1 /*- 2 * Copyright (c) 2003-2007 Tim Kientzle 3 * All rights reserved. 4 * 5 * Redistribution and use in source and binary forms, with or without 6 * modification, are permitted provided that the following conditions 7 * are met: 8 * 1. Redistributions of source code must retain the above copyright 9 * notice, this list of conditions and the following disclaimer. 10 * 2. Redistributions in binary form must reproduce the above copyright 11 * notice, this list of conditions and the following disclaimer in the 12 * documentation and/or other materials provided with the distribution. 13 * 14 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR(S) ``AS IS'' AND ANY EXPRESS OR 15 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES 16 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. 17 * IN NO EVENT SHALL THE AUTHOR(S) BE LIABLE FOR ANY DIRECT, INDIRECT, 18 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT 19 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, 20 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY 21 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT 22 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF 23 * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. 24 * 25 * $FreeBSD: src/lib/libarchive/archive_read_private.h,v 1.6 2008/03/15 11:09:16 kientzle Exp $ 26 */ 27 28 #ifndef ARCHIVE_READ_PRIVATE_H_INCLUDED 29 #define ARCHIVE_READ_PRIVATE_H_INCLUDED 30 31 #include "archive.h" 32 #include "archive_string.h" 33 #include "archive_private.h" 34 35 struct archive_read { 36 struct archive archive; 37 38 struct archive_entry *entry; 39 40 /* Dev/ino of the archive being read/written. */ 41 dev_t skip_file_dev; 42 ino_t skip_file_ino; 43 44 /* 45 * Used by archive_read_data() to track blocks and copy 46 * data to client buffers, filling gaps with zero bytes. 47 */ 48 const char *read_data_block; 49 off_t read_data_offset; 50 off_t read_data_output_offset; 51 size_t read_data_remaining; 52 53 /* Callbacks to open/read/write/close archive stream. */ 54 archive_open_callback *client_opener; 55 archive_read_callback *client_reader; 56 archive_skip_callback *client_skipper; 57 archive_close_callback *client_closer; 58 void *client_data; 59 60 /* File offset of beginning of most recently-read header. */ 61 off_t header_position; 62 63 /* 64 * Decompressors have a very specific lifecycle: 65 * public setup function initializes a slot in this table 66 * 'config' holds minimal configuration data 67 * bid() examines a block of data and returns a bid [1] 68 * init() is called for successful bidder 69 * 'data' is initialized by init() 70 * read() returns a pointer to the next block of data 71 * consume() indicates how much data is used 72 * skip() ignores bytes of data 73 * finish() cleans up and frees 'data' and 'config' 74 * 75 * [1] General guideline: bid the number of bits that you actually 76 * test, e.g., 16 if you test a 2-byte magic value. 77 */ 78 struct decompressor_t { 79 void *config; 80 void *data; 81 int (*bid)(const void *buff, size_t); 82 int (*init)(struct archive_read *, 83 const void *buff, size_t); 84 int (*finish)(struct archive_read *); 85 ssize_t (*read_ahead)(struct archive_read *, 86 const void **, size_t); 87 ssize_t (*consume)(struct archive_read *, size_t); 88 off_t (*skip)(struct archive_read *, off_t); 89 } decompressors[4]; 90 91 /* Pointer to current decompressor. */ 92 struct decompressor_t *decompressor; 93 94 /* 95 * Format detection is mostly the same as compression 96 * detection, with one significant difference: The bidders 97 * use the read_ahead calls above to examine the stream rather 98 * than having the supervisor hand them a block of data to 99 * examine. 100 */ 101 102 struct archive_format_descriptor { 103 void *data; 104 int (*bid)(struct archive_read *); 105 int (*read_header)(struct archive_read *, struct archive_entry *); 106 int (*read_data)(struct archive_read *, const void **, size_t *, off_t *); 107 int (*read_data_skip)(struct archive_read *); 108 int (*cleanup)(struct archive_read *); 109 } formats[8]; 110 struct archive_format_descriptor *format; /* Active format. */ 111 112 /* 113 * Various information needed by archive_extract. 114 */ 115 struct extract *extract; 116 int (*cleanup_archive_extract)(struct archive_read *); 117 }; 118 119 int __archive_read_register_format(struct archive_read *a, 120 void *format_data, 121 int (*bid)(struct archive_read *), 122 int (*read_header)(struct archive_read *, struct archive_entry *), 123 int (*read_data)(struct archive_read *, const void **, size_t *, off_t *), 124 int (*read_data_skip)(struct archive_read *), 125 int (*cleanup)(struct archive_read *)); 126 127 struct decompressor_t 128 *__archive_read_register_compression(struct archive_read *a, 129 int (*bid)(const void *, size_t), 130 int (*init)(struct archive_read *, const void *, size_t)); 131 132 const void 133 *__archive_read_ahead(struct archive_read *, size_t); 134 135 #endif 136