1 files changed, 100 insertions, 0 deletions
diff --git a/src/rocksdb/util/file_checksum_helper.h b/src/rocksdb/util/file_checksum_helper.h
new file mode 100644
index 000000000..d622e9bba
--- /dev/null
+++ b/src/rocksdb/util/file_checksum_helper.h
@@ -0,0 +1,100 @@
+//  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).
+
+#pragma once
+#include <cassert>
+#include <unordered_map>
+
+#include "port/port.h"
+#include "rocksdb/file_checksum.h"
+#include "rocksdb/status.h"
+#include "util/coding.h"
+#include "util/crc32c.h"
+#include "util/math.h"
+
+namespace ROCKSDB_NAMESPACE {
+
+// This is the class to generate the file checksum based on Crc32. It
+// will be used as the default checksum method for SST file checksum
+class FileChecksumGenCrc32c : public FileChecksumGenerator {
+ public:
+  FileChecksumGenCrc32c(const FileChecksumGenContext& /*context*/) {
+    checksum_ = 0;
+  }
+
+  void Update(const char* data, size_t n) override {
+    checksum_ = crc32c::Extend(checksum_, data, n);
+  }
+
+  void Finalize() override {
+    assert(checksum_str_.empty());
+    // Store as big endian raw bytes
+    PutFixed32(&checksum_str_, EndianSwapValue(checksum_));
+  }
+
+  std::string GetChecksum() const override {
+    assert(!checksum_str_.empty());
+    return checksum_str_;
+  }
+
+  const char* Name() const override { return "FileChecksumCrc32c"; }
+
+ private:
+  uint32_t checksum_;
+  std::string checksum_str_;
+};
+
+class FileChecksumGenCrc32cFactory : public FileChecksumGenFactory {
+ public:
+  std::unique_ptr<FileChecksumGenerator> CreateFileChecksumGenerator(
+      const FileChecksumGenContext& context) override {
+    if (context.requested_checksum_func_name.empty() ||
+        context.requested_checksum_func_name == "FileChecksumCrc32c") {
+      return std::unique_ptr<FileChecksumGenerator>(
+          new FileChecksumGenCrc32c(context));
+    } else {
+      return nullptr;
+    }
+  }
+
+  static const char* kClassName() { return "FileChecksumGenCrc32cFactory"; }
+  const char* Name() const override { return kClassName(); }
+};
+
+// The default implementaion of FileChecksumList
+class FileChecksumListImpl : public FileChecksumList {
+ public:
+  FileChecksumListImpl() {}
+  void reset() override;
+
+  size_t size() const override;
+
+  Status GetAllFileChecksums(
+      std::vector<uint64_t>* file_numbers, std::vector<std::string>* checksums,
+      std::vector<std::string>* checksum_func_names) override;
+
+  Status SearchOneFileChecksum(uint64_t file_number, std::string* checksum,
+                               std::string* checksum_func_name) override;
+
+  Status InsertOneFileChecksum(uint64_t file_number,
+                               const std::string& checksum,
+                               const std::string& checksum_func_name) override;
+
+  Status RemoveOneFileChecksum(uint64_t file_number) override;
+
+ private:
+  // Key is the file number, the first portion of the value is checksum, the
+  // second portion of the value is checksum function name.
+  std::unordered_map<uint64_t, std::pair<std::string, std::string>>
+      checksum_map_;
+};
+
+// If manifest_file_size < std::numeric_limits<uint64_t>::max(), only use
+// that length prefix of the manifest file.
+Status GetFileChecksumsFromManifest(Env* src_env, const std::string& abs_path,
+                                    uint64_t manifest_file_size,
+                                    FileChecksumList* checksum_list);
+
+}  // namespace ROCKSDB_NAMESPACE