integrate lzma

[zpackage] / lzma / common / stream_buffer_decoder.c

diff --git a/lzma/common/stream_buffer_decoder.c b/lzma/common/stream_buffer_decoder.c
new file mode 100644 (file)
index 0000000..b9745b5
--- /dev/null
+++ b/lzma/common/stream_buffer_decoder.c
@@ -0,0 +1,91 @@
+///////////////////////////////////////////////////////////////////////////////
+//
+/// \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,
+               const 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;
+}