Re-organized sub-directory by category

[staging/basesystem.git] / service / native / backup_manager / server / src / bkup_crc32.cpp

diff --git a/service/native/backup_manager/server/src/bkup_crc32.cpp b/service/native/backup_manager/server/src/bkup_crc32.cpp
new file mode 100755 (executable)
index 0000000..f1d8449
--- /dev/null
+++ b/service/native/backup_manager/server/src/bkup_crc32.cpp
@@ -0,0 +1,62 @@
+/*
+ * @copyright Copyright (c) 2016-2020 TOYOTA MOTOR CORPORATION.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+#include <cstdio>
+#include "bkup_crc32.h"
+#include "bkup_util.h"
+
+/*
+ * CRC-32C lookup table
+ *
+ * Polynomial 0x1EDC6F41
+ */
+static const uint32_t kBkupCrc32Lookup[4][256] = {
+  {
+  },
+  {
+  },
+  {
+  },
+  {
+  }
+};
+
+/**
+ * compute CRC-32C (Slicing-by-4)
+ */
+uint32_t BkupCrc32(const void *data, size_t length) {
+  uint32_t crc = 0xFFFFFFFF;
+  const uint32_t *current = (const uint32_t *)data;
+
+  if (data == NULL) {
+    return -1;
+  }
+  while (length >= 4) {
+    uint32_t one = *current++ ^ crc;
+    crc = kBkupCrc32Lookup[0][(one >> 24) & 0xFF] ^
+          kBkupCrc32Lookup[1][(one >> 16) & 0xFF] ^
+          kBkupCrc32Lookup[2][(one >> 8) & 0xFF] ^
+          kBkupCrc32Lookup[3][one & 0xFF];
+    length -= 4;
+  }
+
+  const uint8_t *current_char = (const uint8_t *)current;
+  while (length-- > 0) {
+    crc = (crc >> 8) ^ kBkupCrc32Lookup[0][(crc & 0xFF) ^ *current_char++];
+  }
+
+  return ~crc;
+}