1 files changed, 90 insertions, 0 deletions

diff --git a/C/Xz.c b/C/Xz.c
new file mode 100644
index 0000000..7c53b60
--- /dev/null
+++ b/C/Xz.c
@@ -0,0 +1,90 @@
+/* Xz.c - Xz
+2021-02-09 : Igor Pavlov : Public domain */
+
+#include "Precomp.h"
+
+#include "7zCrc.h"
+#include "CpuArch.h"
+#include "Xz.h"
+#include "XzCrc64.h"
+
+const Byte XZ_SIG[XZ_SIG_SIZE] = { 0xFD, '7', 'z', 'X', 'Z', 0 };
+/* const Byte XZ_FOOTER_SIG[XZ_FOOTER_SIG_SIZE] = { 'Y', 'Z' }; */
+
+unsigned Xz_WriteVarInt(Byte *buf, UInt64 v)
+{
+  unsigned i = 0;
+  do
+  {
+    buf[i++] = (Byte)((v & 0x7F) | 0x80);
+    v >>= 7;
+  }
+  while (v != 0);
+  buf[(size_t)i - 1] &= 0x7F;
+  return i;
+}
+
+void Xz_Construct(CXzStream *p)
+{
+  p->numBlocks = 0;
+  p->blocks = NULL;
+  p->flags = 0;
+}
+
+void Xz_Free(CXzStream *p, ISzAllocPtr alloc)
+{
+  ISzAlloc_Free(alloc, p->blocks);
+  p->numBlocks = 0;
+  p->blocks = NULL;
+}
+
+unsigned XzFlags_GetCheckSize(CXzStreamFlags f)
+{
+  unsigned t = XzFlags_GetCheckType(f);
+  return (t == 0) ? 0 : ((unsigned)4 << ((t - 1) / 3));
+}
+
+void XzCheck_Init(CXzCheck *p, unsigned mode)
+{
+  p->mode = mode;
+  switch (mode)
+  {
+    case XZ_CHECK_CRC32: p->crc = CRC_INIT_VAL; break;
+    case XZ_CHECK_CRC64: p->crc64 = CRC64_INIT_VAL; break;
+    case XZ_CHECK_SHA256: Sha256_Init(&p->sha); break;
+  }
+}
+
+void XzCheck_Update(CXzCheck *p, const void *data, size_t size)
+{
+  switch (p->mode)
+  {
+    case XZ_CHECK_CRC32: p->crc = CrcUpdate(p->crc, data, size); break;
+    case XZ_CHECK_CRC64: p->crc64 = Crc64Update(p->crc64, data, size); break;
+    case XZ_CHECK_SHA256: Sha256_Update(&p->sha, (const Byte *)data, size); break;
+  }
+}
+
+int XzCheck_Final(CXzCheck *p, Byte *digest)
+{
+  switch (p->mode)
+  {
+    case XZ_CHECK_CRC32:
+      SetUi32(digest, CRC_GET_DIGEST(p->crc));
+      break;
+    case XZ_CHECK_CRC64:
+    {
+      int i;
+      UInt64 v = CRC64_GET_DIGEST(p->crc64);
+      for (i = 0; i < 8; i++, v >>= 8)
+        digest[i] = (Byte)(v & 0xFF);
+      break;
+    }
+    case XZ_CHECK_SHA256:
+      Sha256_Final(&p->sha, digest);
+      break;
+    default:
+      return 0;
+  }
+  return 1;
+}