/*-
 * 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: src/lib/libarchive/archive_read_private.h,v 1.7 2008/12/06 06:45:15 kientzle Exp $
 */

#ifndef __LIBARCHIVE_BUILD
#error This header is only to be used internally to libarchive.
#endif

#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_read_filter_bidder;
struct archive_read_filter;

/*
 * How bidding works for filters:
 *   * The bid manager reads the first block from the current source.
 *   * It shows that block to each registered bidder.
 *   * The bid manager creates a new filter structure for the winning
 *     bidder and gives the winning bidder a chance to initialize it.
 *   * The new filter becomes the top filter in the archive_read structure
 *     and we repeat the process.
 * This ends only when no bidder provides a non-zero bid.
 */
struct archive_read_filter_bidder {
    /* Configuration data for the bidder. */
    void *data;
    /* Taste the upstream filter to see if we handle this. */
    int (*bid)(struct archive_read_filter_bidder *,
        struct archive_read_filter *);
    /* Initialize a newly-created filter. */
    int (*init)(struct archive_read_filter *);
    /* Set an option for the filter bidder. */
    int (*options)(struct archive_read_filter_bidder *,
        const char *key, const char *value);
    /* Release the bidder's configuration data. */
    int (*free)(struct archive_read_filter_bidder *);
};

/*
 * This structure is allocated within the archive_read core
 * and initialized by archive_read and the init() method of the
 * corresponding bidder above.
 */
struct archive_read_filter {
    /* Essentially all filters will need these values, so
     * just declare them here. */
    struct archive_read_filter_bidder *bidder; /* My bidder. */
    struct archive_read_filter *upstream; /* Who I read from. */
    struct archive_read *archive; /* Associated archive. */
    /* Return next block. */
    ssize_t (*read)(struct archive_read_filter *, const void **);
    /* Skip forward this many bytes. */
    int64_t (*skip)(struct archive_read_filter *self, int64_t request);
    /* Close (just this filter) and free(self). */
    int (*close)(struct archive_read_filter *self);
    /* My private data. */
    void *data;

    const char  *name;
    int      code;

    /* Used by reblocking logic. */
    char        *buffer;
    size_t       buffer_size;
    char        *next;      /* Current read location. */
    size_t       avail;     /* Bytes in my buffer. */
    const void  *client_buff;   /* Client buffer information. */
    size_t       client_total;
    const char  *client_next;
    size_t       client_avail;
    int64_t      position;
    char         end_of_file;
    char         fatal;
};

/*
 * The client looks a lot like a filter, so we just wrap it here.
 *
 * TODO: Make archive_read_filter and archive_read_client identical so
 * that users of the library can easily register their own
 * transformation filters.  This will probably break the API/ABI and
 * so should be deferred at least until libarchive 3.0.
 */
struct archive_read_client {
    archive_read_callback   *reader;
    archive_skip_callback   *skipper;
    archive_close_callback  *closer;
};

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;

    /*
     * 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 client archive stream. */
    struct archive_read_client client;

    /* Registered filter bidders. */
    struct archive_read_filter_bidder bidders[8];

    /* Last filter in chain */
    struct archive_read_filter *filter;

    /* File offset of beginning of most recently-read header. */
    off_t         header_position;

    /*
     * Format detection is mostly the same as compression
     * detection, with one significant difference: 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.
     */

    struct archive_format_descriptor {
        void     *data;
        const char *name;
        int (*bid)(struct archive_read *);
        int (*options)(struct archive_read *, const char *key,
            const char *value);
        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. */

    /*
     * 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,
        const char *name,
        int (*bid)(struct archive_read *),
        int (*options)(struct archive_read *, const char *, const char *),
        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 archive_read_filter_bidder
    *__archive_read_get_bidder(struct archive_read *a);

const void *__archive_read_ahead(struct archive_read *, size_t, ssize_t *);
const void *__archive_read_filter_ahead(struct archive_read_filter *,
    size_t, ssize_t *);
ssize_t __archive_read_consume(struct archive_read *, size_t);
ssize_t __archive_read_filter_consume(struct archive_read_filter *, size_t);
int64_t __archive_read_skip(struct archive_read *, int64_t);
int64_t __archive_read_skip_lenient(struct archive_read *, int64_t);
int64_t __archive_read_filter_skip(struct archive_read_filter *, int64_t);
int __archive_read_program(struct archive_read_filter *, const char *);
#endif
