LCOM1920-T02G10

/**

 * \file        lzma/stream_flags.h

 * \brief       .xz Stream Header and Stream Footer encoder and decoder

 */

/*

 * Author: Lasse Collin

 *

 * This file has been put into the public domain.

 * You can do whatever you want with this file.

 *

 * See ../lzma.h for information about liblzma as a whole.

 */

#ifndef LZMA_H_INTERNAL

#        error Never include this file directly. Use <lzma.h> instead.

#endif

/**

 * \brief       Size of Stream Header and Stream Footer

 *

 * Stream Header and Stream Footer have the same size and they are not

 * going to change even if a newer version of the .xz file format is

 * developed in future.

 */

#define LZMA_STREAM_HEADER_SIZE 12

/**

 * \brief       Options for encoding/decoding Stream Header and Stream Footer

 */

typedef struct {

        /**

         * \brief       Stream Flags format version

         *

         * To prevent API and ABI breakages if new features are needed in

         * Stream Header or Stream Footer, a version number is used to

         * indicate which fields in this structure are in use. For now,

         * version must always be zero. With non-zero version, the

         * lzma_stream_header_encode() and lzma_stream_footer_encode()

         * will return LZMA_OPTIONS_ERROR.

         *

         * lzma_stream_header_decode() and lzma_stream_footer_decode()

         * will always set this to the lowest value that supports all the

         * features indicated by the Stream Flags field. The application

         * must check that the version number set by the decoding functions

         * is supported by the application. Otherwise it is possible that

         * the application will decode the Stream incorrectly.

         */

        uint32_t version;

        /**

         * \brief       Backward Size

         *

         * Backward Size must be a multiple of four bytes. In this Stream

         * format version, Backward Size is the size of the Index field.

         *

         * Backward Size isn't actually part of the Stream Flags field, but

         * it is convenient to include in this structure anyway. Backward

         * Size is present only in the Stream Footer. There is no need to

         * initialize backward_size when encoding Stream Header.

         *

         * lzma_stream_header_decode() always sets backward_size to

         * LZMA_VLI_UNKNOWN so that it is convenient to use

         * lzma_stream_flags_compare() when both Stream Header and Stream

         * Footer have been decoded.

         */

        lzma_vli backward_size;

#        define LZMA_BACKWARD_SIZE_MIN 4

#        define LZMA_BACKWARD_SIZE_MAX (LZMA_VLI_C(1) << 34)

        /**

         * \brief       Check ID

         *

         * This indicates the type of the integrity check calculated from

         * uncompressed data.

         */

        lzma_check check;

        /*

         * Reserved space to allow possible future extensions without

         * breaking the ABI. You should not touch these, because the

         * names of these variables may change.

         *

         * (We will never be able to use all of these since Stream Flags

         * is just two bytes plus Backward Size of four bytes. But it's

         * nice to have the proper types when they are needed.)

         */

        lzma_reserved_enum reserved_enum1;

        lzma_reserved_enum reserved_enum2;

        lzma_reserved_enum reserved_enum3;

        lzma_reserved_enum reserved_enum4;

        lzma_bool reserved_bool1;

        lzma_bool reserved_bool2;

        lzma_bool reserved_bool3;

        lzma_bool reserved_bool4;

        lzma_bool reserved_bool5;

        lzma_bool reserved_bool6;

        lzma_bool reserved_bool7;

        lzma_bool reserved_bool8;

        uint32_t reserved_int1;

        uint32_t reserved_int2;

} lzma_stream_flags;

/**

 * \brief       Encode Stream Header

 *

 * \param       options     Stream Header options to be encoded.

 *                          options->backward_size is ignored and doesn't

 *                          need to be initialized.

 * \param       out         Beginning of the output buffer of

 *                          LZMA_STREAM_HEADER_SIZE bytes.

 *

 * \return      - LZMA_OK: Encoding was successful.

 *              - LZMA_OPTIONS_ERROR: options->version is not supported by

 *                this liblzma version.

 *              - LZMA_PROG_ERROR: Invalid options.

 */

extern LZMA_API(lzma_ret) lzma_stream_header_encode(

                const lzma_stream_flags *options, uint8_t *out)

                lzma_nothrow lzma_attr_warn_unused_result;

/**

 * \brief       Encode Stream Footer

 *

 * \param       options     Stream Footer options to be encoded.

 * \param       out         Beginning of the output buffer of

 *                          LZMA_STREAM_HEADER_SIZE bytes.

 *

 * \return      - LZMA_OK: Encoding was successful.

 *              - LZMA_OPTIONS_ERROR: options->version is not supported by

 *                this liblzma version.

 *              - LZMA_PROG_ERROR: Invalid options.

 */

extern LZMA_API(lzma_ret) lzma_stream_footer_encode(

                const lzma_stream_flags *options, uint8_t *out)

                lzma_nothrow lzma_attr_warn_unused_result;

/**

 * \brief       Decode Stream Header

 *

 * \param       options     Target for the decoded Stream Header options.

 * \param       in          Beginning of the input buffer of

 *                          LZMA_STREAM_HEADER_SIZE bytes.

 *

 * options->backward_size is always set to LZMA_VLI_UNKNOWN. This is to

 * help comparing Stream Flags from Stream Header and Stream Footer with

 * lzma_stream_flags_compare().

 *

 * \return      - LZMA_OK: Decoding was successful.

 *              - LZMA_FORMAT_ERROR: Magic bytes don't match, thus the given

 *                buffer cannot be Stream Header.

 *              - LZMA_DATA_ERROR: CRC32 doesn't match, thus the header

 *                is corrupt.

 *              - LZMA_OPTIONS_ERROR: Unsupported options are present

 *                in the header.

 *

 * \note        When decoding .xz files that contain multiple Streams, it may

 *              make sense to print "file format not recognized" only if

 *              decoding of the Stream Header of the _first_ Stream gives

 *              LZMA_FORMAT_ERROR. If non-first Stream Header gives

 *              LZMA_FORMAT_ERROR, the message used for LZMA_DATA_ERROR is

 *              probably more appropriate.

 *

 *              For example, Stream decoder in liblzma uses LZMA_DATA_ERROR if

 *              LZMA_FORMAT_ERROR is returned by lzma_stream_header_decode()

 *              when decoding non-first Stream.

 */

extern LZMA_API(lzma_ret) lzma_stream_header_decode(

                lzma_stream_flags *options, const uint8_t *in)

                lzma_nothrow lzma_attr_warn_unused_result;

/**

 * \brief       Decode Stream Footer

 *

 * \param       options     Target for the decoded Stream Header options.

 * \param       in          Beginning of the input buffer of

 *                          LZMA_STREAM_HEADER_SIZE bytes.

 *

 * \return      - LZMA_OK: Decoding was successful.

 *              - LZMA_FORMAT_ERROR: Magic bytes don't match, thus the given

 *                buffer cannot be Stream Footer.

 *              - LZMA_DATA_ERROR: CRC32 doesn't match, thus the Stream Footer

 *                is corrupt.

 *              - LZMA_OPTIONS_ERROR: Unsupported options are present

 *                in Stream Footer.

 *

 * \note        If Stream Header was already decoded successfully, but

 *              decoding Stream Footer returns LZMA_FORMAT_ERROR, the

 *              application should probably report some other error message

 *              than "file format not recognized", since the file more likely

 *              is corrupt (possibly truncated). Stream decoder in liblzma

 *              uses LZMA_DATA_ERROR in this situation.

 */

extern LZMA_API(lzma_ret) lzma_stream_footer_decode(

                lzma_stream_flags *options, const uint8_t *in)

                lzma_nothrow lzma_attr_warn_unused_result;

/**

 * \brief       Compare two lzma_stream_flags structures

 *

 * backward_size values are compared only if both are not

 * LZMA_VLI_UNKNOWN.

 *

 * \return      - LZMA_OK: Both are equal. If either had backward_size set

 *                to LZMA_VLI_UNKNOWN, backward_size values were not

 *                compared or validated.

 *              - LZMA_DATA_ERROR: The structures differ.

 *              - LZMA_OPTIONS_ERROR: version in either structure is greater

 *                than the maximum supported version (currently zero).

 *              - LZMA_PROG_ERROR: Invalid value, e.g. invalid check or

 *                backward_size.

 */

extern LZMA_API(lzma_ret) lzma_stream_flags_compare(

                const lzma_stream_flags *a, const lzma_stream_flags *b)

                lzma_nothrow lzma_attr_pure;