blob: 45881b2baca76afd16bf45e966923eb4088283ff [file] [log] [blame]
/* mz_strm_mem.c -- Stream for memory access
part of the minizip-ng project
This interface is designed to access memory rather than files.
We do use a region of memory to put data in to and take it out of.
Based on Unzip ioapi.c version 0.22, May 19th, 2003
Copyright (C) Nathan Moinvaziri
https://github.com/zlib-ng/minizip-ng
Copyright (C) 2003 Justin Fletcher
Copyright (C) 1998-2003 Gilles Vollant
https://www.winimage.com/zLibDll/minizip.html
This program is distributed under the terms of the same license as zlib.
See the accompanying LICENSE file for the full text of the license.
*/
#include "mz.h"
#include "mz_strm.h"
#include "mz_strm_mem.h"
/***************************************************************************/
static mz_stream_vtbl mz_stream_mem_vtbl = {
mz_stream_mem_open,
mz_stream_mem_is_open,
mz_stream_mem_read,
mz_stream_mem_write,
mz_stream_mem_tell,
mz_stream_mem_seek,
mz_stream_mem_close,
mz_stream_mem_error,
mz_stream_mem_create,
mz_stream_mem_delete,
NULL,
NULL
};
/***************************************************************************/
typedef struct mz_stream_mem_s {
mz_stream stream;
int32_t mode;
uint8_t *buffer; /* Memory buffer pointer */
int32_t size; /* Size of the memory buffer */
int32_t limit; /* Furthest we've written */
int32_t position; /* Current position in the memory */
int32_t grow_size; /* Size to grow when full */
} mz_stream_mem;
/***************************************************************************/
static int32_t mz_stream_mem_set_size(void *stream, int32_t size) {
mz_stream_mem *mem = (mz_stream_mem *)stream;
int32_t new_size = size;
uint8_t *new_buf = NULL;
new_buf = (uint8_t *)malloc((uint32_t)new_size);
if (!new_buf)
return MZ_BUF_ERROR;
if (mem->buffer) {
memcpy(new_buf, mem->buffer, mem->size);
free(mem->buffer);
}
mem->buffer = new_buf;
mem->size = new_size;
return MZ_OK;
}
int32_t mz_stream_mem_open(void *stream, const char *path, int32_t mode) {
mz_stream_mem *mem = (mz_stream_mem *)stream;
int32_t err = MZ_OK;
MZ_UNUSED(path);
mem->mode = mode;
mem->limit = 0;
mem->position = 0;
if (mem->mode & MZ_OPEN_MODE_CREATE)
err = mz_stream_mem_set_size(stream, mem->grow_size);
else
mem->limit = mem->size;
return err;
}
int32_t mz_stream_mem_is_open(void *stream) {
mz_stream_mem *mem = (mz_stream_mem *)stream;
if (!mem->buffer)
return MZ_OPEN_ERROR;
return MZ_OK;
}
int32_t mz_stream_mem_read(void *stream, void *buf, int32_t size) {
mz_stream_mem *mem = (mz_stream_mem *)stream;
if (size > mem->size - mem->position)
size = mem->size - mem->position;
if (mem->position + size > mem->limit)
size = mem->limit - mem->position;
if (size <= 0)
return 0;
memcpy(buf, mem->buffer + mem->position, size);
mem->position += size;
return size;
}
int32_t mz_stream_mem_write(void *stream, const void *buf, int32_t size) {
mz_stream_mem *mem = (mz_stream_mem *)stream;
int32_t new_size = 0;
int32_t err = MZ_OK;
if (!size)
return size;
if (size > mem->size - mem->position) {
if (mem->mode & MZ_OPEN_MODE_CREATE) {
new_size = mem->size;
if (size < mem->grow_size)
new_size += mem->grow_size;
else
new_size += size;
err = mz_stream_mem_set_size(stream, new_size);
if (err != MZ_OK)
return err;
} else {
size = mem->size - mem->position;
}
}
memcpy(mem->buffer + mem->position, buf, size);
mem->position += size;
if (mem->position > mem->limit)
mem->limit = mem->position;
return size;
}
int64_t mz_stream_mem_tell(void *stream) {
mz_stream_mem *mem = (mz_stream_mem *)stream;
return mem->position;
}
int32_t mz_stream_mem_seek(void *stream, int64_t offset, int32_t origin) {
mz_stream_mem *mem = (mz_stream_mem *)stream;
int64_t new_pos = 0;
int32_t err = MZ_OK;
switch (origin) {
case MZ_SEEK_CUR:
new_pos = mem->position + offset;
break;
case MZ_SEEK_END:
new_pos = mem->limit + offset;
break;
case MZ_SEEK_SET:
new_pos = offset;
break;
default:
return MZ_SEEK_ERROR;
}
if (new_pos > mem->size) {
if ((mem->mode & MZ_OPEN_MODE_CREATE) == 0)
return MZ_SEEK_ERROR;
err = mz_stream_mem_set_size(stream, (int32_t)new_pos);
if (err != MZ_OK)
return err;
} else if (new_pos < 0) {
return MZ_SEEK_ERROR;
}
mem->position = (int32_t)new_pos;
return MZ_OK;
}
int32_t mz_stream_mem_close(void *stream) {
MZ_UNUSED(stream);
/* We never return errors */
return MZ_OK;
}
int32_t mz_stream_mem_error(void *stream) {
MZ_UNUSED(stream);
/* We never return errors */
return MZ_OK;
}
void mz_stream_mem_set_buffer(void *stream, void *buf, int32_t size) {
mz_stream_mem *mem = (mz_stream_mem *)stream;
mem->buffer = (uint8_t *)buf;
mem->size = size;
mem->limit = size;
}
int32_t mz_stream_mem_get_buffer(void *stream, const void **buf) {
return mz_stream_mem_get_buffer_at(stream, 0, buf);
}
int32_t mz_stream_mem_get_buffer_at(void *stream, int64_t position, const void **buf) {
mz_stream_mem *mem = (mz_stream_mem *)stream;
if (!buf || position < 0 || !mem->buffer|| mem->size < position)
return MZ_SEEK_ERROR;
*buf = mem->buffer + position;
return MZ_OK;
}
int32_t mz_stream_mem_get_buffer_at_current(void *stream, const void **buf) {
mz_stream_mem *mem = (mz_stream_mem *)stream;
return mz_stream_mem_get_buffer_at(stream, mem->position, buf);
}
void mz_stream_mem_get_buffer_length(void *stream, int32_t *length) {
mz_stream_mem *mem = (mz_stream_mem *)stream;
*length = mem->limit;
}
void mz_stream_mem_set_buffer_limit(void *stream, int32_t limit) {
mz_stream_mem *mem = (mz_stream_mem *)stream;
mem->limit = limit;
}
void mz_stream_mem_set_grow_size(void *stream, int32_t grow_size) {
mz_stream_mem *mem = (mz_stream_mem *)stream;
mem->grow_size = grow_size;
}
void *mz_stream_mem_create(void) {
mz_stream_mem *mem = (mz_stream_mem *)calloc(1, sizeof(mz_stream_mem));
if (mem) {
mem->stream.vtbl = &mz_stream_mem_vtbl;
mem->grow_size = 4096;
}
return mem;
}
void mz_stream_mem_delete(void **stream) {
mz_stream_mem *mem = NULL;
if (!stream)
return;
mem = (mz_stream_mem *)*stream;
if (mem) {
if ((mem->mode & MZ_OPEN_MODE_CREATE) && (mem->buffer))
free(mem->buffer);
free(mem);
}
*stream = NULL;
}
void *mz_stream_mem_get_interface(void) {
return (void *)&mz_stream_mem_vtbl;
}