Merge commit 'b3cd242c6a0c1ef3e7dc63c870604f4ccc92c7a8' as 'Subtrees/hyperleveldb'

Subtrees/hyperleveldb/table/iterator.cc

@@ -0,0 +1,67 @@
+// 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 "hyperleveldb/iterator.h"
+
+namespace leveldb {
+
+Iterator::Iterator() {
+  cleanup_.function = NULL;
+  cleanup_.next = NULL;
+}
+
+Iterator::~Iterator() {
+  if (cleanup_.function != NULL) {
+    (*cleanup_.function)(cleanup_.arg1, cleanup_.arg2);
+    for (Cleanup* c = cleanup_.next; c != NULL; ) {
+      (*c->function)(c->arg1, c->arg2);
+      Cleanup* next = c->next;
+      delete c;
+      c = next;
+    }
+  }
+}
+
+void Iterator::RegisterCleanup(CleanupFunction func, void* arg1, void* arg2) {
+  assert(func != NULL);
+  Cleanup* c;
+  if (cleanup_.function == NULL) {
+    c = &cleanup_;
+  } else {
+    c = new Cleanup;
+    c->next = cleanup_.next;
+    cleanup_.next = c;
+  }
+  c->function = func;
+  c->arg1 = arg1;
+  c->arg2 = arg2;
+}
+
+namespace {
+class EmptyIterator : public Iterator {
+ public:
+  EmptyIterator(const Status& s) : status_(s) { }
+  virtual bool Valid() const { return false; }
+  virtual void Seek(const Slice& target) { }
+  virtual void SeekToFirst() { }
+  virtual void SeekToLast() { }
+  virtual void Next() { assert(false); }
+  virtual void Prev() { assert(false); }
+  Slice key() const { assert(false); return Slice(); }
+  Slice value() const { assert(false); return Slice(); }
+  virtual Status status() const { return status_; }
+ private:
+  Status status_;
+};
+}  // namespace
+
+Iterator* NewEmptyIterator() {
+  return new EmptyIterator(Status::OK());
+}
+
+Iterator* NewErrorIterator(const Status& status) {
+  return new EmptyIterator(status);
+}
+
+}  // namespace leveldb