integrate lzma

[zpackage] / lzma / common / stream_flags_encoder.c

diff --git a/lzma/common/stream_flags_encoder.c b/lzma/common/stream_flags_encoder.c
new file mode 100644 (file)
index 0000000..4e71715
--- /dev/null
+++ b/lzma/common/stream_flags_encoder.c
@@ -0,0 +1,86 @@
+///////////////////////////////////////////////////////////////////////////////
+//
+/// \file       stream_flags_encoder.c
+/// \brief      Encodes Stream Header and Stream Footer for .xz files
+//
+//  Author:     Lasse Collin
+//
+//  This file has been put into the public domain.
+//  You can do whatever you want with this file.
+//
+///////////////////////////////////////////////////////////////////////////////
+
+#include "stream_flags_common.h"
+
+
+static bool
+stream_flags_encode(const lzma_stream_flags *options, uint8_t *out)
+{
+       if ((unsigned int)(options->check) > LZMA_CHECK_ID_MAX)
+               return true;
+
+       out[0] = 0x00;
+       out[1] = options->check;
+
+       return false;
+}
+
+
+extern LZMA_API(lzma_ret)
+lzma_stream_header_encode(const lzma_stream_flags *options, uint8_t *out)
+{
+       assert(sizeof(lzma_header_magic) + LZMA_STREAM_FLAGS_SIZE
+                       + 4 == LZMA_STREAM_HEADER_SIZE);
+
+       if (options->version != 0)
+               return LZMA_OPTIONS_ERROR;
+
+       // Magic
+       memcpy(out, lzma_header_magic, sizeof(lzma_header_magic));
+
+       // Stream Flags
+       if (stream_flags_encode(options, out + sizeof(lzma_header_magic)))
+               return LZMA_PROG_ERROR;
+
+       // CRC32 of the Stream Header
+       const uint32_t crc = lzma_crc32(out + sizeof(lzma_header_magic),
+                       LZMA_STREAM_FLAGS_SIZE, 0);
+
+       unaligned_write32le(out + sizeof(lzma_header_magic)
+                       + LZMA_STREAM_FLAGS_SIZE, crc);
+
+       return LZMA_OK;
+}
+
+
+extern LZMA_API(lzma_ret)
+lzma_stream_footer_encode(const lzma_stream_flags *options, uint8_t *out)
+{
+       assert(2 * 4 + LZMA_STREAM_FLAGS_SIZE + sizeof(lzma_footer_magic)
+                       == LZMA_STREAM_HEADER_SIZE);
+
+       if (options->version != 0)
+               return LZMA_OPTIONS_ERROR;
+
+       // Backward Size
+       if (!is_backward_size_valid(options))
+               return LZMA_PROG_ERROR;
+
+       unaligned_write32le(out + 4, options->backward_size / 4 - 1);
+
+       // Stream Flags
+       if (stream_flags_encode(options, out + 2 * 4))
+               return LZMA_PROG_ERROR;
+
+       // CRC32
+       const uint32_t crc = lzma_crc32(
+                       out + 4, 4 + LZMA_STREAM_FLAGS_SIZE, 0);
+
+       unaligned_write32le(out, crc);
+
+       // Magic
+       memcpy(out + 2 * 4 + LZMA_STREAM_FLAGS_SIZE,
+                       lzma_footer_magic, sizeof(lzma_footer_magic));
+
+       return LZMA_OK;
+}