Index: xz/src/liblzma/delta/delta_encoder.c |
=================================================================== |
--- xz/src/liblzma/delta/delta_encoder.c (revision 0) |
+++ xz/src/liblzma/delta/delta_encoder.c (revision 0) |
@@ -0,0 +1,121 @@ |
+/////////////////////////////////////////////////////////////////////////////// |
+// |
+/// \file delta_encoder.c |
+/// \brief Delta filter encoder |
+// |
+// Author: Lasse Collin |
+// |
+// This file has been put into the public domain. |
+// You can do whatever you want with this file. |
+// |
+/////////////////////////////////////////////////////////////////////////////// |
+ |
+#include "delta_encoder.h" |
+#include "delta_private.h" |
+ |
+ |
+/// Copies and encodes the data at the same time. This is used when Delta |
+/// is the first filter in the chain (and thus the last filter in the |
+/// encoder's filter stack). |
+static void |
+copy_and_encode(lzma_coder *coder, |
+ const uint8_t *restrict in, uint8_t *restrict out, size_t size) |
+{ |
+ const size_t distance = coder->distance; |
+ |
+ for (size_t i = 0; i < size; ++i) { |
+ const uint8_t tmp = coder->history[ |
+ (distance + coder->pos) & 0xFF]; |
+ coder->history[coder->pos-- & 0xFF] = in[i]; |
+ out[i] = in[i] - tmp; |
+ } |
+} |
+ |
+ |
+/// Encodes the data in place. This is used when we are the last filter |
+/// in the chain (and thus non-last filter in the encoder's filter stack). |
+static void |
+encode_in_place(lzma_coder *coder, uint8_t *buffer, size_t size) |
+{ |
+ const size_t distance = coder->distance; |
+ |
+ for (size_t i = 0; i < size; ++i) { |
+ const uint8_t tmp = coder->history[ |
+ (distance + coder->pos) & 0xFF]; |
+ coder->history[coder->pos-- & 0xFF] = buffer[i]; |
+ buffer[i] -= tmp; |
+ } |
+} |
+ |
+ |
+static lzma_ret |
+delta_encode(lzma_coder *coder, lzma_allocator *allocator, |
+ const uint8_t *restrict in, size_t *restrict in_pos, |
+ size_t in_size, uint8_t *restrict out, |
+ size_t *restrict out_pos, size_t out_size, lzma_action action) |
+{ |
+ lzma_ret ret; |
+ |
+ if (coder->next.code == NULL) { |
+ const size_t in_avail = in_size - *in_pos; |
+ const size_t out_avail = out_size - *out_pos; |
+ const size_t size = my_min(in_avail, out_avail); |
+ |
+ copy_and_encode(coder, in + *in_pos, out + *out_pos, size); |
+ |
+ *in_pos += size; |
+ *out_pos += size; |
+ |
+ ret = action != LZMA_RUN && *in_pos == in_size |
+ ? LZMA_STREAM_END : LZMA_OK; |
+ |
+ } else { |
+ const size_t out_start = *out_pos; |
+ |
+ ret = coder->next.code(coder->next.coder, allocator, |
+ in, in_pos, in_size, out, out_pos, out_size, |
+ action); |
+ |
+ encode_in_place(coder, out + out_start, *out_pos - out_start); |
+ } |
+ |
+ return ret; |
+} |
+ |
+ |
+static lzma_ret |
+delta_encoder_update(lzma_coder *coder, lzma_allocator *allocator, |
+ const lzma_filter *filters_null lzma_attribute((unused)), |
+ const lzma_filter *reversed_filters) |
+{ |
+ // Delta doesn't and will never support changing the options in |
+ // the middle of encoding. If the app tries to change them, we |
+ // simply ignore them. |
+ return lzma_next_filter_update( |
+ &coder->next, allocator, reversed_filters + 1); |
+} |
+ |
+ |
+extern lzma_ret |
+lzma_delta_encoder_init(lzma_next_coder *next, lzma_allocator *allocator, |
+ const lzma_filter_info *filters) |
+{ |
+ next->code = &delta_encode; |
+ next->update = &delta_encoder_update; |
+ return lzma_delta_coder_init(next, allocator, filters); |
+} |
+ |
+ |
+extern lzma_ret |
+lzma_delta_props_encode(const void *options, uint8_t *out) |
+{ |
+ // The caller must have already validated the options, so it's |
+ // LZMA_PROG_ERROR if they are invalid. |
+ if (lzma_delta_coder_memusage(options) == UINT64_MAX) |
+ return LZMA_PROG_ERROR; |
+ |
+ const lzma_options_delta *opt = options; |
+ out[0] = opt->dist - LZMA_DELTA_DIST_MIN; |
+ |
+ return LZMA_OK; |
+} |
Property changes on: xz/src/liblzma/delta/delta_encoder.c |
___________________________________________________________________ |
Added: svn:eol-style |
+ LF |