1 files changed, 141 insertions, 0 deletions
diff --git a/src/rocksdb/utilities/transactions/lock/range/range_tree/lib/util/memarena.h b/src/rocksdb/utilities/transactions/lock/range/range_tree/lib/util/memarena.h
new file mode 100644
index 000000000..ddcc1144f
--- /dev/null
+++ b/src/rocksdb/utilities/transactions/lock/range/range_tree/lib/util/memarena.h
@@ -0,0 +1,141 @@
+/* -*- mode: C++; c-basic-offset: 4; indent-tabs-mode: nil -*- */
+// vim: ft=cpp:expandtab:ts=8:sw=4:softtabstop=4:
+#ident "$Id$"
+/*======
+This file is part of PerconaFT.
+
+
+Copyright (c) 2006, 2015, Percona and/or its affiliates. All rights reserved.
+
+    PerconaFT is free software: you can redistribute it and/or modify
+    it under the terms of the GNU General Public License, version 2,
+    as published by the Free Software Foundation.
+
+    PerconaFT is distributed in the hope that it will be useful,
+    but WITHOUT ANY WARRANTY; without even the implied warranty of
+    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+    GNU General Public License for more details.
+
+    You should have received a copy of the GNU General Public License
+    along with PerconaFT.  If not, see <http://www.gnu.org/licenses/>.
+
+----------------------------------------
+
+    PerconaFT is free software: you can redistribute it and/or modify
+    it under the terms of the GNU Affero General Public License, version 3,
+    as published by the Free Software Foundation.
+
+    PerconaFT is distributed in the hope that it will be useful,
+    but WITHOUT ANY WARRANTY; without even the implied warranty of
+    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+    GNU Affero General Public License for more details.
+
+    You should have received a copy of the GNU Affero General Public License
+    along with PerconaFT.  If not, see <http://www.gnu.org/licenses/>.
+
+----------------------------------------
+
+   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.
+======= */
+
+#ident \
+    "Copyright (c) 2006, 2015, Percona and/or its affiliates. All rights reserved."
+
+#pragma once
+
+#include <stdlib.h>
+
+/*
+ * A memarena is used to efficiently store a collection of objects that never
+ * move The pattern is allocate more and more stuff and free all of the items at
+ * once. The underlying memory will store 1 or more objects per chunk. Each
+ * chunk is contiguously laid out in memory but chunks are not necessarily
+ * contiguous with each other.
+ */
+class memarena {
+ public:
+  memarena()
+      : _current_chunk(arena_chunk()),
+        _other_chunks(nullptr),
+        _n_other_chunks(0),
+        _size_of_other_chunks(0),
+        _footprint_of_other_chunks(0) {}
+
+  // Effect: Create a memarena with the specified initial size
+  void create(size_t initial_size);
+
+  void destroy(void);
+
+  // Effect: Allocate some memory.  The returned value remains valid until the
+  // memarena is cleared or closed.
+  //  In case of ENOMEM, aborts.
+  void *malloc_from_arena(size_t size);
+
+  // Effect: Move all the memory from this memarena into DEST.
+  //         When SOURCE is closed the memory won't be freed.
+  //         When DEST is closed, the memory will be freed, unless DEST moves
+  //         its memory to another memarena...
+  void move_memory(memarena *dest);
+
+  // Effect: Calculate the amount of memory used by a memory arena.
+  size_t total_memory_size(void) const;
+
+  // Effect: Calculate the used space of the memory arena (ie: excludes unused
+  // space)
+  size_t total_size_in_use(void) const;
+
+  // Effect: Calculate the amount of memory used, according to
+  // toku_memory_footprint(),
+  //         which is a more expensive but more accurate count of memory used.
+  size_t total_footprint(void) const;
+
+  // iterator over the underlying chunks that store objects in the memarena.
+  // a chunk is represented by a pointer to const memory and a usable byte
+  // count.
+  class chunk_iterator {
+   public:
+    chunk_iterator(const memarena *ma) : _ma(ma), _chunk_idx(-1) {}
+
+    // returns: base pointer to the current chunk
+    //          *used set to the number of usable bytes
+    //          if more() is false, returns nullptr and *used = 0
+    const void *current(size_t *used) const;
+
+    // requires: more() is true
+    void next();
+
+    bool more() const;
+
+   private:
+    // -1 represents the 'initial' chunk in a memarena, ie: ma->_current_chunk
+    // >= 0 represents the i'th chunk in the ma->_other_chunks array
+    const memarena *_ma;
+    int _chunk_idx;
+  };
+
+ private:
+  struct arena_chunk {
+    arena_chunk() : buf(nullptr), used(0), size(0) {}
+    char *buf;
+    size_t used;
+    size_t size;
+  };
+
+  struct arena_chunk _current_chunk;
+  struct arena_chunk *_other_chunks;
+  int _n_other_chunks;
+  size_t _size_of_other_chunks;       // the buf_size of all the other chunks.
+  size_t _footprint_of_other_chunks;  // the footprint of all the other chunks.
+
+  friend class memarena_unit_test;
+};