diff options
Diffstat (limited to 'Godeps/_workspace/src/github.com/syndtr/goleveldb/leveldb/opt/options.go')
| -rw-r--r-- | Godeps/_workspace/src/github.com/syndtr/goleveldb/leveldb/opt/options.go | 684 |
1 files changed, 0 insertions, 684 deletions
diff --git a/Godeps/_workspace/src/github.com/syndtr/goleveldb/leveldb/opt/options.go b/Godeps/_workspace/src/github.com/syndtr/goleveldb/leveldb/opt/options.go deleted file mode 100644 index 44e7d9adc..000000000 --- a/Godeps/_workspace/src/github.com/syndtr/goleveldb/leveldb/opt/options.go +++ /dev/null @@ -1,684 +0,0 @@ -// Copyright (c) 2012, Suryandaru Triandana <syndtr@gmail.com> -// All rights reserved. -// -// Use of this source code is governed by a BSD-style license that can be -// found in the LICENSE file. - -// Package opt provides sets of options used by LevelDB. -package opt - -import ( - "math" - - "github.com/syndtr/goleveldb/leveldb/cache" - "github.com/syndtr/goleveldb/leveldb/comparer" - "github.com/syndtr/goleveldb/leveldb/filter" -) - -const ( - KiB = 1024 - MiB = KiB * 1024 - GiB = MiB * 1024 -) - -var ( - DefaultBlockCacher = LRUCacher - DefaultBlockCacheCapacity = 8 * MiB - DefaultBlockRestartInterval = 16 - DefaultBlockSize = 4 * KiB - DefaultCompactionExpandLimitFactor = 25 - DefaultCompactionGPOverlapsFactor = 10 - DefaultCompactionL0Trigger = 4 - DefaultCompactionSourceLimitFactor = 1 - DefaultCompactionTableSize = 2 * MiB - DefaultCompactionTableSizeMultiplier = 1.0 - DefaultCompactionTotalSize = 10 * MiB - DefaultCompactionTotalSizeMultiplier = 10.0 - DefaultCompressionType = SnappyCompression - DefaultIteratorSamplingRate = 1 * MiB - DefaultOpenFilesCacher = LRUCacher - DefaultOpenFilesCacheCapacity = 500 - DefaultWriteBuffer = 4 * MiB - DefaultWriteL0PauseTrigger = 12 - DefaultWriteL0SlowdownTrigger = 8 -) - -// Cacher is a caching algorithm. -type Cacher interface { - New(capacity int) cache.Cacher -} - -type CacherFunc struct { - NewFunc func(capacity int) cache.Cacher -} - -func (f *CacherFunc) New(capacity int) cache.Cacher { - if f.NewFunc != nil { - return f.NewFunc(capacity) - } - return nil -} - -func noCacher(int) cache.Cacher { return nil } - -var ( - // LRUCacher is the LRU-cache algorithm. - LRUCacher = &CacherFunc{cache.NewLRU} - - // NoCacher is the value to disable caching algorithm. - NoCacher = &CacherFunc{} -) - -// Compression is the 'sorted table' block compression algorithm to use. -type Compression uint - -func (c Compression) String() string { - switch c { - case DefaultCompression: - return "default" - case NoCompression: - return "none" - case SnappyCompression: - return "snappy" - } - return "invalid" -} - -const ( - DefaultCompression Compression = iota - NoCompression - SnappyCompression - nCompression -) - -// Strict is the DB 'strict level'. -type Strict uint - -const ( - // If present then a corrupted or invalid chunk or block in manifest - // journal will cause an error instead of being dropped. - // This will prevent database with corrupted manifest to be opened. - StrictManifest Strict = 1 << iota - - // If present then journal chunk checksum will be verified. - StrictJournalChecksum - - // If present then a corrupted or invalid chunk or block in journal - // will cause an error instead of being dropped. - // This will prevent database with corrupted journal to be opened. - StrictJournal - - // If present then 'sorted table' block checksum will be verified. - // This has effect on both 'read operation' and compaction. - StrictBlockChecksum - - // If present then a corrupted 'sorted table' will fails compaction. - // The database will enter read-only mode. - StrictCompaction - - // If present then a corrupted 'sorted table' will halts 'read operation'. - StrictReader - - // If present then leveldb.Recover will drop corrupted 'sorted table'. - StrictRecovery - - // This only applicable for ReadOptions, if present then this ReadOptions - // 'strict level' will override global ones. - StrictOverride - - // StrictAll enables all strict flags. - StrictAll = StrictManifest | StrictJournalChecksum | StrictJournal | StrictBlockChecksum | StrictCompaction | StrictReader | StrictRecovery - - // DefaultStrict is the default strict flags. Specify any strict flags - // will override default strict flags as whole (i.e. not OR'ed). - DefaultStrict = StrictJournalChecksum | StrictBlockChecksum | StrictCompaction | StrictReader - - // NoStrict disables all strict flags. Override default strict flags. - NoStrict = ^StrictAll -) - -// Options holds the optional parameters for the DB at large. -type Options struct { - // AltFilters defines one or more 'alternative filters'. - // 'alternative filters' will be used during reads if a filter block - // does not match with the 'effective filter'. - // - // The default value is nil - AltFilters []filter.Filter - - // BlockCacher provides cache algorithm for LevelDB 'sorted table' block caching. - // Specify NoCacher to disable caching algorithm. - // - // The default value is LRUCacher. - BlockCacher Cacher - - // BlockCacheCapacity defines the capacity of the 'sorted table' block caching. - // Use -1 for zero, this has same effect as specifying NoCacher to BlockCacher. - // - // The default value is 8MiB. - BlockCacheCapacity int - - // BlockRestartInterval is the number of keys between restart points for - // delta encoding of keys. - // - // The default value is 16. - BlockRestartInterval int - - // BlockSize is the minimum uncompressed size in bytes of each 'sorted table' - // block. - // - // The default value is 4KiB. - BlockSize int - - // CompactionExpandLimitFactor limits compaction size after expanded. - // This will be multiplied by table size limit at compaction target level. - // - // The default value is 25. - CompactionExpandLimitFactor int - - // CompactionGPOverlapsFactor limits overlaps in grandparent (Level + 2) that a - // single 'sorted table' generates. - // This will be multiplied by table size limit at grandparent level. - // - // The default value is 10. - CompactionGPOverlapsFactor int - - // CompactionL0Trigger defines number of 'sorted table' at level-0 that will - // trigger compaction. - // - // The default value is 4. - CompactionL0Trigger int - - // CompactionSourceLimitFactor limits compaction source size. This doesn't apply to - // level-0. - // This will be multiplied by table size limit at compaction target level. - // - // The default value is 1. - CompactionSourceLimitFactor int - - // CompactionTableSize limits size of 'sorted table' that compaction generates. - // The limits for each level will be calculated as: - // CompactionTableSize * (CompactionTableSizeMultiplier ^ Level) - // The multiplier for each level can also fine-tuned using CompactionTableSizeMultiplierPerLevel. - // - // The default value is 2MiB. - CompactionTableSize int - - // CompactionTableSizeMultiplier defines multiplier for CompactionTableSize. - // - // The default value is 1. - CompactionTableSizeMultiplier float64 - - // CompactionTableSizeMultiplierPerLevel defines per-level multiplier for - // CompactionTableSize. - // Use zero to skip a level. - // - // The default value is nil. - CompactionTableSizeMultiplierPerLevel []float64 - - // CompactionTotalSize limits total size of 'sorted table' for each level. - // The limits for each level will be calculated as: - // CompactionTotalSize * (CompactionTotalSizeMultiplier ^ Level) - // The multiplier for each level can also fine-tuned using - // CompactionTotalSizeMultiplierPerLevel. - // - // The default value is 10MiB. - CompactionTotalSize int - - // CompactionTotalSizeMultiplier defines multiplier for CompactionTotalSize. - // - // The default value is 10. - CompactionTotalSizeMultiplier float64 - - // CompactionTotalSizeMultiplierPerLevel defines per-level multiplier for - // CompactionTotalSize. - // Use zero to skip a level. - // - // The default value is nil. - CompactionTotalSizeMultiplierPerLevel []float64 - - // Comparer defines a total ordering over the space of []byte keys: a 'less - // than' relationship. The same comparison algorithm must be used for reads - // and writes over the lifetime of the DB. - // - // The default value uses the same ordering as bytes.Compare. - Comparer comparer.Comparer - - // Compression defines the 'sorted table' block compression to use. - // - // The default value (DefaultCompression) uses snappy compression. - Compression Compression - - // DisableBufferPool allows disable use of util.BufferPool functionality. - // - // The default value is false. - DisableBufferPool bool - - // DisableBlockCache allows disable use of cache.Cache functionality on - // 'sorted table' block. - // - // The default value is false. - DisableBlockCache bool - - // DisableCompactionBackoff allows disable compaction retry backoff. - // - // The default value is false. - DisableCompactionBackoff bool - - // DisableLargeBatchTransaction allows disabling switch-to-transaction mode - // on large batch write. If enable batch writes large than WriteBuffer will - // use transaction. - // - // The default is false. - DisableLargeBatchTransaction bool - - // ErrorIfExist defines whether an error should returned if the DB already - // exist. - // - // The default value is false. - ErrorIfExist bool - - // ErrorIfMissing defines whether an error should returned if the DB is - // missing. If false then the database will be created if missing, otherwise - // an error will be returned. - // - // The default value is false. - ErrorIfMissing bool - - // Filter defines an 'effective filter' to use. An 'effective filter' - // if defined will be used to generate per-table filter block. - // The filter name will be stored on disk. - // During reads LevelDB will try to find matching filter from - // 'effective filter' and 'alternative filters'. - // - // Filter can be changed after a DB has been created. It is recommended - // to put old filter to the 'alternative filters' to mitigate lack of - // filter during transition period. - // - // A filter is used to reduce disk reads when looking for a specific key. - // - // The default value is nil. - Filter filter.Filter - - // IteratorSamplingRate defines approximate gap (in bytes) between read - // sampling of an iterator. The samples will be used to determine when - // compaction should be triggered. - // - // The default is 1MiB. - IteratorSamplingRate int - - // NoSync allows completely disable fsync. - // - // The default is false. - NoSync bool - - // NoWriteMerge allows disabling write merge. - // - // The default is false. - NoWriteMerge bool - - // OpenFilesCacher provides cache algorithm for open files caching. - // Specify NoCacher to disable caching algorithm. - // - // The default value is LRUCacher. - OpenFilesCacher Cacher - - // OpenFilesCacheCapacity defines the capacity of the open files caching. - // Use -1 for zero, this has same effect as specifying NoCacher to OpenFilesCacher. - // - // The default value is 500. - OpenFilesCacheCapacity int - - // If true then opens DB in read-only mode. - // - // The default value is false. - ReadOnly bool - - // Strict defines the DB strict level. - Strict Strict - - // WriteBuffer defines maximum size of a 'memdb' before flushed to - // 'sorted table'. 'memdb' is an in-memory DB backed by an on-disk - // unsorted journal. - // - // LevelDB may held up to two 'memdb' at the same time. - // - // The default value is 4MiB. - WriteBuffer int - - // WriteL0StopTrigger defines number of 'sorted table' at level-0 that will - // pause write. - // - // The default value is 12. - WriteL0PauseTrigger int - - // WriteL0SlowdownTrigger defines number of 'sorted table' at level-0 that - // will trigger write slowdown. - // - // The default value is 8. - WriteL0SlowdownTrigger int -} - -func (o *Options) GetAltFilters() []filter.Filter { - if o == nil { - return nil - } - return o.AltFilters -} - -func (o *Options) GetBlockCacher() Cacher { - if o == nil || o.BlockCacher == nil { - return DefaultBlockCacher - } else if o.BlockCacher == NoCacher { - return nil - } - return o.BlockCacher -} - -func (o *Options) GetBlockCacheCapacity() int { - if o == nil || o.BlockCacheCapacity == 0 { - return DefaultBlockCacheCapacity - } else if o.BlockCacheCapacity < 0 { - return 0 - } - return o.BlockCacheCapacity -} - -func (o *Options) GetBlockRestartInterval() int { - if o == nil || o.BlockRestartInterval <= 0 { - return DefaultBlockRestartInterval - } - return o.BlockRestartInterval -} - -func (o *Options) GetBlockSize() int { - if o == nil || o.BlockSize <= 0 { - return DefaultBlockSize - } - return o.BlockSize -} - -func (o *Options) GetCompactionExpandLimit(level int) int { - factor := DefaultCompactionExpandLimitFactor - if o != nil && o.CompactionExpandLimitFactor > 0 { - factor = o.CompactionExpandLimitFactor - } - return o.GetCompactionTableSize(level+1) * factor -} - -func (o *Options) GetCompactionGPOverlaps(level int) int { - factor := DefaultCompactionGPOverlapsFactor - if o != nil && o.CompactionGPOverlapsFactor > 0 { - factor = o.CompactionGPOverlapsFactor - } - return o.GetCompactionTableSize(level+2) * factor -} - -func (o *Options) GetCompactionL0Trigger() int { - if o == nil || o.CompactionL0Trigger == 0 { - return DefaultCompactionL0Trigger - } - return o.CompactionL0Trigger -} - -func (o *Options) GetCompactionSourceLimit(level int) int { - factor := DefaultCompactionSourceLimitFactor - if o != nil && o.CompactionSourceLimitFactor > 0 { - factor = o.CompactionSourceLimitFactor - } - return o.GetCompactionTableSize(level+1) * factor -} - -func (o *Options) GetCompactionTableSize(level int) int { - var ( - base = DefaultCompactionTableSize - mult float64 - ) - if o != nil { - if o.CompactionTableSize > 0 { - base = o.CompactionTableSize - } - if level < len(o.CompactionTableSizeMultiplierPerLevel) && o.CompactionTableSizeMultiplierPerLevel[level] > 0 { - mult = o.CompactionTableSizeMultiplierPerLevel[level] - } else if o.CompactionTableSizeMultiplier > 0 { - mult = math.Pow(o.CompactionTableSizeMultiplier, float64(level)) - } - } - if mult == 0 { - mult = math.Pow(DefaultCompactionTableSizeMultiplier, float64(level)) - } - return int(float64(base) * mult) -} - -func (o *Options) GetCompactionTotalSize(level int) int64 { - var ( - base = DefaultCompactionTotalSize - mult float64 - ) - if o != nil { - if o.CompactionTotalSize > 0 { - base = o.CompactionTotalSize - } - if level < len(o.CompactionTotalSizeMultiplierPerLevel) && o.CompactionTotalSizeMultiplierPerLevel[level] > 0 { - mult = o.CompactionTotalSizeMultiplierPerLevel[level] - } else if o.CompactionTotalSizeMultiplier > 0 { - mult = math.Pow(o.CompactionTotalSizeMultiplier, float64(level)) - } - } - if mult == 0 { - mult = math.Pow(DefaultCompactionTotalSizeMultiplier, float64(level)) - } - return int64(float64(base) * mult) -} - -func (o *Options) GetComparer() comparer.Comparer { - if o == nil || o.Comparer == nil { - return comparer.DefaultComparer - } - return o.Comparer -} - -func (o *Options) GetCompression() Compression { - if o == nil || o.Compression <= DefaultCompression || o.Compression >= nCompression { - return DefaultCompressionType - } - return o.Compression -} - -func (o *Options) GetDisableBufferPool() bool { - if o == nil { - return false - } - return o.DisableBufferPool -} - -func (o *Options) GetDisableBlockCache() bool { - if o == nil { - return false - } - return o.DisableBlockCache -} - -func (o *Options) GetDisableCompactionBackoff() bool { - if o == nil { - return false - } - return o.DisableCompactionBackoff -} - -func (o *Options) GetDisableLargeBatchTransaction() bool { - if o == nil { - return false - } - return o.DisableLargeBatchTransaction -} - -func (o *Options) GetErrorIfExist() bool { - if o == nil { - return false - } - return o.ErrorIfExist -} - -func (o *Options) GetErrorIfMissing() bool { - if o == nil { - return false - } - return o.ErrorIfMissing -} - -func (o *Options) GetFilter() filter.Filter { - if o == nil { - return nil - } - return o.Filter -} - -func (o *Options) GetIteratorSamplingRate() int { - if o == nil || o.IteratorSamplingRate <= 0 { - return DefaultIteratorSamplingRate - } - return o.IteratorSamplingRate -} - -func (o *Options) GetNoSync() bool { - if o == nil { - return false - } - return o.NoSync -} - -func (o *Options) GetNoWriteMerge() bool { - if o == nil { - return false - } - return o.NoWriteMerge -} - -func (o *Options) GetOpenFilesCacher() Cacher { - if o == nil || o.OpenFilesCacher == nil { - return DefaultOpenFilesCacher - } - if o.OpenFilesCacher == NoCacher { - return nil - } - return o.OpenFilesCacher -} - -func (o *Options) GetOpenFilesCacheCapacity() int { - if o == nil || o.OpenFilesCacheCapacity == 0 { - return DefaultOpenFilesCacheCapacity - } else if o.OpenFilesCacheCapacity < 0 { - return 0 - } - return o.OpenFilesCacheCapacity -} - -func (o *Options) GetReadOnly() bool { - if o == nil { - return false - } - return o.ReadOnly -} - -func (o *Options) GetStrict(strict Strict) bool { - if o == nil || o.Strict == 0 { - return DefaultStrict&strict != 0 - } - return o.Strict&strict != 0 -} - -func (o *Options) GetWriteBuffer() int { - if o == nil || o.WriteBuffer <= 0 { - return DefaultWriteBuffer - } - return o.WriteBuffer -} - -func (o *Options) GetWriteL0PauseTrigger() int { - if o == nil || o.WriteL0PauseTrigger == 0 { - return DefaultWriteL0PauseTrigger - } - return o.WriteL0PauseTrigger -} - -func (o *Options) GetWriteL0SlowdownTrigger() int { - if o == nil || o.WriteL0SlowdownTrigger == 0 { - return DefaultWriteL0SlowdownTrigger - } - return o.WriteL0SlowdownTrigger -} - -// ReadOptions holds the optional parameters for 'read operation'. The -// 'read operation' includes Get, Find and NewIterator. -type ReadOptions struct { - // DontFillCache defines whether block reads for this 'read operation' - // should be cached. If false then the block will be cached. This does - // not affects already cached block. - // - // The default value is false. - DontFillCache bool - - // Strict will be OR'ed with global DB 'strict level' unless StrictOverride - // is present. Currently only StrictReader that has effect here. - Strict Strict -} - -func (ro *ReadOptions) GetDontFillCache() bool { - if ro == nil { - return false - } - return ro.DontFillCache -} - -func (ro *ReadOptions) GetStrict(strict Strict) bool { - if ro == nil { - return false - } - return ro.Strict&strict != 0 -} - -// WriteOptions holds the optional parameters for 'write operation'. The -// 'write operation' includes Write, Put and Delete. -type WriteOptions struct { - // NoWriteMerge allows disabling write merge. - // - // The default is false. - NoWriteMerge bool - - // Sync is whether to sync underlying writes from the OS buffer cache - // through to actual disk, if applicable. Setting Sync can result in - // slower writes. - // - // If false, and the machine crashes, then some recent writes may be lost. - // Note that if it is just the process that crashes (and the machine does - // not) then no writes will be lost. - // - // In other words, Sync being false has the same semantics as a write - // system call. Sync being true means write followed by fsync. - // - // The default value is false. - Sync bool -} - -func (wo *WriteOptions) GetNoWriteMerge() bool { - if wo == nil { - return false - } - return wo.NoWriteMerge -} - -func (wo *WriteOptions) GetSync() bool { - if wo == nil { - return false - } - return wo.Sync -} - -func GetStrict(o *Options, ro *ReadOptions, strict Strict) bool { - if ro.GetStrict(StrictOverride) { - return ro.GetStrict(strict) - } else { - return o.GetStrict(strict) || ro.GetStrict(strict) - } -} |