feat(memtable): Add kernel function in cuda code

Signed-off-by: KunoiSayami <[email protected]>

1 files changed, 90 insertions, 0 deletions

diff --git a/db/memtable.cuh b/db/memtable.cuh
new file mode 100644
index 0000000..ac3c2b6
--- /dev/null
+++ b/db/memtable.cuh
@@ -0,0 +1,90 @@
+// 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.
+
+#ifndef STORAGE_LEVELDB_DB_MEMTABLE_H_
+#define STORAGE_LEVELDB_DB_MEMTABLE_H_
+
+#include <string>
+
+#include "db/dbformat.h"
+#include "db/skiplist.cuh"
+#include "leveldb/db.h"
+#include "util/arena.cuh"
+
+namespace leveldb {
+
+class InternalKeyComparator;
+class MemTableIterator;
+
+class MemTable {
+ public:
+  // MemTables are reference counted.  The initial reference count
+  // is zero and the caller must call Ref() at least once.
+  __device__ explicit MemTable(const InternalKeyComparator& comparator);
+
+  MemTable(const MemTable&) = delete;
+  MemTable& operator=(const MemTable&) = delete;
+
+  // Increase reference count.
+  void Ref() { ++refs_; }
+
+  // Drop reference count.  Delete if no more references exist.
+  void Unref() {
+    --refs_;
+    assert(refs_ >= 0);
+    if (refs_ <= 0) {
+      delete this;
+    }
+  }
+
+  // Returns an estimate of the number of bytes of data in use by this
+  // data structure. It is safe to call when MemTable is being modified.
+  size_t ApproximateMemoryUsage();
+
+  // Return an iterator that yields the contents of the memtable.
+  //
+  // The caller must ensure that the underlying MemTable remains live
+  // while the returned iterator is live.  The keys returned by this
+  // iterator are internal keys encoded by AppendInternalKey in the
+  // db/format.{h,cc} module.
+  Iterator* NewIterator();
+
+  // Add an entry into memtable that maps key to value at the
+  // specified sequence number and with the specified type.
+  // Typically value will be empty if type==kTypeDeletion.
+  void Add(SequenceNumber seq, ValueType type, const Slice& key,
+           const Slice& value);
+
+  // If memtable contains a value for key, store it in *value and return true.
+  // If memtable contains a deletion for key, store a NotFound() error
+  // in *status and return true.
+  // Else, return false.
+  bool Get(const LookupKey& key, std::string* value, Status* s);
+
+ private:
+  friend class MemTableIterator;
+  friend class MemTableBackwardIterator;
+  friend __global__ void Add_(MemTable *, SequenceNumber, ValueType, size_t, size_t, char*, size_t, char *, size_t);
+  friend __global__ void Get_(MemTable *, bool * ret);
+
+  struct KeyComparator {
+    const InternalKeyComparator comparator;
+    __device__ explicit KeyComparator(const InternalKeyComparator& c) : comparator(c) {}
+    __device__ int operator()(const char* a, const char* b) const;
+    __device__ ~KeyComparator() = default;
+  };
+
+  typedef SkipList<const char*, KeyComparator> Table;
+
+  ~MemTable();  // Private since only Unref() should be used to delete it
+
+  KeyComparator comparator_;
+  int refs_;
+  Arena arena_;
+  Table table_;
+};
+
+}  // namespace leveldb
+
+#endif  // STORAGE_LEVELDB_DB_MEMTABLE_H_