d3817f058d
Summary: and remove deprecated DB::MaxMemCompactionLevel(). In the process of pushing through a relatively clean refactoring of uses of the old functions, some other minor public APIs are also migrated from raw DB pointers to unique_ptr. Claude did pretty much all the work, but requiring dozens of prompts to actually push through relatively clean phase out of raw DB pointers from what needed to be touched, and leaving that code in better shape. (Hundreds of `DB*` still remain all over the place even outside C and Java bindings.) Pull Request resolved: https://github.com/facebook/rocksdb/pull/14335 Test Plan: existing tests; no functional changes intended Reviewed By: xingbowang, mszeszko-meta Differential Revision: D93523820 Pulled By: pdillinger fbshipit-source-id: e4ca22ad81cd2cfe91122d7507d7ca34fe03d043
133 lines
4.6 KiB
C++
133 lines
4.6 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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// This file demonstrates how to use the utility functions defined in
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// rocksdb/utilities/options_util.h to open a rocksdb database without
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// remembering all the rocksdb options.
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#include <cstdio>
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#include <memory>
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#include <string>
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#include <vector>
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#include "rocksdb/cache.h"
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#include "rocksdb/compaction_filter.h"
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#include "rocksdb/db.h"
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#include "rocksdb/options.h"
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#include "rocksdb/slice.h"
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#include "rocksdb/table.h"
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#include "rocksdb/utilities/options_util.h"
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using ROCKSDB_NAMESPACE::BlockBasedTableOptions;
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using ROCKSDB_NAMESPACE::ColumnFamilyDescriptor;
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using ROCKSDB_NAMESPACE::ColumnFamilyHandle;
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using ROCKSDB_NAMESPACE::ColumnFamilyOptions;
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using ROCKSDB_NAMESPACE::CompactionFilter;
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using ROCKSDB_NAMESPACE::ConfigOptions;
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using ROCKSDB_NAMESPACE::DB;
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using ROCKSDB_NAMESPACE::DBOptions;
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using ROCKSDB_NAMESPACE::NewLRUCache;
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using ROCKSDB_NAMESPACE::Options;
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using ROCKSDB_NAMESPACE::Slice;
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using ROCKSDB_NAMESPACE::Status;
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#if defined(OS_WIN)
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std::string kDBPath = "C:\\Windows\\TEMP\\rocksdb_options_file_example";
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#else
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std::string kDBPath = "/tmp/rocksdb_options_file_example";
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#endif
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namespace {
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// A dummy compaction filter
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class DummyCompactionFilter : public CompactionFilter {
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public:
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virtual ~DummyCompactionFilter() {}
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virtual bool Filter(int level, const Slice& key, const Slice& existing_value,
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std::string* new_value, bool* value_changed) const {
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return false;
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}
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virtual const char* Name() const { return "DummyCompactionFilter"; }
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};
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} // namespace
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int main() {
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DBOptions db_opt;
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db_opt.create_if_missing = true;
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std::vector<ColumnFamilyDescriptor> cf_descs;
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cf_descs.push_back(
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{ROCKSDB_NAMESPACE::kDefaultColumnFamilyName, ColumnFamilyOptions()});
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cf_descs.push_back({"new_cf", ColumnFamilyOptions()});
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// initialize BlockBasedTableOptions
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auto cache = NewLRUCache(1 * 1024 * 1024 * 1024);
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BlockBasedTableOptions bbt_opts;
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bbt_opts.block_size = 32 * 1024;
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bbt_opts.block_cache = cache;
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// initialize column families options
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std::unique_ptr<CompactionFilter> compaction_filter;
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compaction_filter.reset(new DummyCompactionFilter());
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cf_descs[0].options.table_factory.reset(NewBlockBasedTableFactory(bbt_opts));
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cf_descs[0].options.compaction_filter = compaction_filter.get();
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cf_descs[1].options.table_factory.reset(NewBlockBasedTableFactory(bbt_opts));
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// destroy and open DB
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std::unique_ptr<DB> db;
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Status s = ROCKSDB_NAMESPACE::DestroyDB(kDBPath,
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Options(db_opt, cf_descs[0].options));
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assert(s.ok());
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s = DB::Open(Options(db_opt, cf_descs[0].options), kDBPath, &db);
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assert(s.ok());
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// Create column family, and rocksdb will persist the options.
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ColumnFamilyHandle* cf;
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s = db->CreateColumnFamily(ColumnFamilyOptions(), "new_cf", &cf);
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assert(s.ok());
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// close DB
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delete cf;
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db.reset();
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// In the following code, we will reopen the rocksdb instance using
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// the options file stored in the db directory.
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// Load the options file.
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DBOptions loaded_db_opt;
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std::vector<ColumnFamilyDescriptor> loaded_cf_descs;
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ConfigOptions config_options;
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s = LoadLatestOptions(config_options, kDBPath, &loaded_db_opt,
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&loaded_cf_descs);
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assert(s.ok());
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assert(loaded_db_opt.create_if_missing == db_opt.create_if_missing);
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// Initialize pointer options for each column family
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for (size_t i = 0; i < loaded_cf_descs.size(); ++i) {
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auto* loaded_bbt_opt =
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loaded_cf_descs[0]
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.options.table_factory->GetOptions<BlockBasedTableOptions>();
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// Expect the same as BlockBasedTableOptions will be loaded form file.
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assert(loaded_bbt_opt->block_size == bbt_opts.block_size);
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// However, block_cache needs to be manually initialized as documented
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// in rocksdb/utilities/options_util.h.
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loaded_bbt_opt->block_cache = cache;
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}
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// In addition, as pointer options are initialized with default value,
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// we need to properly initialized all the pointer options if non-defalut
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// values are used before calling DB::Open().
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assert(loaded_cf_descs[0].options.compaction_filter == nullptr);
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loaded_cf_descs[0].options.compaction_filter = compaction_filter.get();
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// reopen the db using the loaded options.
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std::vector<ColumnFamilyHandle*> handles;
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s = DB::Open(loaded_db_opt, kDBPath, loaded_cf_descs, &handles, &db);
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assert(s.ok());
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// close DB
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for (auto* handle : handles) {
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delete handle;
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}
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db.reset();
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}
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