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curl/lib/bufref.c
Patrick Monnerat 34cf40321c
bufref: buffer reference support
A struct bufref holds a buffer pointer, a data size and a destructor.
When freed or its contents are changed, the previous buffer is implicitly
released by the associated destructor. The data size, although not used
internally, allows binary data support.

A unit test checks its handling methods: test 1661

Closes #6654
2021-04-22 09:05:53 +02:00

128 lines
3.1 KiB
C

/***************************************************************************
* _ _ ____ _
* Project ___| | | | _ \| |
* / __| | | | |_) | |
* | (__| |_| | _ <| |___
* \___|\___/|_| \_\_____|
*
* Copyright (C) 2021, Daniel Stenberg, <daniel@haxx.se>, et al.
*
* This software is licensed as described in the file COPYING, which
* you should have received as part of this distribution. The terms
* are also available at https://curl.se/docs/copyright.html.
*
* You may opt to use, copy, modify, merge, publish, distribute and/or sell
* copies of the Software, and permit persons to whom the Software is
* furnished to do so, under the terms of the COPYING file.
*
* This software is distributed on an "AS IS" basis, WITHOUT WARRANTY OF ANY
* KIND, either express or implied.
*
***************************************************************************/
#include "curl_setup.h"
#include "urldata.h"
#include "bufref.h"
#include "curl_memory.h"
#include "memdebug.h"
#define SIGNATURE 0x5c48e9b2 /* Random pattern. */
/*
* Init a bufref struct.
*/
void Curl_bufref_init(struct bufref *br)
{
DEBUGASSERT(br);
br->dtor = NULL;
br->ptr = NULL;
br->len = 0;
#ifdef DEBUGBUILD
br->signature = SIGNATURE;
#endif
}
/*
* Free the buffer and re-init the necessary fields. It doesn't touch the
* 'signature' field and thus this buffer reference can be reused.
*/
void Curl_bufref_free(struct bufref *br)
{
DEBUGASSERT(br);
DEBUGASSERT(br->signature == SIGNATURE);
DEBUGASSERT(br->ptr || !br->len);
if(br->ptr && br->dtor)
br->dtor((void *) br->ptr);
br->dtor = NULL;
br->ptr = NULL;
br->len = 0;
}
/*
* Set the buffer reference to new values. The previously referenced buffer
* is released before assignment.
*/
void Curl_bufref_set(struct bufref *br, const void *ptr, size_t len,
void (*dtor)(void *))
{
DEBUGASSERT(ptr || !len);
DEBUGASSERT(len <= CURL_MAX_INPUT_LENGTH);
Curl_bufref_free(br);
br->ptr = (const unsigned char *) ptr;
br->len = len;
br->dtor = dtor;
}
/*
* Get a pointer to the referenced buffer.
*/
const unsigned char *Curl_bufref_ptr(const struct bufref *br)
{
DEBUGASSERT(br);
DEBUGASSERT(br->signature == SIGNATURE);
DEBUGASSERT(br->ptr || !br->len);
return br->ptr;
}
/*
* Get the length of the referenced buffer data.
*/
size_t Curl_bufref_len(const struct bufref *br)
{
DEBUGASSERT(br);
DEBUGASSERT(br->signature == SIGNATURE);
DEBUGASSERT(br->ptr || !br->len);
return br->len;
}
CURLcode Curl_bufref_memdup(struct bufref *br, const void *ptr, size_t len)
{
unsigned char *cpy = NULL;
DEBUGASSERT(br);
DEBUGASSERT(br->signature == SIGNATURE);
DEBUGASSERT(br->ptr || !br->len);
DEBUGASSERT(ptr || !len);
DEBUGASSERT(len <= CURL_MAX_INPUT_LENGTH);
if(ptr) {
cpy = malloc(len + 1);
if(!cpy)
return CURLE_OUT_OF_MEMORY;
if(len)
memcpy(cpy, ptr, len);
cpy[len] = '\0';
}
Curl_bufref_set(br, cpy, len, curl_free);
return CURLE_OK;
}