db

package
v0.32.0-dev2 Latest Latest
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 Go to latest Published: Jun 22, 2019 License: Apache-2.0 Imports: 15 Imported by: 0

Documentation

Index

Constants

This section is empty.

Variables

This section is empty.

Functions

func IsKeyInDomain 

func IsKeyInDomain(key, start, end []byte) 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.

Types

type Batch 

type Batch interface {
	SetDeleter
	Write()
	WriteSync()
	Close()
}

Batch Close must be called when the program no longer needs the object.

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

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

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

	// Delete deletes the key.
	// A nil key is interpreted as an empty byteslice.
	// CONTRACT: key readonly []byte
	Delete([]byte)
	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 less than end, or the Iterator is invalid.
	// If start is nil, iterates up to the first/least item (inclusive).
	// If end is nil, iterates from the last/greatest 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

	// 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) DB

NewDB creates a new database of type backend with the given name. NOTE: function panics if:

  • backend is unknown (not registered)
  • creator function, provided during registration, returns error

type DBBackendType 

type DBBackendType string
const (
	// GoLevelDBBackend represents goleveldb (github.com/syndtr/goleveldb - most
	// popular implementation)
	//   - pure go
	//   - stable
	GoLevelDBBackend DBBackendType = "goleveldb"
	// CLevelDBBackend represents cleveldb (uses levigo wrapper)
	//   - fast
	//   - requires gcc
	//   - use cleveldb build tag (go build -tags cleveldb)
	CLevelDBBackend DBBackendType = "cleveldb"
	// MemDBBackend represents in-memoty key value store, which is mostly used
	// for testing.
	MemDBBackend DBBackendType = "memdb"
	// FSDBBackend represents filesystem database
	//	 - EXPERIMENTAL
	//   - slow
	FSDBBackend DBBackendType = "fsdb"
	// BoltDBBackend represents bolt (uses etcd's fork of bolt -
	// github.com/etcd-io/bbolt)
	//   - EXPERIMENTAL
	//   - may be faster is some use-cases (random reads - indexer)
	//   - use boltdb build tag (go build -tags boltdb)
	BoltDBBackend DBBackendType = "boltdb"
)

These are valid backend types.

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) Delete 

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

func (*FSDB) DeleteNoLock 

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

NOTE: Implements atomicSetDeleter.

func (*FSDB) DeleteSync 

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

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) 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) Print 

func (db *FSDB) Print()

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) 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) (*GoLevelDB, error)

func NewGoLevelDBWithOpts 

func NewGoLevelDBWithOpts(name string, dir string, o *opt.Options) (*GoLevelDB, error)

func (*GoLevelDB) Close 

func (db *GoLevelDB) Close()

Implements DB.

func (*GoLevelDB) DB 

func (db *GoLevelDB) DB() *leveldb.DB

func (*GoLevelDB) Delete 

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

Implements DB.

func (*GoLevelDB) DeleteSync 

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

Implements DB.

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) NewBatch 

func (db *GoLevelDB) NewBatch() Batch

Implements DB.

func (*GoLevelDB) Print 

func (db *GoLevelDB) Print()

Implements DB.

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()

	// 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) 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) 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) Mutex 

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

Implements atomicSetDeleter.

func (*MemDB) NewBatch 

func (db *MemDB) NewBatch() Batch

Implements DB.

func (*MemDB) Print 

func (db *MemDB) Print()

Implements DB.

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 SetDeleter 

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

Source Files

View all Source files

Directories

Path Synopsis
remotedb is a package for connecting to distributed Tendermint db.DB instances.
 remotedb is a package for connecting to distributed Tendermint db.DB instances.
grpcdb
grpcdb is the distribution of Tendermint's db.DB instances using the gRPC transport to decouple local db.DB usages from applications, to using them over a network in a highly performant manner.
 grpcdb is the distribution of Tendermint's db.DB instances using the gRPC transport to decouple local db.DB usages from applications, to using them over a network in a highly performant manner.
proto
Package protodb is a generated protocol buffer package.
 Package protodb is a generated protocol buffer package.

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