blob: 772c34448d9562143f24ddf9ed974461f3b147ab [file] [log] [blame]
/*
* Copyright © 2010 Intel Corporation
*
* Permission is hereby granted, free of charge, to any person obtaining a
* copy of this software and associated documentation files (the "Software"),
* to deal in the Software without restriction, including without limitation
* the rights to use, copy, modify, merge, publish, distribute, sublicense,
* and/or sell copies of the Software, and to permit persons to whom the
* Software is furnished to do so, subject to the following conditions:
*
* The above copyright notice and this permission notice (including the next
* paragraph) shall be included in all copies or substantial portions of the
* Software.
*
* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
* IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
* FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
* THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
* LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
* FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER
* DEALINGS IN THE SOFTWARE.
*/
#include <assert.h>
#include <stdlib.h>
#include <stdarg.h>
#include <stdio.h>
#include <string.h>
#include <stdint.h>
/* Some versions of MinGW are missing _vscprintf's declaration, although they
* still provide the symbol in the import library. */
#ifdef __MINGW32__
_CRTIMP int _vscprintf(const char *format, va_list argptr);
#endif
#include "ralloc.h"
#pragma GCC diagnostic ignored "-Wformat-nonliteral"
#ifndef va_copy
#ifdef __va_copy
#define va_copy(dest, src) __va_copy((dest), (src))
#else
#define va_copy(dest, src) (dest) = (src)
#endif
#endif
#define CANARY 0x5A1106
struct ralloc_header
{
/* A canary value used to determine whether a pointer is ralloc'd. */
unsigned canary;
struct ralloc_header *parent;
/* The first child (head of a linked list) */
struct ralloc_header *child;
/* Linked list of siblings */
struct ralloc_header *prev;
struct ralloc_header *next;
void (*destructor)(void *);
};
typedef struct ralloc_header ralloc_header;
static void unlink_block(ralloc_header *info);
static void unsafe_free(ralloc_header *info);
static ralloc_header *
get_header(const void *ptr)
{
ralloc_header *info = (ralloc_header *) (((char *) ptr) -
sizeof(ralloc_header));
assert(info->canary == CANARY);
return info;
}
#define PTR_FROM_HEADER(info) (((char *) info) + sizeof(ralloc_header))
static void
add_child(ralloc_header *parent, ralloc_header *info)
{
if (parent != NULL) {
info->parent = parent;
info->next = parent->child;
parent->child = info;
if (info->next != NULL)
info->next->prev = info;
}
}
void *
ralloc_context(const void *ctx)
{
return ralloc_size(ctx, 0);
}
void *
ralloc_size(const void *ctx, size_t size)
{
void *block = calloc(1, size + sizeof(ralloc_header));
ralloc_header *info = (ralloc_header *) block;
ralloc_header *parent = ctx != NULL ? get_header(ctx) : NULL;
add_child(parent, info);
info->canary = CANARY;
return PTR_FROM_HEADER(info);
}
void *
rzalloc_size(const void *ctx, size_t size)
{
void *ptr = ralloc_size(ctx, size);
if (likely(ptr != NULL))
memset(ptr, 0, size);
return ptr;
}
/* helper function - assumes ptr != NULL */
static void *
resize(void *ptr, size_t size)
{
ralloc_header *child, *old, *info;
old = get_header(ptr);
info = realloc(old, size + sizeof(ralloc_header));
if (info == NULL)
return NULL;
/* Update parent and sibling's links to the reallocated node. */
if (info != old && info->parent != NULL) {
if (info->parent->child == old)
info->parent->child = info;
if (info->prev != NULL)
info->prev->next = info;
if (info->next != NULL)
info->next->prev = info;
}
/* Update child->parent links for all children */
for (child = info->child; child != NULL; child = child->next)
child->parent = info;
return PTR_FROM_HEADER(info);
}
void *
reralloc_size(const void *ctx, void *ptr, size_t size)
{
if (unlikely(ptr == NULL))
return ralloc_size(ctx, size);
assert(ralloc_parent(ptr) == ctx);
return resize(ptr, size);
}
void *
ralloc_array_size(const void *ctx, size_t size, unsigned count)
{
if (count > SIZE_MAX/size)
return NULL;
return ralloc_size(ctx, size * count);
}
void *
rzalloc_array_size(const void *ctx, size_t size, unsigned count)
{
if (count > SIZE_MAX/size)
return NULL;
return rzalloc_size(ctx, size * count);
}
void *
reralloc_array_size(const void *ctx, void *ptr, size_t size, unsigned count)
{
if (count > SIZE_MAX/size)
return NULL;
return reralloc_size(ctx, ptr, size * count);
}
void
ralloc_free(void *ptr)
{
ralloc_header *info;
if (ptr == NULL)
return;
info = get_header(ptr);
unlink_block(info);
unsafe_free(info);
}
static void
unlink_block(ralloc_header *info)
{
/* Unlink from parent & siblings */
if (info->parent != NULL) {
if (info->parent->child == info)
info->parent->child = info->next;
if (info->prev != NULL)
info->prev->next = info->next;
if (info->next != NULL)
info->next->prev = info->prev;
}
info->parent = NULL;
info->prev = NULL;
info->next = NULL;
}
static void
unsafe_free(ralloc_header *info)
{
/* Recursively free any children...don't waste time unlinking them. */
ralloc_header *temp;
while (info->child != NULL) {
temp = info->child;
info->child = temp->next;
unsafe_free(temp);
}
/* Free the block itself. Call the destructor first, if any. */
if (info->destructor != NULL)
info->destructor(PTR_FROM_HEADER(info));
free(info);
}
void
ralloc_steal(const void *new_ctx, void *ptr)
{
ralloc_header *info, *parent;
if (unlikely(ptr == NULL))
return;
info = get_header(ptr);
parent = get_header(new_ctx);
unlink_block(info);
add_child(parent, info);
}
void *
ralloc_parent(const void *ptr)
{
ralloc_header *info;
if (unlikely(ptr == NULL))
return NULL;
info = get_header(ptr);
return info->parent ? PTR_FROM_HEADER(info->parent) : NULL;
}
static void *autofree_context = NULL;
static void
autofree(void)
{
ralloc_free(autofree_context);
}
void *
ralloc_autofree_context(void)
{
if (unlikely(autofree_context == NULL)) {
autofree_context = ralloc_context(NULL);
atexit(autofree);
}
return autofree_context;
}
void
ralloc_set_destructor(const void *ptr, void(*destructor)(void *))
{
ralloc_header *info = get_header(ptr);
info->destructor = destructor;
}
char *
ralloc_strdup(const void *ctx, const char *str)
{
size_t n;
char *ptr;
if (unlikely(str == NULL))
return NULL;
n = strlen(str);
ptr = ralloc_array(ctx, char, n + 1);
memcpy(ptr, str, n);
ptr[n] = '\0';
return ptr;
}
char *
ralloc_strndup(const void *ctx, const char *str, size_t max)
{
size_t n;
char *ptr;
if (unlikely(str == NULL))
return NULL;
n = strlen(str);
if (n > max)
n = max;
ptr = ralloc_array(ctx, char, n + 1);
memcpy(ptr, str, n);
ptr[n] = '\0';
return ptr;
}
/* helper routine for strcat/strncat - n is the exact amount to copy */
static bool
cat(char **dest, const char *str, size_t n)
{
char *both;
size_t existing_length;
assert(dest != NULL && *dest != NULL);
existing_length = strlen(*dest);
both = resize(*dest, existing_length + n + 1);
if (unlikely(both == NULL))
return false;
memcpy(both + existing_length, str, n);
both[existing_length + n] = '\0';
*dest = both;
return true;
}
bool
ralloc_strcat(char **dest, const char *str)
{
return cat(dest, str, strlen(str));
}
bool
ralloc_strncat(char **dest, const char *str, size_t n)
{
/* Clamp n to the string length */
size_t str_length = strlen(str);
if (str_length < n)
n = str_length;
return cat(dest, str, n);
}
char *
ralloc_asprintf(const void *ctx, const char *fmt, ...)
{
char *ptr;
va_list args;
va_start(args, fmt);
ptr = ralloc_vasprintf(ctx, fmt, args);
va_end(args);
return ptr;
}
/* Return the length of the string that would be generated by a printf-style
* format and argument list, not including the \0 byte.
*/
static size_t
printf_length(const char *fmt, va_list untouched_args)
{
int size;
char junk;
/* Make a copy of the va_list so the original caller can still use it */
va_list args;
va_copy(args, untouched_args);
#ifdef _WIN32
/* We need to use _vcsprintf to calculate the size as vsnprintf returns -1
* if the number of characters to write is greater than count.
*/
size = _vscprintf(fmt, args);
(void)junk;
#else
size = vsnprintf(&junk, 1, fmt, args);
#endif
assert(size >= 0);
va_end(args);
return size;
}
char *
ralloc_vasprintf(const void *ctx, const char *fmt, va_list args)
{
size_t size = printf_length(fmt, args) + 1;
char *ptr = ralloc_size(ctx, size);
if (ptr != NULL)
vsnprintf(ptr, size, fmt, args);
return ptr;
}
bool
ralloc_asprintf_append(char **str, const char *fmt, ...)
{
bool success;
va_list args;
va_start(args, fmt);
success = ralloc_vasprintf_append(str, fmt, args);
va_end(args);
return success;
}
bool
ralloc_vasprintf_append(char **str, const char *fmt, va_list args)
{
size_t existing_length;
assert(str != NULL);
existing_length = *str ? strlen(*str) : 0;
return ralloc_vasprintf_rewrite_tail(str, &existing_length, fmt, args);
}
bool
ralloc_asprintf_rewrite_tail(char **str, size_t *start, const char *fmt, ...)
{
bool success;
va_list args;
va_start(args, fmt);
success = ralloc_vasprintf_rewrite_tail(str, start, fmt, args);
va_end(args);
return success;
}
bool
ralloc_vasprintf_rewrite_tail(char **str, size_t *start, const char *fmt,
va_list args)
{
size_t new_length;
char *ptr;
assert(str != NULL);
if (unlikely(*str == NULL)) {
// Assuming a NULL context is probably bad, but it's expected behavior.
*str = ralloc_vasprintf(NULL, fmt, args);
return true;
}
new_length = printf_length(fmt, args);
ptr = resize(*str, *start + new_length + 1);
if (unlikely(ptr == NULL))
return false;
vsnprintf(ptr + *start, new_length + 1, fmt, args);
*str = ptr;
*start += new_length;
return true;
}