Colin Cross | 28fa5bc | 2012-05-20 13:28:05 -0700 | [diff] [blame^] | 1 | /* |
| 2 | * Copyright (C) 2012 The Android Open Source Project |
| 3 | * |
| 4 | * Licensed under the Apache License, Version 2.0 (the "License"); |
| 5 | * you may not use this file except in compliance with the License. |
| 6 | * You may obtain a copy of the License at |
| 7 | * |
| 8 | * http://www.apache.org/licenses/LICENSE-2.0 |
| 9 | * |
| 10 | * Unless required by applicable law or agreed to in writing, software |
| 11 | * distributed under the License is distributed on an "AS IS" BASIS, |
| 12 | * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. |
| 13 | * See the License for the specific language governing permissions and |
| 14 | * limitations under the License. |
| 15 | */ |
| 16 | |
| 17 | #ifndef _LIBSPARSE_SPARSE_H_ |
| 18 | #define _LIBSPARSE_SPARSE_H_ |
| 19 | |
| 20 | #include <stdbool.h> |
| 21 | #include <stdint.h> |
| 22 | |
| 23 | struct sparse_file; |
| 24 | |
| 25 | /** |
| 26 | * sparse_file_new - create a new sparse file cookie |
| 27 | * |
| 28 | * @block_size - minimum size of a chunk |
| 29 | * @len - size of the expanded sparse file. |
| 30 | * |
| 31 | * Creates a new sparse_file cookie that can be used to associate data |
| 32 | * blocks. Can later be written to a file with a variety of options. |
| 33 | * block_size specifies the minimum size of a chunk in the file. The maximum |
| 34 | * size of the file is 2**32 * block_size (16TB for 4k block size). |
| 35 | * |
| 36 | * Returns the sparse file cookie, or NULL on error. |
| 37 | */ |
| 38 | struct sparse_file *sparse_file_new(unsigned int block_size, int64_t len); |
| 39 | |
| 40 | /** |
| 41 | * sparse_file_destroy - destroy a sparse file cookie |
| 42 | * |
| 43 | * @s - sparse file cookie |
| 44 | * |
| 45 | * Destroys a sparse file cookie. After destroy, all memory passed in to |
| 46 | * sparse_file_add_data can be freed by the caller |
| 47 | */ |
| 48 | void sparse_file_destroy(struct sparse_file *s); |
| 49 | |
| 50 | /** |
| 51 | * sparse_file_add_data - associate a data chunk with a sparse file |
| 52 | * |
| 53 | * @s - sparse file cookie |
| 54 | * @data - pointer to data block |
| 55 | * @len - length of the data block |
| 56 | * @block - offset in blocks into the sparse file to place the data chunk |
| 57 | * |
| 58 | * Associates a data chunk with a sparse file cookie. The region |
| 59 | * [block * block_size : block * block_size + len) must not already be used in |
| 60 | * the sparse file. If len is not a multiple of the block size the data |
| 61 | * will be padded with zeros. |
| 62 | * |
| 63 | * The data pointer must remain valid until the sparse file is closed or the |
| 64 | * data block is removed from the sparse file. |
| 65 | * |
| 66 | * Returns 0 on success, negative errno on error. |
| 67 | */ |
| 68 | int sparse_file_add_data(struct sparse_file *s, |
| 69 | void *data, unsigned int len, unsigned int block); |
| 70 | |
| 71 | /** |
| 72 | * sparse_file_add_fill - associate a fill chunk with a sparse file |
| 73 | * |
| 74 | * @s - sparse file cookie |
| 75 | * @fill_val - 32 bit fill data |
| 76 | * @len - length of the fill block |
| 77 | * @block - offset in blocks into the sparse file to place the fill chunk |
| 78 | * |
| 79 | * Associates a chunk filled with fill_val with a sparse file cookie. |
| 80 | * The region [block * block_size : block * block_size + len) must not already |
| 81 | * be used in the sparse file. If len is not a multiple of the block size the |
| 82 | * data will be padded with zeros. |
| 83 | * |
| 84 | * Returns 0 on success, negative errno on error. |
| 85 | */ |
| 86 | int sparse_file_add_fill(struct sparse_file *s, |
| 87 | uint32_t fill_val, unsigned int len, unsigned int block); |
| 88 | |
| 89 | /** |
| 90 | * sparse_file_add_file - associate a chunk of a file with a sparse file |
| 91 | * |
| 92 | * @s - sparse file cookie |
| 93 | * @filename - filename of the file to be copied |
| 94 | * @file_offset - offset into the copied file |
| 95 | * @len - length of the copied block |
| 96 | * @block - offset in blocks into the sparse file to place the file chunk |
| 97 | * |
| 98 | * Associates a chunk of an existing file with a sparse file cookie. |
| 99 | * The region [block * block_size : block * block_size + len) must not already |
| 100 | * be used in the sparse file. If len is not a multiple of the block size the |
| 101 | * data will be padded with zeros. |
| 102 | * |
| 103 | * Allows adding large amounts of data to a sparse file without needing to keep |
| 104 | * it all mapped. File size is limited by available virtual address space, |
| 105 | * exceptionally large files may need to be added in multiple chunks. |
| 106 | * |
| 107 | * Returns 0 on success, negative errno on error. |
| 108 | */ |
| 109 | int sparse_file_add_file(struct sparse_file *s, |
| 110 | const char *filename, int64_t file_offset, unsigned int len, |
| 111 | unsigned int block); |
| 112 | |
| 113 | /** |
| 114 | * sparse_file_write - write a sparse file to a file |
| 115 | * |
| 116 | * @s - sparse file cookie |
| 117 | * @fd - file descriptor to write to |
| 118 | * @gz - write a gzipped file |
| 119 | * @sparse - write in the Android sparse file format |
| 120 | * @crc - append a crc chunk |
| 121 | * |
| 122 | * Writes a sparse file to a file. If gz is true, the data will be passed |
| 123 | * through zlib. If sparse is true, the file will be written in the Android |
| 124 | * sparse file format. If sparse is false, the file will be written by seeking |
| 125 | * over unused chunks, producing a smaller file if the filesystem supports |
| 126 | * sparse files. If crc is true, the crc of the expanded data will be |
| 127 | * calculated and appended in a crc chunk. |
| 128 | * |
| 129 | * Returns 0 on success, negative errno on error. |
| 130 | */ |
| 131 | int sparse_file_write(struct sparse_file *s, int fd, bool gz, bool sparse, |
| 132 | bool crc); |
| 133 | |
| 134 | #endif |