add memory-pool based string field management for structures

convert chan_sip sip_pvt and sip_registry structures to use string fields
add 'const' qualifiers to a few API calls that don't modify their input strings
add an asprintf() wrapper to astmm


git-svn-id: https://origsvn.digium.com/svn/asterisk/trunk@7797 65c4cc65-6c06-0410-ace0-fbb531ad65f3

astmm.c

@@ -1,7 +1,7 @@
 /*
  * Asterisk -- An open source telephony toolkit.
  *
- * Copyright (C) 1999 - 2005, Digium, Inc.
+ * Copyright (C) 1999 - 2006, Digium, Inc.
  *
  * Mark Spencer <markster@digium.com>
  *
@@ -47,6 +47,7 @@ ASTERISK_FILE_VERSION(__FILE__, "$Revision$")
 #define FUNC_STRDUP	4
 #define FUNC_STRNDUP	5
 #define FUNC_VASPRINTF	6
+#define FUNC_ASPRINTF   7
 
 /* Undefine all our macros */
 #undef malloc
@@ -56,6 +57,7 @@ ASTERISK_FILE_VERSION(__FILE__, "$Revision$")
 #undef strndup
 #undef free
 #undef vasprintf
+#undef asprintf
 
 #define FENCE_MAGIC 0xdeadbeef
 
@@ -253,6 +255,28 @@ char *__ast_strndup(const char *s, size_t n, const char *file, int lineno, const
 	return ptr;
 }
 
+int __ast_asprintf(const char *file, int lineno, const char *func, char **strp, const char *fmt, ...)
+{
+	int size;
+	va_list ap, ap2;
+	char s;
+
+	*strp = NULL;
+	va_start(ap, fmt);
+	va_copy(ap2, ap);
+	size = vsnprintf(&s, 1, fmt, ap2);
+	va_end(ap2);
+	*strp = __ast_alloc_region(size + 1, FUNC_ASPRINTF, file, lineno, func);
+	if (!*strp) {
+		va_end(ap);
+		return -1;
+	}
+	vsnprintf(*strp, size + 1, fmt, ap);
+	va_end(ap);
+
+	return size;
+}
+
 int __ast_vasprintf(char **strp, const char *fmt, va_list ap, const char *file, int lineno, const char *func) 
 {
 	int size;
@@ -264,8 +288,10 @@ int __ast_vasprintf(char **strp, const char *fmt, va_list ap, const char *file,
 	size = vsnprintf(&s, 1, fmt, ap2);
 	va_end(ap2);
 	*strp = __ast_alloc_region(size + 1, FUNC_VASPRINTF, file, lineno, func);
-	if (!*strp)
+	if (!*strp) {
+		va_end(ap);
 		return -1;
+	}
 	vsnprintf(*strp, size + 1, fmt, ap);
 
 	return size;

include/asterisk/astmm.h

@@ -1,7 +1,7 @@
 /*
  * Asterisk -- An open source telephony toolkit.
  *
- * Copyright (C) 1999 - 2005, Digium, Inc.
+ * Copyright (C) 1999 - 2006, Digium, Inc.
  *
  * Mark Spencer <markster@digium.com>
  *
@@ -38,6 +38,7 @@
 #undef realloc
 #undef strdup
 #undef strndup
+#undef asprintf
 #undef vasprintf
 
 void *__ast_calloc(size_t nmemb, size_t size, const char *file, int lineno, const char *func);
@@ -46,6 +47,7 @@ void __ast_free(void *ptr, const char *file, int lineno, const char *func);
 void *__ast_realloc(void *ptr, size_t size, const char *file, int lineno, const char *func);
 char *__ast_strdup(const char *s, const char *file, int lineno, const char *func);
 char *__ast_strndup(const char *s, size_t n, const char *file, int lineno, const char *func);
+int __ast_asprintf(const char *file, int lineno, const char *func, char **strp, const char *format, ...);
 int __ast_vasprintf(char **strp, const char *format, va_list ap, const char *file, int lineno, const char *func);
 
 void __ast_mm_init(void);
@@ -70,6 +72,9 @@ void __ast_mm_init(void);
 #define strndup(a,b) \
 	__ast_strndup(a,b,__FILE__, __LINE__, __PRETTY_FUNCTION__)
 
+#define asprintf(a, b, c...) \
+	__ast_asprintf(__FILE__, __LINE__, __PRETTY_FUNCTION__, a, b, c)
+
 #define vasprintf(a,b,c) \
 	__ast_vasprintf(a,b,c,__FILE__, __LINE__, __PRETTY_FUNCTION__)
 

include/asterisk/pbx.h

@@ -287,7 +287,7 @@ int ast_unregister_application(const char *app);
  * \param exten which extension to get state
  * Returns extension state !! = AST_EXTENSION_???
  */
-int ast_extension_state(struct ast_channel *c, char *context, char *exten);
+int ast_extension_state(struct ast_channel *c, const char *context, const char *exten);
 
 /*! Return string of the state of an extension */
 /*!

include/asterisk/stringfields.h

@@ -0,0 +1,288 @@
+/*
+ * Asterisk -- An open source telephony toolkit.
+ *
+ * Copyright (C) 2006, Digium, Inc.
+ *
+ * Kevin P. Fleming <kpfleming@digium.com>
+ *
+ * See http://www.asterisk.org for more information about
+ * the Asterisk project. Please do not directly contact
+ * any of the maintainers of this project for assistance;
+ * the project provides a web site, mailing lists and IRC
+ * channels for your use.
+ *
+ * This program is free software, distributed under the terms of
+ * the GNU General Public License Version 2. See the LICENSE file
+ * at the top of the source tree.
+ */
+
+/*! \file
+  \brief String fields in structures
+
+  This file contains objects and macros used to manage string
+  fields in structures without requiring them to be allocated
+  as fixed-size buffers or requiring individual allocations for
+  for each field.
+  
+  Using this functionality is quite simple... an example structure
+  with three fields is defined like this:
+  
+  \code
+  struct sample_fields {
+	  int x1;
+	  AST_DECLARE_STRING_FIELDS(
+		  AST_STRING_FIELD(name);
+		  AST_STRING_FIELD(address);
+		  AST_STRING_FIELD(password);
+	  );
+	  long x2;
+  };
+  \endcode
+  
+  When an instance of this structure is allocated, the fields
+  (and the pool of storage for them) must be initialized:
+  
+  \code
+  struct sample_fields *sample;
+  
+  sample = calloc(1, sizeof(*sample));
+  if (sample) {
+	  if (!ast_string_field_init(sample)) {
+		  free(sample);
+		  sample = NULL;
+	  }
+  }
+  
+  if (!sample) {
+  ...
+  }
+  \endcode
+  
+  Fields will default to pointing to an empty string, and will
+  revert to that when ast_string_field_free() is called. This means
+  that a string field will \b never contain NULL.
+  
+  Using the fields is much like using regular 'char *' fields
+  in the structure, except that writing into them must be done
+  using wrapper macros defined in this file.
+  
+  Storing simple values into fields can be done using ast_string_field_set();
+  more complex values (using printf-style format strings) can be stored
+  using ast_string_field_build().
+  
+  When the structure instance is no longer needed, the fields
+  and their storage pool must be freed:
+  
+  \code
+  ast_string_field_free_all(sample);
+  free(sample);
+  \endcode
+*/
+
+#ifndef _ASTERISK_STRINGFIELDS_H
+#define _ASTERISK_STRINGFIELDS_H
+
+#include <string.h>
+#include <stdarg.h>
+#include <stddef.h>
+
+#include "asterisk/inline_api.h"
+#include "asterisk/compiler.h"
+#include "asterisk/compat.h"
+
+/*!
+  \internal
+  \brief An opaque type for managed string fields in structures
+
+  Don't declare instances of this type directly; use the AST_STRING_FIELD()
+  macro instead.
+*/
+typedef const char * ast_string_field;
+
+/*!
+  \internal
+  \brief A constant empty string used for fields that have no other value
+*/
+extern const char *__ast_string_field_empty;
+
+/*!
+  \internal
+  \brief Structure used to manage the storage for a field pool
+*/
+struct ast_string_field_pool {
+	char *base;	/*!< the address of the pool's base in memory */
+	size_t size;	/*!< the total size of the pool */
+	size_t space;	/*!< the space available in the pool */
+	size_t used;	/*!< the space used in the pool */
+};
+
+/*!
+  \internal
+  \brief Initialize a field pool and fields
+  \param pool Pointer to the pool structure
+  \param size Amount of storage to allocate
+  \param fields Pointer to the first entry of the field array
+  \param num_fields Number of fields in the array
+  \return 0 on failure, non-zero on success
+*/
+int __ast_string_field_init(struct ast_string_field_pool *pool, size_t size,
+			    ast_string_field *fields, int num_fields);
+
+/*!
+  \internal
+  \brief Allocate space for field in the pool
+  \param pool Pointer to the pool structure
+  \param needed Amount of space needed for this field
+  \param fields Pointer to the first entry of the field array
+  \param num_fields Number of fields in the array
+  \return NULL on failure, an address for the field on success
+
+  This function will allocate the requested amount of space from
+  the field pool. If the requested amount of space is not available,
+  the pool will be expanded until enough space becomes available,
+  and the existing fields stored there will be updated to point
+  into the new pool.
+*/
+char *__ast_string_field_alloc_space(struct ast_string_field_pool *pool, size_t needed,
+				     ast_string_field *fields, int num_fields);
+
+/*!
+  The default amount of storage to be allocated for a field pool.
+*/
+#define AST_STRING_FIELD_DEFAULT_POOL 512
+
+/*!
+  \brief Declare a string field
+  \param name The field name
+*/
+#define AST_STRING_FIELD(name) const ast_string_field name;
+
+/*!
+  \brief Declare the fields needed in a structure
+  \param field_list The list of fields to declare, using AST_STRING_FIELD() for each one
+*/
+#define AST_DECLARE_STRING_FIELDS(field_list) \
+	ast_string_field __begin_field[0]; \
+	field_list \
+	ast_string_field __end_field[0]; \
+	struct ast_string_field_pool __field_pool;
+
+/*!
+  \brief Get the number of string fields in a structure
+  \param x Pointer to a structure containing fields
+  \return the number of fields in the structure's definition
+*/
+#define ast_string_field_count(x) \
+	(offsetof(typeof(*x), __end_field) - offsetof(typeof(*x), __begin_field)) / sizeof(ast_string_field)
+
+/*!
+  \brief Get the index of a field in a structure
+  \param x Pointer to a structure containing fields
+  \param field Name of the field to locate
+  \return the position (index) of the field within the structure's
+  array of fields
+*/
+#define ast_string_field_index(x, field) \
+	(offsetof(typeof(*x), field) - offsetof(typeof(*x), __begin_field)) / sizeof(ast_string_field)
+
+/*!
+  \brief Initialize a field pool and fields
+  \param x Pointer to a structure containing fields
+  \return 0 on failure, non-zero on success
+*/
+#define ast_string_field_init(x) \
+	__ast_string_field_init(&x->__field_pool, AST_STRING_FIELD_DEFAULT_POOL, &x->__begin_field[0], ast_string_field_count(x))
+
+/*!
+  \brief Set a field to a simple string value
+  \param x Pointer to a structure containing fields
+  \param index Index position of the field within the structure
+  \param data String value to be copied into the field
+  \return nothing
+*/
+#define ast_string_field_index_set(x, index, data) do { \
+	if ((x->__begin_field[index] = __ast_string_field_alloc_space(&x->__field_pool, strlen(data) + 1, &x->__begin_field[0], ast_string_field_count(x)))) \
+		strcpy((char *) x->__begin_field[index], data); \
+	} while (0)
+
+/*!
+  \brief Set a field to a simple string value
+  \param x Pointer to a structure containing fields
+  \param field Name of the field to set
+  \param data String value to be copied into the field
+  \return nothing
+*/
+#define ast_string_field_set(x, field, data) \
+	ast_string_field_index_set(x, ast_string_field_index(x, field), data)
+
+/*!
+  \brief Set a field to a simple complex (built) value
+  \param x Pointer to a structure containing fields
+  \param index Index position of the field within the structure
+  \param fmt printf-style format string
+  \param args Arguments for format string
+  \return nothing
+*/
+#define ast_string_field_index_build(x, index, fmt, args...) do { \
+	char s; \
+	size_t needed; \
+	needed = snprintf(&s, 1, fmt, args) + 1; \
+	if ((x->__begin_field[index] = __ast_string_field_alloc_space(&x->__field_pool, needed, &x->__begin_field[0], ast_string_field_count(x)))) \
+		sprintf((char *) x->__begin_field[index], fmt, args); \
+	} while (0)
+
+/*!
+  \brief Set a field to a simple complex (built) value
+  \param x Pointer to a structure containing fields
+  \param field Name of the field to set
+  \param fmt printf-style format string
+  \param args Arguments for format string
+  \return nothing
+*/
+#define ast_string_field_build(x, field, fmt, args...) \
+	ast_string_field_index_build(x, ast_string_field_index(x, field), fmt, args)
+
+/*!
+  \brief Free a field's value.
+  \param x Pointer to a structure containing fields
+  \param index Index position of the field within the structure
+  \return nothing
+
+  \note Because of the storage pool used, the memory
+  occupied by the field's value is \b not recovered; the field
+  pointer is just changed to point to an empty string.
+*/
+#define ast_string_field_index_free(x, index) do { \
+	x->__begin_field[index] = __ast_string_field_empty; \
+	} while(0)
+
+/*!
+  \brief Free a field's value.
+  \param x Pointer to a structure containing fields
+  \param field Name of the field to free
+  \return nothing
+
+  \note Because of the storage pool used, the memory
+  occupied by the field's value is \b not recovered; the field
+  pointer is just changed to point to an empty string.
+*/
+#define ast_string_field_free(x, field) \
+	ast_string_field_index_free(x, ast_string_field_index(x, field))
+
+/*!
+  \brief Free all fields (and the storage pool) in a structure
+  \param x Pointer to a structure containing fields
+  \return nothing
+
+  After calling this macro, fields can no longer be accessed in
+  structure; it should only be called immediately before freeing
+  the structure itself.
+*/
+#define ast_string_field_free_all(x) do { \
+	int index; \
+	for (index = 0; index < ast_string_field_count(x); index ++) \
+		ast_string_field_index_free(x, index); \
+	free(x->__field_pool.base); \
+	} while(0)
+
+#endif /* _ASTERISK_STRINGFIELDS_H */

include/asterisk/utils.h

@@ -1,7 +1,7 @@
 /*
  * Asterisk -- An open source telephony toolkit.
  *
- * Copyright (C) 1999 - 2005, Digium, Inc.
+ * Copyright (C) 1999 - 2006, Digium, Inc.
  *
  * Mark Spencer <markster@digium.com>
  *
@@ -162,7 +162,7 @@ int ast_base64decode(unsigned char *dst, const char *src, int max);
 	\param doreserved	Convert reserved characters
 */
 
-char *ast_uri_encode(char *string, char *outbuf, int buflen, int doreserved);
+char *ast_uri_encode(const char *string, char *outbuf, int buflen, int doreserved);
 
 /*!	\brief Decode URI, URN, URL (overwrite string)
 	\param s	String to be decoded 

pbx.c

@@ -1849,7 +1849,7 @@ const char *ast_extension_state2str(int extension_state)
 }
 
 /*! \brief  ast_extension_state: Check extension state for an extension by using hint */
-int ast_extension_state(struct ast_channel *c, char *context, char *exten)
+int ast_extension_state(struct ast_channel *c, const char *context, const char *exten)
 {
 	struct ast_exten *e;
 

utils.c

@@ -1,7 +1,7 @@
 /*
  * Asterisk -- An open source telephony toolkit.
  *
- * Copyright (C) 1999 - 2005, Digium, Inc.
+ * Copyright (C) 1999 - 2006, Digium, Inc.
  *
  * See http://www.asterisk.org for more information about
  * the Asterisk project. Please do not directly contact
@@ -52,6 +52,9 @@ ASTERISK_FILE_VERSION(__FILE__, "$Revision$")
 #define AST_API_MODULE		/* ensure that inlinable API functions will be built in this module if required */
 #include "asterisk/time.h"
 
+#define AST_API_MODULE		/* ensure that inlinable API functions will be built in this module if required */
+#include "asterisk/stringfields.h"
+
 #define AST_API_MODULE		/* ensure that inlinable API functions will be built in this module if required */
 #include "asterisk/utils.h"
 
@@ -421,11 +424,11 @@ static void base64_init(void)
 	Note: The doreserved option is needed for replaces header in
 	SIP transfers.
 */
-char *ast_uri_encode(char *string, char *outbuf, int buflen, int doreserved) 
+char *ast_uri_encode(const char *string, char *outbuf, int buflen, int doreserved) 
 {
 	char *reserved = ";/?:@&=+$, ";	/* Reserved chars */
 
- 	char *ptr  = string;	/* Start with the string */
+ 	const char *ptr  = string;	/* Start with the string */
 	char *out = NULL;
 	char *buf = NULL;
 
@@ -922,3 +925,52 @@ void ast_join(char *s, size_t len, char * const w[])
 		ofs--;
 	s[ofs] = '\0';
 }
+
+const char const *__ast_string_field_empty = "";
+
+int __ast_string_field_init(struct ast_string_field_pool *pool, size_t size,
+			    ast_string_field *fields, int num_fields)
+{
+	int index;
+
+	pool->base = calloc(1, size);
+	if (pool->base) {
+		pool->size = size;
+		pool->space = size;
+		for (index = 0; index < num_fields; index++)
+			fields[index] = __ast_string_field_empty;
+	}
+	return pool->base ? 0 : -1;
+}
+
+char *__ast_string_field_alloc_space(struct ast_string_field_pool *pool, size_t needed,
+				     ast_string_field *fields, int num_fields)
+{
+	char *result = NULL;
+
+	if (__builtin_expect(needed > pool->space, 0)) {
+		int index;
+		char *new_base;
+		size_t new_size = pool->size * 2;
+
+		while (new_size < (pool->used + needed))
+			new_size *= 2;
+
+		if (!(new_base = realloc(pool->base, new_size)))
+			return NULL;
+
+		for (index = 0; index < num_fields; index++) {
+			if (fields[index] != __ast_string_field_empty)
+				fields[index] = new_base + (fields[index] - pool->base);
+		}
+
+		pool->base = new_base;
+		pool->space += new_size - pool->size;
+		pool->size = new_size;
+	}
+
+	result = pool->base + pool->used;
+	pool->used += needed;
+	pool->space -= needed;
+	return result;
+}