8673a8c567
Summary: Closes https://github.com/facebook/rocksdb/pull/2589 Differential Revision: D5431502 Pulled By: siying fbshipit-source-id: 8ebf8c87883daa9daa54b2303d11ce01ab1f6f75
88 lines
2.4 KiB
C++
88 lines
2.4 KiB
C++
// Copyright (c) 2011-present, Facebook, Inc. All rights reserved.
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// This source code is licensed under both the GPLv2 (found in the
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// COPYING file in the root directory) and Apache 2.0 License
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// (found in the LICENSE.Apache file in the root directory).
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//
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#pragma once
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#include <algorithm>
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#include <memory>
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#include <utility>
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#include <vector>
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#include "table/internal_iterator.h"
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namespace rocksdb {
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// PinnedIteratorsManager will be notified whenever we need to pin an Iterator
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// and it will be responsible for deleting pinned Iterators when they are
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// not needed anymore.
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class PinnedIteratorsManager : public Cleanable {
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public:
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PinnedIteratorsManager() : pinning_enabled(false) {}
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~PinnedIteratorsManager() {
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if (pinning_enabled) {
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ReleasePinnedData();
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}
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}
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// Enable Iterators pinning
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void StartPinning() {
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assert(pinning_enabled == false);
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pinning_enabled = true;
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}
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// Is pinning enabled ?
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bool PinningEnabled() { return pinning_enabled; }
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// Take ownership of iter and delete it when ReleasePinnedData() is called
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void PinIterator(InternalIterator* iter, bool arena = false) {
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if (arena) {
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PinPtr(iter, &PinnedIteratorsManager::ReleaseArenaInternalIterator);
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} else {
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PinPtr(iter, &PinnedIteratorsManager::ReleaseInternalIterator);
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}
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}
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typedef void (*ReleaseFunction)(void* arg1);
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void PinPtr(void* ptr, ReleaseFunction release_func) {
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assert(pinning_enabled);
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if (ptr == nullptr) {
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return;
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}
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pinned_ptrs_.emplace_back(ptr, release_func);
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}
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// Release pinned Iterators
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inline void ReleasePinnedData() {
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assert(pinning_enabled == true);
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pinning_enabled = false;
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// Remove duplicate pointers
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std::sort(pinned_ptrs_.begin(), pinned_ptrs_.end());
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auto unique_end = std::unique(pinned_ptrs_.begin(), pinned_ptrs_.end());
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for (auto i = pinned_ptrs_.begin(); i != unique_end; ++i) {
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void* ptr = i->first;
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ReleaseFunction release_func = i->second;
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release_func(ptr);
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}
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pinned_ptrs_.clear();
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// Also do cleanups from the base Cleanable
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Cleanable::Reset();
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}
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private:
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static void ReleaseInternalIterator(void* ptr) {
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delete reinterpret_cast<InternalIterator*>(ptr);
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}
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static void ReleaseArenaInternalIterator(void* ptr) {
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reinterpret_cast<InternalIterator*>(ptr)->~InternalIterator();
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}
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bool pinning_enabled;
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std::vector<std::pair<void*, ReleaseFunction>> pinned_ptrs_;
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};
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} // namespace rocksdb
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