db

package
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 Go to latest Published: Sep 25, 2019 License: Apache-2.0 Imports: 21 Imported by: 0

README

TODO: syndtr/goleveldb should be replaced with actual LevelDB instance

Documentation

Index

Constants

View Source 
const IdealBatchSize = 100 * 1024

Code using batches should try to add this much data to the batch. The value was determined empirically.

Variables

This section is empty.

Functions

func IsKeyInDomain 

func IsKeyInDomain(key, start, end []byte, isReverse bool) bool

See DB interface documentation for more information.

func NewDebugBatch 

func NewDebugBatch(label string, bch Batch) debugBatch

For printing all operationgs to the console for debugging.

func NewDebugDB 

func NewDebugDB(label string, db DB) debugDB

For printing all operationgs to the console for debugging.

func NewDebugIterator 

func NewDebugIterator(label string, itr Iterator) debugIterator

For printing all operationgs to the console for debugging.

func NewPrefixDB 

func NewPrefixDB(db DB, prefix []byte) *prefixDB

NewPrefixDB lets you namespace multiple DBs within a single DB.

func PrefixToEnd 

func PrefixToEnd(prefix []byte) []byte

PrefixToEnd returns end that satisfy the given prefix. This only applicable for the standard 'bytes comparer'.

Types

type BadgerDB 

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

func NewBadgerDB 

func NewBadgerDB(name string, dir string, counts uint64) (*BadgerDB, error)

func (*BadgerDB) Close 

func (db *BadgerDB) Close()

Implements DB.

func (*BadgerDB) Del 

func (db *BadgerDB) Del(key []byte) error

func (*BadgerDB) Delete 

func (db *BadgerDB) Delete(key []byte)

Implements DB.

func (*BadgerDB) DeleteSync 

func (db *BadgerDB) DeleteSync(key []byte)

Implements DB.

func (*BadgerDB) Dir 

func (db *BadgerDB) Dir() string

func (*BadgerDB) Exist 

func (db *BadgerDB) Exist(key []byte) (bool, error)

func (*BadgerDB) Get 

func (db *BadgerDB) Get(key []byte) []byte

Implements DB.

func (*BadgerDB) Has 

func (db *BadgerDB) Has(key []byte) bool

Implements DB.

func (*BadgerDB) Iterator 

func (db *BadgerDB) Iterator(start, end []byte) Iterator

Implements DB.

func (*BadgerDB) Load 

func (db *BadgerDB) Load(key []byte) ([]byte, error)

func (*BadgerDB) NewBatch 

func (db *BadgerDB) NewBatch() Batch

Implements DB.

func (*BadgerDB) NewIteratorWithPrefix 

func (db *BadgerDB) NewIteratorWithPrefix(prefix []byte) Iterator

func (*BadgerDB) Print 

func (db *BadgerDB) Print()

Implements DB.

func (*BadgerDB) Put 

func (db *BadgerDB) Put(key []byte, val []byte) error

func (*BadgerDB) ReverseIterator 

func (db *BadgerDB) ReverseIterator(start, end []byte) Iterator

Implements DB.

func (*BadgerDB) Set 

func (db *BadgerDB) Set(key []byte, val []byte)

Implements DB.

func (*BadgerDB) SetSync 

func (db *BadgerDB) SetSync(key []byte, val []byte)

Implements DB.

func (*BadgerDB) Stats 

func (db *BadgerDB) Stats() map[string]string

Implements DB.

type Batch 

type Batch interface {
	SetDeleter
	Write()
	Commit() error
	WriteSync()
	ValueSize() int // amount of data in the batch
	Reset()         // Reset resets the batch for reuse
}

type BoltDB 

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

func NewBoltDB 

func NewBoltDB(name string, dir string, count uint64) (*BoltDB, error)

func (*BoltDB) Close 

func (db *BoltDB) Close()

func (*BoltDB) Del 

func (db *BoltDB) Del(key []byte) error

func (*BoltDB) Delete 

func (db *BoltDB) Delete(key []byte)

func (*BoltDB) DeleteSync 

func (db *BoltDB) DeleteSync(key []byte)

func (*BoltDB) Dir 

func (db *BoltDB) Dir() string

func (*BoltDB) Exist 

func (db *BoltDB) Exist(key []byte) (bool, error)

func (*BoltDB) Get 

func (db *BoltDB) Get(key []byte) []byte

Implements DB.

func (*BoltDB) Has 

func (db *BoltDB) Has(key []byte) bool

func (*BoltDB) Iterator 

func (db *BoltDB) Iterator(start, end []byte) Iterator

func (*BoltDB) Load 

func (db *BoltDB) Load(key []byte) ([]byte, error)

func (*BoltDB) NewBatch 

func (db *BoltDB) NewBatch() Batch

func (*BoltDB) NewIteratorWithPrefix 

func (db *BoltDB) NewIteratorWithPrefix(prefix []byte) Iterator

func (*BoltDB) Print 

func (db *BoltDB) Print()

func (*BoltDB) Put 

func (db *BoltDB) Put(key []byte, val []byte) error

func (*BoltDB) ReverseIterator 

func (db *BoltDB) ReverseIterator(start, end []byte) Iterator

func (*BoltDB) Set 

func (db *BoltDB) Set(key []byte, val []byte)

func (*BoltDB) SetSync 

func (db *BoltDB) SetSync(key []byte, val []byte)

func (*BoltDB) Stats 

func (db *BoltDB) Stats() map[string]string

type DB 

type DB interface {

	// Get returns nil iff key doesn't exist.
	// A nil key is interpreted as an empty byteslice.
	// CONTRACT: key, value readonly []byte
	Get([]byte) []byte
	Load([]byte) ([]byte, error)

	// Has checks if a key exists.
	// A nil key is interpreted as an empty byteslice.
	// CONTRACT: key, value readonly []byte
	Has(key []byte) bool
	Exist(key []byte) (bool, error)

	// Set sets the key.
	// A nil key is interpreted as an empty byteslice.
	// CONTRACT: key, value readonly []byte
	Set([]byte, []byte)
	Put([]byte, []byte) error
	SetSync([]byte, []byte)

	// Delete deletes the key.
	// A nil key is interpreted as an empty byteslice.
	// CONTRACT: key readonly []byte
	Delete([]byte)
	Del([]byte) error
	DeleteSync([]byte)

	// Iterate over a domain of keys in ascending order. End is exclusive.
	// Start must be less than end, or the Iterator is invalid.
	// A nil start is interpreted as an empty byteslice.
	// If end is nil, iterates up to the last item (inclusive).
	// CONTRACT: No writes may happen within a domain while an iterator exists over it.
	// CONTRACT: start, end readonly []byte
	Iterator(start, end []byte) Iterator

	// Iterate over a domain of keys in descending order. End is exclusive.
	// Start must be greater than end, or the Iterator is invalid.
	// If start is nil, iterates from the last/greatest item (inclusive).
	// If end is nil, iterates up to the first/least item (inclusive).
	// CONTRACT: No writes may happen within a domain while an iterator exists over it.
	// CONTRACT: start, end readonly []byte
	ReverseIterator(start, end []byte) Iterator
	NewIteratorWithPrefix(prefix []byte) Iterator

	Dir() string

	// Closes the connection.
	Close()

	// Creates a batch for atomic updates.
	NewBatch() Batch

	// For debugging
	Print()

	// Stats returns a map of property values for all keys and the size of the cache.
	Stats() map[string]string
}

DBs are goroutine safe.

func NewDB 

func NewDB(name string, backend DBBackendType, dir string, counts uint64) DB

type DBBackendCounts 

type DBBackendCounts uint64

type DBBackendType 

type DBBackendType string
const (
	LevelDBBackend   DBBackendType = "leveldb" // legacy, defaults to goleveldb unless +gcc
	CLevelDBBackend  DBBackendType = "cleveldb"
	GoLevelDBBackend DBBackendType = "goleveldb"
	MemDBBackend     DBBackendType = "memdb"
	FSDBBackend      DBBackendType = "fsdb"   // using the filesystem naively
	BadgerBackend    DBBackendType = "badger" // using badger
	BoltBackend      DBBackendType = "bolt"   // using bolt
)

type FSDB 

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

It's slow.

func NewFSDB 

func NewFSDB(dir string) *FSDB

func (*FSDB) Close 

func (db *FSDB) Close()

func (*FSDB) Del 

func (db *FSDB) Del(key []byte) error

func (*FSDB) Delete 

func (db *FSDB) Delete(key []byte)

func (*FSDB) DeleteNoLock 

func (db *FSDB) DeleteNoLock(key []byte)

NOTE: Implements atomicSetDeleter.

func (*FSDB) DeleteNoLockNoPanic 

func (db *FSDB) DeleteNoLockNoPanic(key []byte) error

func (*FSDB) DeleteSync 

func (db *FSDB) DeleteSync(key []byte)

func (*FSDB) Dir 

func (db *FSDB) Dir() string

func (*FSDB) Exist 

func (db *FSDB) Exist(key []byte) (bool, error)

func (*FSDB) Get 

func (db *FSDB) Get(key []byte) []byte

func (*FSDB) Has 

func (db *FSDB) Has(key []byte) bool

func (*FSDB) Iterator 

func (db *FSDB) Iterator(start, end []byte) Iterator

func (*FSDB) Load 

func (db *FSDB) Load(key []byte) ([]byte, error)

func (*FSDB) MakeIterator 

func (db *FSDB) MakeIterator(start, end []byte, isReversed bool) Iterator

func (*FSDB) Mutex 

func (db *FSDB) Mutex() *sync.Mutex

func (*FSDB) NewBatch 

func (db *FSDB) NewBatch() Batch

func (*FSDB) NewIteratorWithPrefix 

func (db *FSDB) NewIteratorWithPrefix(prefix []byte) Iterator

func (*FSDB) Print 

func (db *FSDB) Print()

func (*FSDB) Put 

func (db *FSDB) Put(key []byte, value []byte) error

func (*FSDB) ReverseIterator 

func (db *FSDB) ReverseIterator(start, end []byte) Iterator

func (*FSDB) Set 

func (db *FSDB) Set(key []byte, value []byte)

func (*FSDB) SetNoLock 

func (db *FSDB) SetNoLock(key []byte, value []byte)

NOTE: Implements atomicSetDeleter.

func (*FSDB) SetNoLockNoPanic 

func (db *FSDB) SetNoLockNoPanic(key []byte, value []byte) error

func (*FSDB) SetSync 

func (db *FSDB) SetSync(key []byte, value []byte)

func (*FSDB) Stats 

func (db *FSDB) Stats() map[string]string

type GoLevelDB 

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

func NewGoLevelDB 

func NewGoLevelDB(name string, dir string, counts uint64) (*GoLevelDB, error)

func (*GoLevelDB) Close 

func (db *GoLevelDB) Close()

Implements DB.

func (*GoLevelDB) Del 

func (db *GoLevelDB) Del(key []byte) error

func (*GoLevelDB) Delete 

func (db *GoLevelDB) Delete(key []byte)

Implements DB.

func (*GoLevelDB) DeleteSync 

func (db *GoLevelDB) DeleteSync(key []byte)

Implements DB.

func (*GoLevelDB) Dir 

func (db *GoLevelDB) Dir() string

func (*GoLevelDB) Exist 

func (db *GoLevelDB) Exist(key []byte) (bool, error)

func (*GoLevelDB) Get 

func (db *GoLevelDB) Get(key []byte) []byte

Implements DB.

func (*GoLevelDB) Has 

func (db *GoLevelDB) Has(key []byte) bool

Implements DB.

func (*GoLevelDB) Iterator 

func (db *GoLevelDB) Iterator(start, end []byte) Iterator

Implements DB.

func (*GoLevelDB) Load 

func (db *GoLevelDB) Load(key []byte) ([]byte, error)

func (*GoLevelDB) NewBatch 

func (db *GoLevelDB) NewBatch() Batch

Implements DB.

func (*GoLevelDB) NewIteratorWithPrefix 

func (db *GoLevelDB) NewIteratorWithPrefix(prefix []byte) Iterator

func (*GoLevelDB) Print 

func (db *GoLevelDB) Print()

Implements DB.

func (*GoLevelDB) Put 

func (db *GoLevelDB) Put(key []byte, value []byte) error

func (*GoLevelDB) ReverseIterator 

func (db *GoLevelDB) ReverseIterator(start, end []byte) Iterator

Implements DB.

func (*GoLevelDB) Set 

func (db *GoLevelDB) Set(key []byte, value []byte)

Implements DB.

func (*GoLevelDB) SetSync 

func (db *GoLevelDB) SetSync(key []byte, value []byte)

Implements DB.

func (*GoLevelDB) Stats 

func (db *GoLevelDB) Stats() map[string]string

Implements DB.

type Iterator 

type Iterator interface {

	// The start & end (exclusive) limits to iterate over.
	// If end < start, then the Iterator goes in reverse order.
	//
	// A domain of ([]byte{12, 13}, []byte{12, 14}) will iterate
	// over anything with the prefix []byte{12, 13}.
	//
	// The smallest key is the empty byte array []byte{} - see BeginningKey().
	// The largest key is the nil byte array []byte(nil) - see EndingKey().
	// CONTRACT: start, end readonly []byte
	Domain() (start []byte, end []byte)

	// Valid returns whether the current position is valid.
	// Once invalid, an Iterator is forever invalid.
	Valid() bool

	// Next moves the iterator to the next sequential key in the database, as
	// defined by order of iteration.
	//
	// If Valid returns false, this method will panic.
	Next() bool // No panic when returned to false

	Seek(key []byte) bool
	// Key returns the key of the cursor.
	// If Valid returns false, this method will panic.
	// CONTRACT: key readonly []byte
	Key() (key []byte)

	// Value returns the value of the cursor.
	// If Valid returns false, this method will panic.
	// CONTRACT: value readonly []byte
	Value() (value []byte)

	// Close releases the Iterator.
	Close()
}

Usage:

var itr Iterator = ... defer itr.Close() 

for ; itr.Valid(); itr.Next() {
	k, v := itr.Key(); itr.Value()
	// ...
}

func IteratePrefix 

func IteratePrefix(db DB, prefix []byte) Iterator

IteratePrefix is a convenience function for iterating over a key domain restricted by prefix.

type MemDB 

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

func NewMemDB 

func NewMemDB() *MemDB

func (*MemDB) Close 

func (db *MemDB) Close()

Implements DB.

func (*MemDB) Del 

func (db *MemDB) Del(key []byte) error

func (*MemDB) Delete 

func (db *MemDB) Delete(key []byte)

Implements DB.

func (*MemDB) DeleteNoLock 

func (db *MemDB) DeleteNoLock(key []byte)

Implements atomicSetDeleter.

func (*MemDB) DeleteNoLockSync 

func (db *MemDB) DeleteNoLockSync(key []byte)

Implements atomicSetDeleter.

func (*MemDB) DeleteSync 

func (db *MemDB) DeleteSync(key []byte)

Implements DB.

func (*MemDB) Dir 

func (db *MemDB) Dir() string

func (*MemDB) Exist 

func (db *MemDB) Exist(key []byte) (bool, error)

func (*MemDB) Get 

func (db *MemDB) Get(key []byte) []byte

Implements DB.

func (*MemDB) Has 

func (db *MemDB) Has(key []byte) bool

Implements DB.

func (*MemDB) Iterator 

func (db *MemDB) Iterator(start, end []byte) Iterator

Implements DB.

func (*MemDB) Keys 

func (db *MemDB) Keys() [][]byte

func (*MemDB) Len 

func (db *MemDB) Len() int

func (*MemDB) Load 

func (db *MemDB) Load(key []byte) ([]byte, error)

func (*MemDB) Mutex 

func (db *MemDB) Mutex() *sync.Mutex

Implements atomicSetDeleter.

func (*MemDB) NewBatch 

func (db *MemDB) NewBatch() Batch

Implements DB.

func (*MemDB) NewIteratorWithPrefix 

func (db *MemDB) NewIteratorWithPrefix(prefix []byte) Iterator

func (*MemDB) Print 

func (db *MemDB) Print()

Implements DB.

func (*MemDB) Put 

func (db *MemDB) Put(key []byte, value []byte) error

func (*MemDB) ReverseIterator 

func (db *MemDB) ReverseIterator(start, end []byte) Iterator

Implements DB.

func (*MemDB) Set 

func (db *MemDB) Set(key []byte, value []byte)

Implements DB.

func (*MemDB) SetNoLock 

func (db *MemDB) SetNoLock(key []byte, value []byte)

Implements atomicSetDeleter.

func (*MemDB) SetNoLockSync 

func (db *MemDB) SetNoLockSync(key []byte, value []byte)

Implements atomicSetDeleter.

func (*MemDB) SetSync 

func (db *MemDB) SetSync(key []byte, value []byte)

Implements DB.

func (*MemDB) Stats 

func (db *MemDB) Stats() map[string]string

Implements DB.

type Putter 

type Putter interface {
	Put(key []byte, value []byte) error
}

Putter wraps the database write operation supported by both batches and regular databases.

type SetDeleter 

type SetDeleter interface {
	Set(key, value []byte) // CONTRACT: key, value readonly []byte
	Delete(key []byte)     // CONTRACT: key readonly []byte
}

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