freebsd-skq/lib/libarchive/archive_read_private.h
Dag-Erling Smørgrav 4823b3de93 Add an internal utility function to simplify the many, many places where
the number of bytes read is actually not important as long as we have at
least what we ask for.  Illustrate its benefits by using it throughout
the ZIP support code, except for the few cases where it doesn't apply.

Approved by:	kientzle
2008-01-03 17:54:26 +00:00

180 lines
6.3 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;
/*
* Decompressors have a very specific lifecycle:
* public setup function initializes a slot in this table
* 'config' holds minimal configuration data
* bid() examines a block of data and returns a bid [1]
* init() is called for successful bidder
* 'data' is initialized by init()
* read() returns a pointer to the next block of data
* consume() indicates how much data is used
* skip() ignores bytes of data
* finish() cleans up and frees 'data' and 'config'
*
* [1] General guideline: bid the number of bits that you actually
* test, e.g., 16 if you test a 2-byte magic value.
*/
struct decompressor_t {
void *config;
void *data;
int (*bid)(const void *buff, size_t);
int (*init)(struct archive_read *,
const void *buff, size_t);
int (*finish)(struct archive_read *);
ssize_t (*read_ahead)(struct archive_read *,
const void **, size_t);
ssize_t (*consume)(struct archive_read *, size_t);
off_t (*skip)(struct archive_read *, off_t);
} decompressors[4];
/* Pointer to current decompressor. */
struct decompressor_t *decompressor;
/*
* 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 {
void *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 *);
} formats[8];
struct archive_format_descriptor *format; /* Active format. */
/*
* 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 *));
struct decompressor_t
*__archive_read_register_compression(struct archive_read *a,
int (*bid)(const void *, size_t),
int (*init)(struct archive_read *, const void *, size_t));
const void
*__archive_read_ahead(struct archive_read *, size_t);
#endif