Function deflate_stored

extern/zlib/src/deflate.c:1627–1802

=========================================================================== * Copy without compression as much as possible from the input stream, return * the current block state. * * In case deflateParams() is used to later switch to a non-zero compression * level, s->matches (otherwise unused when storing) keeps track of the number * of hash table slides to perform. If s->matches is 1, the

 * maximizes the opportunities to have a single copy from next_in to next_out.
 */
local block_state deflate_stored(deflate_state *s, int flush) {
    /* Smallest worthy block size when not flushing or finishing. By default
     * this is 32K. This can be as small as 507 bytes for memLevel == 1. For
     * large input and output buffers, the stored block size will be larger.
     */
    unsigned min_block = MIN(s->pending_buf_size - 5, s->w_size);

    /* Copy as many min_block or larger stored blocks directly to next_out as
     * possible. If flushing, copy the remaining available input to next_out as
     * stored blocks, if there is enough space.
     */
    unsigned len, left, have, last = 0;
    unsigned used = s->strm->avail_in;
    do {
        /* Set len to the maximum size block that we can copy directly with the
         * available input data and output space. Set left to how much of that
         * would be copied from what's left in the window.
         */
        len = MAX_STORED;       /* maximum deflate stored block length */
        have = (s->bi_valid + 42) >> 3;         /* number of header bytes */
        if (s->strm->avail_out < have)          /* need room for header */
            break;
            /* maximum stored block length that will fit in avail_out: */
        have = s->strm->avail_out - have;
        left = s->strstart - s->block_start;    /* bytes left in window */
        if (len > (ulg)left + s->strm->avail_in)
            len = left + s->strm->avail_in;     /* limit len to the input */
        if (len > have)
            len = have;                         /* limit len to the output */

        /* If the stored block would be less than min_block in length, or if
         * unable to copy all of the available input when flushing, then try
         * copying to the window and the pending buffer instead. Also don't
         * write an empty block when flushing -- deflate() does that.
         */
        if (len < min_block && ((len == 0 && flush != Z_FINISH) ||
                                flush == Z_NO_FLUSH ||
                                len != left + s->strm->avail_in))
            break;

        /* Make a dummy stored block in pending to get the header bytes,
         * including any pending bits. This also updates the debugging counts.
         */
        last = flush == Z_FINISH && len == left + s->strm->avail_in ? 1 : 0;
        _tr_stored_block(s, (char *)0, 0L, last);

        /* Replace the lengths in the dummy stored block with len. */
        s->pending_buf[s->pending - 4] = len;
        s->pending_buf[s->pending - 3] = len >> 8;
        s->pending_buf[s->pending - 2] = ~len;
        s->pending_buf[s->pending - 1] = ~len >> 8;

        /* Write the stored block header bytes. */
        flush_pending(s->strm);

#ifdef ZLIB_DEBUG
        /* Update debugging counts for the data about to be copied. */
        s->compressed_len += len << 3;