Summary: Quick fixes to examples to make it easier to get familiar with RocksDB for Windows users: - Set proper temporary directory path on Windows for all examples (with C++17 we should start using std::filesystem) - Fixed typo and got rid of warnings treated as errors in multi_processes_example.cc - Get number of available cores on Windows in c_simple_example.c - Add command to remove DB directory for Windows in compaction_filter_example.cc (print error, but carry on with example upon error, because error code is returned if there is no such directory on Windows) Pull Request resolved: https://github.com/facebook/rocksdb/pull/7304 Reviewed By: jay-zhuang Differential Revision: D23450900 Pulled By: pdillinger fbshipit-source-id: 4256134deb6ae6bb267ed1bd69f814842b95f60f
97 lines
3.3 KiB
C++
97 lines
3.3 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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#include <rocksdb/compaction_filter.h>
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#include <rocksdb/db.h>
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#include <rocksdb/merge_operator.h>
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#include <rocksdb/options.h>
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class MyMerge : public ROCKSDB_NAMESPACE::MergeOperator {
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public:
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virtual bool FullMergeV2(const MergeOperationInput& merge_in,
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MergeOperationOutput* merge_out) const override {
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merge_out->new_value.clear();
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if (merge_in.existing_value != nullptr) {
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merge_out->new_value.assign(merge_in.existing_value->data(),
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merge_in.existing_value->size());
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}
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for (const ROCKSDB_NAMESPACE::Slice& m : merge_in.operand_list) {
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fprintf(stderr, "Merge(%s)\n", m.ToString().c_str());
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// the compaction filter filters out bad values
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assert(m.ToString() != "bad");
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merge_out->new_value.assign(m.data(), m.size());
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}
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return true;
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}
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const char* Name() const override { return "MyMerge"; }
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};
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class MyFilter : public ROCKSDB_NAMESPACE::CompactionFilter {
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public:
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bool Filter(int level, const ROCKSDB_NAMESPACE::Slice& key,
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const ROCKSDB_NAMESPACE::Slice& existing_value,
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std::string* new_value, bool* value_changed) const override {
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fprintf(stderr, "Filter(%s)\n", key.ToString().c_str());
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++count_;
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assert(*value_changed == false);
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return false;
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}
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bool FilterMergeOperand(
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int level, const ROCKSDB_NAMESPACE::Slice& key,
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const ROCKSDB_NAMESPACE::Slice& existing_value) const override {
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fprintf(stderr, "FilterMerge(%s)\n", key.ToString().c_str());
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++merge_count_;
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return existing_value == "bad";
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}
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const char* Name() const override { return "MyFilter"; }
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mutable int count_ = 0;
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mutable int merge_count_ = 0;
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};
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#if defined(OS_WIN)
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std::string kDBPath = "C:\\Windows\\TEMP\\rocksmergetest";
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std::string kRemoveDirCommand = "rmdir /Q /S ";
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#else
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std::string kDBPath = "/tmp/rocksmergetest";
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std::string kRemoveDirCommand = "rm -rf ";
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#endif
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int main() {
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ROCKSDB_NAMESPACE::DB* raw_db;
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ROCKSDB_NAMESPACE::Status status;
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MyFilter filter;
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std::string rm_cmd = kRemoveDirCommand + kDBPath;
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int ret = system(rm_cmd.c_str());
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if (ret != 0) {
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fprintf(stderr, "Error deleting %s, code: %d\n", kDBPath.c_str(), ret);
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}
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ROCKSDB_NAMESPACE::Options options;
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options.create_if_missing = true;
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options.merge_operator.reset(new MyMerge);
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options.compaction_filter = &filter;
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status = ROCKSDB_NAMESPACE::DB::Open(options, kDBPath, &raw_db);
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assert(status.ok());
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std::unique_ptr<ROCKSDB_NAMESPACE::DB> db(raw_db);
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ROCKSDB_NAMESPACE::WriteOptions wopts;
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db->Merge(wopts, "0", "bad"); // This is filtered out
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db->Merge(wopts, "1", "data1");
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db->Merge(wopts, "1", "bad");
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db->Merge(wopts, "1", "data2");
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db->Merge(wopts, "1", "bad");
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db->Merge(wopts, "3", "data3");
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db->CompactRange(ROCKSDB_NAMESPACE::CompactRangeOptions(), nullptr, nullptr);
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fprintf(stderr, "filter.count_ = %d\n", filter.count_);
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assert(filter.count_ == 0);
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fprintf(stderr, "filter.merge_count_ = %d\n", filter.merge_count_);
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assert(filter.merge_count_ == 6);
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}
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