Add an unpatched version of xz, XZ Utils, to /trunk/deps/third_party

xz/src/liblzma/common/block_encoder.c

+///////////////////////////////////////////////////////////////////////////////
+//
+/// \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, 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, lzma_allocator *allocator)
+{
+        lzma_next_end(&coder->next, allocator);
+        lzma_free(coder, allocator);
+        return;
+}
+
+
+static lzma_ret
+block_encoder_update(lzma_coder *coder, 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, lzma_allocator *allocator,
+                lzma_block *block)
+{
+        lzma_next_coder_init(&lzma_block_encoder_init, next, allocator);
+
+        if (block->version != 0)
+                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;
+}