1 files changed, 684 insertions, 0 deletions
diff --git a/vendor/github.com/syndtr/goleveldb/leveldb/opt/options.go b/vendor/github.com/syndtr/goleveldb/leveldb/opt/options.go
new file mode 100644
index 0000000..44e7d9a
--- /dev/null
+++ b/vendor/github.com/syndtr/goleveldb/leveldb/opt/options.go
@@ -0,0 +1,684 @@
+// 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)
+	}
+}