1 files changed, 52 insertions, 0 deletions
diff --git a/src/rocksdb/table/block_based/reader_common.cc b/src/rocksdb/table/block_based/reader_common.cc
new file mode 100644
index 000000000..0ff43e9b4
--- /dev/null
+++ b/src/rocksdb/table/block_based/reader_common.cc
@@ -0,0 +1,52 @@
+//  Copyright (c) 2011-present, Facebook, Inc.  All rights reserved.
+//  This source code is licensed under both the GPLv2 (found in the
+//  COPYING file in the root directory) and Apache 2.0 License
+//  (found in the LICENSE.Apache file in the root directory).
+//
+// Copyright (c) 2011 The LevelDB Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file. See the AUTHORS file for names of contributors.
+#include "table/block_based/reader_common.h"
+
+#include "monitoring/perf_context_imp.h"
+#include "rocksdb/table.h"
+#include "table/format.h"
+#include "util/coding.h"
+#include "util/crc32c.h"
+#include "util/string_util.h"
+
+namespace ROCKSDB_NAMESPACE {
+void ForceReleaseCachedEntry(void* arg, void* h) {
+  Cache* cache = reinterpret_cast<Cache*>(arg);
+  Cache::Handle* handle = reinterpret_cast<Cache::Handle*>(h);
+  cache->Release(handle, true /* erase_if_last_ref */);
+}
+
+// WART: this is specific to block-based table
+Status VerifyBlockChecksum(ChecksumType type, const char* data,
+                           size_t block_size, const std::string& file_name,
+                           uint64_t offset) {
+  PERF_TIMER_GUARD(block_checksum_time);
+  // After block_size bytes is compression type (1 byte), which is part of
+  // the checksummed section.
+  size_t len = block_size + 1;
+  // And then the stored checksum value (4 bytes).
+  uint32_t stored = DecodeFixed32(data + len);
+
+  uint32_t computed = ComputeBuiltinChecksum(type, data, len);
+  if (stored == computed) {
+    return Status::OK();
+  } else {
+    // Unmask for people who might look for reference crc value
+    if (type == kCRC32c) {
+      stored = crc32c::Unmask(stored);
+      computed = crc32c::Unmask(computed);
+    }
+    return Status::Corruption(
+        "block checksum mismatch: stored = " + std::to_string(stored) +
+        ", computed = " + std::to_string(computed) +
+        ", type = " + std::to_string(type) + "  in " + file_name + " offset " +
+        std::to_string(offset) + " size " + std::to_string(block_size));
+  }
+}
+}  // namespace ROCKSDB_NAMESPACE