godot/thirdparty/libktx/lib/memstream.c

562 lines
16 KiB
C

/* -*- tab-width: 4; -*- */
/* vi: set sw=2 ts=4 expandtab: */
/*
* Copyright 2010-2020 The Khronos Group Inc.
* SPDX-License-Identifier: Apache-2.0
*/
/**
* @file
* @~English
*
* @brief Implementation of ktxStream for memory.
*
* @author Maksim Kolesin, Under Development
* @author Georg Kolling, Imagination Technology
* @author Mark Callow, HI Corporation
*/
#include <assert.h>
#include <string.h>
#include <stdlib.h>
#include "ktx.h"
#include "ktxint.h"
#include "memstream.h"
/**
* @brief Default allocation size for a ktxMemStream.
*/
#define KTX_MEM_DEFAULT_ALLOCATED_SIZE 256
/**
* @brief Structure to store information about data allocated for ktxMemStream.
*/
struct ktxMem
{
const ktx_uint8_t* robytes;/*!< pointer to read-only data */
ktx_uint8_t* bytes; /*!< pointer to rw data. */
ktx_size_t alloc_size; /*!< allocated size of the memory block. */
ktx_size_t used_size; /*!< bytes used. Effectively the write position. */
ktx_off_t pos; /*!< read/write position. */
};
static KTX_error_code ktxMem_expand(ktxMem* pMem, const ktx_size_t size);
/**
* @brief Initialize a ktxMem struct for read-write.
*
* Memory for the stream data is allocated internally but the
* caller is responsible for freeing the memory. A pointer to
* the memory can be obtained with ktxMem_getdata().
*
* @sa ktxMem_getdata.
*
* @param [in] pMem pointer to the @c ktxMem to initialize.
*/
static KTX_error_code
ktxMem_construct(ktxMem* pMem)
{
pMem->pos = 0;
pMem->alloc_size = 0;
pMem->robytes = 0;
pMem->bytes = 0;
pMem->used_size = 0;
return ktxMem_expand(pMem, KTX_MEM_DEFAULT_ALLOCATED_SIZE);
}
/**
* @brief Create & initialize a ktxMem struct for read-write.
*
* @sa ktxMem_construct.
*
* @param [in,out] ppMem pointer to the location in which to return
* a pointer to the newly created @c ktxMem.
*
* @return KTX_SUCCESS on success, KTX_OUT_OF_MEMORY on error.
*
* @exception KTX_OUT_OF_MEMORY System failed to allocate sufficient pMemory.
*/
static KTX_error_code
ktxMem_create(ktxMem** ppMem)
{
ktxMem* pNewMem = (ktxMem*)malloc(sizeof(ktxMem));
if (pNewMem) {
KTX_error_code result = ktxMem_construct(pNewMem);
if (result == KTX_SUCCESS)
*ppMem = pNewMem;
return result;
}
else {
return KTX_OUT_OF_MEMORY;
}
}
/**
* @brief Initialize a ktxMem struct for read-only.
*
* @param [in] pMem pointer to the @c ktxMem to initialize.
* @param [in] bytes pointer to the data to be read.
* @param [in] numBytes number of bytes of data.
*/
static void
ktxMem_construct_ro(ktxMem* pMem, const void* bytes, ktx_size_t numBytes)
{
pMem->pos = 0;
pMem->robytes = bytes;
pMem->bytes = 0;
pMem->used_size = numBytes;
pMem->alloc_size = numBytes;
}
/**
* @brief Create & initialize a ktxMem struct for read-only.
*
* @sa ktxMem_construct.
*
* @param [in,out] ppMem pointer to the location in which to return
* a pointer to the newly created @c ktxMem.
* @param [in] bytes pointer to the data to be read.
* @param [in] numBytes number of bytes of data.
*
* @return KTX_SUCCESS on success, KTX_OUT_OF_MEMORY on error.
*
* @exception KTX_OUT_OF_MEMORY System failed to allocate sufficient pMemory.
*/
static KTX_error_code
ktxMem_create_ro(ktxMem** ppMem, const void* bytes, ktx_size_t numBytes)
{
ktxMem* pNewMem = (ktxMem*)malloc(sizeof(ktxMem));
if (pNewMem) {
ktxMem_construct_ro(pNewMem, bytes, numBytes);
*ppMem = pNewMem;
return KTX_SUCCESS;
}
else {
return KTX_OUT_OF_MEMORY;
}
}
/*
* ktxMem_destruct not needed as ktxMem_construct caller is reponsible
* for freeing the data written.
*/
/**
* @brief Free the memory of a struct ktxMem.
*
* @param pMem pointer to ktxMem to free.
*/
static void
ktxMem_destroy(ktxMem* pMem, ktx_bool_t freeData)
{
assert(pMem != NULL);
if (freeData) {
free(pMem->bytes);
}
free(pMem);
}
#ifdef KTXMEM_CLEAR_USED
/**
* @brief Clear the data of a memory stream.
*
* @param pMem pointer to ktxMem to clear.
*/
static void
ktxMem_clear(ktxMem* pMem)
{
assert(pMem != NULL);
memset(pMem, 0, sizeof(ktxMem));
}
#endif
/**
* @~English
* @brief Expand a ktxMem to fit to a new size.
*
* @param [in] pMem pointer to ktxMem struct to expand.
* @param [in] newsize minimum new size required.
*
* @return KTX_SUCCESS on success, KTX_OUT_OF_MEMORY on error.
*
* @exception KTX_OUT_OF_MEMORY System failed to allocate sufficient pMemory.
*/
static KTX_error_code
ktxMem_expand(ktxMem *pMem, const ktx_size_t newsize)
{
ktx_size_t new_alloc_size;
assert(pMem != NULL && newsize != 0);
new_alloc_size = pMem->alloc_size == 0 ?
KTX_MEM_DEFAULT_ALLOCATED_SIZE : pMem->alloc_size;
while (new_alloc_size < newsize) {
ktx_size_t alloc_size = new_alloc_size;
new_alloc_size <<= 1;
if (new_alloc_size < alloc_size) {
/* Overflow. Set to maximum size. newsize can't be larger. */
new_alloc_size = (ktx_size_t)-1L;
}
}
if (new_alloc_size == pMem->alloc_size)
return KTX_SUCCESS;
if (!pMem->bytes)
pMem->bytes = (ktx_uint8_t*)malloc(new_alloc_size);
else
pMem->bytes = (ktx_uint8_t*)realloc(pMem->bytes, new_alloc_size);
if (!pMem->bytes)
{
pMem->alloc_size = 0;
pMem->used_size = 0;
return KTX_OUT_OF_MEMORY;
}
pMem->alloc_size = new_alloc_size;
return KTX_SUCCESS;
}
/**
* @~English
* @brief Read bytes from a ktxMemStream.
*
* @param [in] str pointer to ktxMem struct, converted to a void*, that
* specifies an input stream.
* @param [in,out] dst pointer to memory where to copy read bytes.
* @param [in,out] count pointer to number of bytes to read.
*
* @return KTX_SUCCESS on success, KTX_INVALID_VALUE on error.
*
* @exception KTX_INVALID_VALUE @p str or @p dst is @c NULL or @p str->data is
* @c NULL.
* @exception KTX_FILE_UNEXPECTED_EOF not enough data to satisfy the request.
*/
static
KTX_error_code ktxMemStream_read(ktxStream* str, void* dst, const ktx_size_t count)
{
ktxMem* mem;
ktx_off_t newpos;
const ktx_uint8_t* bytes;
if (!str || (mem = str->data.mem)== 0)
return KTX_INVALID_VALUE;
newpos = mem->pos + count;
/* The first clause checks for overflow. */
if (newpos < mem->pos || (ktx_uint32_t)newpos > mem->used_size)
return KTX_FILE_UNEXPECTED_EOF;
bytes = mem->robytes ? mem->robytes : mem->bytes;
memcpy(dst, bytes + mem->pos, count);
mem->pos = newpos;
return KTX_SUCCESS;
}
/**
* @~English
* @brief Skip bytes in a ktxMemStream.
*
* @param [in] str pointer to the ktxStream on which to operate.
* @param [in] count number of bytes to skip.
*
* @return KTX_SUCCESS on success, KTX_INVALID_VALUE on error.
*
* @exception KTX_INVALID_VALUE @p str or @p mem is @c NULL or sufficient
* data is not available in ktxMem.
* @exception KTX_FILE_UNEXPECTED_EOF not enough data to satisfy the request.
*/
static
KTX_error_code ktxMemStream_skip(ktxStream* str, const ktx_size_t count)
{
ktxMem* mem;
ktx_off_t newpos;
if (!str || (mem = str->data.mem) == 0)
return KTX_INVALID_VALUE;
newpos = mem->pos + count;
/* The first clause checks for overflow. */
if (newpos < mem->pos || (ktx_uint32_t)newpos > mem->used_size)
return KTX_FILE_UNEXPECTED_EOF;
mem->pos = newpos;
return KTX_SUCCESS;
}
/**
* @~English
* @brief Write bytes to a ktxMemStream.
*
* @param [out] str pointer to the ktxStream that specifies the destination.
* @param [in] src pointer to the array of elements to be written,
* converted to a const void*.
* @param [in] size size in bytes of each element to be written.
* @param [in] count number of elements, each one with a @p size of size
* bytes.
*
* @return KTX_SUCCESS on success, other KTX_* enum values on error.
*
* @exception KTX_FILE_OVERFLOW write would result in file exceeding the
* maximum permissible size.
* @exception KTX_INVALID_OPERATION @p str is a read-only stream.
* @exception KTX_INVALID_VALUE @p dst is @c NULL or @p mem is @c NULL.
* @exception KTX_OUT_OF_MEMORY See ktxMem_expand() for causes.
*/
static
KTX_error_code ktxMemStream_write(ktxStream* str, const void* src,
const ktx_size_t size, const ktx_size_t count)
{
ktxMem* mem;
KTX_error_code rc = KTX_SUCCESS;
ktx_size_t new_size;
if (!str || (mem = str->data.mem) == 0)
return KTX_INVALID_VALUE;
if (mem->robytes)
return KTX_INVALID_OPERATION; /* read-only */
new_size = mem->pos + (size*count);
//if (new_size < mem->used_size)
if ((ktx_off_t)new_size < mem->pos)
return KTX_FILE_OVERFLOW;
if (mem->alloc_size < new_size) {
rc = ktxMem_expand(mem, new_size);
if (rc != KTX_SUCCESS)
return rc;
}
memcpy(mem->bytes + mem->pos, src, size*count);
mem->pos += size*count;
if (mem->pos > (ktx_off_t)mem->used_size)
mem->used_size = mem->pos;
return KTX_SUCCESS;
}
/**
* @~English
* @brief Get the current read/write position in a ktxMemStream.
*
* @param [in] str pointer to the ktxStream to query.
* @param [in,out] off pointer to variable to receive the offset value.
*
* @return KTX_SUCCESS on success, other KTX_* enum values on error.
*
* @exception KTX_INVALID_VALUE @p str or @p pos is @c NULL.
*/
static
KTX_error_code ktxMemStream_getpos(ktxStream* str, ktx_off_t* const pos)
{
if (!str || !pos)
return KTX_INVALID_VALUE;
assert(str->type == eStreamTypeMemory);
*pos = str->data.mem->pos;
return KTX_SUCCESS;
}
/**
* @~English
* @brief Set the current read/write position in a ktxMemStream.
*
* Offset of 0 is the start of the file.
*
* @param [in] str pointer to the ktxStream whose r/w position is to be set.
* @param [in] off pointer to the offset value to set.
*
* @return KTX_SUCCESS on success, other KTX_* enum values on error.
*
* @exception KTX_INVALID_VALUE @p str is @c NULL.
* @exception KTX_INVALID_OPERATION @p pos > size of the allocated memory.
*/
static
KTX_error_code ktxMemStream_setpos(ktxStream* str, ktx_off_t pos)
{
if (!str)
return KTX_INVALID_VALUE;
assert(str->type == eStreamTypeMemory);
if (pos > (ktx_off_t)str->data.mem->alloc_size)
return KTX_INVALID_OPERATION;
str->data.mem->pos = pos;
return KTX_SUCCESS;
}
/**
* @~English
* @brief Get a pointer to a ktxMemStream's data.
*
* Gets a pointer to data that has been written to the stream. Returned
* pointer will be 0 if stream is read-only.
*
* @param [in] str pointer to the ktxStream whose data pointer is to
* be queried.
* @param [in,out] ppBytes pointer to a variable in which the data pointer
* will be written.
*
* @return KTX_SUCCESS on success, other KTX_* enum values on error.
*
* @exception KTX_INVALID_VALUE @p str or @p ppBytes is @c NULL.
*/
KTX_error_code ktxMemStream_getdata(ktxStream* str, ktx_uint8_t** ppBytes)
{
if (!str || !ppBytes)
return KTX_INVALID_VALUE;
assert(str->type == eStreamTypeMemory);
*ppBytes = str->data.mem->bytes;
return KTX_SUCCESS;
}
/**
* @~English
* @brief Get the size of a ktxMemStream in bytes.
*
* @param [in] str pointer to the ktxStream whose size is to be queried.
* @param [in,out] size pointer to a variable in which size will be written.
*
* @return KTX_SUCCESS on success, other KTX_* enum values on error.
*
* @exception KTX_INVALID_VALUE @p str or @p pSize is @c NULL.
*/
static
KTX_error_code ktxMemStream_getsize(ktxStream* str, ktx_size_t* pSize)
{
if (!str || !pSize)
return KTX_INVALID_VALUE;
assert(str->type == eStreamTypeMemory);
*pSize = str->data.mem->used_size;
return KTX_SUCCESS;
}
/**
* @~English
* @brief Setup ktxMemStream function pointers.
*/
void
ktxMemStream_setup(ktxStream* str)
{
str->type = eStreamTypeMemory;
str->read = ktxMemStream_read;
str->skip = ktxMemStream_skip;
str->write = ktxMemStream_write;
str->getpos = ktxMemStream_getpos;
str->setpos = ktxMemStream_setpos;
str->getsize = ktxMemStream_getsize;
str->destruct = ktxMemStream_destruct;
}
/**
* @~English
* @brief Initialize a read-write ktxMemStream.
*
* Memory is allocated as data is written. The caller of this is
* responsible for freeing this memory unless @a freeOnDestruct
* is not KTX_FALSE.
*
* @param [in] str pointer to a ktxStream struct to initialize.
* @param [in] freeOnDestruct If not KTX_FALSE memory holding the data will
* be freed by the destructor.
*
* @return KTX_SUCCESS on success, other KTX_* enum values on error.
*
* @exception KTX_INVALID_VALUE @p str is @c NULL.
* @exception KTX_OUT_OF_MEMORY system failed to allocate sufficient memory.
*/
KTX_error_code ktxMemStream_construct(ktxStream* str,
ktx_bool_t freeOnDestruct)
{
ktxMem* mem;
KTX_error_code result = KTX_SUCCESS;
if (!str)
return KTX_INVALID_VALUE;
result = ktxMem_create(&mem);
if (KTX_SUCCESS == result) {
str->data.mem = mem;
ktxMemStream_setup(str);
str->closeOnDestruct = freeOnDestruct;
}
return result;
}
/**
* @~English
* @brief Initialize a read-only ktxMemStream.
*
* @param [in] str pointer to a ktxStream struct to initialize.
* @param [in] bytes pointer to an array of bytes containing the data.
* @param [in] numBytes size of array of data for ktxMemStream.
*
* @return KTX_SUCCESS on success, other KTX_* enum values on error.
*
* @exception KTX_INVALID_VALUE @p str or @p mem is @c NULL or @p numBytes
* is 0.
* or @p size is less than 0.
* @exception KTX_OUT_OF_MEMORY system failed to allocate sufficient memory.
*/
KTX_error_code ktxMemStream_construct_ro(ktxStream* str,
const ktx_uint8_t* bytes,
const ktx_size_t numBytes)
{
ktxMem* mem;
KTX_error_code result = KTX_SUCCESS;
if (!str || !bytes || numBytes == 0)
return KTX_INVALID_VALUE;
result = ktxMem_create_ro(&mem, bytes, numBytes);
if (KTX_SUCCESS == result) {
str->data.mem = mem;
ktxMemStream_setup(str);
str->closeOnDestruct = KTX_FALSE;
}
return result;
}
/**
* @~English
* @brief Free the memory used by a ktxMemStream.
*
* This only frees the memory used to store the data written to the stream,
* if the @c freeOnDestruct parameter to ktxMemStream_construct() was not
* @c KTX_FALSE. Otherwise it is the responsibility of the caller of
* ktxMemStream_construct() and a pointer to this memory should be retrieved
* using ktxMemStream_getdata() before calling this function.
*
* @sa ktxMemStream_construct, ktxMemStream_getdata.
*
* @param [in] str pointer to the ktxStream whose memory is
* to be freed.
*/
void
ktxMemStream_destruct(ktxStream* str)
{
assert(str && str->type == eStreamTypeMemory);
ktxMem_destroy(str->data.mem, str->closeOnDestruct);
str->data.mem = NULL;
}