--- /dev/null
+///////////////////////////////////////////////////////////////////////////////
+//
+/// \file block_encoder.c
+/// \brief Encodes .xz Blocks
+//
+// Author: Lasse Collin
+//
+// This file has been put into the public domain.
+// You can do whatever you want with this file.
+//
+///////////////////////////////////////////////////////////////////////////////
+
+#include "block_encoder.h"
+#include "filter_encoder.h"
+#include "check.h"
+
+
+struct lzma_coder_s {
+ /// The filters in the chain; initialized with lzma_raw_decoder_init().
+ lzma_next_coder next;
+
+ /// Encoding options; we also write Unpadded Size, Compressed Size,
+ /// and Uncompressed Size back to this structure when the encoding
+ /// has been finished.
+ lzma_block *block;
+
+ enum {
+ SEQ_CODE,
+ SEQ_PADDING,
+ SEQ_CHECK,
+ } sequence;
+
+ /// Compressed Size calculated while encoding
+ lzma_vli compressed_size;
+
+ /// Uncompressed Size calculated while encoding
+ lzma_vli uncompressed_size;
+
+ /// Position in the Check field
+ size_t pos;
+
+ /// Check of the uncompressed data
+ lzma_check_state check;
+};
+
+
+static lzma_ret
+block_encode(lzma_coder *coder, const 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)
+{
+ // Check that our amount of input stays in proper limits.
+ if (LZMA_VLI_MAX - coder->uncompressed_size < in_size - *in_pos)
+ return LZMA_DATA_ERROR;
+
+ switch (coder->sequence) {
+ case SEQ_CODE: {
+ const size_t in_start = *in_pos;
+ const size_t out_start = *out_pos;
+
+ const lzma_ret ret = coder->next.code(coder->next.coder,
+ allocator, in, in_pos, in_size,
+ out, out_pos, out_size, action);
+
+ const size_t in_used = *in_pos - in_start;
+ const size_t out_used = *out_pos - out_start;
+
+ if (COMPRESSED_SIZE_MAX - coder->compressed_size < out_used)
+ return LZMA_DATA_ERROR;
+
+ coder->compressed_size += out_used;
+
+ // No need to check for overflow because we have already
+ // checked it at the beginning of this function.
+ coder->uncompressed_size += in_used;
+
+ lzma_check_update(&coder->check, coder->block->check,
+ in + in_start, in_used);
+
+ if (ret != LZMA_STREAM_END || action == LZMA_SYNC_FLUSH)
+ return ret;
+
+ assert(*in_pos == in_size);
+ assert(action == LZMA_FINISH);
+
+ // Copy the values into coder->block. The caller
+ // may use this information to construct Index.
+ coder->block->compressed_size = coder->compressed_size;
+ coder->block->uncompressed_size = coder->uncompressed_size;
+
+ coder->sequence = SEQ_PADDING;
+ }
+
+ // Fall through
+
+ case SEQ_PADDING:
+ // Pad Compressed Data to a multiple of four bytes. We can
+ // use coder->compressed_size for this since we don't need
+ // it for anything else anymore.
+ while (coder->compressed_size & 3) {
+ if (*out_pos >= out_size)
+ return LZMA_OK;
+
+ out[*out_pos] = 0x00;
+ ++*out_pos;
+ ++coder->compressed_size;
+ }
+
+ if (coder->block->check == LZMA_CHECK_NONE)
+ return LZMA_STREAM_END;
+
+ lzma_check_finish(&coder->check, coder->block->check);
+
+ coder->sequence = SEQ_CHECK;
+
+ // Fall through
+
+ case SEQ_CHECK: {
+ const size_t check_size = lzma_check_size(coder->block->check);
+ lzma_bufcpy(coder->check.buffer.u8, &coder->pos, check_size,
+ out, out_pos, out_size);
+ if (coder->pos < check_size)
+ return LZMA_OK;
+
+ memcpy(coder->block->raw_check, coder->check.buffer.u8,
+ check_size);
+ return LZMA_STREAM_END;
+ }
+ }
+
+ return LZMA_PROG_ERROR;
+}
+
+
+static void
+block_encoder_end(lzma_coder *coder, const lzma_allocator *allocator)
+{
+ lzma_next_end(&coder->next, allocator);
+ lzma_free(coder, allocator);
+ return;
+}
+
+
+static lzma_ret
+block_encoder_update(lzma_coder *coder, const lzma_allocator *allocator,
+ const lzma_filter *filters lzma_attribute((__unused__)),
+ const lzma_filter *reversed_filters)
+{
+ if (coder->sequence != SEQ_CODE)
+ return LZMA_PROG_ERROR;
+
+ return lzma_next_filter_update(
+ &coder->next, allocator, reversed_filters);
+}
+
+
+extern lzma_ret
+lzma_block_encoder_init(lzma_next_coder *next, const lzma_allocator *allocator,
+ lzma_block *block)
+{
+ lzma_next_coder_init(&lzma_block_encoder_init, next, allocator);
+
+ if (block == NULL)
+ return LZMA_PROG_ERROR;
+
+ // The contents of the structure may depend on the version so
+ // check the version first.
+ if (block->version > 1)
+ return LZMA_OPTIONS_ERROR;
+
+ // If the Check ID is not supported, we cannot calculate the check and
+ // thus not create a proper Block.
+ if ((unsigned int)(block->check) > LZMA_CHECK_ID_MAX)
+ return LZMA_PROG_ERROR;
+
+ if (!lzma_check_is_supported(block->check))
+ return LZMA_UNSUPPORTED_CHECK;
+
+ // Allocate and initialize *next->coder if needed.
+ if (next->coder == NULL) {
+ next->coder = lzma_alloc(sizeof(lzma_coder), allocator);
+ if (next->coder == NULL)
+ return LZMA_MEM_ERROR;
+
+ next->code = &block_encode;
+ next->end = &block_encoder_end;
+ next->update = &block_encoder_update;
+ next->coder->next = LZMA_NEXT_CODER_INIT;
+ }
+
+ // Basic initializations
+ next->coder->sequence = SEQ_CODE;
+ next->coder->block = block;
+ next->coder->compressed_size = 0;
+ next->coder->uncompressed_size = 0;
+ next->coder->pos = 0;
+
+ // Initialize the check
+ lzma_check_init(&next->coder->check, block->check);
+
+ // Initialize the requested filters.
+ return lzma_raw_encoder_init(&next->coder->next, allocator,
+ block->filters);
+}
+
+
+extern LZMA_API(lzma_ret)
+lzma_block_encoder(lzma_stream *strm, lzma_block *block)
+{
+ lzma_next_strm_init(lzma_block_encoder_init, strm, block);
+
+ strm->internal->supported_actions[LZMA_RUN] = true;
+ strm->internal->supported_actions[LZMA_FINISH] = true;
+
+ return LZMA_OK;
+}
projects / zpackage / blobdiff