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/* Copyright (C) 2010-2020 The RetroArch team
*
* ---------------------------------------------------------------------------------------
* The following license statement only applies to this file (rzip_stream.h).
* ---------------------------------------------------------------------------------------
*
* 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 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.
*/
#ifndef _LIBRETRO_SDK_FILE_RZIP_STREAM_H
#define _LIBRETRO_SDK_FILE_RZIP_STREAM_H
#include <stdio.h>
#include <stdint.h>
#include <stddef.h>
#include <stdarg.h>
#include <retro_common_api.h>
RETRO_BEGIN_DECLS
/* Rudimentary interface for streaming data to/from a
* zlib-compressed chunk-based RZIP archive file.
*
* This is somewhat less efficient than using regular
* gzip code, but this is by design - the intention here
* is to create an interface that integrates seamlessly
* with normal RetroArch functionality, using only
* standard/existing libretro-common routines.
* (Actual efficiency is pretty good, regardless:
* archived file size is almost identical to a solid
* zip file, and compression/decompression speed is
* not substantially worse than external archiving tools;
* it is certainly acceptable for use in real-time
* frontend applications)
*
* When reading existing files, uncompressed content
* is handled automatically. File type (compressed/
* uncompressed) is detected via the RZIP header.
*
* ## RZIP file format:
*
* <file id header>: 8 bytes
* - [#][R][Z][I][P][v][file format version][#]
* <uncompressed chunk size>: 4 bytes, little endian order
* - nominal (maximum) size of each uncompressed
* chunk, in bytes
* <total uncompressed data size>: 8 bytes, little endian order
* <size of next compressed chunk>: 4 bytes, little endian order
* - size on-disk of next compressed data
* chunk, in bytes
* <next compressed chunk>: n bytes of zlib compressed data
* ...
* <size of next compressed chunk> : repeated until end of file
* <next compressed chunk> :
*
*/
/* Prevent direct access to rzipstream_t members */
typedef struct rzipstream rzipstream_t;
/* File Open */
/* Opens a new or existing RZIP file
* > Supported 'mode' values are:
* - RETRO_VFS_FILE_ACCESS_READ
* - RETRO_VFS_FILE_ACCESS_WRITE
* > When reading, 'path' may reference compressed
* or uncompressed data
* Returns NULL if arguments are invalid, file
* is invalid or an IO error occurs */
rzipstream_t* rzipstream_open(const char *path, unsigned mode);
/* File Read */
/* Reads (a maximum of) 'len' bytes from an RZIP file.
* Returns actual number of bytes read, or -1 in
* the event of an error */
int64_t rzipstream_read(rzipstream_t *stream, void *data, int64_t len);
/* Reads next character from an RZIP file.
* Returns character value, or EOF if no data
* remains.
* Note: Always returns EOF if file is open
* for writing. */
int rzipstream_getc(rzipstream_t *stream);
/* Reads one line from an RZIP file and stores it
* in the character array pointed to by 's'.
* It stops reading when either (len-1) characters
* are read, the newline character is read, or the
* end-of-file is reached, whichever comes first.
* On success, returns 's'. In the event of an error,
* or if end-of-file is reached and no characters
* have been read, returns NULL. */
char* rzipstream_gets(rzipstream_t *stream, char *s, size_t len);
/* Reads all data from file specified by 'path' and
* copies it to 'buf'.
* - 'buf' will be allocated and must be free()'d manually.
* - Allocated 'buf' size is equal to 'len'.
* Returns false in the event of an error */
bool rzipstream_read_file(const char *path, void **buf, int64_t *len);
/* File Write */
/* Writes 'len' bytes to an RZIP file.
* Returns actual number of bytes written, or -1
* in the event of an error */
int64_t rzipstream_write(rzipstream_t *stream, const void *data, int64_t len);
/* Writes a single character to an RZIP file.
* Returns character written, or EOF in the event
* of an error */
int rzipstream_putc(rzipstream_t *stream, int c);
/* Writes a variable argument list to an RZIP file.
* Ugly 'internal' function, required to enable
* 'printf' support in the higher level 'interface_stream'.
* Returns actual number of bytes written, or -1
* in the event of an error */
int rzipstream_vprintf(rzipstream_t *stream, const char* format, va_list args);
/* Writes formatted output to an RZIP file.
* Returns actual number of bytes written, or -1
* in the event of an error */
int rzipstream_printf(rzipstream_t *stream, const char* format, ...);
/* Writes contents of 'data' buffer to file
* specified by 'path'.
* Returns false in the event of an error */
bool rzipstream_write_file(const char *path, const void *data, int64_t len);
/* File Control */
/* Sets file position to the beginning of the
* specified RZIP file.
* Note: It is not recommended to rewind a file
* that is open for writing, since the caller
* may end up with a file containing junk data
* at the end (harmless, but a waste of space). */
void rzipstream_rewind(rzipstream_t *stream);
/* File Status */
/* Returns total size (in bytes) of the *uncompressed*
* data in an RZIP file.
* (If reading an uncompressed file, this corresponds
* to the 'physical' file size in bytes)
* Returns -1 in the event of a error. */
int64_t rzipstream_get_size(rzipstream_t *stream);
/* Returns EOF when no further *uncompressed* data
* can be read from an RZIP file. */
int rzipstream_eof(rzipstream_t *stream);
/* Returns the offset of the current byte of *uncompressed*
* data relative to the beginning of an RZIP file.
* Returns -1 in the event of a error. */
int64_t rzipstream_tell(rzipstream_t *stream);
/* Returns true if specified RZIP file contains
* compressed content */
bool rzipstream_is_compressed(rzipstream_t *stream);
/* File Close */
/* Closes RZIP file. If file is open for writing,
* flushes any remaining buffered data to disk.
* Returns -1 in the event of a error. */
int rzipstream_close(rzipstream_t *stream);
RETRO_END_DECLS
#endif
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