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

xz/src/liblzma/common/stream_buffer_decoder.c

+///////////////////////////////////////////////////////////////////////////////
+//
+/// \file       stream_buffer_decoder.c
+/// \brief      Single-call .xz Stream decoder
+//
+//  Author:     Lasse Collin
+//
+//  This file has been put into the public domain.
+//  You can do whatever you want with this file.
+//
+///////////////////////////////////////////////////////////////////////////////
+
+#include "stream_decoder.h"
+
+
+extern LZMA_API(lzma_ret)
+lzma_stream_buffer_decode(uint64_t *memlimit, uint32_t flags,
+                lzma_allocator *allocator,
+                const uint8_t *in, size_t *in_pos, size_t in_size,
+                uint8_t *out, size_t *out_pos, size_t out_size)
+{
+        // Sanity checks
+        if (in_pos == NULL || (in == NULL && *in_pos != in_size)
+                        || *in_pos > in_size || out_pos == NULL
+                        || (out == NULL && *out_pos != out_size)
+                        || *out_pos > out_size)
+                return LZMA_PROG_ERROR;
+
+        // Catch flags that are not allowed in buffer-to-buffer decoding.
+        if (flags & LZMA_TELL_ANY_CHECK)
+                return LZMA_PROG_ERROR;
+
+        // Initialize the Stream decoder.
+        // TODO: We need something to tell the decoder that it can use the
+        // output buffer as workspace, and thus save significant amount of RAM.
+        lzma_next_coder stream_decoder = LZMA_NEXT_CODER_INIT;
+        lzma_ret ret = lzma_stream_decoder_init(
+                        &stream_decoder, allocator, *memlimit, flags);
+
+        if (ret == LZMA_OK) {
+                // Save the positions so that we can restore them in case
+                // an error occurs.
+                const size_t in_start = *in_pos;
+                const size_t out_start = *out_pos;
+
+                // Do the actual decoding.
+                ret = stream_decoder.code(stream_decoder.coder, allocator,
+                                in, in_pos, in_size, out, out_pos, out_size,
+                                LZMA_FINISH);
+
+                if (ret == LZMA_STREAM_END) {
+                        ret = LZMA_OK;
+                } else {
+                        // Something went wrong, restore the positions.
+                        *in_pos = in_start;
+                        *out_pos = out_start;
+
+                        if (ret == LZMA_OK) {
+                                // Either the input was truncated or the
+                                // output buffer was too small.
+                                assert(*in_pos == in_size
+                                                || *out_pos == out_size);
+
+                                // If all the input was consumed, then the
+                                // input is truncated, even if the output
+                                // buffer is also full. This is because
+                                // processing the last byte of the Stream
+                                // never produces output.
+                                if (*in_pos == in_size)
+                                        ret = LZMA_DATA_ERROR;
+                                else
+                                        ret = LZMA_BUF_ERROR;
+
+                        } else if (ret == LZMA_MEMLIMIT_ERROR) {
+                                // Let the caller know how much memory would
+                                // have been needed.
+                                uint64_t memusage;
+                                (void)stream_decoder.memconfig(
+                                                stream_decoder.coder,
+                                                memlimit, &memusage, 0);
+                        }
+                }
+        }
+
+        // Free the decoder memory. This needs to be done even if
+        // initialization fails, because the internal API doesn't
+        // require the initialization function to free its memory on error.
+        lzma_next_end(&stream_decoder, allocator);
+
+        return ret;
+}