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

xz/src/liblzma/common/stream_buffer_encoder.c

+///////////////////////////////////////////////////////////////////////////////
+//
+/// \file       stream_buffer_encoder.c
+/// \brief      Single-call .xz Stream encoder
+//
+//  Author:     Lasse Collin
+//
+//  This file has been put into the public domain.
+//  You can do whatever you want with this file.
+//
+///////////////////////////////////////////////////////////////////////////////
+
+#include "index.h"
+
+
+/// Maximum size of Index that has exactly one Record.
+/// Index Indicator + Number of Records + Record + CRC32 rounded up to
+/// the next multiple of four.
+#define INDEX_BOUND ((1 + 1 + 2 * LZMA_VLI_BYTES_MAX + 4 + 3) & ~3)
+
+/// Stream Header, Stream Footer, and Index
+#define HEADERS_BOUND (2 * LZMA_STREAM_HEADER_SIZE + INDEX_BOUND)
+
+
+extern LZMA_API(size_t)
+lzma_stream_buffer_bound(size_t uncompressed_size)
+{
+        // Get the maximum possible size of a Block.
+        const size_t block_bound = lzma_block_buffer_bound(uncompressed_size);
+        if (block_bound == 0)
+                return 0;
+
+        // Catch the possible integer overflow and also prevent the size of
+        // the Stream exceeding LZMA_VLI_MAX (theoretically possible on
+        // 64-bit systems).
+        if (my_min(SIZE_MAX, LZMA_VLI_MAX) - block_bound < HEADERS_BOUND)
+                return 0;
+
+        return block_bound + HEADERS_BOUND;
+}
+
+
+extern LZMA_API(lzma_ret)
+lzma_stream_buffer_encode(lzma_filter *filters, lzma_check check,
+                lzma_allocator *allocator, const uint8_t *in, size_t in_size,
+                uint8_t *out, size_t *out_pos_ptr, size_t out_size)
+{
+        // Sanity checks
+        if (filters == NULL || (unsigned int)(check) > LZMA_CHECK_ID_MAX
+                        || (in == NULL && in_size != 0) || out == NULL
+                        || out_pos_ptr == NULL || *out_pos_ptr > out_size)
+                return LZMA_PROG_ERROR;
+
+        // Note for the paranoids: Index encoder prevents the Stream from
+        // getting too big and still being accepted with LZMA_OK, and Block
+        // encoder catches if the input is too big. So we don't need to
+        // separately check if the buffers are too big.
+
+        // Use a local copy. We update *out_pos_ptr only if everything
+        // succeeds.
+        size_t out_pos = *out_pos_ptr;
+
+        // Check that there's enough space for both Stream Header and
+        // Stream Footer.
+        if (out_size - out_pos <= 2 * LZMA_STREAM_HEADER_SIZE)
+                return LZMA_BUF_ERROR;
+
+        // Reserve space for Stream Footer so we don't need to check for
+        // available space again before encoding Stream Footer.
+        out_size -= LZMA_STREAM_HEADER_SIZE;
+
+        // Encode the Stream Header.
+        lzma_stream_flags stream_flags = {
+                .version = 0,
+                .check = check,
+        };
+
+        if (lzma_stream_header_encode(&stream_flags, out + out_pos)
+                        != LZMA_OK)
+                return LZMA_PROG_ERROR;
+
+        out_pos += LZMA_STREAM_HEADER_SIZE;
+
+        // Block
+        lzma_block block = {
+                .version = 0,
+                .check = check,
+                .filters = filters,
+        };
+
+        return_if_error(lzma_block_buffer_encode(&block, allocator,
+                        in, in_size, out, &out_pos, out_size));
+
+        // Index
+        {
+                // Create an Index with one Record.
+                lzma_index *i = lzma_index_init(allocator);
+                if (i == NULL)
+                        return LZMA_MEM_ERROR;
+
+                lzma_ret ret = lzma_index_append(i, allocator,
+                                lzma_block_unpadded_size(&block),
+                                block.uncompressed_size);
+
+                // If adding the Record was successful, encode the Index
+                // and get its size which will be stored into Stream Footer.
+                if (ret == LZMA_OK) {
+                        ret = lzma_index_buffer_encode(
+                                        i, out, &out_pos, out_size);
+
+                        stream_flags.backward_size = lzma_index_size(i);
+                }
+
+                lzma_index_end(i, allocator);
+
+                if (ret != LZMA_OK)
+                        return ret;
+        }
+
+        // Stream Footer. We have already reserved space for this.
+        if (lzma_stream_footer_encode(&stream_flags, out + out_pos)
+                        != LZMA_OK)
+                return LZMA_PROG_ERROR;
+
+        out_pos += LZMA_STREAM_HEADER_SIZE;
+
+        // Everything went fine, make the new output position available
+        // to the application.
+        *out_pos_ptr = out_pos;
+        return LZMA_OK;
+}