| Denis Vlasenko | c4f623e | 2006-12-26 01:30:59 +0000 | [diff] [blame] | 1 | /* vi: set sw=4 ts=4: */ |
| 2 | /* |
| 3 | * io.h --- the I/O manager abstraction |
| 4 | * |
| 5 | * Copyright (C) 1993, 1994, 1995, 1996 Theodore Ts'o. |
| 6 | * |
| 7 | * %Begin-Header% |
| 8 | * This file may be redistributed under the terms of the GNU Public |
| 9 | * License. |
| 10 | * %End-Header% |
| 11 | */ |
| 12 | |
| 13 | #ifndef _EXT2FS_EXT2_IO_H |
| 14 | #define _EXT2FS_EXT2_IO_H |
| 15 | |
| 16 | /* |
| 17 | * ext2_loff_t is defined here since unix_io.c needs it. |
| 18 | */ |
| 19 | #if defined(__GNUC__) || defined(HAS_LONG_LONG) |
| 20 | typedef long long ext2_loff_t; |
| 21 | #else |
| 22 | typedef long ext2_loff_t; |
| 23 | #endif |
| 24 | |
| 25 | /* llseek.c */ |
| 26 | /* ext2_loff_t ext2fs_llseek (int, ext2_loff_t, int); */ |
| 27 | #ifdef CONFIG_LFS |
| 28 | # define ext2fs_llseek lseek64 |
| 29 | #else |
| 30 | # define ext2fs_llseek lseek |
| 31 | #endif |
| 32 | |
| 33 | typedef struct struct_io_manager *io_manager; |
| 34 | typedef struct struct_io_channel *io_channel; |
| 35 | |
| 36 | #define CHANNEL_FLAGS_WRITETHROUGH 0x01 |
| 37 | |
| 38 | struct struct_io_channel { |
| 39 | errcode_t magic; |
| 40 | io_manager manager; |
| 41 | char *name; |
| 42 | int block_size; |
| 43 | errcode_t (*read_error)(io_channel channel, |
| 44 | unsigned long block, |
| 45 | int count, |
| 46 | void *data, |
| 47 | size_t size, |
| 48 | int actual_bytes_read, |
| 49 | errcode_t error); |
| 50 | errcode_t (*write_error)(io_channel channel, |
| 51 | unsigned long block, |
| 52 | int count, |
| 53 | const void *data, |
| 54 | size_t size, |
| 55 | int actual_bytes_written, |
| 56 | errcode_t error); |
| 57 | int refcount; |
| 58 | int flags; |
| 59 | int reserved[14]; |
| 60 | void *private_data; |
| 61 | void *app_data; |
| 62 | }; |
| 63 | |
| 64 | struct struct_io_manager { |
| 65 | errcode_t magic; |
| 66 | const char *name; |
| 67 | errcode_t (*open)(const char *name, int flags, io_channel *channel); |
| 68 | errcode_t (*close)(io_channel channel); |
| 69 | errcode_t (*set_blksize)(io_channel channel, int blksize); |
| 70 | errcode_t (*read_blk)(io_channel channel, unsigned long block, |
| 71 | int count, void *data); |
| 72 | errcode_t (*write_blk)(io_channel channel, unsigned long block, |
| 73 | int count, const void *data); |
| 74 | errcode_t (*flush)(io_channel channel); |
| 75 | errcode_t (*write_byte)(io_channel channel, unsigned long offset, |
| 76 | int count, const void *data); |
| 77 | errcode_t (*set_option)(io_channel channel, const char *option, |
| 78 | const char *arg); |
| 79 | int reserved[14]; |
| 80 | }; |
| 81 | |
| 82 | #define IO_FLAG_RW 1 |
| 83 | |
| 84 | /* |
| 85 | * Convenience functions.... |
| 86 | */ |
| 87 | #define io_channel_close(c) ((c)->manager->close((c))) |
| 88 | #define io_channel_set_blksize(c,s) ((c)->manager->set_blksize((c),s)) |
| 89 | #define io_channel_read_blk(c,b,n,d) ((c)->manager->read_blk((c),b,n,d)) |
| 90 | #define io_channel_write_blk(c,b,n,d) ((c)->manager->write_blk((c),b,n,d)) |
| 91 | #define io_channel_flush(c) ((c)->manager->flush((c))) |
| 92 | #define io_channel_bumpcount(c) ((c)->refcount++) |
| 93 | |
| 94 | /* io_manager.c */ |
| 95 | extern errcode_t io_channel_set_options(io_channel channel, |
| 96 | const char *options); |
| 97 | extern errcode_t io_channel_write_byte(io_channel channel, |
| 98 | unsigned long offset, |
| 99 | int count, const void *data); |
| 100 | |
| 101 | /* unix_io.c */ |
| 102 | extern io_manager unix_io_manager; |
| 103 | |
| 104 | /* test_io.c */ |
| 105 | extern io_manager test_io_manager, test_io_backing_manager; |
| 106 | extern void (*test_io_cb_read_blk) |
| 107 | (unsigned long block, int count, errcode_t err); |
| 108 | extern void (*test_io_cb_write_blk) |
| 109 | (unsigned long block, int count, errcode_t err); |
| 110 | extern void (*test_io_cb_set_blksize) |
| 111 | (int blksize, errcode_t err); |
| 112 | |
| 113 | #endif /* _EXT2FS_EXT2_IO_H */ |
| 114 | |