nutsdb

package module
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 Go to latest Published: Nov 25, 2025 License: Apache-2.0 Imports: 34 Imported by: 49

README

What is NutsDB?

English | 简体中文

NutsDB is a simple, fast, embeddable and persistent key/value store written in pure Go.

It supports fully serializable transactions and many data structures such as list、set、sorted set. All operations happen inside a Tx. Tx represents a transaction, which can be read-only or read-write. Read-only transactions can read values for a given bucket and a given key or iterate over a set of key-value pairs. Read-write transactions can read, update and delete keys from the DB.

We can learn more about NutsDB in details on the documents site of NutsDB: NutsDB Documents

Announcement

📢 Note: Starting from v0.9.0, defaultSegmentSize in DefaultOptions has been adjusted from 8MB to 256MB. The original value is the default value, which needs to be manually changed to 8MB, otherwise the original data will not be parsed. The reason for the size adjustment here is that there is a cache for file descriptors starting from v0.9.0 (detail see https://github.com/nutsdb/nutsdb/pull/164 ), so users need to look at the number of fds they use on the server, which can be set manually. If you have any questions, you can open an issue.

After nutsdb v1.0.0, due to changes in the underlying data storage protocol, the data of the old version is not compatible. Please rewrite it before using the new version. And the current Bucket needs to be created manually. Please see the Bucket usage documentation for details.

Architecture

nutsdb-架构图

Welcome contributions to NutsDB.

Quick start

Install NutsDB

To start using NutsDB, first needs Go installed (version 1.18+ is required). and run go get:

go get -u github.com/nutsdb/nutsdb

Opening a database

To open your database, use the nutsdb.Open() function,with the appropriate options.The Dir , EntryIdxMode and SegmentSize options are must be specified by the client. About options see here for detail.

package main

import (
    "log"

    "github.com/nutsdb/nutsdb"
)

func main() {
    // Open the database located in the /tmp/nutsdb directory.
    // It will be created if it doesn't exist.
    db, err := nutsdb.Open(
        nutsdb.DefaultOptions,
        nutsdb.WithDir("/tmp/nutsdb"),
    )
    if err != nil {
        log.Fatal(err)
    }
    defer db.Close()

    ...
}

Merge V2 and HintFile

Overview

NutsDB introduces Merge V2 and HintFile features to significantly improve database performance, especially for startup time and memory efficiency during large-scale compaction operations.

Merge V2

Merge V2 is a high-performance compaction algorithm that optimizes memory usage while maintaining data consistency. It's designed to handle large-scale data compaction efficiently.

Key Features
  • Memory Efficiency: Reduces memory usage by ~65% during merge operations (from ~145 bytes/entry to ~50 bytes/entry)
  • Concurrent Safety: Allows concurrent writes during merge operations
  • Atomic Operations: Ensures data consistency through atomic commit and rollback
  • Large-Scale Support: Optimized for handling 10GB+ datasets efficiently
How It Works
  1. Preparation Phase: Enumerates files and validates merge state
  2. Rewrite Phase: Processes data files and rewrites valid entries to new merge files
  3. Commit Phase: Updates in-memory indexes and writes hint files
  4. Finalization: Ensures all data is persisted and cleans up old files
File ID Strategy

Merge V2 uses negative FileIDs for merge files to ensure correct processing order:

  • Merge files: Negative IDs (starting from math.MinInt64)
  • Normal data files: Positive IDs (starting from 0)
  • Processing order: Merge files are always processed before normal files during index rebuild
Configuration
// Merge V2 is enabled by default and works automatically
// You can configure merge behavior through options

options := nutsdb.DefaultOptions
options.SegmentSize = 256 * 1024 * 1024 // 256MB segments

db, err := nutsdb.Open(options, nutsdb.WithDir("/tmp/nutsdb"))

HintFile

HintFile is an index persistence feature that dramatically reduces database startup time by maintaining persistent indexes of key metadata.

Key Features
  • Fast Startup: Eliminates full data file scans during database recovery
  • Automatic Fallback: Gracefully falls back to traditional scanning if hint files are missing or corrupted
  • Transparent Operation: Works seamlessly with existing data structures
  • Configurable: Can be enabled/disabled via configuration
How It Works
  1. During Merge: Hint files are automatically created alongside merge data files
  2. During Startup: Database loads hint files to reconstruct in-memory indexes instantly
  3. Fallback Mechanism: If hint files are unavailable, the system falls back to scanning data files
Hint File Structure

Each hint entry contains:

  • Bucket ID, Key metadata, Value size
  • Timestamp, TTL, and operation flags
  • File ID and data position for direct access
  • Key data for lookup operations
Configuration
// Basic configuration with both features enabled
options := nutsdb.DefaultOptions
options.EnableHintFile = true
options.EnableMergeV2 = true
options.SegmentSize = 256 * 1024 * 1024 // 256MB segments

// Or use option functions
db, err := nutsdb.Open(
    nutsdb.DefaultOptions,
    nutsdb.WithDir("/tmp/nutsdb"),
    nutsdb.WithEnableHintFile(true),
    nutsdb.WithEnableMergeV2(true),
)
Configuration Options
Option Type Default Description
EnableHintFile bool false Enable/disable hint file feature
EnableMergeV2 bool false Enable/disable Merge V2 algorithm
SegmentSize int64 256MB Size of data files before rotation

Performance Benefits

Memory Efficiency
  • Traditional Merge: ~145 bytes per entry
  • Merge V2: ~50 bytes per entry
  • Savings: ~65% memory reduction for large datasets
Startup Time
  • With HintFile: Index reconstruction in milliseconds
  • Without HintFile: Full data file scanning (seconds to minutes)
  • Fallback: Automatic degradation if hint files are unavailable
Benchmark Results

Performance testing with Intel Core i5-14600KF on large datasets:

Configuration Total Time Memory Usage Allocations Avg Restart Merge Time
Merge V1 + No HintFile 4.29s 2.32GB 40.4M 4.27s 12.86s
Merge V1 + HintFile 1.69s 1.56GB 25.4M 1.64s 16.37s
Merge V2 + HintFile 1.87s 1.56GB 25.4M 1.83s 8.63s
Key Performance Insights
  • HintFile Impact: 61.6% faster startup time (4.27s → 1.64s)
  • Memory Optimization: 32.9% reduction in memory allocation with HintFile
  • Merge V2 Efficiency: 47.3% faster merge operations (16.37s → 8.63s)
  • Overall Performance: Best balance with Merge V2 + HintFile combination
Use Cases
  • Large Datasets: Essential for databases with millions of entries
  • Frequent Restarts: Critical for applications requiring fast restarts
  • Memory-Constrained Environments: Reduces peak memory usage during maintenance
  • High Availability: Enables quick database recovery after failures

Best Practices

  1. Enable HintFile for production workloads with large datasets
  2. Monitor Disk Space - Hint files add additional storage overhead
  3. Regular Merges - Schedule merges during low-traffic periods
  4. Backup Strategy - Include hint files in your backup process

Migration Guide

Enabling HintFile in Existing Database
// Step 1: Backup your database
// Step 2: Enable HintFile and perform a merge to create hint files
options := nutsdb.DefaultOptions
options.EnableHintFile = true
options.EnableMergeV2 = true

db, err := nutsdb.Open(options)
if err != nil {
    log.Fatal(err)
}

// Step 3: Perform a merge to generate hint files
if err := db.Merge(); err != nil {
    log.Fatal(err)
}

// Step 4: Restart database - hint files will be used for fast startup
db.Close()
db, err = nutsdb.Open(options)
Disabling HintFile
// Simply set EnableHintFile to false
options := nutsdb.DefaultOptions
options.EnableHintFile = false
options.EnableMergeV2 = true // Keep Merge V2 if desired

// Hint files will be ignored but not automatically deleted
// You can manually delete .hint files if you want to reclaim space

Troubleshooting

Common Issues

  1. HintFile Corruption

    Symptom: Database startup fails or takes long time
Solution: NutsDB automatically falls back to scanning data files

  2. Merge V2 Memory Usage

    Symptom: High memory usage during merge operations
Solution: Reduce SegmentSize or disable HintFile temporarily

  3. Slow Startup with Large Dataset

    Symptom: Database takes minutes to start
Solution: Enable HintFile and perform a manual merge
Recovery Procedures
// Check database health
db, err := nutsdb.Open(options)
if err != nil {
    // Try disabling HintFile if corruption suspected
    options.EnableHintFile = false
    db, err = nutsdb.Open(options)
}

// Force rebuild hint files
if err := db.Merge(); err != nil {
    log.Printf("Merge failed: %v", err)
}

Compatibility

  • Backward Compatible: Works with existing NutsDB databases
  • Configurable: HintFile can be disabled if not needed
  • Data Structures: Supports all NutsDB data structures (BTree, Set, List, SortedSet)
  • Graceful Degradation: Automatic fallback when hint files are unavailable

Documentation

Buckets
Pairs
Iterator
Data Structures
Database Options
Advanced Features
Comparison
Benchmark

Contributors

Thank you for considering contributing to NutsDB! The contribution guide can be found in the CONTRIBUTING for details on submitting patches and the contribution workflow.

Acknowledgements

This package is inspired by the following:

License

The NutsDB is open-sourced software licensed under the Apache 2.0 license.

Documentation

Overview

Package nutsdb implements a simple, fast, embeddable and persistent key/value store written in pure Go. It supports fully serializable transactions. And it also supports data structure such as list、set、sorted set etc.

NutsDB currently works on Mac OS, Linux and Windows.

Usage

NutsDB has the following main types: DB, BPTree, Entry, DataFile And Tx. and NutsDB supports bucket, A bucket is a collection of unique keys that are associated with values.

All operations happen inside a Tx. Tx represents a transaction, which can be read-only or read-write. Read-only transactions can read values for a given key , or iterate over a set of key-value pairs (prefix scanning or range scanning). read-write transactions can also update and delete keys from the DB.

See the examples for more usage details.

Index

Constants

View Source 
const (
	IdSize = 8
	DsSize = 2
)
View Source 
const (
	MaxEntryHeaderSize = 4 + binary.MaxVarintLen32*3 + binary.MaxVarintLen64*3 + binary.MaxVarintLen16*3
	MinEntryHeaderSize = 4 + 9
)
View Source 
const (
	// UnCommitted represents the tx unCommitted status
	UnCommitted uint16 = 0

	// Committed represents the tx committed status
	Committed uint16 = 1
)
View Source 
const (
	// ListImplDoublyLinkedList uses doubly linked list implementation (default).
	// Advantages: O(1) head/tail operations, lower memory overhead
	// Best for: High-frequency LPush/RPush/LPop/RPop operations
	ListImplDoublyLinkedList = iota

	// ListImplBTree uses BTree implementation.
	// Advantages: O(log n + k) range queries, efficient random access
	// Best for: Frequent range queries or indexed access patterns
	ListImplBTree
)
View Source 
const (
	B  = fileio.B
	KB = fileio.KB
	MB = fileio.MB
	GB = fileio.GB
)
View Source 
const (
	// BucketStatusExistAlready means this bucket already exists
	BucketStatusExistAlready = 1
	// BucketStatusDeleted means this bucket is already deleted
	BucketStatusDeleted = 2
	// BucketStatusNew means this bucket is created in current Tx
	BucketStatusNew = 3
	// BucketStatusUpdated means this bucket is updated in current Tx
	BucketStatusUpdated = 4
	// BucketStatusUnknown means this bucket doesn't exist
	BucketStatusUnknown = 5
)
View Source 
const (
	// SkipListMaxLevel represents the skipList max level number.
	SkipListMaxLevel = 32

	// SkipListP represents the p parameter of the skipList.
	SkipListP = 0.25
)
View Source 
const (
	MessagePriorityHigh   = iota // the messages must be ensured to deliver to distributor
	MessagePriorityMedium = 1    // the messages may be dropped
)

message priority

View Source 
const BucketStoreFileName = "bucket.Meta"
View Source 
const (
	// DataSuffix returns the data suffix
	DataSuffix = ".dat"
)
View Source 
const (
	DefaultCallbackTimeout = 1 * time.Second
)
View Source 
const DefaultHintCollectorFlushEvery = 1024
View Source 
const (
	DefaultThrottleSize = 16
)
View Source 
const FLockName = "nutsdb-flock"
View Source 
const (
	// HintSuffix returns the hint file suffix
	HintSuffix = ".hint"
)
View Source 
const KvWriteChCapacity = 1000
View Source 
const MAX_SIZE = math.MaxUint32
View Source 
const MergeFileIDBase int64 = math.MinInt64
View Source 
const Persistent uint32 = data.Persistent

Persistent represents the data persistent flag

View Source 
const ScanNoLimit int = -1

ScanNoLimit represents the data scan no limit flag

View Source 
const SeparatorForListKey = "|"

SeparatorForListKey represents separator for listKey

View Source 
const SeparatorForZSetKey = "|"

SeparatorForZSetKey represents separator for zSet key.

Variables

View Source 
var (
	// ErrCrc is returned when crc is error
	ErrCrc = errors.New("crc error")

	// ErrCapacity is returned when capacity is error.
	ErrCapacity = errors.New("capacity error")

	ErrEntryZero = errors.New("entry is zero ")
)
View Source 
var (
	// ErrDBClosed is returned when db is closed.
	ErrDBClosed = errors.New("db is closed")

	// ErrBucket is returned when bucket is not in the HintIdx.
	ErrBucket = errors.New("err bucket")

	// ErrFn is returned when fn is nil.
	ErrFn = errors.New("err fn")

	// ErrBucketNotFound is returned when looking for bucket that does not exist
	ErrBucketNotFound = errors.New("bucket not found")

	// ErrDataStructureNotSupported is returned when pass a not supported data structure
	ErrDataStructureNotSupported = errors.New("this data structure is not supported for now")

	// ErrDirLocked is returned when can't get the file lock of dir
	ErrDirLocked = errors.New("the dir of db is locked")

	// ErrDirUnlocked is returned when the file lock already unlocked
	ErrDirUnlocked = errors.New("the dir of db is unlocked")

	// ErrIsMerging is returned when merge in progress
	ErrIsMerging = errors.New("merge in progress")

	// ErrNotSupportMergeWhenUsingList is returned calling 'Merge' when using list
	ErrNotSupportMergeWhenUsingList = errors.New("not support merge when using list for now")

	// ErrRecordIsNil is returned when Record is nil
	ErrRecordIsNil = errors.New("the record is nil")

	// ErrWatchFeatureDisabled is returned when the watch feature is disabled
	ErrWatchFeatureDisabled = errors.New("watch feature is disabled")

	// ErrWatchingCallbackTimeout is returned when the callback timeout
	ErrWatchingCallbackTimeout = errors.New("watching callback timeout")
)
View Source 
var (
	ErrPayLoadSizeMismatch   = errors.New("the payload size in Meta mismatch with the payload size needed")
	ErrHeaderSizeOutOfBounds = errors.New("the header size is out of bounds")
)
View Source 
var (
	// ErrHintFileCorrupted is returned when hint file is corrupted
	ErrHintFileCorrupted = errors.New("hint file is corrupted")
	// ErrHintFileEntryInvalid is returned when hint entry is invalid
	ErrHintFileEntryInvalid = errors.New("hint file entry is invalid")
)
View Source 
var (
	ErrSortedSetNotFound = errors.New("the sortedSet does not exist")

	ErrSortedSetMemberNotExist = errors.New("the member of sortedSet does not exist")

	ErrSortedSetIsEmpty = errors.New("the sortedSet if empty")
)
View Source 
var (
	// ErrDataSizeExceed is returned when given key and value size is too big.
	ErrDataSizeExceed = errors.New("data size too big")

	// ErrTxClosed is returned when committing or rolling back a transaction
	// that has already been committed or rolled back.
	ErrTxClosed = errors.New("tx is closed")

	// ErrTxNotWritable is returned when performing a write operation on
	// a read-only transaction.
	ErrTxNotWritable = errors.New("tx not writable")

	// ErrKeyEmpty is returned if an empty key is passed on an update function.
	ErrKeyEmpty = errors.New("key cannot be empty")

	// ErrBucketEmpty is returned if bucket is empty.
	ErrBucketEmpty = errors.New("bucket is empty")

	// ErrRangeScan is returned when range scanning not found the result
	ErrRangeScan = errors.New("range scans not found")

	// ErrPrefixScan is returned when prefix scanning not found the result
	ErrPrefixScan = errors.New("prefix scans not found")

	// ErrPrefixSearchScan is returned when prefix and search scanning not found the result
	ErrPrefixSearchScan = errors.New("prefix and search scans not found")

	// ErrNotFoundKey is returned when key not found int the bucket on an view function.
	ErrNotFoundKey = errors.New("key not found in the bucket")
	ErrKeyNotFound = ErrNotFoundKey

	// ErrCannotCommitAClosedTx is returned when the tx committing a closed tx
	ErrCannotCommitAClosedTx = errors.New("can not commit a closed tx")

	// ErrCannotRollbackACommittingTx is returned when the tx rollback a committing tx
	ErrCannotRollbackACommittingTx = errors.New("can not rollback a committing tx")

	ErrCannotRollbackAClosedTx = errors.New("can not rollback a closed tx")

	// ErrNotFoundBucket is returned when bucket not found int the bucket on an view function.
	ErrNotFoundBucket = errors.New("bucket not found")

	// ErrTxnTooBig is returned if too many writes are fit into a single transaction.
	ErrTxnTooBig = errors.New("txn is too big to fit into one request")

	// ErrTxnExceedWriteLimit is returned when this tx's write is exceed max write record
	ErrTxnExceedWriteLimit = errors.New("txn is exceed max write record count")

	ErrBucketAlreadyExist = errors.New("bucket is already exist")

	ErrValueNotInteger = errors.New("value is not an integer")

	ErrOffsetInvalid = errors.New("offset is invalid")

	ErrKVArgsLenNotEven = errors.New("parameters is used to represent key value pairs and cannot be odd numbers")

	ErrStartGreaterThanEnd = errors.New("start is greater than end")

	ErrInvalidKey = errors.New("invalid key")
)
View Source 
var (
	// ErrListNotFound is returned when the list not found.
	ErrListNotFound = data.ErrListNotFound

	// ErrCount is returned when count is error.
	ErrCount = data.ErrCount

	// ErrEmptyList is returned when the list is empty.
	ErrEmptyList = data.ErrEmptyList

	// ErrStartOrEnd is returned when start > end
	ErrStartOrEnd = data.ErrStartOrEnd

	// ErrSeparatorForListKey returns when list key contains the SeparatorForListKey.
	ErrSeparatorForListKey = errors.Errorf("contain separator (%s) for List key", SeparatorForListKey)
)
View Source 
var (
	// ErrSetNotExist is returned when the key does not exist.
	ErrSetNotExist = data.ErrSetNotExist

	// ErrSetMemberNotExist is returned when the member of set does not exist
	ErrSetMemberNotExist = data.ErrSetMemberNotExist

	// ErrMemberEmpty is returned when the item received is nil
	ErrMemberEmpty = data.ErrMemberEmpty
)
View Source 
var (
	ErrBucketSubscriberNotFound = errors.New("bucket subscriber not found")
	ErrKeySubscriberNotFound    = errors.New("key subscriber not found")
	ErrSubscriberNotFound       = errors.New("subscriber not found")
	ErrWatchChanCannotSend      = errors.New("watch channel cannot send")
	ErrKeyAlreadySubscribed     = errors.New("key already subscribed")
	ErrWatchManagerClosed       = errors.New("watch manager closed")
	ErrWatchingCallbackFailed   = errors.New("watching callback failed")
	ErrWatchingChannelClosed    = errors.New("watching channel closed")
	ErrChannelNotAvailable      = errors.New("channel not available")
)

errors

View Source 
var BucketMetaSize int64
View Source 
var DefaultOptions = func() Options {
	return Options{
		EntryIdxMode:              HintKeyValAndRAMIdxMode,
		SegmentSize:               defaultSegmentSize,
		NodeNum:                   1,
		RWMode:                    FileIO,
		SyncEnable:                true,
		CommitBufferSize:          4 * MB,
		MergeInterval:             2 * time.Hour,
		MaxBatchSize:              (15 * defaultSegmentSize / 4) / 100,
		MaxBatchCount:             (15 * defaultSegmentSize / 4) / 100 / 100,
		HintKeyAndRAMIdxCacheSize: 0,
		ExpiredDeleteType:         TimeWheel,
		EnableHintFile:            false,
		EnableMergeV2:             false,
		ListImpl:                  ListImplementationType(ListImplBTree),
		EnableWatch:               false,
	}
}()

DefaultOptions represents the default options.

View Source 
var ErrBucketCrcInvalid = errors.New("bucket crc invalid")
View Source 
var ErrBucketNotExist = errors.New("bucket not found")
View Source 
var ErrCommitAfterFinish = errors.New("batch commit not permitted after finish")

ErrCommitAfterFinish indicates that write batch commit was called after

View Source 
var ErrDontNeedMerge = errors.New("the number of files waiting to be merged is less than 2")
View Source 
var (
	ErrIndexOutOfBound = fileio.ErrIndexOutOfBound
)

Functions

func ErrBucketAndKey 

func ErrBucketAndKey(bucket string, key []byte) error

ErrBucketAndKey returns when bucket or key not found.

func ErrNotFoundKeyInBucket 

func ErrNotFoundKeyInBucket(bucket string, key []byte) error

ErrNotFoundKeyInBucket returns when key not in the bucket.

func ErrSeparatorForZSetKey 

func ErrSeparatorForZSetKey() error

ErrSeparatorForZSetKey returns when zSet key contains the SeparatorForZSetKey flag.

func GetMergeFileID added in v1.1.0 

func GetMergeFileID(seq int) int64

func GetMergeSeq added in v1.1.0 

func GetMergeSeq(fileID int64) int

func IsBucketEmpty 

func IsBucketEmpty(err error) bool

IsBucketEmpty is true if the bucket is empty.

func IsBucketNotFound 

func IsBucketNotFound(err error) bool

IsBucketNotFound is true if the error indicates the bucket is not exists.

func IsDBClosed 

func IsDBClosed(err error) bool

IsDBClosed is true if the error indicates the db was closed.

func IsKeyEmpty 

func IsKeyEmpty(err error) bool

IsKeyEmpty is true if the key is empty.

func IsKeyNotFound 

func IsKeyNotFound(err error) bool

IsKeyNotFound is true if the error indicates the key is not found.

func IsMergeFile added in v1.1.0 

func IsMergeFile(fileID int64) bool

func IsPrefixScan 

func IsPrefixScan(err error) bool

IsPrefixScan is true if prefix scanning not found the result.

func IsPrefixSearchScan 

func IsPrefixSearchScan(err error) bool

IsPrefixSearchScan is true if prefix and search scanning not found the result.

func NewWatchManager added in v1.1.0 

func NewWatchManager() *watchManager

Types

type BTreeIdx added in v0.13.1 

type BTreeIdx struct {
	// contains filtered or unexported fields
}

type Bucket added in v1.0.0 

type Bucket struct {
	// Meta: the metadata for this bucket
	Meta *BucketMeta
	// Id: is the marker for this bucket, every bucket creation activity will generate a new Id for it.
	// for example. If you have a bucket called "bucket_1", and you just delete bucket and create it again.
	// the last bucket will have a different Id from the previous one.
	Id BucketId
	// Ds: the data structure for this bucket. (List, Set, SortSet, String)
	Ds Ds
	// Name: the name of this bucket.
	Name string
}

Bucket is the disk structure of bucket

func (*Bucket) Decode added in v1.0.0 

func (b *Bucket) Decode(bytes []byte) error

Decode : Meta | BucketId | Ds | BucketName

func (*Bucket) Encode added in v1.0.0 

func (b *Bucket) Encode() []byte

Encode : Meta | BucketId | Ds | BucketName

func (*Bucket) GetCRC added in v1.0.0 

func (b *Bucket) GetCRC(headerBuf []byte, dataBuf []byte) uint32

func (*Bucket) GetEntrySize added in v1.0.0 

func (b *Bucket) GetEntrySize() int

func (*Bucket) GetPayloadSize added in v1.0.0 

func (b *Bucket) GetPayloadSize() int

type BucketId added in v1.0.0 

type BucketId = uint64

type BucketManager added in v1.0.0 

type BucketManager struct {

	// BucketInfoMapper BucketID => Bucket itself
	BucketInfoMapper InfoMapperInBucket

	BucketIDMarker IDMarkerInBucket

	// IDGenerator helps generates an ID for every single bucket
	Gen *IDGenerator
	// contains filtered or unexported fields
}

func NewBucketManager added in v1.0.0 

func NewBucketManager(dir string) (*BucketManager, error)

func (*BucketManager) ExistBucket added in v1.0.0 

func (bm *BucketManager) ExistBucket(ds Ds, name BucketName) bool

func (*BucketManager) GetBucket added in v1.0.0 

func (bm *BucketManager) GetBucket(ds Ds, name BucketName) (b *Bucket, err error)

func (*BucketManager) GetBucketById added in v1.0.0 

func (bm *BucketManager) GetBucketById(id BucketId) (*Bucket, error)

func (*BucketManager) GetBucketID added in v1.0.0 

func (bm *BucketManager) GetBucketID(ds Ds, name BucketName) (BucketId, error)

func (*BucketManager) SubmitPendingBucketChange added in v1.0.0 

func (bm *BucketManager) SubmitPendingBucketChange(reqs []*bucketSubmitRequest) error

type BucketMeta 

type BucketMeta struct {
	Crc uint32
	// Op: Mark the latest operation (e.g. delete, insert, update) for this bucket.
	Op BucketOperation
	// Size: the size of payload.
	Size uint32
}

BucketMeta stores the Meta info of a Bucket. E.g. the size of bucket it store in disk.

func (*BucketMeta) Decode added in v1.0.0 

func (meta *BucketMeta) Decode(bytes []byte)

Decode : CRC | op | size

type BucketName added in v1.0.0 

type BucketName = string

type BucketOperation added in v1.0.0 

type BucketOperation uint16
const (
	BucketInsertOperation BucketOperation = 1
	BucketUpdateOperation BucketOperation = 2
	BucketDeleteOperation BucketOperation = 3
)

type BucketStatus added in v1.0.2 

type BucketStatus = uint8

BucketStatus represents the current status of bucket in current Tx

type CEntries added in v0.13.0 

type CEntries struct {
	Entries
	LessFunc func(l, r string) bool
}

func (CEntries) Len added in v0.13.0 

func (c CEntries) Len() int

func (CEntries) Less added in v0.13.0 

func (c CEntries) Less(i, j int) bool

func (CEntries) Swap added in v0.13.0 

func (c CEntries) Swap(i, j int)

type DB 

type DB struct {
	Index      *index
	ActiveFile *DataFile
	MaxFileID  int64

	KeyCount int // total key number ,include expired, deleted, repeated.

	RecordCount int64 // current valid record count, exclude deleted, repeated
	// contains filtered or unexported fields
}

DB represents a collection of buckets that persist on disk.

func Open 

func Open(options Options, ops ...Option) (*DB, error)

Open returns a newly initialized DB object with Option.

func (*DB) Backup 

func (db *DB) Backup(dir string) error

Backup copies the database to file directory at the given dir.

func (*DB) BackupTarGZ 

func (db *DB) BackupTarGZ(w io.Writer) error

BackupTarGZ Backup copy the database to writer.

func (*DB) Begin 

func (db *DB) Begin(writable bool) (tx *Tx, err error)

Begin opens a new transaction. Multiple read-only transactions can be opened at the same time but there can only be one read/write transaction at a time. Attempting to open a read/write transactions while another one is in progress will result in blocking until the current read/write transaction is completed. All transactions must be closed by calling Commit() or Rollback() when done.

func (*DB) Close 

func (db *DB) Close() error

Close releases all db resources.

func (*DB) IsClose added in v0.12.1 

func (db *DB) IsClose() bool

IsClose return the value that represents the status of DB

func (*DB) Merge 

func (db *DB) Merge() error

func (*DB) NewWriteBatch added in v0.13.1 

func (db *DB) NewWriteBatch() (*WriteBatch, error)

func (*DB) Update 

func (db *DB) Update(fn func(tx *Tx) error) error

Update executes a function within a managed read/write transaction.

func (*DB) View 

func (db *DB) View(fn func(tx *Tx) error) error

View executes a function within a managed read-only transaction.

func (*DB) Watch added in v1.1.0 

func (db *DB) Watch(bucket string, key []byte, cb func(message *Message) error, opts ...WatchOptions) error

*

  • Watch watches the key and bucket and calls the callback function for each message received.
  • The callback will be called once for each individual message in the batch. *
  • @param bucket - the bucket name to watch
  • @param key - the key in the bucket to watch
  • @param cb - the callback function to call for each message received
  • @param opts - the options for the watch
  • - CallbackTimeout - the timeout for the callback, default is 1 second *
  • @return error - the error if the watch is stopped

type DataFile 

type DataFile struct {
	ActualSize int64
	// contains filtered or unexported fields
}

DataFile records about data file information.

func NewDataFile 

func NewDataFile(path string, rwManager fileio.RWManager) *DataFile

NewDataFile will return a new DataFile Object.

func (*DataFile) Close 

func (df *DataFile) Close() (err error)

Close closes the RWManager. If RWManager is FileRWManager represents closes the File, rendering it unusable for I/O. If RWManager is a MMapRWManager represents Unmap deletes the memory mapped region, flushes any remaining changes.

func (*DataFile) ReadEntry added in v1.0.0 

func (df *DataFile) ReadEntry(off int, payloadSize int64) (e *Entry, err error)

ReadEntry returns entry at the given off(offset). payloadSize = bucketSize + keySize + valueSize

func (*DataFile) Release 

func (df *DataFile) Release() (err error)

func (*DataFile) Sync 

func (df *DataFile) Sync() (err error)

Sync commits the current contents of the file to stable storage. Typically, this means flushing the file system's in-memory copy of recently written data to disk.

func (*DataFile) WriteAt 

func (df *DataFile) WriteAt(b []byte, off int64) (n int, err error)

WriteAt copies data to mapped region from the b slice starting at given off and returns number of bytes copied to the mapped region.

type DataFlag added in v1.0.2 

type DataFlag = uint16

DataFlag means the data operations have done by users. 

const (
	// DataDeleteFlag represents the data delete flag
	DataDeleteFlag DataFlag = 0

	// DataSetFlag represents the data set flag
	DataSetFlag DataFlag = 1

	// DataLPushFlag represents the data LPush flag
	DataLPushFlag DataFlag = 2

	// DataRPushFlag represents the data RPush flag
	DataRPushFlag DataFlag = 3

	// DataLRemFlag represents the data LRem flag
	DataLRemFlag DataFlag = 4

	// DataLPopFlag represents the data LPop flag
	DataLPopFlag DataFlag = 5

	// DataRPopFlag represents the data RPop flag
	DataRPopFlag DataFlag = 6

	// DataLTrimFlag represents the data LTrim flag
	DataLTrimFlag DataFlag = 8

	// DataZAddFlag represents the data ZAdd flag
	DataZAddFlag DataFlag = 9

	// DataZRemFlag represents the data ZRem flag
	DataZRemFlag DataFlag = 10

	// DataZRemRangeByRankFlag represents the data ZRemRangeByRank flag
	DataZRemRangeByRankFlag DataFlag = 11

	// DataZPopMaxFlag represents the data ZPopMax flag
	DataZPopMaxFlag DataFlag = 12

	// DataZPopMinFlag represents the data aZPopMin flag
	DataZPopMinFlag DataFlag = 13

	// DataSetBucketDeleteFlag represents the delete Set bucket flag
	DataSetBucketDeleteFlag DataFlag = 14

	// DataSortedSetBucketDeleteFlag represents the delete Sorted Set bucket flag
	DataSortedSetBucketDeleteFlag DataFlag = 15

	// DataBTreeBucketDeleteFlag represents the delete BTree bucket flag
	DataBTreeBucketDeleteFlag DataFlag = 16

	// DataListBucketDeleteFlag represents the delete List bucket flag
	DataListBucketDeleteFlag DataFlag = 17

	// DataLRemByIndex represents the data LRemByIndex flag
	DataLRemByIndex DataFlag = 18

	// DataExpireListFlag represents that set ttl for the list
	DataExpireListFlag DataFlag = 19

	// DataBucketDeleteFlag represents the delete bucket flag
	// This is used for watch manager to delete the bucket when the bucket is deleted.
	DataBucketDeleteFlag DataFlag = 20
)

type DataStatus added in v1.0.2 

type DataStatus = uint16

DataStatus means the status of data

type DataStructure added in v1.0.2 

type DataStructure = uint16

DataStructure represents the data structure we have already supported 

const (
	// DataStructureSet represents the data structure set flag
	DataStructureSet DataStructure = 0

	// DataStructureSortedSet represents the data structure sorted set flag
	DataStructureSortedSet DataStructure = 1

	// DataStructureBTree represents the data structure b tree flag
	DataStructureBTree DataStructure = 2

	// DataStructureList represents the data structure list flag
	DataStructureList DataStructure = 3
)

type Ds added in v1.0.0 

type Ds = uint16

type Entries 

type Entries []*Entry

Entries represents entries

func (Entries) Len added in v0.13.0 

func (e Entries) Len() int

func (Entries) Less added in v0.13.0 

func (e Entries) Less(i, j int) bool

func (Entries) Swap added in v0.13.0 

func (e Entries) Swap(i, j int)

func (Entries) ToCEntries added in v0.13.0 

func (e Entries) ToCEntries(lFunc func(l, r string) bool) CEntries

type Entry 

type Entry struct {
	Key   []byte
	Value []byte
	Meta  *MetaData
}

Entry represents the data item.

func NewEntry added in v0.12.4 

func NewEntry() *Entry

NewEntry new Entry Object

func (*Entry) Encode 

func (e *Entry) Encode() []byte

Encode returns the slice after the entry be encoded. 

the entry stored format:
|----------------------------------------------------------------------------------------------------------|
|  crc  | timestamp | ksz | valueSize | flag  | TTL  | status | ds   | txId |  bucketId |  key  | value    |
|----------------------------------------------------------------------------------------------------------|
| uint32| uint64  |uint32 |  uint32 | uint16  | uint32| uint16 | uint16 |uint64 | uint64 | []byte | []byte |
|----------------------------------------------------------------------------------------------------------|

func (*Entry) GetCrc 

func (e *Entry) GetCrc(buf []byte) uint32

GetCrc returns the crc at given buf slice.

func (*Entry) GetTxIDBytes added in v0.12.4 

func (e *Entry) GetTxIDBytes() []byte

GetTxIDBytes return the bytes of TxID

func (*Entry) IsBelongsToBPlusTree added in v1.0.2 

func (e *Entry) IsBelongsToBPlusTree() bool

IsBelongsToBPlusTree is kept for backward compatibility with legacy naming. Internally nutsdb uses a B+ tree implementation for primary indexes, so both helpers map to the same metadata flag.

func (*Entry) IsBelongsToBTree added in v1.1.0 

func (e *Entry) IsBelongsToBTree() bool

func (*Entry) IsBelongsToList added in v1.0.2 

func (e *Entry) IsBelongsToList() bool

func (*Entry) IsBelongsToSet added in v1.0.2 

func (e *Entry) IsBelongsToSet() bool

func (*Entry) IsBelongsToSortSet added in v1.0.2 

func (e *Entry) IsBelongsToSortSet() bool

func (*Entry) IsZero 

func (e *Entry) IsZero() bool

IsZero checks if the entry is zero or not.

func (*Entry) ParseMeta 

func (e *Entry) ParseMeta(buf []byte) (int64, error)

ParseMeta parse Meta object to entry

func (*Entry) ParsePayload 

func (e *Entry) ParsePayload(data []byte) error

ParsePayload means this function will parse a byte array to bucket, key, size of an entry

func (*Entry) Size 

func (e *Entry) Size() int64

Size returns the size of the entry.

func (*Entry) WithKey added in v0.12.4 

func (e *Entry) WithKey(key []byte) *Entry

WithKey set key to Entry

func (*Entry) WithMeta added in v0.12.4 

func (e *Entry) WithMeta(meta *MetaData) *Entry

WithMeta set Meta to Entry

func (*Entry) WithValue added in v0.12.4 

func (e *Entry) WithValue(value []byte) *Entry

WithValue set value to Entry

type EntryIdxMode 

type EntryIdxMode int

EntryIdxMode represents entry index mode. 

const (
	// HintKeyValAndRAMIdxMode represents ram index (key and value) mode.
	HintKeyValAndRAMIdxMode EntryIdxMode = iota

	// HintKeyAndRAMIdxMode represents ram index (only key) mode.
	HintKeyAndRAMIdxMode
)

type EntryStatus added in v1.0.3 

type EntryStatus = uint8

EntryStatus represents the Entry status in the current Tx 

const (
	// NotFoundEntry means there is no changes for this entry in current Tx
	NotFoundEntry EntryStatus = 0
	// EntryDeleted means this Entry has been deleted in the current Tx
	EntryDeleted EntryStatus = 1
	// EntryUpdated means this Entry has been updated in the current Tx
	EntryUpdated EntryStatus = 2
)

type EntryWhenRecovery added in v0.14.0 

type EntryWhenRecovery struct {
	Entry
	// contains filtered or unexported fields
}

type ErrorHandler added in v0.13.0 

type ErrorHandler interface {
	HandleError(err error)
}

An ErrorHandler handles an error occurred during transaction.

type ErrorHandlerFunc added in v0.13.0 

type ErrorHandlerFunc func(err error)

The ErrorHandlerFunc type is an adapter to ErrorHandler.

func (ErrorHandlerFunc) HandleError added in v0.13.0 

func (fn ErrorHandlerFunc) HandleError(err error)

type ExpiredDeleteType added in v0.14.0 

type ExpiredDeleteType uint8
const (
	// TimeWheel represents use time wheel to do expired deletion
	TimeWheel ExpiredDeleteType = iota

	// TimeHeap represents use time heap to do expired deletion
	TimeHeap
)

type FileManager added in v1.1.0 

type FileManager struct {
	// contains filtered or unexported fields
}

FileManager holds the fd cache and file-related operations go through the manager to obtain the file processing object

func NewFileManager added in v1.1.0 

func NewFileManager(rwMode RWMode, maxFdNums int, cleanThreshold float64, segmentSize int64) (fm *FileManager)

NewFileManager will create a NewFileManager object

func (*FileManager) Close added in v1.1.0 

func (fm *FileManager) Close() error

Close will Close fdm resource

func (*FileManager) GetDataFile added in v1.1.0 

func (fm *FileManager) GetDataFile(path string, capacity int64) (datafile *DataFile, err error)

GetDataFile will return a DataFile Object

func (*FileManager) GetDataFileByID added in v1.1.0 

func (fm *FileManager) GetDataFileByID(dir string, fileID int64, capacity int64) (*DataFile, error)

func (*FileManager) GetDataFileReadOnly added in v1.1.0 

func (fm *FileManager) GetDataFileReadOnly(path string, capacity int64) (datafile *DataFile, err error)

GetDataFileReadOnly will return a DataFile Object for read-only operations This method skips file truncation to improve read performance

func (*FileManager) GetFileRWManager added in v1.1.0 

func (fm *FileManager) GetFileRWManager(path string, capacity int64, segmentSize int64, readOnly bool) (*fileio.FileIORWManager, error)

GetFileRWManager will return a FileIORWManager Object

func (*FileManager) GetMMapRWManager added in v1.1.0 

func (fm *FileManager) GetMMapRWManager(path string, capacity int64, segmentSize int64, readOnly bool) (*fileio.MMapRWManager, error)

GetMMapRWManager will return a MMapRWManager Object

type GetByScoreRangeOptions added in v0.14.0 

type GetByScoreRangeOptions struct {
	Limit        int  // limit the max nodes to return
	ExcludeStart bool // exclude start value, so it search in interval (start, end] or (start, end)
	ExcludeEnd   bool // exclude end value, so it search in interval [start, end) or (start, end)
}

GetByScoreRangeOptions represents the options of the GetByScoreRange function.

type HintCollector added in v1.1.0 

type HintCollector struct {
	// contains filtered or unexported fields
}

func NewHintCollector added in v1.1.0 

func NewHintCollector(fileID int64, writer hintWriter, flushEvery int) *HintCollector

func (*HintCollector) Add added in v1.1.0 

func (hc *HintCollector) Add(entry *HintEntry) error

func (*HintCollector) Close added in v1.1.0 

func (hc *HintCollector) Close() error

func (*HintCollector) Flush added in v1.1.0 

func (hc *HintCollector) Flush() error

func (*HintCollector) Sync added in v1.1.0 

func (hc *HintCollector) Sync() error

type HintEntry added in v1.1.0 

type HintEntry struct {
	BucketId  uint64
	KeySize   uint32
	ValueSize uint32
	Timestamp uint64
	TTL       uint32
	Flag      uint16
	Status    uint16
	Ds        uint16
	DataPos   uint64
	FileID    int64
	Key       []byte
}

HintEntry represents an entry in the hint file

func (*HintEntry) Decode added in v1.1.0 

func (h *HintEntry) Decode(buf []byte) error

Decode decodes the hint entry from bytes

func (*HintEntry) Encode added in v1.1.0 

func (h *HintEntry) Encode() []byte

Encode encodes the hint entry to bytes

func (*HintEntry) Size added in v1.1.0 

func (h *HintEntry) Size() int64

Size returns the size of the hint entry

type HintFileReader added in v1.1.0 

type HintFileReader struct {
	// contains filtered or unexported fields
}

HintFileReader is used to read hint files

func (*HintFileReader) Close added in v1.1.0 

func (r *HintFileReader) Close() error

Close closes the hint file

func (*HintFileReader) Open added in v1.1.0 

func (r *HintFileReader) Open(path string) error

Open opens a hint file for reading

func (*HintFileReader) Read added in v1.1.0 

func (r *HintFileReader) Read() (*HintEntry, error)

Read reads a hint entry from the file

type HintFileWriter added in v1.1.0 

type HintFileWriter struct {
	// contains filtered or unexported fields
}

HintFileWriter is used to write hint files

func (*HintFileWriter) Close added in v1.1.0 

func (w *HintFileWriter) Close() error

Close closes the hint file

func (*HintFileWriter) Create added in v1.1.0 

func (w *HintFileWriter) Create(path string) error

Create creates a hint file for writing

func (*HintFileWriter) Sync added in v1.1.0 

func (w *HintFileWriter) Sync() error

Sync flushes the buffer and syncs the file to disk

func (*HintFileWriter) Write added in v1.1.0 

func (w *HintFileWriter) Write(entry *HintEntry) error

Write writes a hint entry to the file

type IDGenerator added in v1.0.0 

type IDGenerator struct {
	// contains filtered or unexported fields
}

func (*IDGenerator) CompareAndSetMaxId added in v1.1.0 

func (g *IDGenerator) CompareAndSetMaxId(id uint64)

func (*IDGenerator) GenId added in v1.0.0 

func (g *IDGenerator) GenId() uint64

type IDMarkerInBucket added in v1.0.2 

type IDMarkerInBucket map[BucketName]map[Ds]BucketId

type IdxType added in v0.14.1 

type IdxType interface {
	data.BTree | data.Set | SortedSet | data.List
}

type InfoMapperInBucket added in v1.0.2 

type InfoMapperInBucket map[BucketId]*Bucket

type Iterator 

type Iterator struct {
	// contains filtered or unexported fields
}

func NewIterator 

func NewIterator(tx *Tx, bucket string, options IteratorOptions) *Iterator

Returns a new iterator. The Release method must be called when finished with the iterator.

func (*Iterator) Item added in v1.1.0 

func (it *Iterator) Item() *data.Item[data.Record]

Item returns the current item (key + record) if valid This is useful for advanced use cases that need direct access to the record

func (*Iterator) Key added in v0.13.1 

func (it *Iterator) Key() []byte

func (*Iterator) Next added in v0.13.1 

func (it *Iterator) Next() bool

func (*Iterator) Release added in v1.1.0 

func (it *Iterator) Release()

func (*Iterator) Rewind added in v0.13.1 

func (it *Iterator) Rewind() bool

func (*Iterator) Seek 

func (it *Iterator) Seek(key []byte) bool

func (*Iterator) Valid added in v0.13.1 

func (it *Iterator) Valid() bool

func (*Iterator) Value added in v0.13.1 

func (it *Iterator) Value() ([]byte, error)

type IteratorOptions 

type IteratorOptions struct {
	Reverse bool
}

type LessFunc added in v0.13.0 

type LessFunc func(l, r string) bool

type ListIdx 

type ListIdx struct {
	// contains filtered or unexported fields
}

type ListImplementationType added in v1.1.0 

type ListImplementationType data.ListImplementationType

ListImplementationType defines the implementation type for List data structure.

type Message added in v1.1.0 

type Message struct {
	BucketName BucketName
	Key        string
	Value      []byte
	Flag       DataFlag
	Timestamp  uint64
	// contains filtered or unexported fields
}

func NewMessage added in v1.1.0 

func NewMessage(bucketName BucketName, key string, value []byte, flag DataFlag, timestamp uint64, options ...MessageOptions) *Message

type MessageOptions added in v1.1.0 

type MessageOptions struct {
	Priority MessagePriority
}

type MessagePriority added in v1.1.0 

type MessagePriority int

type MetaData 

type MetaData struct {
	KeySize    uint32
	ValueSize  uint32
	Timestamp  uint64
	TTL        uint32
	Flag       DataFlag // delete / set
	BucketSize uint32
	TxID       uint64
	Status     DataStatus    // committed / uncommitted
	Ds         DataStructure // data structure
	Crc        uint32
	BucketId   BucketId
}

func NewMetaData added in v0.12.6 

func NewMetaData() *MetaData

func (*MetaData) IsBTree added in v1.1.0 

func (meta *MetaData) IsBTree() bool

func (*MetaData) IsList added in v1.0.2 

func (meta *MetaData) IsList() bool

func (*MetaData) IsSet added in v1.0.2 

func (meta *MetaData) IsSet() bool

func (*MetaData) IsSortSet added in v1.0.2 

func (meta *MetaData) IsSortSet() bool

func (*MetaData) PayloadSize 

func (meta *MetaData) PayloadSize() int64

func (*MetaData) Size added in v1.0.0 

func (meta *MetaData) Size() int64

func (*MetaData) WithBucketId added in v1.0.0 

func (meta *MetaData) WithBucketId(bucketID uint64) *MetaData

func (*MetaData) WithBucketSize added in v0.12.6 

func (meta *MetaData) WithBucketSize(bucketSize uint32) *MetaData

func (*MetaData) WithCrc added in v0.12.6 

func (meta *MetaData) WithCrc(crc uint32) *MetaData

func (*MetaData) WithDs added in v0.12.6 

func (meta *MetaData) WithDs(ds uint16) *MetaData

func (*MetaData) WithFlag added in v0.12.6 

func (meta *MetaData) WithFlag(flag uint16) *MetaData

func (*MetaData) WithKeySize added in v0.12.6 

func (meta *MetaData) WithKeySize(keySize uint32) *MetaData

func (*MetaData) WithStatus added in v0.12.6 

func (meta *MetaData) WithStatus(status uint16) *MetaData

func (*MetaData) WithTTL added in v0.12.6 

func (meta *MetaData) WithTTL(ttl uint32) *MetaData

func (*MetaData) WithTimeStamp added in v0.12.6 

func (meta *MetaData) WithTimeStamp(timestamp uint64) *MetaData

func (*MetaData) WithTxID added in v0.12.6 

func (meta *MetaData) WithTxID(txID uint64) *MetaData

func (*MetaData) WithValueSize added in v0.12.6 

func (meta *MetaData) WithValueSize(valueSize uint32) *MetaData

type Option 

type Option func(*Options)

func WithBufferSizeOfRecovery 

func WithBufferSizeOfRecovery(size int) Option

func WithCleanFdsCacheThreshold 

func WithCleanFdsCacheThreshold(threshold float64) Option

func WithCommitBufferSize added in v0.13.0 

func WithCommitBufferSize(commitBufferSize int64) Option

func WithDir 

func WithDir(dir string) Option

func WithEnableHintFile added in v1.1.0 

func WithEnableHintFile(enable bool) Option

func WithEnableMergeV2 added in v1.1.0 

func WithEnableMergeV2(enable bool) Option

func WithEntryIdxMode 

func WithEntryIdxMode(entryIdxMode EntryIdxMode) Option

func WithErrorHandler added in v0.13.0 

func WithErrorHandler(errorHandler ErrorHandler) Option

func WithGCWhenClose added in v0.12.4 

func WithGCWhenClose(enable bool) Option

func WithHintKeyAndRAMIdxCacheSize added in v1.0.0 

func WithHintKeyAndRAMIdxCacheSize(size int) Option

func WithLessFunc added in v0.13.0 

func WithLessFunc(lessFunc LessFunc) Option

func WithListImpl added in v1.1.0 

func WithListImpl(implType ListImplementationType) Option

func WithMaxBatchCount added in v0.13.1 

func WithMaxBatchCount(count int64) Option

func WithMaxBatchSize added in v0.13.1 

func WithMaxBatchSize(size int64) Option

func WithMaxFdNumsInCache 

func WithMaxFdNumsInCache(num int) Option

func WithMaxWriteRecordCount added in v0.14.1 

func WithMaxWriteRecordCount(maxWriteRecordCount int64) Option

func WithNodeNum 

func WithNodeNum(num int64) Option

func WithRWMode 

func WithRWMode(rwMode RWMode) Option

func WithSegmentSize 

func WithSegmentSize(size int64) Option

func WithSyncEnable 

func WithSyncEnable(enable bool) Option

type Options 

type Options struct {
	// Dir represents Open the database located in which dir.
	Dir string

	// EntryIdxMode represents using which mode to index the entries.
	EntryIdxMode EntryIdxMode

	// RWMode represents the read and write mode.
	// RWMode includes two options: FileIO and MMap.
	// FileIO represents the read and write mode using standard I/O.
	// MMap represents the read and write mode using mmap.
	RWMode      RWMode
	SegmentSize int64

	// NodeNum represents the node number.
	// Default NodeNum is 1. NodeNum range [1,1023].
	NodeNum int64

	// SyncEnable represents if call Sync() function.
	// if SyncEnable is false, high write performance but potential data loss likely.
	// if SyncEnable is true, slower but persistent.
	SyncEnable bool

	// MaxFdNumsInCache represents the max numbers of fd in cache.
	MaxFdNumsInCache int

	// CleanFdsCacheThreshold represents the maximum threshold for recycling fd, it should be between 0 and 1.
	CleanFdsCacheThreshold float64

	// BufferSizeOfRecovery represents the buffer size of recoveryReader buffer Size
	BufferSizeOfRecovery int

	// GcWhenClose represent initiative GC when calling db.Close()
	GCWhenClose bool

	// CommitBufferSize represent allocated memory for tx
	CommitBufferSize int64

	// ErrorHandler handles an error occurred during transaction.
	// Example:
	//     func triggerAlertError(err error) {
	//     	   if errors.Is(err, targetErr) {
	//         		alertManager.TriggerAlert()
	//     	   }
	//     })
	ErrorHandler ErrorHandler

	// LessFunc is a function that sorts keys.
	LessFunc LessFunc

	// MergeInterval represent the interval for automatic merges, with 0 meaning automatic merging is disabled.
	MergeInterval time.Duration

	// MaxBatchCount represents max entries in batch
	MaxBatchCount int64

	// MaxBatchSize represents max batch size in bytes
	MaxBatchSize int64

	// ExpiredDeleteType represents the data structure used for expired deletion
	// TimeWheel means use the time wheel, You can use it when you need high performance or low memory usage
	// TimeHeap means use the time heap, You can use it when you need to delete precisely or memory usage will be high
	ExpiredDeleteType ExpiredDeleteType

	// max write record num
	MaxWriteRecordCount int64

	// cache size for HintKeyAndRAMIdxMode
	HintKeyAndRAMIdxCacheSize int

	// EnableHintFile represents if enable hint file feature.
	// If EnableHintFile is true, hint files will be created and used for faster database startup.
	// If EnableHintFile is false, hint files will not be created or used.
	EnableHintFile bool

	// EnableMergeV2 toggles the redesigned merge pipeline with deterministic merge files and manifest support.
	// When disabled, NutsDB falls back to the legacy merge logic.
	EnableMergeV2 bool

	// ListImpl specifies the implementation type for List data structure.
	// Default: ListImplDoublyLinkedList (maintains backward compatibility)
	ListImpl ListImplementationType

	// EnableWatch toggles the watch feature.
	// If EnableWatch is true, the watch feature will be enabled. The watch feature will be disabled by default.
	EnableWatch bool
}

Options records params for creating DB object.

type RWMode 

type RWMode int

RWMode represents the read and write mode. 

const (
	// FileIO represents the read and write mode using standard I/O.
	FileIO RWMode = iota

	// MMap represents the read and write mode using mmap.
	MMap
)

type SCORE added in v0.14.0 

type SCORE float64

SCORE represents the score type.

type SetIdx 

type SetIdx struct {
	// contains filtered or unexported fields
}

type SkipList added in v0.14.0 

type SkipList struct {
	// contains filtered or unexported fields
}

The SkipList represents the sorted set.

func (*SkipList) FindRank added in v0.14.0 

func (sl *SkipList) FindRank(hash uint32) int

FindRank Returns the rank of member in the sorted set stored at key, with the scores ordered from low to high. Note that the rank is 1-based integer. Rank 1 means the first node If the node is not found, 0 is returned. Otherwise rank(> 0) is returned.

Time complexity of this method is : O(log(N)).

func (*SkipList) FindRevRank added in v0.14.0 

func (sl *SkipList) FindRevRank(hash uint32) int

FindRevRank Returns the rank of member in the sorted set stored at key, with the scores ordered from high to low.

func (*SkipList) GetByRank added in v0.14.0 

func (sl *SkipList) GetByRank(rank int, remove bool) *SkipListNode

GetByRank returns the node at given rank. Note that the rank is 1-based integer. Rank 1 means the first node; Rank -1 means the last node. If remove is true, the returned nodes are removed If node is not found at specific rank, nil is returned.

Time complexity of this method is : O(log(N)).

func (*SkipList) GetByRankRange added in v0.14.0 

func (sl *SkipList) GetByRankRange(start, end int, remove bool) []*SkipListNode

GetByRankRange returns nodes within specific rank range [start, end]. Note that the rank is 1-based integer. Rank 1 means the first node; Rank -1 means the last node If start is greater than end, the returned array is in reserved order If remove is true, the returned nodes are removed.

Time complexity of this method is : O(log(N)).

func (*SkipList) GetByScoreRange added in v0.14.0 

func (sl *SkipList) GetByScoreRange(start SCORE, end SCORE, options *GetByScoreRangeOptions) []*SkipListNode

GetByScoreRange returns the nodes whose score within the specific range. If options is nil, it searches in interval [start, end] without any limit by default.

Time complexity of this method is : O(log(N)).

func (*SkipList) GetByValue added in v0.14.0 

func (sl *SkipList) GetByValue(value []byte) *SkipListNode

GetByValue returns the node at given key. If node is not found, nil is returned

Time complexity : O(1).

func (*SkipList) PeekMax added in v0.14.0 

func (sl *SkipList) PeekMax() *SkipListNode

PeekMax returns the element with maximum score, nil if the set is empty.

Time Complexity : O(1).

func (*SkipList) PeekMin added in v0.14.0 

func (sl *SkipList) PeekMin() *SkipListNode

PeekMin returns the element with minimum score, nil if the set is empty.

Time complexity of this method is : O(log(N)).

func (*SkipList) PopMax added in v0.14.0 

func (sl *SkipList) PopMax() *SkipListNode

PopMax returns and remove the element with maximum score, nil if the set is empty.

Time complexity of this method is : O(log(N)).

func (*SkipList) PopMin added in v0.14.0 

func (sl *SkipList) PopMin() *SkipListNode

PopMin returns and remove the element with minimal score, nil if the set is empty.

Time complexity of this method is : O(log(N)).

func (*SkipList) Put added in v0.14.0 

func (sl *SkipList) Put(score SCORE, value []byte, record *data.Record) error

Put puts an element into the sorted set with specific key / value / score.

Time complexity of this method is : O(log(N)).

func (*SkipList) Remove added in v0.14.0 

func (sl *SkipList) Remove(hash uint32) *SkipListNode

Remove removes element specified at given key.

Time complexity of this method is : O(log(N)).

func (*SkipList) Size added in v0.14.0 

func (sl *SkipList) Size() int

Size returns the number of elements in the SkipList.

type SkipListLevel added in v0.14.0 

type SkipListLevel struct {
	// contains filtered or unexported fields
}

SkipListLevel records forward and span.

type SkipListNode added in v0.14.0 

type SkipListNode struct {
	// contains filtered or unexported fields
}

SkipListNode represents a node in the SkipList.

func (*SkipListNode) Hash added in v0.14.0 

func (sln *SkipListNode) Hash() uint32

Hash returns the key of the node.

func (*SkipListNode) Score added in v0.14.0 

func (sln *SkipListNode) Score() SCORE

Score returns the score of the node.

type SnowflakeManager added in v1.1.0 

type SnowflakeManager struct {
	// contains filtered or unexported fields
}

SnowflakeManager manages snowflake node initialization and caching

func NewSnowflakeManager added in v1.1.0 

func NewSnowflakeManager(nodeNum int64) *SnowflakeManager

NewSnowflakeManager creates a new SnowflakeManager with the given node number

func (*SnowflakeManager) GetNode added in v1.1.0 

func (sm *SnowflakeManager) GetNode() *snowflake.Node

GetNode returns the snowflake node, initializing it once. If initialization fails, it will fatal the program.

type SortedSet added in v0.14.0 

type SortedSet struct {
	M map[string]*SkipList
	// contains filtered or unexported fields
}

func NewSortedSet added in v0.14.0 

func NewSortedSet(db *DB) *SortedSet

func (*SortedSet) ZAdd added in v0.14.0 

func (z *SortedSet) ZAdd(key string, score SCORE, value []byte, record *data.Record) error

func (*SortedSet) ZCard added in v0.14.0 

func (z *SortedSet) ZCard(key string) (int, error)

func (*SortedSet) ZCount added in v0.14.0 

func (z *SortedSet) ZCount(key string, start SCORE, end SCORE, opts *GetByScoreRangeOptions) (int, error)

func (*SortedSet) ZExist added in v0.14.0 

func (z *SortedSet) ZExist(key string, value []byte) (bool, error)

func (*SortedSet) ZMembers added in v0.14.0 

func (z *SortedSet) ZMembers(key string) (map[*data.Record]SCORE, error)

func (*SortedSet) ZPeekMax added in v0.14.0 

func (z *SortedSet) ZPeekMax(key string) (*data.Record, SCORE, error)

func (*SortedSet) ZPeekMin added in v0.14.0 

func (z *SortedSet) ZPeekMin(key string) (*data.Record, SCORE, error)

func (*SortedSet) ZPopMax added in v0.14.0 

func (z *SortedSet) ZPopMax(key string) (*data.Record, SCORE, error)

func (*SortedSet) ZPopMin added in v0.14.0 

func (z *SortedSet) ZPopMin(key string) (*data.Record, SCORE, error)

func (*SortedSet) ZRangeByRank added in v0.14.0 

func (z *SortedSet) ZRangeByRank(key string, start int, end int) ([]*data.Record, []float64, error)

func (*SortedSet) ZRangeByScore added in v0.14.0 

func (z *SortedSet) ZRangeByScore(key string, start SCORE, end SCORE, opts *GetByScoreRangeOptions) ([]*data.Record, []float64, error)

func (*SortedSet) ZRank added in v0.14.0 

func (z *SortedSet) ZRank(key string, value []byte) (int, error)

func (*SortedSet) ZRem added in v0.14.0 

func (z *SortedSet) ZRem(key string, value []byte) (*data.Record, error)

func (*SortedSet) ZRemRangeByRank added in v0.14.0 

func (z *SortedSet) ZRemRangeByRank(key string, start int, end int) error

func (*SortedSet) ZRevRank added in v0.14.0 

func (z *SortedSet) ZRevRank(key string, value []byte) (int, error)

func (*SortedSet) ZScore added in v0.14.0 

func (z *SortedSet) ZScore(key string, value []byte) (float64, error)

type SortedSetIdx 

type SortedSetIdx struct {
	// contains filtered or unexported fields
}

type SortedSetMember added in v0.14.0 

type SortedSetMember struct {
	Value []byte
	Score float64
}

type Throttle added in v0.13.1 

type Throttle struct {
	// contains filtered or unexported fields
}

Throttle allows a limited number of workers to run at a time. It also provides a mechanism to check for errors encountered by workers and wait for them to finish.

func NewThrottle added in v0.13.1 

func NewThrottle(max int) *Throttle

NewThrottle creates a new throttle with a max number of workers.

func (*Throttle) Do added in v0.13.1 

func (t *Throttle) Do() error

Do should be called by workers before they start working. It blocks if there are already maximum number of workers working. If it detects an error from previously Done workers, it would return it.

func (*Throttle) Done added in v0.13.1 

func (t *Throttle) Done(err error)

Done should be called by workers when they finish working. They can also pass the error status of work done.

func (*Throttle) Finish added in v0.13.1 

func (t *Throttle) Finish() error

Finish waits until all workers have finished working. It would return any error passed by Done. If Finish is called multiple time, it will wait for workers to finish only once(first time). From next calls, it will return same error as found on first call.

type Tx 

type Tx struct {
	// contains filtered or unexported fields
}

Tx represents a transaction.

func (*Tx) Append added in v1.0.3 

func (tx *Tx) Append(bucket string, key, appendage []byte) error

func (*Tx) CheckExpire 

func (tx *Tx) CheckExpire(bucket string, key []byte) bool

func (*Tx) Commit 

func (tx *Tx) Commit() (err error)

Commit commits the transaction, following these steps:

1. check the length of pendingWrites.If there are no writes, return immediately.

2. check if the ActiveFile has not enough space to store entry. if not, call rotateActiveFile function.

3. write pendingWrites to disk, if a non-nil error,return the error.

4. build Hint index.

5. send updated entries to watch manager if watch feature is enabled.

6. Unlock the database and clear the db field.

func (*Tx) CommitWith added in v0.13.1 

func (tx *Tx) CommitWith(cb func(error))

func (*Tx) Decr added in v1.0.2 

func (tx *Tx) Decr(bucket string, key []byte) error

func (*Tx) DecrBy added in v1.0.2 

func (tx *Tx) DecrBy(bucket string, key []byte, decrement int64) error

func (*Tx) Delete 

func (tx *Tx) Delete(bucket string, key []byte) error

Delete removes a key from the bucket at given bucket and key.

func (*Tx) DeleteBucket 

func (tx *Tx) DeleteBucket(ds uint16, bucket string) error

DeleteBucket delete bucket depends on ds (represents the data structure)

func (*Tx) ExistBucket added in v0.13.0 

func (tx *Tx) ExistBucket(ds uint16, bucket string) bool

func (*Tx) ExpireList 

func (tx *Tx) ExpireList(bucket string, key []byte, ttl uint32) error

func (*Tx) Get 

func (tx *Tx) Get(bucket string, key []byte) (value []byte, err error)

Get retrieves the value for a key in the bucket. The returned value is only valid for the life of the transaction.

func (*Tx) GetAll 

func (tx *Tx) GetAll(bucket string) ([][]byte, [][]byte, error)

GetAll returns all keys and values in the given bucket.

func (*Tx) GetBit added in v1.0.3 

func (tx *Tx) GetBit(bucket string, key []byte, offset int) (byte, error)

func (*Tx) GetKeys added in v1.0.3 

func (tx *Tx) GetKeys(bucket string) ([][]byte, error)

GetKeys returns all keys in the given bucket.

func (*Tx) GetListTTL added in v0.12.1 

func (tx *Tx) GetListTTL(bucket string, key []byte) (uint32, error)

func (*Tx) GetMaxKey added in v1.0.2 

func (tx *Tx) GetMaxKey(bucket string) ([]byte, error)

func (*Tx) GetMinKey added in v1.0.2 

func (tx *Tx) GetMinKey(bucket string) ([]byte, error)

func (*Tx) GetRange added in v1.0.3 

func (tx *Tx) GetRange(bucket string, key []byte, start, end int) ([]byte, error)

func (*Tx) GetSet added in v1.0.2 

func (tx *Tx) GetSet(bucket string, key, value []byte) (oldValue []byte, err error)

func (*Tx) GetTTL added in v1.0.3 

func (tx *Tx) GetTTL(bucket string, key []byte) (int64, error)

GetTTL returns remaining TTL of a value by key. It returns (-1, nil) If TTL is Persistent (0, ErrBucketNotFound|ErrKeyNotFound) If expired or not found (TTL, nil) If the record exists with a TTL Note: The returned remaining TTL will be in seconds. For example, remainingTTL is 500ms, It'll return 0.

func (*Tx) GetValues added in v1.0.3 

func (tx *Tx) GetValues(bucket string) ([][]byte, error)

GetValues returns all values in the given bucket.

func (*Tx) Has added in v1.1.0 

func (tx *Tx) Has(bucket string, key []byte) (exists bool, err error)

Has returns true if the record exists. It checks without retrieving the value from disk making lookups significantly faster while keeping memory usage down as well. It does require the `HintKeyAndRAMIdxMode` option to be enabled to function as described.

func (*Tx) Incr added in v1.0.2 

func (tx *Tx) Incr(bucket string, key []byte) error

func (*Tx) IncrBy added in v1.0.2 

func (tx *Tx) IncrBy(bucket string, key []byte, increment int64) error

func (*Tx) IterateBuckets 

func (tx *Tx) IterateBuckets(ds uint16, pattern string, f func(bucket string) bool) error

IterateBuckets iterate over all the bucket depends on ds (represents the data structure)

func (*Tx) LKeys 

func (tx *Tx) LKeys(bucket, pattern string, f func(key string) bool) error

LKeys find all keys matching a given pattern

func (*Tx) LPeek 

func (tx *Tx) LPeek(bucket string, key []byte) (item []byte, err error)

LPeek returns the first element of the list stored in the bucket at given bucket and key.

func (*Tx) LPop 

func (tx *Tx) LPop(bucket string, key []byte) (item []byte, err error)

LPop removes and returns the first element of the list stored in the bucket at given bucket and key.

func (*Tx) LPush 

func (tx *Tx) LPush(bucket string, key []byte, values ...[]byte) error

LPush inserts the values at the head of the list stored in the bucket at given bucket,key and values.

func (*Tx) LPushRaw added in v0.14.2 

func (tx *Tx) LPushRaw(bucket string, key []byte, values ...[]byte) error

func (*Tx) LRange 

func (tx *Tx) LRange(bucket string, key []byte, start, end int) ([][]byte, error)

LRange returns the specified elements of the list stored in the bucket at given bucket,key, start and end. The offsets start and stop are zero-based indexes 0 being the first element of the list (the head of the list), 1 being the next element and so on. Start and end can also be negative numbers indicating offsets from the end of the list, where -1 is the last element of the list, -2 the penultimate element and so on.

func (*Tx) LRem 

func (tx *Tx) LRem(bucket string, key []byte, count int, value []byte) error

LRem removes the first count occurrences of elements equal to value from the list stored in the bucket at given bucket,key,count. The count argument influences the operation in the following ways: count > 0: Remove elements equal to value moving from head to tail. count < 0: Remove elements equal to value moving from tail to head. count = 0: Remove all elements equal to value.

func (*Tx) LRemByIndex 

func (tx *Tx) LRemByIndex(bucket string, key []byte, indexes ...int) error

LRemByIndex remove the list element at specified index

func (*Tx) LSize 

func (tx *Tx) LSize(bucket string, key []byte) (int, error)

LSize returns the size of key in the bucket in the bucket at given bucket and key.

func (*Tx) LTrim 

func (tx *Tx) LTrim(bucket string, key []byte, start, end int) error

LTrim trims an existing list so that it will contain only the specified range of elements specified. the offsets start and stop are zero-based indexes 0 being the first element of the list (the head of the list), 1 being the next element and so on. start and end can also be negative numbers indicating offsets from the end of the list, where -1 is the last element of the list, -2 the penultimate element and so on.

func (*Tx) MGet added in v1.0.3 

func (tx *Tx) MGet(bucket string, keys ...[]byte) ([][]byte, error)

func (*Tx) MSet added in v1.0.3 

func (tx *Tx) MSet(bucket string, ttl uint32, args ...[]byte) error

func (*Tx) NewBucket added in v1.0.0 

func (tx *Tx) NewBucket(ds uint16, name string) (err error)

func (*Tx) NewKVBucket added in v1.0.0 

func (tx *Tx) NewKVBucket(name string) error

func (*Tx) NewListBucket added in v1.0.0 

func (tx *Tx) NewListBucket(name string) error

func (*Tx) NewSetBucket added in v1.0.0 

func (tx *Tx) NewSetBucket(name string) error

func (*Tx) NewSortSetBucket added in v1.0.0 

func (tx *Tx) NewSortSetBucket(name string) error

func (*Tx) Persist added in v1.0.3 

func (tx *Tx) Persist(bucket string, key []byte) error

Persist updates record's TTL as Persistent if the record exists.

func (*Tx) PrefixScan 

func (tx *Tx) PrefixScan(bucket string, prefix []byte, offsetNum int, limitNum int) (values [][]byte, err error)

PrefixScan iterates over a key prefix at given bucket, prefix and limitNum. LimitNum will limit the number of entries return.

func (*Tx) PrefixScanEntries added in v1.1.0 

func (tx *Tx) PrefixScanEntries(bucket string, prefix []byte, reg string, offsetNum int, limitNum int, includeKeys, includeValues bool) (keys, values [][]byte, err error)

PrefixScanEntries iterates over a key prefix at given bucket, prefix and limitNum. If reg is set a regular expression will be used to filter the found entries. LimitNum will limit the number of entries return. It will return keys and/or values based on the includeKeys and includeValues flags.

func (*Tx) PrefixSearchScan 

func (tx *Tx) PrefixSearchScan(bucket string, prefix []byte, reg string, offsetNum int, limitNum int) (values [][]byte, err error)

PrefixSearchScan iterates over a key prefix at given bucket, prefix, match regular expression and limitNum. LimitNum will limit the number of entries return.

func (*Tx) Put 

func (tx *Tx) Put(bucket string, key, value []byte, ttl uint32) error

Put sets the value for a key in the bucket. a wrapper of the function put.

func (*Tx) PutIfExists added in v1.0.2 

func (tx *Tx) PutIfExists(bucket string, key, value []byte, ttl uint32) error

PutIfExists set the value for a key in the bucket only if the key already exits.

func (*Tx) PutIfNotExists added in v1.0.2 

func (tx *Tx) PutIfNotExists(bucket string, key, value []byte, ttl uint32) error

PutIfNotExists set the value for a key in the bucket only if the key doesn't exist already.

func (*Tx) PutWithTimestamp 

func (tx *Tx) PutWithTimestamp(bucket string, key, value []byte, ttl uint32, timestamp uint64) error

func (*Tx) RPeek 

func (tx *Tx) RPeek(bucket string, key []byte) ([]byte, error)

RPeek returns the last element of the list stored in the bucket at given bucket and key.

func (*Tx) RPop 

func (tx *Tx) RPop(bucket string, key []byte) (item []byte, err error)

RPop removes and returns the last element of the list stored in the bucket at given bucket and key.

func (*Tx) RPush 

func (tx *Tx) RPush(bucket string, key []byte, values ...[]byte) error

RPush inserts the values at the tail of the list stored in the bucket at given bucket,key and values.

func (*Tx) RPushRaw added in v0.14.2 

func (tx *Tx) RPushRaw(bucket string, key []byte, values ...[]byte) error

func (*Tx) RangeScan 

func (tx *Tx) RangeScan(bucket string, start, end []byte) (values [][]byte, err error)

RangeScan query a range at given bucket, start and end slice.

func (*Tx) RangeScanEntries added in v1.1.0 

func (tx *Tx) RangeScanEntries(bucket string, start, end []byte, includeKeys, includeValues bool) (keys, values [][]byte, err error)

RangeScanEntries query a range at given bucket, start and end slice. It will return keys and/or values based on the includeKeys and includeValues flags.

func (*Tx) Rollback 

func (tx *Tx) Rollback() error

Rollback closes the transaction.

func (*Tx) SAdd 

func (tx *Tx) SAdd(bucket string, key []byte, items ...[]byte) error

SAdd adds the specified members to the set stored int the bucket at given bucket,key and items.

func (*Tx) SAreMembers 

func (tx *Tx) SAreMembers(bucket string, key []byte, items ...[]byte) (bool, error)

SAreMembers returns if the specified members are the member of the set int the bucket at given bucket,key and items.

func (*Tx) SCard 

func (tx *Tx) SCard(bucket string, key []byte) (int, error)

SCard returns the set cardinality (number of elements) of the set stored in the bucket at given bucket and key.

func (*Tx) SDiffByOneBucket 

func (tx *Tx) SDiffByOneBucket(bucket string, key1, key2 []byte) ([][]byte, error)

SDiffByOneBucket returns the members of the set resulting from the difference between the first set and all the successive sets in one bucket.

func (*Tx) SDiffByTwoBuckets 

func (tx *Tx) SDiffByTwoBuckets(bucket1 string, key1 []byte, bucket2 string, key2 []byte) ([][]byte, error)

SDiffByTwoBuckets returns the members of the set resulting from the difference between the first set and all the successive sets in two buckets.

func (*Tx) SHasKey 

func (tx *Tx) SHasKey(bucket string, key []byte) (bool, error)

SHasKey returns if the set in the bucket at given bucket and key.

func (*Tx) SIsMember 

func (tx *Tx) SIsMember(bucket string, key, item []byte) (bool, error)

SIsMember returns if member is a member of the set stored int the bucket at given bucket,key and item.

func (*Tx) SKeys 

func (tx *Tx) SKeys(bucket, pattern string, f func(key string) bool) error

SKeys find all keys matching a given pattern

func (*Tx) SMembers 

func (tx *Tx) SMembers(bucket string, key []byte) ([][]byte, error)

SMembers returns all the members of the set value stored int the bucket at given bucket and key.

func (*Tx) SMoveByOneBucket 

func (tx *Tx) SMoveByOneBucket(bucket string, key1, key2, item []byte) (bool, error)

SMoveByOneBucket moves member from the set at source to the set at destination in one bucket.

func (*Tx) SMoveByTwoBuckets 

func (tx *Tx) SMoveByTwoBuckets(bucket1 string, key1 []byte, bucket2 string, key2, item []byte) (bool, error)

SMoveByTwoBuckets moves member from the set at source to the set at destination in two buckets.

func (*Tx) SPop 

func (tx *Tx) SPop(bucket string, key []byte) ([]byte, error)

SPop removes and returns one or more random elements from the set value store in the bucket at given bucket and key.

func (*Tx) SRem 

func (tx *Tx) SRem(bucket string, key []byte, items ...[]byte) error

SRem removes the specified members from the set stored int the bucket at given bucket,key and items.

func (*Tx) SUnionByOneBucket 

func (tx *Tx) SUnionByOneBucket(bucket string, key1, key2 []byte) ([][]byte, error)

SUnionByOneBucket the members of the set resulting from the union of all the given sets in one bucket.

func (*Tx) SUnionByTwoBuckets 

func (tx *Tx) SUnionByTwoBuckets(bucket1 string, key1 []byte, bucket2 string, key2 []byte) ([][]byte, error)

SUnionByTwoBuckets the members of the set resulting from the union of all the given sets in two buckets.

func (*Tx) SetBit added in v1.0.3 

func (tx *Tx) SetBit(bucket string, key []byte, offset int, bit byte) error

func (*Tx) SubmitBucket added in v1.0.0 

func (tx *Tx) SubmitBucket() error

func (*Tx) ValueLen added in v1.0.2 

func (tx *Tx) ValueLen(bucket string, key []byte) (int, error)

func (*Tx) ZAdd 

func (tx *Tx) ZAdd(bucket string, key []byte, score float64, val []byte) error

ZAdd Adds the specified member with the specified score into the sorted set specified by key in a bucket.

func (*Tx) ZCard 

func (tx *Tx) ZCard(bucket string, key []byte) (int, error)

ZCard Returns the sorted set cardinality (number of elements) of the sorted set specified by key in a bucket.

func (*Tx) ZCheck added in v0.14.0 

func (tx *Tx) ZCheck(bucket string) error

func (*Tx) ZCount 

func (tx *Tx) ZCount(bucket string, key []byte, start, end float64, opts *GetByScoreRangeOptions) (int, error)

ZCount Returns the number of elements in the sorted set specified by key in a bucket with a score between min and max and opts. Opt includes the following parameters: Limit int // limit the max nodes to return ExcludeStart bool // exclude start value, so it search in interval (start, end] or (start, end) ExcludeEnd bool // exclude end value, so it search in interval [start, end) or (start, end)

func (*Tx) ZKeys 

func (tx *Tx) ZKeys(bucket, pattern string, f func(key string) bool) error

ZKeys find all keys matching a given pattern in a bucket

func (*Tx) ZMembers 

func (tx *Tx) ZMembers(bucket string, key []byte) (map[*SortedSetMember]struct{}, error)

ZMembers Returns all the members and scores of members of the set specified by key in a bucket.

func (*Tx) ZPeekMax 

func (tx *Tx) ZPeekMax(bucket string, key []byte) (*SortedSetMember, error)

ZPeekMax Returns the member with the highest score in the sorted set specified by key in a bucket.

func (*Tx) ZPeekMin 

func (tx *Tx) ZPeekMin(bucket string, key []byte) (*SortedSetMember, error)

ZPeekMin Returns the member with the lowest score in the sorted set specified by key in a bucket.

func (*Tx) ZPopMax 

func (tx *Tx) ZPopMax(bucket string, key []byte) (*SortedSetMember, error)

ZPopMax Removes and returns the member with the highest score in the sorted set specified by key in a bucket.

func (*Tx) ZPopMin 

func (tx *Tx) ZPopMin(bucket string, key []byte) (*SortedSetMember, error)

ZPopMin Removes and returns the member with the lowest score in the sorted set specified by key in a bucket.

func (*Tx) ZRangeByRank 

func (tx *Tx) ZRangeByRank(bucket string, key []byte, start, end int) ([]*SortedSetMember, error)

ZRangeByRank Returns all the elements in the sorted set specified by key in a bucket with a rank between start and end (including elements with rank equal to start or end).

func (*Tx) ZRangeByScore 

func (tx *Tx) ZRangeByScore(bucket string, key []byte, start, end float64, opts *GetByScoreRangeOptions) ([]*SortedSetMember, error)

ZRangeByScore Returns all the elements in the sorted set specified by key in a bucket with a score between min and max. And the parameter `Opts` is the same as ZCount's.

func (*Tx) ZRank 

func (tx *Tx) ZRank(bucket string, key, value []byte) (int, error)

ZRank Returns the rank of member in the sorted set specified by key in a bucket, with the scores ordered from low to high.

func (*Tx) ZRem 

func (tx *Tx) ZRem(bucket string, key []byte, value []byte) error

ZRem removes the specified members from the sorted set stored in one bucket at given bucket and key.

func (*Tx) ZRemRangeByRank 

func (tx *Tx) ZRemRangeByRank(bucket string, key []byte, start, end int) error

ZRemRangeByRank removes all elements in the sorted set stored in one bucket at given bucket with rank between start and end. the rank is 1-based integer. Rank 1 means the first node; Rank -1 means the last node.

func (*Tx) ZRevRank 

func (tx *Tx) ZRevRank(bucket string, key, value []byte) (int, error)

ZRevRank Returns the rank of member in the sorted set specified by key in a bucket, with the scores ordered from high to low.

func (*Tx) ZScore 

func (tx *Tx) ZScore(bucket string, key, value []byte) (float64, error)

ZScore Returns the score of members in a sorted set specified by key in a bucket.

type WatchOptions added in v1.1.0 

type WatchOptions struct {
	CallbackTimeout time.Duration
}

func NewWatchOptions added in v1.1.0 

func NewWatchOptions() *WatchOptions

func (*WatchOptions) WithCallbackTimeout added in v1.1.0 

func (opts *WatchOptions) WithCallbackTimeout(timeout time.Duration)

WithCallbackTimeout sets the callback timeout

type WriteBatch added in v0.13.1 

type WriteBatch struct {
	sync.Mutex
	// contains filtered or unexported fields
}

WriteBatch holds the necessary info to perform batched writes.

func (*WriteBatch) Cancel added in v0.13.1 

func (wb *WriteBatch) Cancel() error

func (*WriteBatch) Delete added in v0.13.1 

func (wb *WriteBatch) Delete(bucket string, key []byte) error

func (tx *Tx) Delete(bucket string, key []byte) error

func (*WriteBatch) Error added in v0.13.1 

func (wb *WriteBatch) Error() error

Error returns any errors encountered so far. No commits would be run once an error is detected.

func (*WriteBatch) Flush added in v0.13.1 

func (wb *WriteBatch) Flush() error

func (*WriteBatch) Put added in v0.13.1 

func (wb *WriteBatch) Put(bucket string, key, value []byte, ttl uint32) error

func (*WriteBatch) Reset added in v0.13.1 

func (wb *WriteBatch) Reset() error

func (*WriteBatch) SetMaxPendingTxns added in v0.13.1 

func (wb *WriteBatch) SetMaxPendingTxns(max int)

SetMaxPendingTxns sets a limit on maximum number of pending transactions while writing batches. This function should be called before using WriteBatch. Default value of MaxPendingTxns is 16 to minimise memory usage.

Source Files

View all Source files

Directories

Path Synopsis
examples
basic command
batch/concurrence command
batch/put command
batch/read command
bucket command
emptybucket command
http command
iterator command
k-v/append command
k-v/bit command
k-v/get_range command
k-v/increments command
k-v/multioprations command
list command
set command
sortedSet command
watcher command
internal
data
fileio
testutils
utils

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