
 {
-	struct uci_list list;
+	struct uci_element e;
 	struct uci_list sections;
 	struct uci_context *ctx;
-	char *name;
 	/* private: */
 	int n_section;
 };
 
 struct uci_section
 {
-	struct uci_list list;
+	struct uci_element e;
 	struct uci_list options;
 	struct uci_package *package;
 	char *type;
-	char *name;
 };
 
 struct uci_option
 {
-	struct uci_list list;
+	struct uci_element e;
 	struct uci_section *section;
-	char *name;
 	char *value;
 };
 
-enum uci_type {
-	UCI_TYPE_PACKAGE,
-	UCI_TYPE_SECTION,
-	UCI_TYPE_OPTION
-};
-
 enum uci_command {
 	UCI_CMD_ADD,
 	UCI_CMD_REMOVE,
@@ -188,19 +201,11 @@ struct uci_history
 {
 	struct uci_list list;
 	enum uci_command cmd;
-	enum uci_type type;
 	union {
-		struct {
-			char *name;
-		} p;
-		struct {
-			char *type;
-			char *name;
-		} c;
-		struct {
-			char *name;
-			char *value;
-		} o;
+		struct uci_element element;
+		struct uci_package package;
+		struct uci_section section;
+		struct uci_option option;
 	} data;
 };
 
@@ -209,31 +214,105 @@ struct uci_history
 #define offsetof(TYPE, MEMBER) ((size_t) &((TYPE *)0)->MEMBER)
 #endif
 
-/* returns true if a list is empty */
-#define uci_list_empty(list) ((list)->next == (list))
+/**
+ * container_of - cast a member of a structure out to the containing structure
+ * @ptr:    the pointer to the member.
+ * @type:   the type of the container struct this is embedded in.
+ * @member: the name of the member within the struct.
+ */
+#define container_of(ptr, type, member) \
+	((type *) ((char *)ptr - offsetof(type,member)))
+
 
 /**
  * uci_list_entry: casts an uci_list pointer to the containing struct.
  * @_type: config, section or option
  * @_ptr: pointer to the uci_list struct
  */
-#define uci_list_entry(_type, _ptr) \
-	((struct uci_ ## _type *) ((char *)(_ptr) - offsetof(struct uci_ ## _type,list)))
+#define element_to(type, ptr) \
+	container_of(ptr, struct uci_ ## type, e)
+
+#define list_to_element(ptr) \
+	container_of(ptr, struct uci_element, list)
+
+/**
+ * uci_foreach_entry: loop through a list of uci elements
+ * @_list: pointer to the uci_list struct
+ * @_ptr: iteration variable, struct uci_element
+ *
+ * use like a for loop, e.g:
+ *   uci_foreach(&list, p) {
+ *   	...
+ *   }
+ */
+#define uci_foreach_element(_list, _ptr)		\
+	for(_ptr = list_to_element((_list)->next);	\
+		&_ptr->list != (_list);			\
+		_ptr = list_to_element(_ptr->list.next))
 
 /**
- * uci_foreach_entry: loop through a list of configs, sections or options
- * @_type: see uci_list_entry
+ * uci_foreach_entry_safe: like uci_foreach_safe, but safe for deletion
  * @_list: pointer to the uci_list struct
- * @_ptr: iteration variable
+ * @_tmp: temporary variable, struct uci_element *
+ * @_ptr: iteration variable, struct uci_element *
  *
  * use like a for loop, e.g:
- *   uci_foreach(section, &list, p) {
+ *   uci_foreach(&list, p) {
  *   	...
  *   }
  */
-#define uci_foreach_entry(_type, _list, _ptr)		\
-	for(_ptr = uci_list_entry(_type, (_list)->next);	\
+#define uci_foreach_element_safe(_list, _tmp, _ptr)		\
+	for(_ptr = list_to_element((_list)->next),		\
+		_tmp = list_to_element(_ptr->list.next);	\
 		&_ptr->list != (_list);			\
-		_ptr = uci_list_entry(_type, _ptr->list.next))
+		_ptr = _tmp, _tmp = list_to_element(_ptr->list.next))
+
+/* returns true if a list is empty */
+#define uci_list_empty(list) ((list)->next == (list))
+
+/* element typecasting */
+#ifdef UCI_DEBUG_TYPECAST
+static const char *uci_typestr[] = {
+	[UCI_TYPE_PACKAGE] = "package",
+	[UCI_TYPE_SECTION] = "section",
+	[UCI_TYPE_OPTION] = "option"
+}
+
+static void uci_typecast_error(int from, int to)
+{
+	fprintf(stderr, "Invalid typecast from '%s' to '%s'\n", uci_typestr[from], uci_typestr[to]);
+}
+
+#define BUILD_CAST(type, val) \
+	static inline struct uci_ ## type *uci_to_ ## type (struct uci_element *e) \
+	{ \
+		if (e->type != val) { \
+			uci_typecast_error(e->type, val); \
+		} \
+		return (struct uci_ ## type *) e; \
+	}
+
+BUILD_CAST(package, UCI_TYPE_PACKAGE)
+BUILD_CAST(section, UCI_TYPE_SECTION)
+BUILD_CAST(option,  UCI_TYPE_OPTION)
+
+#else
+#define uci_to_package(ptr) container_of(ptr, struct uci_package, e)
+#define uci_to_section(ptr) container_of(ptr, struct uci_section, e)
+#define uci_to_option(ptr)  container_of(ptr, struct uci_option, e)
+#endif
+
+/**
+ * uci_alloc_element: allocate a generic uci_element, reserve a buffer and typecast
+ * @ctx: uci context
+ * @type: {package,section,option}
+ * @name: string containing the name of the element
+ * @datasize: additional buffer size to reserve at the end of the struct
+ */
+#define uci_alloc_element(ctx, type, name, datasize) \
+	uci_to_ ## type (uci_alloc_generic(ctx, name, sizeof(struct uci_ ## type) + datasize))
+
+#define uci_dataptr(ptr) \
+	(((char *) ptr) + sizeof(*ptr))
 
 #endif