/*
* This file is part of LibParserUtils.
* Licensed under the MIT License,
* http://www.opensource.org/licenses/mit-license.php
* Copyright 2008 John-Mark Bell <jmb@netsurf-browser.org>
*/
#include <string.h>
#include <parserutils/utils/buffer.h>
#define DEFAULT_SIZE (4096)
/**
* Create a memory buffer
*
* \param alloc Memory (de)allocation function
* \param pw Pointer to client-specific private data
* \param buffer Pointer to location to receive memory buffer
* \return PARSERUTILS_OK on success,
* PARSERUTILS_BADPARM on bad parameters,
* PARSERUTILS_NOMEM on memory exhausion
*/
parserutils_error parserutils_buffer_create(parserutils_alloc alloc, void *pw,
parserutils_buffer **buffer)
{
parserutils_buffer *b;
if (alloc == NULL || buffer == NULL)
return PARSERUTILS_BADPARM;
b = alloc(NULL, sizeof(parserutils_buffer), pw);
if (b == NULL)
return PARSERUTILS_NOMEM;
b->data = alloc(NULL, DEFAULT_SIZE, pw);
if (b->data == NULL) {
alloc(b, 0, pw);
return PARSERUTILS_NOMEM;
}
b->length = 0;
b->allocated = DEFAULT_SIZE;
b->alloc = alloc;
b->pw = pw;
*buffer = b;
return PARSERUTILS_OK;
}
/**
* Destroy a memory buffer
*
* \param buffer The buffer to destroy
* \return PARSERUTILS_OK on success, appropriate error otherwise
*/
parserutils_error parserutils_buffer_destroy(parserutils_buffer *buffer)
{
if (buffer == NULL)
return PARSERUTILS_BADPARM;
buffer->alloc(buffer->data, 0, buffer->pw);
buffer->alloc(buffer, 0, buffer->pw);
return PARSERUTILS_OK;
}
/**
* Append data to a memory buffer
*
* \param buffer The buffer to append to
* \param data The data to append
* \param len The length, in bytes, of the data to append
* \return PARSERUTILS_OK on success, appropriate error otherwise.
*/
parserutils_error parserutils_buffer_append(parserutils_buffer *buffer,
const uint8_t *data, size_t len)
{
while (len >= buffer->allocated - buffer->length) {
parserutils_error error = parserutils_buffer_grow(buffer);
if (error != PARSERUTILS_OK)
return error;
}
memcpy(buffer
->data
+ buffer
->length
, data
, len
);
buffer->length += len;
return PARSERUTILS_OK;
}
/**
* Insert data into a memory buffer
*
* \param buffer The buffer to insert into
* \param offset The offset into the buffer to insert at
* \param data The data to insert
* \param len The length, in bytes, of the data to insert
* \return PARSERUTILS_OK on success, appropriate error otherwise
*/
parserutils_error parserutils_buffer_insert(parserutils_buffer *buffer,
size_t offset, const uint8_t *data, size_t len)
{
if (offset > buffer->length)
return PARSERUTILS_BADPARM;
if (offset == buffer->length)
return parserutils_buffer_append(buffer, data, len);
while (len >= buffer->allocated - buffer->length) {
parserutils_error error = parserutils_buffer_grow(buffer);
if (error != PARSERUTILS_OK)
return error;
}
memmove(buffer
->data
+ offset
+ len
, buffer->data + offset, buffer->length - offset);
memcpy(buffer
->data
+ offset
, data
, len
);
buffer->length += len;
return PARSERUTILS_OK;
}
/**
* Discard a section of a memory buffer
*
* \param buffer The buffer to discard data from
* \param offset The offset into the buffer of the start of the section
* \param len The number of bytes to discard
* \return PARSERUTILS_OK on success, appropriate error otherwise.
*/
parserutils_error parserutils_buffer_discard(parserutils_buffer *buffer,
size_t offset, size_t len)
{
if (offset >= buffer->length || offset + len > buffer->length)
return PARSERUTILS_BADPARM;
memmove(buffer
->data
+ offset
, buffer
->data
+ offset
+ len
, buffer->length - len);
buffer->length -= len;
return PARSERUTILS_OK;
}
/**
* Extend the amount of space allocated for a memory buffer
*
* \param buffer The buffer to extend
* \return PARSERUTILS_OK on success, appropriate error otherwise.
*/
parserutils_error parserutils_buffer_grow(parserutils_buffer *buffer)
{
uint8_t *temp = buffer->alloc(buffer->data,
buffer->allocated * 2, buffer->pw);
if (temp == NULL)
return PARSERUTILS_NOMEM;
buffer->data = temp;
buffer->allocated *= 2;
return PARSERUTILS_OK;
}
parserutils_error parserutils_buffer_randomise(parserutils_buffer *buffer)
{
#ifndef NDEBUG
uint8_t *temp;
#endif
if (buffer == NULL)
return PARSERUTILS_BADPARM;
#ifndef NDEBUG
temp = buffer->alloc(NULL, buffer->allocated, buffer->pw);
if (temp == NULL)
return PARSERUTILS_NOMEM;
memcpy(temp
, buffer
->data
, buffer
->length
);
memset(buffer
->data
, 0xff, buffer
->length
);
/* Leak the buffer's current data, so we don't reuse it */
/* buffer->alloc(buffer->data, 0, buffer->pw); */
buffer->data = temp;
#endif
return PARSERUTILS_OK;
}