@ -149,6 +149,7 @@ class Version {
friend class Compaction ;
friend class VersionSet ;
friend class DBImpl ;
friend struct ColumnFamilyData ;
class LevelFileNumIterator ;
Iterator * NewConcatenatingIterator ( const ReadOptions & ,
@ -197,9 +198,6 @@ class Version {
double max_compaction_score_ ; // max score in l1 to ln-1
int max_compaction_score_level_ ; // level on which max score occurs
// The offset in the manifest file where this version is stored.
uint64_t offset_manifest_file_ ;
// A version number that uniquely represents this version. This is
// used for debugging and logging purposes only.
uint64_t version_number_ ;
@ -219,6 +217,20 @@ class Version {
void operator = ( const Version & ) ;
} ;
// column family metadata
struct ColumnFamilyData {
std : : string name ;
Version dummy_versions ; // Head of circular doubly-linked list of versions.
Version * current ; // == dummy_versions.prev_
ColumnFamilyOptions options ;
ColumnFamilyData ( const std : : string & name ,
VersionSet * vset ,
const ColumnFamilyOptions & options )
: name ( name ) , dummy_versions ( vset ) , current ( nullptr ) , options ( options ) { }
~ ColumnFamilyData ( ) { }
} ;
class VersionSet {
public :
VersionSet ( const std : : string & dbname ,
@ -233,8 +245,17 @@ class VersionSet {
// current version. Will release *mu while actually writing to the file.
// REQUIRES: *mu is held on entry.
// REQUIRES: no other thread concurrently calls LogAndApply()
Status LogAndApply ( VersionEdit * edit , port : : Mutex * mu ,
bool new_descriptor_log = false ) ;
Status LogAndApply ( ColumnFamilyData * column_family_data ,
VersionEdit * edit ,
port : : Mutex * mu ,
bool new_descriptor_log = false ) ;
Status LogAndApply ( VersionEdit * edit ,
port : : Mutex * mu ,
bool new_descriptor_log = false ) {
return LogAndApply (
column_family_data_ . find ( 0 ) - > second , edit , mu , new_descriptor_log ) ;
}
// Recover the last saved descriptor from persistent storage.
Status Recover ( ) ;
@ -248,7 +269,10 @@ class VersionSet {
Status ReduceNumberOfLevels ( int new_levels , port : : Mutex * mu ) ;
// Return the current version.
Version * current ( ) const { return current_ ; }
Version * current ( ) const {
// TODO this only works for default column family now
return column_family_data_ . find ( 0 ) - > second - > current ;
}
// Return the current manifest file number
uint64_t ManifestFileNumber ( ) const { return manifest_file_number_ ; }
@ -327,11 +351,13 @@ class VersionSet {
// ending up with nothing to do. We can improve it later.
// TODO: improve this function to be accurate for universal
// compactions.
// TODO this only works for default column family now
Version * version = column_family_data_ . find ( 0 ) - > second - > current ;
int num_levels_to_check =
( options_ - > compaction_style ! = kCompactionStyleUniversal ) ?
NumberLevels ( ) - 1 : 1 ;
for ( int i = 0 ; i < num_levels_to_check ; i + + ) {
if ( current_ - > compaction_score_ [ i ] > = 1 ) {
if ( version - > compaction_score_ [ i ] > = 1 ) {
return true ;
}
}
@ -339,18 +365,23 @@ class VersionSet {
}
// Returns true iff some level needs a compaction.
bool NeedsCompaction ( ) const {
return ( ( current_ - > file_to_compact_ ! = nullptr ) | |
NeedsSizeCompaction ( ) ) ;
// TODO this only works for default column family now
Version * version = column_family_data_ . find ( 0 ) - > second - > current ;
return ( ( version - > file_to_compact_ ! = nullptr ) | | NeedsSizeCompaction ( ) ) ;
}
// Returns the maxmimum compaction score for levels 1 to max
double MaxCompactionScore ( ) const {
return current_ - > max_compaction_score_ ;
// TODO this only works for default column family now
Version * version = column_family_data_ . find ( 0 ) - > second - > current ;
return version - > max_compaction_score_ ;
}
// See field declaration
int MaxCompactionScoreLevel ( ) const {
return current_ - > max_compaction_score_level_ ;
// TODO this only works for default column family now
Version * version = column_family_data_ . find ( 0 ) - > second - > current ;
return version - > max_compaction_score_level_ ;
}
// Add all files listed in any live version to *live.
@ -383,10 +414,12 @@ class VersionSet {
// Return a human-readable short (single-line) summary of files
// in a specified level. Uses *scratch as backing store.
const char * LevelFileSummary ( FileSummaryStorage * scratch , int level ) const ;
const char * LevelFileSummary ( Version * version ,
FileSummaryStorage * scratch ,
int level ) const ;
// Return the size of the current manifest file
const uint64_t ManifestFileSize ( ) { return current_ - > offset_ manifest_file_; }
const uint64_t ManifestFileSize ( ) { return manifest_file_siz e_ ; }
// For the specfied level, pick a compaction.
// Returns nullptr if there is no compaction to be done.
@ -436,17 +469,13 @@ class VersionSet {
void GetObsoleteFiles ( std : : vector < FileMetaData * > * files ) ;
// column family metadata
struct ColumnFamilyData {
std : : string name ;
ColumnFamilyOptions options ;
explicit ColumnFamilyData ( const std : : string & name ) : name ( name ) { }
ColumnFamilyData ( const std : : string & name ,
const ColumnFamilyOptions & options )
: name ( name ) , options ( options ) { }
} ;
ColumnFamilyData * CreateColumnFamily ( const ColumnFamilyOptions & options ,
VersionEdit * edit ) ;
void DropColumnFamily ( VersionEdit * edit ) ;
std : : unordered_map < std : : string , uint32_t > column_families_ ;
std : : unordered_map < uint32_t , ColumnFamilyData > column_family_data_ ;
std : : unordered_map < uint32_t , ColumnFamilyData * > column_family_data_ ;
uint32_t max_column_family_ ;
private :
@ -476,7 +505,7 @@ class VersionSet {
// Save current contents to *log
Status WriteSnapshot ( log : : Writer * log ) ;
void AppendVersion ( Version * v ) ;
void AppendVersion ( ColumnFamilyData * column_family_data , Version * v ) ;
bool ManifestContains ( const std : : string & record ) const ;
@ -499,8 +528,6 @@ class VersionSet {
// Opened lazily
unique_ptr < log : : Writer > descriptor_log_ ;
Version dummy_versions_ ; // Head of circular doubly-linked list of versions.
Version * current_ ; // == dummy_versions_.prev_
// Per-level key at which the next compaction at that level should start.
// Either an empty string, or a valid InternalKey.
@ -521,9 +548,8 @@ class VersionSet {
// Queue of writers to the manifest file
std : : deque < ManifestWriter * > manifest_writers_ ;
// Store the manifest file size when it is checked.
// Save us the cost of checking file size twice in LogAndApply
uint64_t last_observed_manifest_size_ ;
// size of manifest file
uint64_t manifest_file_size_ ;
std : : vector < FileMetaData * > obsolete_files_ ;
@ -616,9 +642,14 @@ class Compaction {
friend class Version ;
friend class VersionSet ;
explicit Compaction ( int level , int out_level , uint64_t target_file_size ,
uint64_t max_grandparent_overlap_bytes , int number_levels ,
bool seek_compaction = false , bool enable_compression = true ) ;
Compaction ( int level ,
int out_level ,
uint64_t target_file_size ,
uint64_t max_grandparent_overlap_bytes ,
int number_levels ,
Version * input_version ,
bool seek_compaction = false ,
bool enable_compression = true ) ;
int level_ ;
int out_level_ ; // levels to which output files are stored