Adding upstream version 18.2.2.upstream/18.2.2

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

1 files changed, 46 insertions, 0 deletions

diff --git a/src/rocksdb/table/persistent_cache_helper.h b/src/rocksdb/table/persistent_cache_helper.h
new file mode 100644
index 000000000..ece339aee
--- /dev/null
+++ b/src/rocksdb/table/persistent_cache_helper.h
@@ -0,0 +1,46 @@
+//  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 <string>
+
+#include "monitoring/statistics.h"
+#include "table/format.h"
+#include "table/persistent_cache_options.h"
+
+namespace ROCKSDB_NAMESPACE {
+
+struct BlockContents;
+
+// PersistentCacheHelper
+//
+// Encapsulates  some of the helper logic for read and writing from the cache
+class PersistentCacheHelper {
+ public:
+  // Insert block into cache of serialized blocks. Size includes block trailer
+  // (if applicable).
+  static void InsertSerialized(const PersistentCacheOptions& cache_options,
+                               const BlockHandle& handle, const char* data,
+                               const size_t size);
+
+  // Insert block into cache of uncompressed blocks. No block trailer.
+  static void InsertUncompressed(const PersistentCacheOptions& cache_options,
+                                 const BlockHandle& handle,
+                                 const BlockContents& contents);
+
+  // Lookup block from cache of serialized blocks. Size includes block trailer
+  // (if applicable).
+  static Status LookupSerialized(const PersistentCacheOptions& cache_options,
+                                 const BlockHandle& handle,
+                                 std::unique_ptr<char[]>* out_data,
+                                 const size_t expected_data_size);
+
+  // Lookup block from uncompressed cache. No block trailer.
+  static Status LookupUncompressed(const PersistentCacheOptions& cache_options,
+                                   const BlockHandle& handle,
+                                   BlockContents* contents);
+};
+
+}  // namespace ROCKSDB_NAMESPACE