@ -327,97 +327,154 @@ class DB {
// use "snapshot" after this call.
virtual void ReleaseSnapshot ( const Snapshot * snapshot ) = 0 ;
// DB implementations can export properties about their state
// via this method. If "property" is a valid property understood by this
// DB implementation, fills "*value" with its current value and returns
// true. Otherwise returns false.
//
//
// Valid property names include:
//
// "rocksdb.num-files-at-level<N>" - return the number of files at level <N>,
// where <N> is an ASCII representation of a level number (e.g. "0").
// "rocksdb.stats" - returns a multi-line string that describes statistics
// about the internal operation of the DB.
// "rocksdb.sstables" - returns a multi-line string that describes all
// of the sstables that make up the db contents.
// "rocksdb.cfstats"
// "rocksdb.dbstats"
// "rocksdb.levelstats"
// "rocksdb.num-immutable-mem-table"
// "rocksdb.mem-table-flush-pending"
// "rocksdb.num-immutable-mem-table-flushed"
// "rocksdb.compaction-pending" - 1 if at least one compaction is pending
// "rocksdb.background-errors" - accumulated number of 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" - estimated keys in the column family
// "rocksdb.estimate-table-readers-mem" - estimated memory used for reding
// SST tables, that is not counted as a part of block cache.
// "rocksdb.is-file-deletions-enabled"
// "rocksdb.num-snapshots"
// "rocksdb.oldest-snapshot-time"
// "rocksdb.num-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.
// "rocksdb.estimate-live-data-size"
// "rocksdb.total-sst-files-size" - total size of all used sst files, this
// may slow down online queries if there are too many files.
// "rocksdb.base-level"
// "rocksdb.estimate-pending-compaction-bytes" - estimated total number of
// bytes compaction needs to rewrite the data to get all levels down
// to under target size. Not valid for other compactions than
// level-based.
// "rocksdb.aggregated-table-properties" - returns a string representation
// of the aggregated table properties of the target column family.
// "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.
// "rocksdb.num-running-compactions" - the number of currently running
// compacitons.
// "rocksdb.num-running-flushes" - the number of currently running flushes.
# ifndef ROCKSDB_LITE
// Contains all valid property arguments for GetProperty().
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.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" - returns a multi-line string with general column
// 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").
static const std : : string kCFStats ;
// "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.
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.estimate-live-data-size" - returns an estimate of the amount of
// live data in bytes.
static const std : : string kEstimateLiveDataSize ;
// "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.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 ;
} ;
# 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 ) {
Andrew Kryczka
9 years ago