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-rw-r--r--src/liblzma/check/crc32_small.c54
1 files changed, 54 insertions, 0 deletions
diff --git a/src/liblzma/check/crc32_small.c b/src/liblzma/check/crc32_small.c
new file mode 100644
index 00000000..db26f8d4
--- /dev/null
+++ b/src/liblzma/check/crc32_small.c
@@ -0,0 +1,54 @@
+///////////////////////////////////////////////////////////////////////////////
+//
+/// \file crc32_small.c
+/// \brief CRC32 calculation (size-optimized)
+//
+// This code has been put into the public domain.
+//
+// This library is distributed in the hope that it will be useful,
+// but WITHOUT ANY WARRANTY; without even the implied warranty of
+// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.
+//
+///////////////////////////////////////////////////////////////////////////////
+
+#include "check.h"
+
+
+uint32_t lzma_crc32_table[1][256];
+
+
+static void
+crc32_init(void)
+{
+ static const uint32_t poly32 = UINT32_C(0xEDB88320);
+
+ for (size_t b = 0; b < 256; ++b) {
+ uint32_t r = b;
+ for (size_t i = 0; i < 8; ++i) {
+ if (r & 1)
+ r = (r >> 1) ^ poly32;
+ else
+ r >>= 1;
+ }
+
+ lzma_crc32_table[0][b] = r;
+ }
+
+ return;
+}
+
+
+extern LZMA_API uint32_t
+lzma_crc32(const uint8_t *buf, size_t size, uint32_t crc)
+{
+ mythread_once(crc32_init);
+
+ crc = ~crc;
+
+ while (size != 0) {
+ crc = lzma_crc32_table[0][*buf++ ^ (crc & 0xFF)] ^ (crc >> 8);
+ --size;
+ }
+
+ return ~crc;
+}