--- /dev/null
+// SPDX-License-Identifier: Zlib
+
+#include "../zlib_deflate/defutil.h"
+#include "dfltcc_util.h"
+#include "dfltcc.h"
+#include <linux/zutil.h>
+
+/*
+ * Compress.
+ */
+int dfltcc_can_deflate(
+ z_streamp strm
+)
+{
+ deflate_state *state = (deflate_state *)strm->state;
+ struct dfltcc_state *dfltcc_state = GET_DFLTCC_STATE(state);
+
+ /* Unsupported compression settings */
+ if (!dfltcc_are_params_ok(state->level, state->w_bits, state->strategy,
+ dfltcc_state->level_mask))
+ return 0;
+
+ /* Unsupported hardware */
+ if (!is_bit_set(dfltcc_state->af.fns, DFLTCC_GDHT) ||
+ !is_bit_set(dfltcc_state->af.fns, DFLTCC_CMPR) ||
+ !is_bit_set(dfltcc_state->af.fmts, DFLTCC_FMT0))
+ return 0;
+
+ return 1;
+}
+
+static void dfltcc_gdht(
+ z_streamp strm
+)
+{
+ deflate_state *state = (deflate_state *)strm->state;
+ struct dfltcc_param_v0 *param = &GET_DFLTCC_STATE(state)->param;
+ size_t avail_in = avail_in = strm->avail_in;
+
+ dfltcc(DFLTCC_GDHT,
+ param, NULL, NULL,
+ &strm->next_in, &avail_in, NULL);
+}
+
+static dfltcc_cc dfltcc_cmpr(
+ z_streamp strm
+)
+{
+ deflate_state *state = (deflate_state *)strm->state;
+ struct dfltcc_param_v0 *param = &GET_DFLTCC_STATE(state)->param;
+ size_t avail_in = strm->avail_in;
+ size_t avail_out = strm->avail_out;
+ dfltcc_cc cc;
+
+ cc = dfltcc(DFLTCC_CMPR | HBT_CIRCULAR,
+ param, &strm->next_out, &avail_out,
+ &strm->next_in, &avail_in, state->window);
+ strm->total_in += (strm->avail_in - avail_in);
+ strm->total_out += (strm->avail_out - avail_out);
+ strm->avail_in = avail_in;
+ strm->avail_out = avail_out;
+ return cc;
+}
+
+static void send_eobs(
+ z_streamp strm,
+ const struct dfltcc_param_v0 *param
+)
+{
+ deflate_state *state = (deflate_state *)strm->state;
+
+ zlib_tr_send_bits(
+ state,
+ bi_reverse(param->eobs >> (15 - param->eobl), param->eobl),
+ param->eobl);
+ flush_pending(strm);
+ if (state->pending != 0) {
+ /* The remaining data is located in pending_out[0:pending]. If someone
+ * calls put_byte() - this might happen in deflate() - the byte will be
+ * placed into pending_buf[pending], which is incorrect. Move the
+ * remaining data to the beginning of pending_buf so that put_byte() is
+ * usable again.
+ */
+ memmove(state->pending_buf, state->pending_out, state->pending);
+ state->pending_out = state->pending_buf;
+ }
+#ifdef ZLIB_DEBUG
+ state->compressed_len += param->eobl;
+#endif
+}
+
+int dfltcc_deflate(
+ z_streamp strm,
+ int flush,
+ block_state *result
+)
+{
+ deflate_state *state = (deflate_state *)strm->state;
+ struct dfltcc_state *dfltcc_state = GET_DFLTCC_STATE(state);
+ struct dfltcc_param_v0 *param = &dfltcc_state->param;
+ uInt masked_avail_in;
+ dfltcc_cc cc;
+ int need_empty_block;
+ int soft_bcc;
+ int no_flush;
+
+ if (!dfltcc_can_deflate(strm))
+ return 0;
+
+again:
+ masked_avail_in = 0;
+ soft_bcc = 0;
+ no_flush = flush == Z_NO_FLUSH;
+
+ /* Trailing empty block. Switch to software, except when Continuation Flag
+ * is set, which means that DFLTCC has buffered some output in the
+ * parameter block and needs to be called again in order to flush it.
+ */
+ if (flush == Z_FINISH && strm->avail_in == 0 && !param->cf) {
+ if (param->bcf) {
+ /* A block is still open, and the hardware does not support closing
+ * blocks without adding data. Thus, close it manually.
+ */
+ send_eobs(strm, param);
+ param->bcf = 0;
+ }
+ return 0;
+ }
+
+ if (strm->avail_in == 0 && !param->cf) {
+ *result = need_more;
+ return 1;
+ }
+
+ /* There is an open non-BFINAL block, we are not going to close it just
+ * yet, we have compressed more than DFLTCC_BLOCK_SIZE bytes and we see
+ * more than DFLTCC_DHT_MIN_SAMPLE_SIZE bytes. Open a new block with a new
+ * DHT in order to adapt to a possibly changed input data distribution.
+ */
+ if (param->bcf && no_flush &&
+ strm->total_in > dfltcc_state->block_threshold &&
+ strm->avail_in >= dfltcc_state->dht_threshold) {
+ if (param->cf) {
+ /* We need to flush the DFLTCC buffer before writing the
+ * End-of-block Symbol. Mask the input data and proceed as usual.
+ */
+ masked_avail_in += strm->avail_in;
+ strm->avail_in = 0;
+ no_flush = 0;
+ } else {
+ /* DFLTCC buffer is empty, so we can manually write the
+ * End-of-block Symbol right away.
+ */
+ send_eobs(strm, param);
+ param->bcf = 0;
+ dfltcc_state->block_threshold =
+ strm->total_in + dfltcc_state->block_size;
+ if (strm->avail_out == 0) {
+ *result = need_more;
+ return 1;
+ }
+ }
+ }
+
+ /* The caller gave us too much data. Pass only one block worth of
+ * uncompressed data to DFLTCC and mask the rest, so that on the next
+ * iteration we start a new block.
+ */
+ if (no_flush && strm->avail_in > dfltcc_state->block_size) {
+ masked_avail_in += (strm->avail_in - dfltcc_state->block_size);
+ strm->avail_in = dfltcc_state->block_size;
+ }
+
+ /* When we have an open non-BFINAL deflate block and caller indicates that
+ * the stream is ending, we need to close an open deflate block and open a
+ * BFINAL one.
+ */
+ need_empty_block = flush == Z_FINISH && param->bcf && !param->bhf;
+
+ /* Translate stream to parameter block */
+ param->cvt = CVT_ADLER32;
+ if (!no_flush)
+ /* We need to close a block. Always do this in software - when there is
+ * no input data, the hardware will not nohor BCC. */
+ soft_bcc = 1;
+ if (flush == Z_FINISH && !param->bcf)
+ /* We are about to open a BFINAL block, set Block Header Final bit
+ * until the stream ends.
+ */
+ param->bhf = 1;
+ /* DFLTCC-CMPR will write to next_out, so make sure that buffers with
+ * higher precedence are empty.
+ */
+ Assert(state->pending == 0, "There must be no pending bytes");
+ Assert(state->bi_valid < 8, "There must be less than 8 pending bits");
+ param->sbb = (unsigned int)state->bi_valid;
+ if (param->sbb > 0)
+ *strm->next_out = (Byte)state->bi_buf;
+ if (param->hl)
+ param->nt = 0; /* Honor history */
+ param->cv = strm->adler;
+
+ /* When opening a block, choose a Huffman-Table Type */
+ if (!param->bcf) {
+ if (strm->total_in == 0 && dfltcc_state->block_threshold > 0) {
+ param->htt = HTT_FIXED;
+ }
+ else {
+ param->htt = HTT_DYNAMIC;
+ dfltcc_gdht(strm);
+ }
+ }
+
+ /* Deflate */
+ do {
+ cc = dfltcc_cmpr(strm);
+ if (strm->avail_in < 4096 && masked_avail_in > 0)
+ /* We are about to call DFLTCC with a small input buffer, which is
+ * inefficient. Since there is masked data, there will be at least
+ * one more DFLTCC call, so skip the current one and make the next
+ * one handle more data.
+ */
+ break;
+ } while (cc == DFLTCC_CC_AGAIN);
+
+ /* Translate parameter block to stream */
+ strm->msg = oesc_msg(dfltcc_state->msg, param->oesc);
+ state->bi_valid = param->sbb;
+ if (state->bi_valid == 0)
+ state->bi_buf = 0; /* Avoid accessing next_out */
+ else
+ state->bi_buf = *strm->next_out & ((1 << state->bi_valid) - 1);
+ strm->adler = param->cv;
+
+ /* Unmask the input data */
+ strm->avail_in += masked_avail_in;
+ masked_avail_in = 0;
+
+ /* If we encounter an error, it means there is a bug in DFLTCC call */
+ Assert(cc != DFLTCC_CC_OP2_CORRUPT || param->oesc == 0, "BUG");
+
+ /* Update Block-Continuation Flag. It will be used to check whether to call
+ * GDHT the next time.
+ */
+ if (cc == DFLTCC_CC_OK) {
+ if (soft_bcc) {
+ send_eobs(strm, param);
+ param->bcf = 0;
+ dfltcc_state->block_threshold =
+ strm->total_in + dfltcc_state->block_size;
+ } else
+ param->bcf = 1;
+ if (flush == Z_FINISH) {
+ if (need_empty_block)
+ /* Make the current deflate() call also close the stream */
+ return 0;
+ else {
+ bi_windup(state);
+ *result = finish_done;
+ }
+ } else {
+ if (flush == Z_FULL_FLUSH)
+ param->hl = 0; /* Clear history */
+ *result = flush == Z_NO_FLUSH ? need_more : block_done;
+ }
+ } else {
+ param->bcf = 1;
+ *result = need_more;
+ }
+ if (strm->avail_in != 0 && strm->avail_out != 0)
+ goto again; /* deflate() must use all input or all output */
+ return 1;
+}
projects / mirror_ubuntu-jammy-kernel.git / blobdiff