libsquashfs  1.3.2
A new set of tools and libraries for working with SquashFS images
meta_reader.h
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1 /* SPDX-License-Identifier: LGPL-3.0-or-later */
2 /*
3  * meta_reader.h - This file is part of libsquashfs
4  *
5  * Copyright (C) 2019 David Oberhollenzer <goliath@infraroot.at>
6  *
7  * This program is free software: you can redistribute it and/or modify
8  * it under the terms of the GNU Lesser General Public License as published
9  * by the Free Software Foundation, either version 3 of the License, or
10  * (at your option) any later version.
11  *
12  * This program is distributed in the hope that it will be useful,
13  * but WITHOUT ANY WARRANTY; without even the implied warranty of
14  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
15  * GNU General Public License for more details.
16  *
17  * You should have received a copy of the GNU Lesser General Public License
18  * along with this program. If not, see <https://www.gnu.org/licenses/>.
19  */
20 #ifndef SQFS_META_READER_H
21 #define SQFS_META_READER_H
22 
23 #include "sqfs/predef.h"
24 #include "sqfs/super.h"
25 
57  struct {
58  sqfs_u64 block;
59  size_t offset;
60  size_t size;
61  } init, current;
62 
63  size_t entries;
64 
65  sqfs_u32 inum_base;
66  sqfs_u64 inode_block;
67 };
68 
77 {
78  s->current = s->init;
79  s->entries = 0;
80 }
81 
82 #ifdef __cplusplus
83 extern "C" {
84 #endif
85 
102  sqfs_compressor_t *cmp,
103  sqfs_u64 start,
104  sqfs_u64 limit);
105 
120 SQFS_API int sqfs_meta_reader_seek(sqfs_meta_reader_t *m, sqfs_u64 block_start,
121  size_t offset);
122 
133  sqfs_u64 *block_start,
134  size_t *offset);
135 
151 SQFS_API int sqfs_meta_reader_read(sqfs_meta_reader_t *m, void *data,
152  size_t size);
153 
168  sqfs_dir_header_t *hdr);
169 
185  sqfs_dir_entry_t **ent);
186 
208 SQFS_API
210  const sqfs_inode_generic_t *inode);
211 
235  sqfs_dir_entry_t **ent,
236  sqfs_u32 *inum, sqfs_u64 *iref);
237 
257 SQFS_API
259  const sqfs_super_t *super,
260  sqfs_u64 block_start, size_t offset,
261  sqfs_inode_generic_t **out);
262 
263 #ifdef __cplusplus
264 }
265 #endif
266 
267 #endif /* SQFS_META_READER_H */
SQFS_API int sqfs_readdir_state_init(sqfs_readdir_state_t *s, const sqfs_super_t *super, const sqfs_inode_generic_t *inode)
Initialize a state object for reading a directory.
static SQFS_INLINE void sqfs_readdir_state_reset(sqfs_readdir_state_t *s)
Rewind a directory state object back to its starting location.
Definition: meta_reader.h:76
Encapsultes a compressor with a simple interface to compress or extract chunks of data...
Definition: compressor.h:40
SQFS_API int sqfs_meta_reader_read_dir_header(sqfs_meta_reader_t *m, sqfs_dir_header_t *hdr)
Read and decode a directory header from a meta data reader.
SQFS_API int sqfs_meta_reader_readdir(sqfs_meta_reader_t *m, sqfs_readdir_state_t *s, sqfs_dir_entry_t **ent, sqfs_u32 *inum, sqfs_u64 *iref)
Simple directory reading interface.
SQFS_API sqfs_meta_reader_t * sqfs_meta_reader_create(sqfs_file_t *file, sqfs_compressor_t *cmp, sqfs_u64 start, sqfs_u64 limit)
Create a meta data reader.
The SquashFS super block, located at the beginning of the file system to describe the layout of the f...
Definition: super.h:47
Encapsulates state for simple directory reading.
Definition: meta_reader.h:56
Abstracts file I/O to make it easy to embedd SquashFS.
Definition: io.h:94
SQFS_API void sqfs_meta_reader_get_position(const sqfs_meta_reader_t *m, sqfs_u64 *block_start, size_t *offset)
Get the current position that the next read will read from.
SQFS_API int sqfs_meta_reader_read_inode(sqfs_meta_reader_t *ir, const sqfs_super_t *super, sqfs_u64 block_start, size_t offset, sqfs_inode_generic_t **out)
Read and decode an inode from a meta data reader.
On-disk data structure of a directory header.
Definition: dir.h:42
SQFS_API int sqfs_meta_reader_seek(sqfs_meta_reader_t *m, sqfs_u64 block_start, size_t offset)
Seek to a specific meta data block and offset.
SQFS_API int sqfs_meta_reader_read(sqfs_meta_reader_t *m, void *data, size_t size)
Read a chunk of data from a meta data reader.
Contains on-disk data structures, identifiers and functions for the SquashFS super block...
On-disk data structure of a directory entry. Many of these follow a single sqfs_dir_header_t.
Definition: dir.h:74
Abstracts reading of meta data blocks.
Includes forward declarations of data structures, macros and integer types.
SQFS_API int sqfs_meta_reader_read_dir_ent(sqfs_meta_reader_t *m, sqfs_dir_entry_t **ent)
Read and decode a directory header from a meta data reader.
A generic inode structure that combines all others and provides additional information.
Definition: inode.h:488