BLI_filereader.h

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/* SPDX-FileCopyrightText: 2001-2002 NaN Holding BV. All rights reserved.
 *
 * SPDX-License-Identifier: GPL-2.0-or-later */

 
#pragma once
 
#ifdef WIN32
#  include "BLI_winstuff.h"
#else
#  include <sys/types.h>
#endif
 
#include "BLI_compiler_attrs.h"
#include "BLI_utildefines.h"
 
#if defined(_MSC_VER) || defined(__APPLE__) || defined(__HAIKU__) || defined(__NetBSD__) || \
    defined(__OpenBSD__)
typedef int64_t off64_t;
#endif
 
struct FileReader;
 
typedef int64_t (*FileReaderReadFn)(struct FileReader *reader, void *buffer, size_t size);
typedef off64_t (*FileReaderSeekFn)(struct FileReader *reader, off64_t offset, int whence);
typedef void (*FileReaderCloseFn)(struct FileReader *reader);

typedef struct FileReader {
  FileReaderReadFn read;
  FileReaderSeekFn seek;
  FileReaderCloseFn close;
 
  off64_t offset;
} FileReader;
 
/* Functions for opening the various types of FileReader.
 * They either succeed and return a valid FileReader, or fail and return NULL.
 *
 * If a FileReader is created, it has to be cleaned up and freed by calling its close()
 * function unless another FileReader has taken ownership - for example, `Zstd` & `Gzip`
 * take over the base FileReader and will clean it up when their clean() is called.
 */

FileReader *BLI_filereader_new_file(int filedes) ATTR_WARN_UNUSED_RESULT;
FileReader *BLI_filereader_new_mmap(int filedes) ATTR_WARN_UNUSED_RESULT;
FileReader *BLI_filereader_new_memory(const void *data, size_t len) ATTR_WARN_UNUSED_RESULT
    ATTR_NONNULL();
FileReader *BLI_filereader_new_zstd(FileReader *base) ATTR_WARN_UNUSED_RESULT ATTR_NONNULL();
FileReader *BLI_filereader_new_gzip(FileReader *base) ATTR_WARN_UNUSED_RESULT ATTR_NONNULL();