+ * 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, then one hash table
+ * slide will be done when switching. If s->matches is 2, the maximum value
+ * allowed here, then the hash table will be cleared, since two or more slides
+ * is the same as a clear.
+ *
+ * deflate_stored() is written to minimize the number of times an input byte is
+ * copied. It is most efficient with large input and output buffers, which
+ * maximizes the opportunites to have a single copy from next_in to next_out.
+ */
+local block_state deflate_stored(s, flush)
+ 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;
+ unsigned used = s->strm->avail_in;
+ for (;;) {
+ /* 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 */
+ /* maximum stored block length that will fit in avail_out: */
+ have = s->strm->avail_out > have ? s->strm->avail_out - have : 0;
+ 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 (left > len)
+ left = len; /* limit window pull to len */
+
+ /* 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_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);
+
+ /* Update debugging counts for the data about to be copied. */
+#ifdef ZLIB_DEBUG
+ s->compressed_len += len << 3;
+ s->bits_sent += len << 3;
+#endif
+
+ /* Copy uncompressed bytes from the window to next_out. */
+ if (left) {
+ zmemcpy(s->strm->next_out, s->window + s->block_start, left);
+ s->strm->next_out += left;
+ s->strm->avail_out -= left;
+ s->strm->total_out += left;
+ s->block_start += left;
+ len -= left;
+ }
+
+ /* Copy uncompressed bytes directly from next_in to next_out, updating
+ * the check value.
+ */
+ if (len) {
+ read_buf(s->strm, s->strm->next_out, len);
+ s->strm->next_out += len;
+ s->strm->avail_out -= len;
+ s->strm->total_out += len;
+ }
+ }
+
+ /* Update the sliding window with the last s->w_size bytes of the copied
+ * data, or append all of the copied data to the existing window if less
+ * than s->w_size bytes were copied. Also update the number of bytes to
+ * insert in the hash tables, in the event that deflateParams() switches to
+ * a non-zero compression level.
+ */
+ used -= s->strm->avail_in; /* number of input bytes directly copied */
+ if (used) {
+ /* If any input was used, then no unused input remains in the window,
+ * therefore s->block_start == s->strstart.
+ */
+ if (used >= s->w_size) { /* supplant the previous history */
+ s->matches = 2; /* clear hash */
+ zmemcpy(s->window, s->strm->next_in - s->w_size, s->w_size);
+ s->strstart = s->w_size;
+ }
+ else {
+ if (s->window_size - s->strstart <= used) {
+ /* Slide the window down. */
+ s->strstart -= s->w_size;
+ zmemcpy(s->window, s->window + s->w_size, s->strstart);
+ if (s->matches < 2)
+ s->matches++; /* add a pending slide_hash() */
+ }
+ zmemcpy(s->window + s->strstart, s->strm->next_in - used, used);
+ s->strstart += used;
+ }
+ s->block_start = s->strstart;
+ s->insert += MIN(used, s->w_size - s->insert);
+ }
+
+ /* If flushing or finishing and all input has been consumed, then done. If
+ * the code above couldn't write a complete block to next_out, then the
+ * code following this won't be able to either.
+ */
+ if (flush != Z_NO_FLUSH && s->strm->avail_in == 0 &&
+ s->strstart == s->block_start)
+ return flush == Z_FINISH ? finish_done : block_done;
+
+ /* Fill the window with any remaining input. */
+ have = s->window_size - s->strstart - 1;
+ if (s->strm->avail_in > have && s->block_start >= s->w_size) {
+ /* Slide the window down. */
+ s->block_start -= s->w_size;
+ s->strstart -= s->w_size;
+ zmemcpy(s->window, s->window + s->w_size, s->strstart);
+ if (s->matches < 2)
+ s->matches++; /* add a pending slide_hash() */
+ have += s->w_size; /* more space now */
+ }
+ if (have > s->strm->avail_in)
+ have = s->strm->avail_in;
+ if (have) {
+ read_buf(s->strm, s->window + s->strstart, have);
+ s->strstart += have;
+ }
+
+ /* There was not enough avail_out to write a complete worthy or flushed
+ * stored block to next_out. Write a stored block to pending instead, if we
+ * have enough input for a worthy block, or if flushing and there is enough
+ * room for the remaining input as a stored block in the pending buffer.
+ */
+ have = (s->bi_valid + 42) >> 3; /* number of header bytes */
+ /* maximum stored block length that will fit in pending: */
+ have = MIN(s->pending_buf_size - have, MAX_STORED);
+ min_block = MIN(have, s->w_size);
+ left = s->strstart - s->block_start;
+ if (left >= min_block ||
+ (left && flush != Z_NO_FLUSH && s->strm->avail_in == 0 &&
+ left <= have)) {
+ len = MIN(left, have);
+ last = flush == Z_FINISH && s->strm->avail_in == 0 &&
+ len == left ? 1 : 0;
+ _tr_stored_block(s, (charf *)s->window + s->block_start, len, last);
+ s->block_start += len;
+ flush_pending(s->strm);
+ if (last)
+ return finish_started;
+ }
+
+ /* We've done all we can with the available input and output. */
+ return need_more;
+}
+
+/* ===========================================================================
+ * Compress as much as possible from the input stream, return the current
+ * block state.
+ * This function does not perform lazy evaluation of matches and inserts