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lib/SPVM/Resource/Zlib/V1_2_11.native/src/deflate.c  view on Meta::CPAN

/* ===========================================================================
 * Slide the hash table when sliding the window down (could be avoided with 32
 * bit values at the expense of memory usage). We slide even when level == 0 to
 * keep the hash table consistent if we switch back to level > 0 later.
 */
local void slide_hash(s)
    deflate_state *s;
{
    unsigned n, m;
    Posf *p;
    uInt wsize = s->w_size;

    n = s->hash_size;
    p = &s->head[n];
    do {
        m = *--p;
        *p = (Pos)(m >= wsize ? m - wsize : NIL);
    } while (--n);
    n = wsize;
#ifndef FASTEST
    p = &s->prev[n];
    do {
        m = *--p;
        *p = (Pos)(m >= wsize ? m - wsize : NIL);
        /* If n is not on any hash chain, prev[n] is garbage but
         * its value will never be used.
         */
    } while (--n);
#endif
}

/* ========================================================================= */
int ZEXPORT deflateInit_(strm, level, version, stream_size)
    z_streamp strm;
    int level;
    const char *version;
    int stream_size;
{
    return deflateInit2_(strm, level, Z_DEFLATED, MAX_WBITS, DEF_MEM_LEVEL,
                         Z_DEFAULT_STRATEGY, version, stream_size);
    /* To do: ignore strm->next_in if we use it as window */
}

/* ========================================================================= */
int ZEXPORT deflateInit2_(strm, level, method, windowBits, memLevel, strategy,
                  version, stream_size)
    z_streamp strm;
    int  level;
    int  method;
    int  windowBits;
    int  memLevel;
    int  strategy;
    const char *version;
    int stream_size;
{
    deflate_state *s;
    int wrap = 1;
    static const char my_version[] = ZLIB_VERSION;

    ushf *overlay;
    /* We overlay pending_buf and d_buf+l_buf. This works since the average
     * output size for (length,distance) codes is <= 24 bits.
     */

    if (version == Z_NULL || version[0] != my_version[0] ||
        stream_size != sizeof(z_stream)) {
        return Z_VERSION_ERROR;
    }
    if (strm == Z_NULL) return Z_STREAM_ERROR;

    strm->msg = Z_NULL;
    if (strm->zalloc == (alloc_func)0) {
#ifdef Z_SOLO
        return Z_STREAM_ERROR;
#else
        strm->zalloc = zcalloc;
        strm->opaque = (voidpf)0;
#endif
    }
    if (strm->zfree == (free_func)0)
#ifdef Z_SOLO
        return Z_STREAM_ERROR;
#else
        strm->zfree = zcfree;
#endif

#ifdef FASTEST
    if (level != 0) level = 1;
#else
    if (level == Z_DEFAULT_COMPRESSION) level = 6;
#endif

    if (windowBits < 0) { /* suppress zlib wrapper */
        wrap = 0;
        windowBits = -windowBits;
    }
#ifdef GZIP
    else if (windowBits > 15) {
        wrap = 2;       /* write gzip wrapper instead */
        windowBits -= 16;
    }
#endif
    if (memLevel < 1 || memLevel > MAX_MEM_LEVEL || method != Z_DEFLATED ||
        windowBits < 8 || windowBits > 15 || level < 0 || level > 9 ||
        strategy < 0 || strategy > Z_FIXED || (windowBits == 8 && wrap != 1)) {
        return Z_STREAM_ERROR;
    }
    if (windowBits == 8) windowBits = 9;  /* until 256-byte window bug fixed */
    s = (deflate_state *) ZALLOC(strm, 1, sizeof(deflate_state));
    if (s == Z_NULL) return Z_MEM_ERROR;
    strm->state = (struct internal_state FAR *)s;
    s->strm = strm;
    s->status = INIT_STATE;     /* to pass state test in deflateReset() */

    s->wrap = wrap;
    s->gzhead = Z_NULL;
    s->w_bits = (uInt)windowBits;
    s->w_size = 1 << s->w_bits;
    s->w_mask = s->w_size - 1;

    s->hash_bits = (uInt)memLevel + 7;
    s->hash_size = 1 << s->hash_bits;
    s->hash_mask = s->hash_size - 1;
    s->hash_shift =  ((s->hash_bits+MIN_MATCH-1)/MIN_MATCH);

    s->window = (Bytef *) ZALLOC(strm, s->w_size, 2*sizeof(Byte));
    s->prev   = (Posf *)  ZALLOC(strm, s->w_size, sizeof(Pos));
    s->head   = (Posf *)  ZALLOC(strm, s->hash_size, sizeof(Pos));

    s->high_water = 0;      /* nothing written to s->window yet */

    s->lit_bufsize = 1 << (memLevel + 6); /* 16K elements by default */

    overlay = (ushf *) ZALLOC(strm, s->lit_bufsize, sizeof(ush)+2);
    s->pending_buf = (uchf *) overlay;
    s->pending_buf_size = (ulg)s->lit_bufsize * (sizeof(ush)+2L);

    if (s->window == Z_NULL || s->prev == Z_NULL || s->head == Z_NULL ||
        s->pending_buf == Z_NULL) {
        s->status = FINISH_STATE;
        strm->msg = ERR_MSG(Z_MEM_ERROR);
        deflateEnd (strm);
        return Z_MEM_ERROR;
    }
    s->d_buf = overlay + s->lit_bufsize/sizeof(ush);
    s->l_buf = s->pending_buf + (1+sizeof(ush))*s->lit_bufsize;

    s->level = level;
    s->strategy = strategy;
    s->method = (Byte)method;

    return deflateReset(strm);
}

/* =========================================================================
 * Check for a valid deflate stream state. Return 0 if ok, 1 if not.
 */
local int deflateStateCheck (strm)
    z_streamp strm;
{
    deflate_state *s;
    if (strm == Z_NULL ||
        strm->zalloc == (alloc_func)0 || strm->zfree == (free_func)0)
        return 1;
    s = strm->state;
    if (s == Z_NULL || s->strm != strm || (s->status != INIT_STATE &&
#ifdef GZIP
                                           s->status != GZIP_STATE &&
#endif
                                           s->status != EXTRA_STATE &&
                                           s->status != NAME_STATE &&
                                           s->status != COMMENT_STATE &&
                                           s->status != HCRC_STATE &&
                                           s->status != BUSY_STATE &&
                                           s->status != FINISH_STATE))
        return 1;
    return 0;
}

/* ========================================================================= */
int ZEXPORT deflateSetDictionary (strm, dictionary, dictLength)
    z_streamp strm;
    const Bytef *dictionary;
    uInt  dictLength;
{
    deflate_state *s;
    uInt str, n;
    int wrap;
    unsigned avail;
    z_const unsigned char *next;

    if (deflateStateCheck(strm) || dictionary == Z_NULL)
        return Z_STREAM_ERROR;
    s = strm->state;
    wrap = s->wrap;
    if (wrap == 2 || (wrap == 1 && s->status != INIT_STATE) || s->lookahead)
        return Z_STREAM_ERROR;

    /* when using zlib wrappers, compute Adler-32 for provided dictionary */
    if (wrap == 1)
        strm->adler = adler32(strm->adler, dictionary, dictLength);
    s->wrap = 0;                    /* avoid computing Adler-32 in read_buf */

    /* if dictionary would fill window, just replace the history */
    if (dictLength >= s->w_size) {

lib/SPVM/Resource/Zlib/V1_2_11.native/src/deflate.c  view on Meta::CPAN

    if (s->wrap == 2) {
        put_byte(s, (Byte)(strm->adler & 0xff));
        put_byte(s, (Byte)((strm->adler >> 8) & 0xff));
        put_byte(s, (Byte)((strm->adler >> 16) & 0xff));
        put_byte(s, (Byte)((strm->adler >> 24) & 0xff));
        put_byte(s, (Byte)(strm->total_in & 0xff));
        put_byte(s, (Byte)((strm->total_in >> 8) & 0xff));
        put_byte(s, (Byte)((strm->total_in >> 16) & 0xff));
        put_byte(s, (Byte)((strm->total_in >> 24) & 0xff));
    }
    else
#endif
    {
        putShortMSB(s, (uInt)(strm->adler >> 16));
        putShortMSB(s, (uInt)(strm->adler & 0xffff));
    }
    flush_pending(strm);
    /* If avail_out is zero, the application will call deflate again
     * to flush the rest.
     */
    if (s->wrap > 0) s->wrap = -s->wrap; /* write the trailer only once! */
    return s->pending != 0 ? Z_OK : Z_STREAM_END;
}

/* ========================================================================= */
int ZEXPORT deflateEnd (strm)
    z_streamp strm;
{
    int status;

    if (deflateStateCheck(strm)) return Z_STREAM_ERROR;

    status = strm->state->status;

    /* Deallocate in reverse order of allocations: */
    TRY_FREE(strm, strm->state->pending_buf);
    TRY_FREE(strm, strm->state->head);
    TRY_FREE(strm, strm->state->prev);
    TRY_FREE(strm, strm->state->window);

    ZFREE(strm, strm->state);
    strm->state = Z_NULL;

    return status == BUSY_STATE ? Z_DATA_ERROR : Z_OK;
}

/* =========================================================================
 * Copy the source state to the destination state.
 * To simplify the source, this is not supported for 16-bit MSDOS (which
 * doesn't have enough memory anyway to duplicate compression states).
 */
int ZEXPORT deflateCopy (dest, source)
    z_streamp dest;
    z_streamp source;
{
#ifdef MAXSEG_64K
    return Z_STREAM_ERROR;
#else
    deflate_state *ds;
    deflate_state *ss;
    ushf *overlay;


    if (deflateStateCheck(source) || dest == Z_NULL) {
        return Z_STREAM_ERROR;
    }

    ss = source->state;

    zmemcpy((voidpf)dest, (voidpf)source, sizeof(z_stream));

    ds = (deflate_state *) ZALLOC(dest, 1, sizeof(deflate_state));
    if (ds == Z_NULL) return Z_MEM_ERROR;
    dest->state = (struct internal_state FAR *) ds;
    zmemcpy((voidpf)ds, (voidpf)ss, sizeof(deflate_state));
    ds->strm = dest;

    ds->window = (Bytef *) ZALLOC(dest, ds->w_size, 2*sizeof(Byte));
    ds->prev   = (Posf *)  ZALLOC(dest, ds->w_size, sizeof(Pos));
    ds->head   = (Posf *)  ZALLOC(dest, ds->hash_size, sizeof(Pos));
    overlay = (ushf *) ZALLOC(dest, ds->lit_bufsize, sizeof(ush)+2);
    ds->pending_buf = (uchf *) overlay;

    if (ds->window == Z_NULL || ds->prev == Z_NULL || ds->head == Z_NULL ||
        ds->pending_buf == Z_NULL) {
        deflateEnd (dest);
        return Z_MEM_ERROR;
    }
    /* following zmemcpy do not work for 16-bit MSDOS */
    zmemcpy(ds->window, ss->window, ds->w_size * 2 * sizeof(Byte));
    zmemcpy((voidpf)ds->prev, (voidpf)ss->prev, ds->w_size * sizeof(Pos));
    zmemcpy((voidpf)ds->head, (voidpf)ss->head, ds->hash_size * sizeof(Pos));
    zmemcpy(ds->pending_buf, ss->pending_buf, (uInt)ds->pending_buf_size);

    ds->pending_out = ds->pending_buf + (ss->pending_out - ss->pending_buf);
    ds->d_buf = overlay + ds->lit_bufsize/sizeof(ush);
    ds->l_buf = ds->pending_buf + (1+sizeof(ush))*ds->lit_bufsize;

    ds->l_desc.dyn_tree = ds->dyn_ltree;
    ds->d_desc.dyn_tree = ds->dyn_dtree;
    ds->bl_desc.dyn_tree = ds->bl_tree;

    return Z_OK;
#endif /* MAXSEG_64K */
}

/* ===========================================================================
 * Read a new buffer from the current input stream, update the adler32
 * and total number of bytes read.  All deflate() input goes through
 * this function so some applications may wish to modify it to avoid
 * allocating a large strm->next_in buffer and copying from it.
 * (See also flush_pending()).
 */
local unsigned read_buf(strm, buf, size)
    z_streamp strm;
    Bytef *buf;
    unsigned size;
{
    unsigned len = strm->avail_in;

    if (len > size) len = size;
    if (len == 0) return 0;

    strm->avail_in  -= len;

    zmemcpy(buf, strm->next_in, len);
    if (strm->state->wrap == 1) {
        strm->adler = adler32(strm->adler, buf, len);
    }
#ifdef GZIP
    else if (strm->state->wrap == 2) {
        strm->adler = crc32(strm->adler, buf, len);
    }
#endif
    strm->next_in  += len;
    strm->total_in += len;

    return len;
}

/* ===========================================================================
 * Initialize the "longest match" routines for a new zlib stream
 */
local void lm_init (s)
    deflate_state *s;
{
    s->window_size = (ulg)2L*s->w_size;

    CLEAR_HASH(s);

    /* Set the default configuration parameters:
     */
    s->max_lazy_match   = configuration_table[s->level].max_lazy;
    s->good_match       = configuration_table[s->level].good_length;
    s->nice_match       = configuration_table[s->level].nice_length;
    s->max_chain_length = configuration_table[s->level].max_chain;