这是一个基于针对时序数据，在LevelDB上进行封装的一个磁盘存储引擎。

Installation

go get github.com/xlwh/tsdb-engine

Usage

opt := tsengine.NewOption()
opt.DataDir = "D:/data"   // 数据存储目录
opt.ExpireTime = 1800     // 数据过期时间，单位秒
opt.PointNumEachBlock = 10   // 在memTable中的最近的数据点的个数，大于这个点的数据将会被刷写到磁盘
opt.GcInterval = 2           // 执行过期数据回收检查的时间间隔，单位秒
opt.FlushInterval = 60       // 自动刷新内存索引数据到磁盘的周期
opt.UseMemCache = false      // 是否使用内存来缓存数据

db, err := tsengine.NewDBEngine(opt)
if err != nil {
	fmt.Println(err)
	return
}

db.Start()

// 读写统计值:数据模型为key,timestamp,cnt,sum,max,min
for i := 0; i < 10; i++ {
	point := NewPoint("test", time.Now().UnixNano()/1e6+int64(i), int64(i), float64(i), float64(i), float64(i))
	err := db.PutStatics(point)
	if err != nil {
		fmt.Printf("Put error:%v \n", err)
	}
}

points, err := db.GetStatics("test", time.Now().UnixNano()/1e6, time.Now().UnixNano()/1e6+int64(10))
for _, point := range points {
	fmt.Println(point.ToString())
}

// 读写简单的时序数据,数据模型:key,timestamp,value
for i := 0; i < 10; i++ {
	err := db.Put("test", time.Now().UnixNano()/1e6+int64(i), float64(i))
	if err != nil {
		fmt.Printf("Put error:%v \n", err)
	}
}

points, err := db.Get("test", time.Now().UnixNano()/1e6, time.Now().UnixNano()/1e6+int64(10))
for _, point := range points {
	fmt.Println(point.ToString())
}

db.Stop()

底层LevelDB的一些配置选项

// 下面是底层LevelDB的配置参数

// 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

// 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

// 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

// 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

// 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

// 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