file_io.h

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// SPDX-License-Identifier: 0BSD
 
//
//
//  Author:     Lasse Collin
//
 
// Some systems have suboptimal BUFSIZ. Use a bit bigger value on them.
// We also need that IO_BUFFER_SIZE is a multiple of 8 (sizeof(uint64_t))
#if BUFSIZ <= 1024
#   define IO_BUFFER_SIZE 8192
#else
#   define IO_BUFFER_SIZE (BUFSIZ & ~7U)
#endif
 
#ifdef _MSC_VER
    // The first one renames both "struct stat" -> "struct _stat64"
    // and stat() -> _stat64(). The documentation mentions only
    // "struct __stat64", not "struct _stat64", but the latter
    // works too.
#   define stat _stat64
#   define fstat _fstat64
#   define off_t __int64
#endif
 
 
typedef union {
    uint8_t u8[IO_BUFFER_SIZE];
    uint32_t u32[IO_BUFFER_SIZE / sizeof(uint32_t)];
    uint64_t u64[IO_BUFFER_SIZE / sizeof(uint64_t)];
} io_buf;
 
 
typedef struct {
    const char *src_name;
 
    char *dest_name;
 
    int src_fd;
 
    int dest_fd;
 
    bool src_eof;
 
    bool src_has_seen_input;
 
    bool flush_needed;
 
    bool dest_try_sparse;
 
    off_t dest_pending_sparse;
 
    struct stat src_st;
 
    struct stat dest_st;
 
} file_pair;
 
 
extern void io_init(void);
 
 
#ifndef TUKLIB_DOSLIKE
extern void io_write_to_user_abort_pipe(void);
#endif
 
 
extern void io_no_sparse(void);
 
 
extern file_pair *io_open_src(const char *src_name);
 
 
extern bool io_open_dest(file_pair *pair);
 
 
extern void io_close(file_pair *pair, bool success);
 
 
extern size_t io_read(file_pair *pair, io_buf *buf, size_t size);
 
 
extern void io_fix_src_pos(file_pair *pair, size_t rewind_size);
 
 
extern bool io_seek_src(file_pair *pair, uint64_t pos);
 
 
extern bool io_pread(file_pair *pair, io_buf *buf, size_t size, uint64_t pos);
 
 
extern bool io_write(file_pair *pair, const io_buf *buf, size_t size);