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// 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).
// 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.
#pragma once
#include <stdint.h>
#include <stdio.h>
#include <map>
#include <memory>
#include <string>
#include <unordered_map>
#include <vector>
#include "rocksdb/iterator.h"
#include "rocksdb/listener.h"
#include "rocksdb/metadata.h"
#include "rocksdb/options.h"
#include "rocksdb/snapshot.h"
#include "rocksdb/sst_file_writer.h"
#include "rocksdb/thread_status.h"
#include "rocksdb/transaction_log.h"
#include "rocksdb/types.h"
#include "rocksdb/version.h"
#ifdef _WIN32
// Windows API macro interference
#undef DeleteFile
#endif
#if defined(__GNUC__) || defined(__clang__)
#define ROCKSDB_DEPRECATED_FUNC __attribute__((__deprecated__))
#elif _WIN32
#define ROCKSDB_DEPRECATED_FUNC __declspec(deprecated)
#endif
namespace rocksdb {
struct Options;
struct DBOptions;
struct ColumnFamilyOptions;
struct ReadOptions;
struct WriteOptions;
struct FlushOptions;
struct CompactionOptions;
struct CompactRangeOptions;
struct TableProperties;
struct ExternalSstFileInfo;
class WriteBatch;
class Env;
class EventListener;
class TraceWriter;
using std::unique_ptr;
extern const std::string kDefaultColumnFamilyName;
struct ColumnFamilyDescriptor {
std::string name;
ColumnFamilyOptions options;
ColumnFamilyDescriptor()
: name(kDefaultColumnFamilyName), options(ColumnFamilyOptions()) {}
ColumnFamilyDescriptor(const std::string& _name,
const ColumnFamilyOptions& _options)
: name(_name), options(_options) {}
};
class ColumnFamilyHandle {
public:
virtual ~ColumnFamilyHandle() {}
// Returns the name of the column family associated with the current handle.
virtual const std::string& GetName() const = 0;
// Returns the ID of the column family associated with the current handle.
virtual uint32_t GetID() const = 0;
// Fills "*desc" with the up-to-date descriptor of the column family
// associated with this handle. Since it fills "*desc" with the up-to-date
// information, this call might internally lock and release DB mutex to
// access the up-to-date CF options. In addition, all the pointer-typed
// options cannot be referenced any longer than the original options exist.
//
// Note that this function is not supported in RocksDBLite.
virtual Status GetDescriptor(ColumnFamilyDescriptor* desc) = 0;
// Returns the comparator of the column family associated with the
// current handle.
virtual const Comparator* GetComparator() const = 0;
};
static const int kMajorVersion = __ROCKSDB_MAJOR__;
static const int kMinorVersion = __ROCKSDB_MINOR__;
// A range of keys
struct Range {
Slice start;
Slice limit;
Range() { }
Range(const Slice& s, const Slice& l) : start(s), limit(l) { }
};
struct RangePtr {
const Slice* start;
const Slice* limit;
RangePtr() : start(nullptr), limit(nullptr) { }
RangePtr(const Slice* s, const Slice* l) : start(s), limit(l) { }
};
// A collections of table properties objects, where
// key: is the table's file name.
// value: the table properties object of the given table.
typedef std::unordered_map<std::string, std::shared_ptr<const TableProperties>>
TablePropertiesCollection;
// A DB is a persistent ordered map from keys to values.
// A DB is safe for concurrent access from multiple threads without
// any external synchronization.
class DB {
public:
// Open the database with the specified "name".
// Stores a pointer to a heap-allocated database in *dbptr and returns
// OK on success.
// Stores nullptr in *dbptr and returns a non-OK status on error.
// Caller should delete *dbptr when it is no longer needed.
static Status Open(const Options& options,
const std::string& name,
DB** dbptr);
// Open the database for read only. All DB interfaces
// that modify data, like put/delete, will return error.
// If the db is opened in read only mode, then no compactions
// will happen.
//
// Not supported in ROCKSDB_LITE, in which case the function will
// return Status::NotSupported.
static Status OpenForReadOnly(const Options& options,
const std::string& name, DB** dbptr,
bool error_if_log_file_exist = false);
// Open the database for read only with column families. When opening DB with
// read only, you can specify only a subset of column families in the
// database that should be opened. However, you always need to specify default
// column family. The default column family name is 'default' and it's stored
// in rocksdb::kDefaultColumnFamilyName
//
// Not supported in ROCKSDB_LITE, in which case the function will
// return Status::NotSupported.
static Status OpenForReadOnly(
const DBOptions& db_options, const std::string& name,
const std::vector<ColumnFamilyDescriptor>& column_families,
std::vector<ColumnFamilyHandle*>* handles, DB** dbptr,
bool error_if_log_file_exist = false);
// Open DB with column families.
// db_options specify database specific options
// column_families is the vector of all column families in the database,
// containing column family name and options. You need to open ALL column
// families in the database. To get the list of column families, you can use
// ListColumnFamilies(). Also, you can open only a subset of column families
// for read-only access.
// The default column family name is 'default' and it's stored
// in rocksdb::kDefaultColumnFamilyName.
// If everything is OK, handles will on return be the same size
// as column_families --- handles[i] will be a handle that you
// will use to operate on column family column_family[i].
// Before delete DB, you have to close All column families by calling
// DestroyColumnFamilyHandle() with all the handles.
static Status Open(const DBOptions& db_options, const std::string& name,
const std::vector<ColumnFamilyDescriptor>& column_families,
std::vector<ColumnFamilyHandle*>* handles, DB** dbptr);
virtual Status Resume() { return Status::NotSupported(); }
// Close the DB by releasing resources, closing files etc. This should be
// called before calling the destructor so that the caller can get back a
// status in case there are any errors. This will not fsync the WAL files.
// If syncing is required, the caller must first call SyncWAL(), or Write()
// using an empty write batch with WriteOptions.sync=true.
// Regardless of the return status, the DB must be freed. If the return
// status is NotSupported(), then the DB implementation does cleanup in the
// destructor
virtual Status Close() { return Status::NotSupported(); }
// ListColumnFamilies will open the DB specified by argument name
// and return the list of all column families in that DB
// through column_families argument. The ordering of
// column families in column_families is unspecified.
static Status ListColumnFamilies(const DBOptions& db_options,
const std::string& name,
std::vector<std::string>* column_families);
DB() { }
virtual ~DB();
// Create a column_family and return the handle of column family
// through the argument handle.
virtual Status CreateColumnFamily(const ColumnFamilyOptions& options,
const std::string& column_family_name,
ColumnFamilyHandle** handle);
// Bulk create column families with the same column family options.
// Return the handles of the column families through the argument handles.
// In case of error, the request may succeed partially, and handles will
// contain column family handles that it managed to create, and have size
// equal to the number of created column families.
virtual Status CreateColumnFamilies(
const ColumnFamilyOptions& options,
const std::vector<std::string>& column_family_names,
std::vector<ColumnFamilyHandle*>* handles);
// Bulk create column families.
// Return the handles of the column families through the argument handles.
// In case of error, the request may succeed partially, and handles will
// contain column family handles that it managed to create, and have size
// equal to the number of created column families.
virtual Status CreateColumnFamilies(
const std::vector<ColumnFamilyDescriptor>& column_families,
std::vector<ColumnFamilyHandle*>* handles);
// Drop a column family specified by column_family handle. This call
// only records a drop record in the manifest and prevents the column
// family from flushing and compacting.
virtual Status DropColumnFamily(ColumnFamilyHandle* column_family);
// Bulk drop column families. This call only records drop records in the
// manifest and prevents the column families from flushing and compacting.
// In case of error, the request may succeed partially. User may call
// ListColumnFamilies to check the result.
virtual Status DropColumnFamilies(
const std::vector<ColumnFamilyHandle*>& column_families);
// Close a column family specified by column_family handle and destroy
// the column family handle specified to avoid double deletion. This call
// deletes the column family handle by default. Use this method to
// close column family instead of deleting column family handle directly
virtual Status DestroyColumnFamilyHandle(ColumnFamilyHandle* column_family);
// Set the database entry for "key" to "value".
// If "key" already exists, it will be overwritten.
// Returns OK on success, and a non-OK status on error.
// Note: consider setting options.sync = true.
virtual Status Put(const WriteOptions& options,
ColumnFamilyHandle* column_family, const Slice& key,
const Slice& value) = 0;
virtual Status Put(const WriteOptions& options, const Slice& key,
const Slice& value) {
return Put(options, DefaultColumnFamily(), key, value);
}
// Remove the database entry (if any) for "key". Returns OK on
// success, and a non-OK status on error. It is not an error if "key"
// did not exist in the database.
// Note: consider setting options.sync = true.
virtual Status Delete(const WriteOptions& options,
ColumnFamilyHandle* column_family,
const Slice& key) = 0;
virtual Status Delete(const WriteOptions& options, const Slice& key) {
return Delete(options, DefaultColumnFamily(), key);
}
// Remove the database entry for "key". Requires that the key exists
// and was not overwritten. Returns OK on success, and a non-OK status
// on error. It is not an error if "key" did not exist in the database.
//
// If a key is overwritten (by calling Put() multiple times), then the result
// of calling SingleDelete() on this key is undefined. SingleDelete() only
// behaves correctly if there has been only one Put() for this key since the
// previous call to SingleDelete() for this key.
//
// This feature is currently an experimental performance optimization
// for a very specific workload. It is up to the caller to ensure that
// SingleDelete is only used for a key that is not deleted using Delete() or
// written using Merge(). Mixing SingleDelete operations with Deletes and
// Merges can result in undefined behavior.
//
// Note: consider setting options.sync = true.
virtual Status SingleDelete(const WriteOptions& options,
ColumnFamilyHandle* column_family,
const Slice& key) = 0;
virtual Status SingleDelete(const WriteOptions& options, const Slice& key) {
return SingleDelete(options, DefaultColumnFamily(), key);
}
// Removes the database entries in the range ["begin_key", "end_key"), i.e.,
// including "begin_key" and excluding "end_key". Returns OK on success, and
// a non-OK status on error. It is not an error if no keys exist in the range
// ["begin_key", "end_key").
//
// This feature is currently an experimental performance optimization for
// deleting very large ranges of contiguous keys. Invoking it many times or on
// small ranges may severely degrade read performance; in particular, the
// resulting performance can be worse than calling Delete() for each key in
// the range. Note also the degraded read performance affects keys outside the
// deleted ranges, and affects database operations involving scans, like flush
// and compaction.
//
// Consider setting ReadOptions::ignore_range_deletions = true to speed
// up reads for key(s) that are known to be unaffected by range deletions.
virtual Status DeleteRange(const WriteOptions& options,
ColumnFamilyHandle* column_family,
const Slice& begin_key, const Slice& end_key);
// Merge the database entry for "key" with "value". Returns OK on success,
// and a non-OK status on error. The semantics of this operation is
// determined by the user provided merge_operator when opening DB.
// Note: consider setting options.sync = true.
virtual Status Merge(const WriteOptions& options,
ColumnFamilyHandle* column_family, const Slice& key,
const Slice& value) = 0;
virtual Status Merge(const WriteOptions& options, const Slice& key,
const Slice& value) {
return Merge(options, DefaultColumnFamily(), key, value);
}
// Apply the specified updates to the database.
// If `updates` contains no update, WAL will still be synced if
// options.sync=true.
// Returns OK on success, non-OK on failure.
// Note: consider setting options.sync = true.
virtual Status Write(const WriteOptions& options, WriteBatch* updates) = 0;
// If the database contains an entry for "key" store the
// corresponding value in *value and return OK.
//
// If there is no entry for "key" leave *value unchanged and return
// a status for which Status::IsNotFound() returns true.
//
// May return some other Status on an error.
virtual inline Status Get(const ReadOptions& options,
ColumnFamilyHandle* column_family, const Slice& key,
std::string* value) {
assert(value != nullptr);
PinnableSlice pinnable_val(value);
assert(!pinnable_val.IsPinned());
auto s = Get(options, column_family, key, &pinnable_val);
if (s.ok() && pinnable_val.IsPinned()) {
value->assign(pinnable_val.data(), pinnable_val.size());
} // else value is already assigned
return s;
}
virtual Status Get(const ReadOptions& options,
ColumnFamilyHandle* column_family, const Slice& key,
PinnableSlice* value) = 0;
virtual Status Get(const ReadOptions& options, const Slice& key, std::string* value) {
return Get(options, DefaultColumnFamily(), key, value);
}
// If keys[i] does not exist in the database, then the i'th returned
// status will be one for which Status::IsNotFound() is true, and
// (*values)[i] will be set to some arbitrary value (often ""). Otherwise,
// the i'th returned status will have Status::ok() true, and (*values)[i]
// will store the value associated with keys[i].
//
// (*values) will always be resized to be the same size as (keys).
// Similarly, the number of returned statuses will be the number of keys.
// Note: keys will not be "de-duplicated". Duplicate keys will return
// duplicate values in order.
virtual std::vector<Status> MultiGet(
const ReadOptions& options,
const std::vector<ColumnFamilyHandle*>& column_family,
const std::vector<Slice>& keys, std::vector<std::string>* values) = 0;
virtual std::vector<Status> MultiGet(const ReadOptions& options,
const std::vector<Slice>& keys,
std::vector<std::string>* values) {
return MultiGet(options, std::vector<ColumnFamilyHandle*>(
keys.size(), DefaultColumnFamily()),
keys, values);
}
// If the key definitely does not exist in the database, then this method
// returns false, else true. If the caller wants to obtain value when the key
// is found in memory, a bool for 'value_found' must be passed. 'value_found'
// will be true on return if value has been set properly.
// This check is potentially lighter-weight than invoking DB::Get(). One way
// to make this lighter weight is to avoid doing any IOs.
// Default implementation here returns true and sets 'value_found' to false
virtual bool KeyMayExist(const ReadOptions& /*options*/,
ColumnFamilyHandle* /*column_family*/,
const Slice& /*key*/, std::string* /*value*/,
bool* value_found = nullptr) {
if (value_found != nullptr) {
*value_found = false;
}
return true;
}
virtual bool KeyMayExist(const ReadOptions& options, const Slice& key,
std::string* value, bool* value_found = nullptr) {
return KeyMayExist(options, DefaultColumnFamily(), key, value, value_found);
}
// Return a heap-allocated iterator over the contents of the database.
// The result of NewIterator() is initially invalid (caller must
// call one of the Seek methods on the iterator before using it).
//
// Caller should delete the iterator when it is no longer needed.
// The returned iterator should be deleted before this db is deleted.
virtual Iterator* NewIterator(const ReadOptions& options,
ColumnFamilyHandle* column_family) = 0;
virtual Iterator* NewIterator(const ReadOptions& options) {
return NewIterator(options, DefaultColumnFamily());
}
// Returns iterators from a consistent database state across multiple
// column families. Iterators are heap allocated and need to be deleted
// before the db is deleted
virtual Status NewIterators(
const ReadOptions& options,
const std::vector<ColumnFamilyHandle*>& column_families,
std::vector<Iterator*>* iterators) = 0;
// Return a handle to the current DB state. Iterators created with
// this handle will all observe a stable snapshot of the current DB
// state. The caller must call ReleaseSnapshot(result) when the
// snapshot is no longer needed.
//
// nullptr will be returned if the DB fails to take a snapshot or does
// not support snapshot.
virtual const Snapshot* GetSnapshot() = 0;
// Release a previously acquired snapshot. The caller must not
// use "snapshot" after this call.
virtual void ReleaseSnapshot(const Snapshot* snapshot) = 0;
#ifndef ROCKSDB_LITE
// Contains all valid property arguments for GetProperty().
//
// NOTE: Property names cannot end in numbers since those are interpreted as
// arguments, e.g., see kNumFilesAtLevelPrefix.
struct Properties {
// "rocksdb.num-files-at-level<N>" - returns string containing the number
// of files at level <N>, where <N> is an ASCII representation of a
// level number (e.g., "0").
static const std::string kNumFilesAtLevelPrefix;
// "rocksdb.compression-ratio-at-level<N>" - returns string containing the
// compression ratio of data at level <N>, where <N> is an ASCII
// representation of a level number (e.g., "0"). Here, compression
// ratio is defined as uncompressed data size / compressed file size.
// Returns "-1.0" if no open files at level <N>.
static const std::string kCompressionRatioAtLevelPrefix;
// "rocksdb.stats" - returns a multi-line string containing the data
// described by kCFStats followed by the data described by kDBStats.
static const std::string kStats;
// "rocksdb.sstables" - returns a multi-line string summarizing current
// SST files.
static const std::string kSSTables;
// "rocksdb.cfstats" - Both of "rocksdb.cfstats-no-file-histogram" and
// "rocksdb.cf-file-histogram" together. See below for description
// of the two.
static const std::string kCFStats;
// "rocksdb.cfstats-no-file-histogram" - returns a multi-line string with
// general columm family stats per-level over db's lifetime ("L<n>"),
// aggregated over db's lifetime ("Sum"), and aggregated over the
// interval since the last retrieval ("Int").
// It could also be used to return the stats in the format of the map.
// In this case there will a pair of string to array of double for
// each level as well as for "Sum". "Int" stats will not be affected
// when this form of stats are retrieved.
static const std::string kCFStatsNoFileHistogram;
// "rocksdb.cf-file-histogram" - print out how many file reads to every
// level, as well as the histogram of latency of single requests.
static const std::string kCFFileHistogram;
// "rocksdb.dbstats" - returns a multi-line string with general database
// stats, both cumulative (over the db's lifetime) and interval (since
// the last retrieval of kDBStats).
static const std::string kDBStats;
// "rocksdb.levelstats" - returns multi-line string containing the number
// of files per level and total size of each level (MB).
static const std::string kLevelStats;
// "rocksdb.num-immutable-mem-table" - returns number of immutable
// memtables that have not yet been flushed.
static const std::string kNumImmutableMemTable;
// "rocksdb.num-immutable-mem-table-flushed" - returns number of immutable
// memtables that have already been flushed.
static const std::string kNumImmutableMemTableFlushed;
// "rocksdb.mem-table-flush-pending" - returns 1 if a memtable flush is
// pending; otherwise, returns 0.
static const std::string kMemTableFlushPending;
// "rocksdb.num-running-flushes" - returns the number of currently running
// flushes.
static const std::string kNumRunningFlushes;
// "rocksdb.compaction-pending" - returns 1 if at least one compaction is
// pending; otherwise, returns 0.
static const std::string kCompactionPending;
// "rocksdb.num-running-compactions" - returns the number of currently
// running compactions.
static const std::string kNumRunningCompactions;
// "rocksdb.background-errors" - returns accumulated number of background
// errors.
static const std::string kBackgroundErrors;
// "rocksdb.cur-size-active-mem-table" - returns approximate size of active
// memtable (bytes).
static const std::string kCurSizeActiveMemTable;
// "rocksdb.cur-size-all-mem-tables" - returns approximate size of active
// and unflushed immutable memtables (bytes).
static const std::string kCurSizeAllMemTables;
// "rocksdb.size-all-mem-tables" - returns approximate size of active,
// unflushed immutable, and pinned immutable memtables (bytes).
static const std::string kSizeAllMemTables;
// "rocksdb.num-entries-active-mem-table" - returns total number of entries
// in the active memtable.
static const std::string kNumEntriesActiveMemTable;
// "rocksdb.num-entries-imm-mem-tables" - returns total number of entries
// in the unflushed immutable memtables.
static const std::string kNumEntriesImmMemTables;
// "rocksdb.num-deletes-active-mem-table" - returns total number of delete
// entries in the active memtable.
static const std::string kNumDeletesActiveMemTable;
// "rocksdb.num-deletes-imm-mem-tables" - returns total number of delete
// entries in the unflushed immutable memtables.
static const std::string kNumDeletesImmMemTables;
// "rocksdb.estimate-num-keys" - returns estimated number of total keys in
// the active and unflushed immutable memtables and storage.
static const std::string kEstimateNumKeys;
// "rocksdb.estimate-table-readers-mem" - returns estimated memory used for
// reading SST tables, excluding memory used in block cache (e.g.,
// filter and index blocks).
static const std::string kEstimateTableReadersMem;
// "rocksdb.is-file-deletions-enabled" - returns 0 if deletion of obsolete
// files is enabled; otherwise, returns a non-zero number.
static const std::string kIsFileDeletionsEnabled;
// "rocksdb.num-snapshots" - returns number of unreleased snapshots of the
// database.
static const std::string kNumSnapshots;
// "rocksdb.oldest-snapshot-time" - returns number representing unix
// timestamp of oldest unreleased snapshot.
static const std::string kOldestSnapshotTime;
// "rocksdb.num-live-versions" - returns number of live versions. `Version`
// is an internal data structure. See version_set.h for details. More
// live versions often mean more SST files are held from being deleted,
// by iterators or unfinished compactions.
static const std::string kNumLiveVersions;
// "rocksdb.current-super-version-number" - returns number of current LSM
// version. It is a uint64_t integer number, incremented after there is
// any change to the LSM tree. The number is not preserved after restarting
// the DB. After DB restart, it will start from 0 again.
static const std::string kCurrentSuperVersionNumber;
// "rocksdb.estimate-live-data-size" - returns an estimate of the amount of
// live data in bytes.
static const std::string kEstimateLiveDataSize;
// "rocksdb.min-log-number-to-keep" - return the minimum log number of the
// log files that should be kept.
static const std::string kMinLogNumberToKeep;
// "rocksdb.total-sst-files-size" - returns total size (bytes) of all SST
// files.
// WARNING: may slow down online queries if there are too many files.
static const std::string kTotalSstFilesSize;
// "rocksdb.live-sst-files-size" - returns total size (bytes) of all SST
// files belong to the latest LSM tree.
static const std::string kLiveSstFilesSize;
// "rocksdb.base-level" - returns number of level to which L0 data will be
// compacted.
static const std::string kBaseLevel;
// "rocksdb.estimate-pending-compaction-bytes" - returns estimated total
// number of bytes compaction needs to rewrite to get all levels down
// to under target size. Not valid for other compactions than level-
// based.
static const std::string kEstimatePendingCompactionBytes;
// "rocksdb.aggregated-table-properties" - returns a string representation
// of the aggregated table properties of the target column family.
static const std::string kAggregatedTableProperties;
// "rocksdb.aggregated-table-properties-at-level<N>", same as the previous
// one but only returns the aggregated table properties of the
// specified level "N" at the target column family.
static const std::string kAggregatedTablePropertiesAtLevel;
// "rocksdb.actual-delayed-write-rate" - returns the current actual delayed
// write rate. 0 means no delay.
static const std::string kActualDelayedWriteRate;
// "rocksdb.is-write-stopped" - Return 1 if write has been stopped.
static const std::string kIsWriteStopped;
// "rocksdb.estimate-oldest-key-time" - returns an estimation of
// oldest key timestamp in the DB. Currently only available for
// FIFO compaction with
// compaction_options_fifo.allow_compaction = false.
static const std::string kEstimateOldestKeyTime;
// "rocksdb.block-cache-capacity" - returns block cache capacity.
static const std::string kBlockCacheCapacity;
// "rocksdb.block-cache-usage" - returns the memory size for the entries
// residing in block cache.
static const std::string kBlockCacheUsage;
// "rocksdb.block-cache-pinned-usage" - returns the memory size for the
// entries being pinned.
static const std::string kBlockCachePinnedUsage;
// "rocksdb.options-statistics" - returns multi-line string
// of options.statistics
static const std::string kOptionsStatistics;
};
#endif /* ROCKSDB_LITE */
// DB implementations can export properties about their state via this method.
// If "property" is a valid property understood by this DB implementation (see
// Properties struct above for valid options), fills "*value" with its current
// value and returns true. Otherwise, returns false.
virtual bool GetProperty(ColumnFamilyHandle* column_family,
const Slice& property, std::string* value) = 0;
virtual bool GetProperty(const Slice& property, std::string* value) {
return GetProperty(DefaultColumnFamily(), property, value);
}
virtual bool GetMapProperty(ColumnFamilyHandle* column_family,
const Slice& property,
std::map<std::string, std::string>* value) = 0;
virtual bool GetMapProperty(const Slice& property,
std::map<std::string, std::string>* value) {
return GetMapProperty(DefaultColumnFamily(), property, value);
}
// Similar to GetProperty(), but only works for a subset of properties whose
// return value is an integer. Return the value by integer. Supported
// properties:
// "rocksdb.num-immutable-mem-table"
// "rocksdb.mem-table-flush-pending"
// "rocksdb.compaction-pending"
// "rocksdb.background-errors"
// "rocksdb.cur-size-active-mem-table"
// "rocksdb.cur-size-all-mem-tables"
// "rocksdb.size-all-mem-tables"
// "rocksdb.num-entries-active-mem-table"
// "rocksdb.num-entries-imm-mem-tables"
// "rocksdb.num-deletes-active-mem-table"
// "rocksdb.num-deletes-imm-mem-tables"
// "rocksdb.estimate-num-keys"
// "rocksdb.estimate-table-readers-mem"
// "rocksdb.is-file-deletions-enabled"
// "rocksdb.num-snapshots"
// "rocksdb.oldest-snapshot-time"
// "rocksdb.num-live-versions"
// "rocksdb.current-super-version-number"
// "rocksdb.estimate-live-data-size"
// "rocksdb.min-log-number-to-keep"
// "rocksdb.total-sst-files-size"
// "rocksdb.live-sst-files-size"
// "rocksdb.base-level"
// "rocksdb.estimate-pending-compaction-bytes"
// "rocksdb.num-running-compactions"
// "rocksdb.num-running-flushes"
// "rocksdb.actual-delayed-write-rate"
// "rocksdb.is-write-stopped"
// "rocksdb.estimate-oldest-key-time"
// "rocksdb.block-cache-capacity"
// "rocksdb.block-cache-usage"
// "rocksdb.block-cache-pinned-usage"
virtual bool GetIntProperty(ColumnFamilyHandle* column_family,
const Slice& property, uint64_t* value) = 0;
virtual bool GetIntProperty(const Slice& property, uint64_t* value) {
return GetIntProperty(DefaultColumnFamily(), property, value);
}
// Reset internal stats for DB and all column families.
// Note this doesn't reset options.statistics as it is not owned by
// DB.
virtual Status ResetStats() {
return Status::NotSupported("Not implemented");
}
// Same as GetIntProperty(), but this one returns the aggregated int
// property from all column families.
virtual bool GetAggregatedIntProperty(const Slice& property,
uint64_t* value) = 0;
// Flags for DB::GetSizeApproximation that specify whether memtable
// stats should be included, or file stats approximation or both
enum SizeApproximationFlags : uint8_t {
NONE = 0,
INCLUDE_MEMTABLES = 1,
INCLUDE_FILES = 1 << 1
};
// For each i in [0,n-1], store in "sizes[i]", the approximate
// file system space used by keys in "[range[i].start .. range[i].limit)".
//
// Note that the returned sizes measure file system space usage, so
// if the user data compresses by a factor of ten, the returned
// sizes will be one-tenth the size of the corresponding user data size.
//
// If include_flags defines whether the returned size should include
// the recently written data in the mem-tables (if
// the mem-table type supports it), data serialized to disk, or both.
// include_flags should be of type DB::SizeApproximationFlags
virtual void GetApproximateSizes(ColumnFamilyHandle* column_family,
const Range* range, int n, uint64_t* sizes,
uint8_t include_flags
= INCLUDE_FILES) = 0;
virtual void GetApproximateSizes(const Range* range, int n, uint64_t* sizes,
uint8_t include_flags
= INCLUDE_FILES) {
GetApproximateSizes(DefaultColumnFamily(), range, n, sizes,
include_flags);
}
// The method is similar to GetApproximateSizes, except it
// returns approximate number of records in memtables.
virtual void GetApproximateMemTableStats(ColumnFamilyHandle* column_family,
const Range& range,
uint64_t* const count,
uint64_t* const size) = 0;
virtual void GetApproximateMemTableStats(const Range& range,
uint64_t* const count,
uint64_t* const size) {
GetApproximateMemTableStats(DefaultColumnFamily(), range, count, size);
}
// Deprecated versions of GetApproximateSizes
ROCKSDB_DEPRECATED_FUNC virtual void GetApproximateSizes(
const Range* range, int n, uint64_t* sizes,
bool include_memtable) {
uint8_t include_flags = SizeApproximationFlags::INCLUDE_FILES;
if (include_memtable) {
include_flags |= SizeApproximationFlags::INCLUDE_MEMTABLES;
}
GetApproximateSizes(DefaultColumnFamily(), range, n, sizes, include_flags);
}
ROCKSDB_DEPRECATED_FUNC virtual void GetApproximateSizes(
ColumnFamilyHandle* column_family,
const Range* range, int n, uint64_t* sizes,
bool include_memtable) {
uint8_t include_flags = SizeApproximationFlags::INCLUDE_FILES;
if (include_memtable) {
include_flags |= SizeApproximationFlags::INCLUDE_MEMTABLES;
}
GetApproximateSizes(column_family, range, n, sizes, include_flags);
}
// Compact the underlying storage for the key range [*begin,*end].
// The actual compaction interval might be superset of [*begin, *end].
// In particular, deleted and overwritten versions are discarded,
// and the data is rearranged to reduce the cost of operations
// needed to access the data. This operation should typically only
// be invoked by users who understand the underlying implementation.
//
// begin==nullptr is treated as a key before all keys in the database.
// end==nullptr is treated as a key after all keys in the database.
// Therefore the following call will compact the entire database:
// db->CompactRange(options, nullptr, nullptr);
// Note that after the entire database is compacted, all data are pushed
// down to the last level containing any data. If the total data size after
// compaction is reduced, that level might not be appropriate for hosting all
// the files. In this case, client could set options.change_level to true, to
// move the files back to the minimum level capable of holding the data set
// or a given level (specified by non-negative options.target_level).
virtual Status CompactRange(const CompactRangeOptions& options,
ColumnFamilyHandle* column_family,
const Slice* begin, const Slice* end) = 0;
virtual Status CompactRange(const CompactRangeOptions& options,
const Slice* begin, const Slice* end) {
return CompactRange(options, DefaultColumnFamily(), begin, end);
}
ROCKSDB_DEPRECATED_FUNC virtual Status CompactRange(
ColumnFamilyHandle* column_family, const Slice* begin, const Slice* end,
bool change_level = false, int target_level = -1,
uint32_t target_path_id = 0) {
CompactRangeOptions options;
options.change_level = change_level;
options.target_level = target_level;
options.target_path_id = target_path_id;
return CompactRange(options, column_family, begin, end);
}
ROCKSDB_DEPRECATED_FUNC virtual Status CompactRange(
const Slice* begin, const Slice* end, bool change_level = false,
int target_level = -1, uint32_t target_path_id = 0) {
CompactRangeOptions options;
options.change_level = change_level;
options.target_level = target_level;
options.target_path_id = target_path_id;
return CompactRange(options, DefaultColumnFamily(), begin, end);
}
virtual Status SetOptions(
ColumnFamilyHandle* /*column_family*/,
const std::unordered_map<std::string, std::string>& /*new_options*/) {
return Status::NotSupported("Not implemented");
}
virtual Status SetOptions(
const std::unordered_map<std::string, std::string>& new_options) {
return SetOptions(DefaultColumnFamily(), new_options);
}
virtual Status SetDBOptions(
const std::unordered_map<std::string, std::string>& new_options) = 0;
// CompactFiles() inputs a list of files specified by file numbers and
// compacts them to the specified level. Note that the behavior is different
// from CompactRange() in that CompactFiles() performs the compaction job
// using the CURRENT thread.
//
// @see GetDataBaseMetaData
// @see GetColumnFamilyMetaData
virtual Status CompactFiles(
const CompactionOptions& compact_options,
ColumnFamilyHandle* column_family,
const std::vector<std::string>& input_file_names,
const int output_level, const int output_path_id = -1,
std::vector<std::string>* const output_file_names = nullptr) = 0;
virtual Status CompactFiles(
const CompactionOptions& compact_options,
const std::vector<std::string>& input_file_names,
const int output_level, const int output_path_id = -1,
std::vector<std::string>* const output_file_names = nullptr) {
return CompactFiles(compact_options, DefaultColumnFamily(),
input_file_names, output_level, output_path_id,
output_file_names);
}
// This function will wait until all currently running background processes
// finish. After it returns, no background process will be run until
// ContinueBackgroundWork is called
virtual Status PauseBackgroundWork() = 0;
virtual Status ContinueBackgroundWork() = 0;
// This function will enable automatic compactions for the given column
// families if they were previously disabled. The function will first set the
// disable_auto_compactions option for each column family to 'false', after
// which it will schedule a flush/compaction.
//
// NOTE: Setting disable_auto_compactions to 'false' through SetOptions() API
// does NOT schedule a flush/compaction afterwards, and only changes the
// parameter itself within the column family option.
//
virtual Status EnableAutoCompaction(
const std::vector<ColumnFamilyHandle*>& column_family_handles) = 0;
// Number of levels used for this DB.
virtual int NumberLevels(ColumnFamilyHandle* column_family) = 0;
virtual int NumberLevels() { return NumberLevels(DefaultColumnFamily()); }
// Maximum level to which a new compacted memtable is pushed if it
// does not create overlap.
virtual int MaxMemCompactionLevel(ColumnFamilyHandle* column_family) = 0;
virtual int MaxMemCompactionLevel() {
return MaxMemCompactionLevel(DefaultColumnFamily());
}
// Number of files in level-0 that would stop writes.
virtual int Level0StopWriteTrigger(ColumnFamilyHandle* column_family) = 0;
virtual int Level0StopWriteTrigger() {
return Level0StopWriteTrigger(DefaultColumnFamily());
}
// Get DB name -- the exact same name that was provided as an argument to
// DB::Open()
virtual const std::string& GetName() const = 0;
// Get Env object from the DB
virtual Env* GetEnv() const = 0;
// Get DB Options that we use. During the process of opening the
// column family, the options provided when calling DB::Open() or
// DB::CreateColumnFamily() will have been "sanitized" and transformed
// in an implementation-defined manner.
virtual Options GetOptions(ColumnFamilyHandle* column_family) const = 0;
virtual Options GetOptions() const {
return GetOptions(DefaultColumnFamily());
}
virtual DBOptions GetDBOptions() const = 0;
// Flush all mem-table data.
virtual Status Flush(const FlushOptions& options,
ColumnFamilyHandle* column_family) = 0;
virtual Status Flush(const FlushOptions& options) {
return Flush(options, DefaultColumnFamily());
}
// Flush the WAL memory buffer to the file. If sync is true, it calls SyncWAL
// afterwards.
virtual Status FlushWAL(bool /*sync*/) {
return Status::NotSupported("FlushWAL not implemented");
}
// Sync the wal. Note that Write() followed by SyncWAL() is not exactly the
// same as Write() with sync=true: in the latter case the changes won't be
// visible until the sync is done.
// Currently only works if allow_mmap_writes = false in Options.
virtual Status SyncWAL() = 0;
// The sequence number of the most recent transaction.
virtual SequenceNumber GetLatestSequenceNumber() const = 0;
// Instructs DB to preserve deletes with sequence numbers >= passed seqnum.
// Has no effect if DBOptions.preserve_deletes is set to false.
// This function assumes that user calls this function with monotonically
// increasing seqnums (otherwise we can't guarantee that a particular delete
// hasn't been already processed); returns true if the value was successfully
// updated, false if user attempted to call if with seqnum <= current value.
virtual bool SetPreserveDeletesSequenceNumber(SequenceNumber seqnum) = 0;
#ifndef ROCKSDB_LITE
// Prevent file deletions. Compactions will continue to occur,
// but no obsolete files will be deleted. Calling this multiple
// times have the same effect as calling it once.
virtual Status DisableFileDeletions() = 0;
// Allow compactions to delete obsolete files.
// If force == true, the call to EnableFileDeletions() will guarantee that
// file deletions are enabled after the call, even if DisableFileDeletions()
// was called multiple times before.
// If force == false, EnableFileDeletions will only enable file deletion
// after it's been called at least as many times as DisableFileDeletions(),
// enabling the two methods to be called by two threads concurrently without
// synchronization -- i.e., file deletions will be enabled only after both
// threads call EnableFileDeletions()
virtual Status EnableFileDeletions(bool force = true) = 0;
// GetLiveFiles followed by GetSortedWalFiles can generate a lossless backup
// Retrieve the list of all files in the database. The files are
// relative to the dbname and are not absolute paths. Despite being relative
// paths, the file names begin with "/". The valid size of the manifest file
// is returned in manifest_file_size. The manifest file is an ever growing
// file, but only the portion specified by manifest_file_size is valid for
// this snapshot. Setting flush_memtable to true does Flush before recording
// the live files. Setting flush_memtable to false is useful when we don't
// want to wait for flush which may have to wait for compaction to complete
// taking an indeterminate time.
//
// In case you have multiple column families, even if flush_memtable is true,
// you still need to call GetSortedWalFiles after GetLiveFiles to compensate
// for new data that arrived to already-flushed column families while other
// column families were flushing
virtual Status GetLiveFiles(std::vector<std::string>&,
uint64_t* manifest_file_size,
bool flush_memtable = true) = 0;
// Retrieve the sorted list of all wal files with earliest file first
virtual Status GetSortedWalFiles(VectorLogPtr& files) = 0;
// Note: this API is not yet consistent with WritePrepared transactions.
// Sets iter to an iterator that is positioned at a write-batch containing
// seq_number. If the sequence number is non existent, it returns an iterator
// at the first available seq_no after the requested seq_no
// Returns Status::OK if iterator is valid
// Must set WAL_ttl_seconds or WAL_size_limit_MB to large values to
// use this api, else the WAL files will get
// cleared aggressively and the iterator might keep getting invalid before
// an update is read.
virtual Status GetUpdatesSince(
SequenceNumber seq_number, unique_ptr<TransactionLogIterator>* iter,
const TransactionLogIterator::ReadOptions&
read_options = TransactionLogIterator::ReadOptions()) = 0;
// Windows API macro interference
#undef DeleteFile
// Delete the file name from the db directory and update the internal state to
// reflect that. Supports deletion of sst and log files only. 'name' must be
// path relative to the db directory. eg. 000001.sst, /archive/000003.log
virtual Status DeleteFile(std::string name) = 0;
// Returns a list of all table files with their level, start key
// and end key
virtual void GetLiveFilesMetaData(
std::vector<LiveFileMetaData>* /*metadata*/) {}
// Obtains the meta data of the specified column family of the DB.
virtual void GetColumnFamilyMetaData(ColumnFamilyHandle* /*column_family*/,
ColumnFamilyMetaData* /*metadata*/) {}
// Get the metadata of the default column family.
void GetColumnFamilyMetaData(
ColumnFamilyMetaData* metadata) {
GetColumnFamilyMetaData(DefaultColumnFamily(), metadata);
}
// IngestExternalFile() will load a list of external SST files (1) into the DB
// Two primary modes are supported:
// - Duplicate keys in the new files will overwrite exiting keys (default)
// - Duplicate keys will be skipped (set ingest_behind=true)
// In the first mode we will try to find the lowest possible level that
// the file can fit in, and ingest the file into this level (2). A file that
// have a key range that overlap with the memtable key range will require us
// to Flush the memtable first before ingesting the file.
// In the second mode we will always ingest in the bottom most level (see
// docs to IngestExternalFileOptions::ingest_behind).
//
// (1) External SST files can be created using SstFileWriter
// (2) We will try to ingest the files to the lowest possible level
// even if the file compression doesn't match the level compression
// (3) If IngestExternalFileOptions->ingest_behind is set to true,
// we always ingest at the bottommost level, which should be reserved
// for this purpose (see DBOPtions::allow_ingest_behind flag).
virtual Status IngestExternalFile(
ColumnFamilyHandle* column_family,
const std::vector<std::string>& external_files,
const IngestExternalFileOptions& options) = 0;
virtual Status IngestExternalFile(
const std::vector<std::string>& external_files,
const IngestExternalFileOptions& options) {
return IngestExternalFile(DefaultColumnFamily(), external_files, options);
}
virtual Status VerifyChecksum() = 0;
// AddFile() is deprecated, please use IngestExternalFile()
ROCKSDB_DEPRECATED_FUNC virtual Status AddFile(
ColumnFamilyHandle* column_family,
const std::vector<std::string>& file_path_list, bool move_file = false,
bool skip_snapshot_check = false) {
IngestExternalFileOptions ifo;
ifo.move_files = move_file;
ifo.snapshot_consistency = !skip_snapshot_check;
ifo.allow_global_seqno = false;
ifo.allow_blocking_flush = false;
return IngestExternalFile(column_family, file_path_list, ifo);
}
ROCKSDB_DEPRECATED_FUNC virtual Status AddFile(
const std::vector<std::string>& file_path_list, bool move_file = false,
bool skip_snapshot_check = false) {
IngestExternalFileOptions ifo;
ifo.move_files = move_file;
ifo.snapshot_consistency = !skip_snapshot_check;
ifo.allow_global_seqno = false;
ifo.allow_blocking_flush = false;
return IngestExternalFile(DefaultColumnFamily(), file_path_list, ifo);
}
// AddFile() is deprecated, please use IngestExternalFile()
ROCKSDB_DEPRECATED_FUNC virtual Status AddFile(
ColumnFamilyHandle* column_family, const std::string& file_path,
bool move_file = false, bool skip_snapshot_check = false) {
IngestExternalFileOptions ifo;
ifo.move_files = move_file;
ifo.snapshot_consistency = !skip_snapshot_check;
ifo.allow_global_seqno = false;
ifo.allow_blocking_flush = false;
return IngestExternalFile(column_family, {file_path}, ifo);
}
ROCKSDB_DEPRECATED_FUNC virtual Status AddFile(
const std::string& file_path, bool move_file = false,
bool skip_snapshot_check = false) {
IngestExternalFileOptions ifo;
ifo.move_files = move_file;
ifo.snapshot_consistency = !skip_snapshot_check;
ifo.allow_global_seqno = false;
ifo.allow_blocking_flush = false;
return IngestExternalFile(DefaultColumnFamily(), {file_path}, ifo);
}
// Load table file with information "file_info" into "column_family"
ROCKSDB_DEPRECATED_FUNC virtual Status AddFile(
ColumnFamilyHandle* column_family,
const std::vector<ExternalSstFileInfo>& file_info_list,
bool move_file = false, bool skip_snapshot_check = false) {
std::vector<std::string> external_files;
for (const ExternalSstFileInfo& file_info : file_info_list) {
external_files.push_back(file_info.file_path);
}
IngestExternalFileOptions ifo;
ifo.move_files = move_file;
ifo.snapshot_consistency = !skip_snapshot_check;
ifo.allow_global_seqno = false;
ifo.allow_blocking_flush = false;
return IngestExternalFile(column_family, external_files, ifo);
}
ROCKSDB_DEPRECATED_FUNC virtual Status AddFile(
const std::vector<ExternalSstFileInfo>& file_info_list,
bool move_file = false, bool skip_snapshot_check = false) {
std::vector<std::string> external_files;
for (const ExternalSstFileInfo& file_info : file_info_list) {
external_files.push_back(file_info.file_path);
}
IngestExternalFileOptions ifo;
ifo.move_files = move_file;
ifo.snapshot_consistency = !skip_snapshot_check;
ifo.allow_global_seqno = false;
ifo.allow_blocking_flush = false;
return IngestExternalFile(DefaultColumnFamily(), external_files, ifo);
}
ROCKSDB_DEPRECATED_FUNC virtual Status AddFile(
ColumnFamilyHandle* column_family, const ExternalSstFileInfo* file_info,
bool move_file = false, bool skip_snapshot_check = false) {
IngestExternalFileOptions ifo;
ifo.move_files = move_file;
ifo.snapshot_consistency = !skip_snapshot_check;
ifo.allow_global_seqno = false;
ifo.allow_blocking_flush = false;
return IngestExternalFile(column_family, {file_info->file_path}, ifo);
}
ROCKSDB_DEPRECATED_FUNC virtual Status AddFile(
const ExternalSstFileInfo* file_info, bool move_file = false,
bool skip_snapshot_check = false) {
IngestExternalFileOptions ifo;
ifo.move_files = move_file;
ifo.snapshot_consistency = !skip_snapshot_check;
ifo.allow_global_seqno = false;
ifo.allow_blocking_flush = false;
return IngestExternalFile(DefaultColumnFamily(), {file_info->file_path},
ifo);
}
#endif // ROCKSDB_LITE
// Sets the globally unique ID created at database creation time by invoking
// Env::GenerateUniqueId(), in identity. Returns Status::OK if identity could
// be set properly
virtual Status GetDbIdentity(std::string& identity) const = 0;
// Returns default column family handle
virtual ColumnFamilyHandle* DefaultColumnFamily() const = 0;
#ifndef ROCKSDB_LITE
virtual Status GetPropertiesOfAllTables(ColumnFamilyHandle* column_family,
TablePropertiesCollection* props) = 0;
virtual Status GetPropertiesOfAllTables(TablePropertiesCollection* props) {
return GetPropertiesOfAllTables(DefaultColumnFamily(), props);
}
virtual Status GetPropertiesOfTablesInRange(
ColumnFamilyHandle* column_family, const Range* range, std::size_t n,
TablePropertiesCollection* props) = 0;
virtual Status SuggestCompactRange(ColumnFamilyHandle* /*column_family*/,
const Slice* /*begin*/,
const Slice* /*end*/) {
return Status::NotSupported("SuggestCompactRange() is not implemented.");
}
virtual Status PromoteL0(ColumnFamilyHandle* /*column_family*/,
int /*target_level*/) {
return Status::NotSupported("PromoteL0() is not implemented.");
}
// Trace DB operations. Use EndTrace() to stop tracing.
virtual Status StartTrace(const TraceOptions& /*options*/,
std::unique_ptr<TraceWriter>&& /*trace_writer*/) {
return Status::NotSupported("StartTrace() is not implemented.");
}
virtual Status EndTrace() {
return Status::NotSupported("EndTrace() is not implemented.");
}
#endif // ROCKSDB_LITE
// Needed for StackableDB
virtual DB* GetRootDB() { return this; }
private:
// No copying allowed
DB(const DB&);
void operator=(const DB&);
};
// Destroy the contents of the specified database.
// Be very careful using this method.
Status DestroyDB(const std::string& name, const Options& options,
const std::vector<ColumnFamilyDescriptor>& column_families =
std::vector<ColumnFamilyDescriptor>());
#ifndef ROCKSDB_LITE
// If a DB cannot be opened, you may attempt to call this method to
// resurrect as much of the contents of the database as possible.
// Some data may be lost, so be careful when calling this function
// on a database that contains important information.
//
// With this API, we will warn and skip data associated with column families not
// specified in column_families.
//
// @param column_families Descriptors for known column families
Status RepairDB(const std::string& dbname, const DBOptions& db_options,
const std::vector<ColumnFamilyDescriptor>& column_families);
// @param unknown_cf_opts Options for column families encountered during the
// repair that were not specified in column_families.
Status RepairDB(const std::string& dbname, const DBOptions& db_options,
const std::vector<ColumnFamilyDescriptor>& column_families,
const ColumnFamilyOptions& unknown_cf_opts);
// @param options These options will be used for the database and for ALL column
// families encountered during the repair
Status RepairDB(const std::string& dbname, const Options& options);
#endif
} // namespace rocksdb