summaryrefslogtreecommitdiffstats
path: root/src/rocksdb/db/pinned_iterators_manager.h
diff options
context:
space:
mode:
Diffstat (limited to 'src/rocksdb/db/pinned_iterators_manager.h')
-rw-r--r--src/rocksdb/db/pinned_iterators_manager.h87
1 files changed, 87 insertions, 0 deletions
diff --git a/src/rocksdb/db/pinned_iterators_manager.h b/src/rocksdb/db/pinned_iterators_manager.h
new file mode 100644
index 000000000..5e8ad51dd
--- /dev/null
+++ b/src/rocksdb/db/pinned_iterators_manager.h
@@ -0,0 +1,87 @@
+// 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 <algorithm>
+#include <memory>
+#include <utility>
+#include <vector>
+
+#include "table/internal_iterator.h"
+
+namespace ROCKSDB_NAMESPACE {
+
+// PinnedIteratorsManager will be notified whenever we need to pin an Iterator
+// and it will be responsible for deleting pinned Iterators when they are
+// not needed anymore.
+class PinnedIteratorsManager : public Cleanable {
+ public:
+ PinnedIteratorsManager() : pinning_enabled(false) {}
+ ~PinnedIteratorsManager() {
+ if (pinning_enabled) {
+ ReleasePinnedData();
+ }
+ }
+
+ // Enable Iterators pinning
+ void StartPinning() {
+ assert(pinning_enabled == false);
+ pinning_enabled = true;
+ }
+
+ // Is pinning enabled ?
+ bool PinningEnabled() { return pinning_enabled; }
+
+ // Take ownership of iter and delete it when ReleasePinnedData() is called
+ void PinIterator(InternalIterator* iter, bool arena = false) {
+ if (arena) {
+ PinPtr(iter, &PinnedIteratorsManager::ReleaseArenaInternalIterator);
+ } else {
+ PinPtr(iter, &PinnedIteratorsManager::ReleaseInternalIterator);
+ }
+ }
+
+ typedef void (*ReleaseFunction)(void* arg1);
+ void PinPtr(void* ptr, ReleaseFunction release_func) {
+ assert(pinning_enabled);
+ if (ptr == nullptr) {
+ return;
+ }
+ pinned_ptrs_.emplace_back(ptr, release_func);
+ }
+
+ // Release pinned Iterators
+ inline void ReleasePinnedData() {
+ assert(pinning_enabled == true);
+ pinning_enabled = false;
+
+ // Remove duplicate pointers
+ std::sort(pinned_ptrs_.begin(), pinned_ptrs_.end());
+ auto unique_end = std::unique(pinned_ptrs_.begin(), pinned_ptrs_.end());
+
+ for (auto i = pinned_ptrs_.begin(); i != unique_end; ++i) {
+ void* ptr = i->first;
+ ReleaseFunction release_func = i->second;
+ release_func(ptr);
+ }
+ pinned_ptrs_.clear();
+ // Also do cleanups from the base Cleanable
+ Cleanable::Reset();
+ }
+
+ private:
+ static void ReleaseInternalIterator(void* ptr) {
+ delete reinterpret_cast<InternalIterator*>(ptr);
+ }
+
+ static void ReleaseArenaInternalIterator(void* ptr) {
+ reinterpret_cast<InternalIterator*>(ptr)->~InternalIterator();
+ }
+
+ bool pinning_enabled;
+ std::vector<std::pair<void*, ReleaseFunction>> pinned_ptrs_;
+};
+
+} // namespace ROCKSDB_NAMESPACE