freebsd-dev/lib/libarchive/archive_read_private.h
Tim Kientzle f81da3e584 libarchive 2.0
* libarchive_test program exercises many of the core features
  * Refactored old "read_extract" into new "archive_write_disk", which
    uses archive_write methods to put entries onto disk.  In particular,
    you can now use archive_write_disk to create objects on disk
    without having an archive available.
  * Pushed some security checks from bsdtar down into libarchive, where
    they can be better optimized.
  * Rearchitected the logic for creating objects on disk to reduce
    the number of system calls.  Several common cases now use a
    minimum number of system calls.
  * Virtualized some internal interfaces to provide a clearer separation
    of read and write handling and make it simpler to override key
    methods.
  * New "empty" format reader.
  * Corrected return types (this ABI breakage required the "2.0" version bump)
  * Many bug fixes.
2007-03-03 07:37:37 +00:00

189 lines
7.1 KiB
C

/*-
* Copyright (c) 2003-2007 Tim Kientzle
* All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
*
* THIS SOFTWARE IS PROVIDED BY THE AUTHOR(S) ``AS IS'' AND ANY EXPRESS OR
* IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
* OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
* IN NO EVENT SHALL THE AUTHOR(S) BE LIABLE FOR ANY DIRECT, INDIRECT,
* INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
* NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
* DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
* THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
* (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
* THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
*
* $FreeBSD$
*/
#ifndef ARCHIVE_READ_PRIVATE_H_INCLUDED
#define ARCHIVE_READ_PRIVATE_H_INCLUDED
#include "archive.h"
#include "archive_string.h"
#include "archive_private.h"
struct archive_read {
struct archive archive;
struct archive_entry *entry;
/* Dev/ino of the archive being read/written. */
dev_t skip_file_dev;
ino_t skip_file_ino;
/* Utility: Pointer to a block of nulls. */
const unsigned char *nulls;
size_t null_length;
/*
* Used by archive_read_data() to track blocks and copy
* data to client buffers, filling gaps with zero bytes.
*/
const char *read_data_block;
off_t read_data_offset;
off_t read_data_output_offset;
size_t read_data_remaining;
/* Callbacks to open/read/write/close archive stream. */
archive_open_callback *client_opener;
archive_read_callback *client_reader;
archive_skip_callback *client_skipper;
archive_write_callback *client_writer;
archive_close_callback *client_closer;
void *client_data;
/*
* Blocking information. Note that bytes_in_last_block is
* misleadingly named; I should find a better name. These
* control the final output from all compressors, including
* compression_none.
*/
int bytes_per_block;
int bytes_in_last_block;
/*
* These control whether data within a gzip/bzip2 compressed
* stream gets padded or not. If pad_uncompressed is set,
* the data will be padded to a full block before being
* compressed. The pad_uncompressed_byte determines the value
* that will be used for padding. Note that these have no
* effect on compression "none."
*/
int pad_uncompressed;
int pad_uncompressed_byte; /* TODO: Support this. */
/* File offset of beginning of most recently-read header. */
off_t header_position;
/*
* Detection functions for decompression: bid functions are
* given a block of data from the beginning of the stream and
* can bid on whether or not they support the data stream.
* General guideline: bid the number of bits that you actually
* test, e.g., 16 if you test a 2-byte magic value. The
* highest bidder will have their init function invoked, which
* can set up pointers to specific handlers.
*
* On write, the client just invokes an archive_write_set function
* which sets up the data here directly.
*/
struct {
int (*bid)(const void *buff, size_t);
int (*init)(struct archive_read *, const void *buff, size_t);
} decompressors[4];
/* Read/write data stream (with compression). */
void *compression_data; /* Data for (de)compressor. */
int (*compression_init)(struct archive_read *); /* Initialize. */
int (*compression_finish)(struct archive_read *);
int (*compression_write)(struct archive_read *, const void *, size_t);
/*
* Read uses a peek/consume I/O model: the decompression code
* returns a pointer to the requested block and advances the
* file position only when requested by a consume call. This
* reduces copying and also simplifies look-ahead for format
* detection.
*/
ssize_t (*compression_read_ahead)(struct archive_read *,
const void **, size_t request);
ssize_t (*compression_read_consume)(struct archive_read *, size_t);
off_t (*compression_skip)(struct archive_read *, off_t);
/*
* Format detection is mostly the same as compression
* detection, with two significant differences: The bidders
* use the read_ahead calls above to examine the stream rather
* than having the supervisor hand them a block of data to
* examine, and the auction is repeated for every header.
* Winning bidders should set the archive_format and
* archive_format_name appropriately. Bid routines should
* check archive_format and decline to bid if the format of
* the last header was incompatible.
*
* Again, write support is considerably simpler because there's
* no need for an auction.
*/
struct archive_format_descriptor {
int (*bid)(struct archive_read *);
int (*read_header)(struct archive_read *, struct archive_entry *);
int (*read_data)(struct archive_read *, const void **, size_t *, off_t *);
int (*read_data_skip)(struct archive_read *);
int (*cleanup)(struct archive_read *);
void *format_data; /* Format-specific data for readers. */
} formats[8];
struct archive_format_descriptor *format; /* Active format. */
/*
* Storage for format-specific data. Note that there can be
* multiple format readers active at one time, so we need to
* allow for multiple format readers to have their data
* available. The pformat_data slot here is the solution: on
* read, it is guaranteed to always point to a void* variable
* that the format can use.
*/
void **pformat_data; /* Pointer to current format_data. */
void *format_data; /* Used by writers. */
/*
* Pointers to format-specific functions for writing. They're
* initialized by archive_write_set_format_XXX() calls.
*/
int (*format_init)(struct archive *); /* Only used on write. */
int (*format_finish)(struct archive *);
int (*format_finish_entry)(struct archive *);
int (*format_write_header)(struct archive *,
struct archive_entry *);
ssize_t (*format_write_data)(struct archive *,
const void *buff, size_t);
/*
* Various information needed by archive_extract.
*/
struct extract *extract;
int (*cleanup_archive_extract)(struct archive_read *);
};
int __archive_read_register_format(struct archive_read *a,
void *format_data,
int (*bid)(struct archive_read *),
int (*read_header)(struct archive_read *, struct archive_entry *),
int (*read_data)(struct archive_read *, const void **, size_t *, off_t *),
int (*read_data_skip)(struct archive_read *),
int (*cleanup)(struct archive_read *));
int __archive_read_register_compression(struct archive_read *a,
int (*bid)(const void *, size_t),
int (*init)(struct archive_read *, const void *, size_t));
#endif