123456789101112131415161718192021222324252627282930313233343536373839404142434445464748495051525354555657585960616263646566676869707172737475767778798081828384858687888990919293949596979899100101102103104105106107108109110111112113114115116117118119120121122123124125126127128129130131132133134135136137138139140141142143144145146147148149150151152153154155156157158159160 |
- // Copyright (C) 2014 The Syncthing Authors.
- //
- // This Source Code Form is subject to the terms of the Mozilla Public
- // License, v. 2.0. If a copy of the MPL was not distributed with this file,
- // You can obtain one at https://mozilla.org/MPL/2.0/.
- package db
- import (
- "encoding/binary"
- "time"
- "github.com/syndtr/goleveldb/leveldb"
- "github.com/syndtr/goleveldb/leveldb/util"
- )
- // NamespacedKV is a simple key-value store using a specific namespace within
- // a leveldb.
- type NamespacedKV struct {
- db *Instance
- prefix []byte
- }
- // NewNamespacedKV returns a new NamespacedKV that lives in the namespace
- // specified by the prefix.
- func NewNamespacedKV(db *Instance, prefix string) *NamespacedKV {
- return &NamespacedKV{
- db: db,
- prefix: []byte(prefix),
- }
- }
- // Reset removes all entries in this namespace.
- func (n *NamespacedKV) Reset() {
- it := n.db.NewIterator(util.BytesPrefix(n.prefix), nil)
- defer it.Release()
- batch := new(leveldb.Batch)
- for it.Next() {
- batch.Delete(it.Key())
- if batch.Len() > batchFlushSize {
- if err := n.db.Write(batch, nil); err != nil {
- panic(err)
- }
- batch.Reset()
- }
- }
- if batch.Len() > 0 {
- if err := n.db.Write(batch, nil); err != nil {
- panic(err)
- }
- }
- }
- // PutInt64 stores a new int64. Any existing value (even if of another type)
- // is overwritten.
- func (n *NamespacedKV) PutInt64(key string, val int64) {
- keyBs := append(n.prefix, []byte(key)...)
- var valBs [8]byte
- binary.BigEndian.PutUint64(valBs[:], uint64(val))
- n.db.Put(keyBs, valBs[:], nil)
- }
- // Int64 returns the stored value interpreted as an int64 and a boolean that
- // is false if no value was stored at the key.
- func (n *NamespacedKV) Int64(key string) (int64, bool) {
- keyBs := append(n.prefix, []byte(key)...)
- valBs, err := n.db.Get(keyBs, nil)
- if err != nil {
- return 0, false
- }
- val := binary.BigEndian.Uint64(valBs)
- return int64(val), true
- }
- // PutTime stores a new time.Time. Any existing value (even if of another
- // type) is overwritten.
- func (n *NamespacedKV) PutTime(key string, val time.Time) {
- keyBs := append(n.prefix, []byte(key)...)
- valBs, _ := val.MarshalBinary() // never returns an error
- n.db.Put(keyBs, valBs, nil)
- }
- // Time returns the stored value interpreted as a time.Time and a boolean
- // that is false if no value was stored at the key.
- func (n NamespacedKV) Time(key string) (time.Time, bool) {
- var t time.Time
- keyBs := append(n.prefix, []byte(key)...)
- valBs, err := n.db.Get(keyBs, nil)
- if err != nil {
- return t, false
- }
- err = t.UnmarshalBinary(valBs)
- return t, err == nil
- }
- // PutString stores a new string. Any existing value (even if of another type)
- // is overwritten.
- func (n *NamespacedKV) PutString(key, val string) {
- keyBs := append(n.prefix, []byte(key)...)
- n.db.Put(keyBs, []byte(val), nil)
- }
- // String returns the stored value interpreted as a string and a boolean that
- // is false if no value was stored at the key.
- func (n NamespacedKV) String(key string) (string, bool) {
- keyBs := append(n.prefix, []byte(key)...)
- valBs, err := n.db.Get(keyBs, nil)
- if err != nil {
- return "", false
- }
- return string(valBs), true
- }
- // PutBytes stores a new byte slice. Any existing value (even if of another type)
- // is overwritten.
- func (n *NamespacedKV) PutBytes(key string, val []byte) {
- keyBs := append(n.prefix, []byte(key)...)
- n.db.Put(keyBs, val, nil)
- }
- // Bytes returns the stored value as a raw byte slice and a boolean that
- // is false if no value was stored at the key.
- func (n NamespacedKV) Bytes(key string) ([]byte, bool) {
- keyBs := append(n.prefix, []byte(key)...)
- valBs, err := n.db.Get(keyBs, nil)
- if err != nil {
- return nil, false
- }
- return valBs, true
- }
- // PutBool stores a new boolean. Any existing value (even if of another type)
- // is overwritten.
- func (n *NamespacedKV) PutBool(key string, val bool) {
- keyBs := append(n.prefix, []byte(key)...)
- if val {
- n.db.Put(keyBs, []byte{0x0}, nil)
- } else {
- n.db.Put(keyBs, []byte{0x1}, nil)
- }
- }
- // Bool returns the stored value as a boolean and a boolean that
- // is false if no value was stored at the key.
- func (n NamespacedKV) Bool(key string) (bool, bool) {
- keyBs := append(n.prefix, []byte(key)...)
- valBs, err := n.db.Get(keyBs, nil)
- if err != nil {
- return false, false
- }
- return valBs[0] == 0x0, true
- }
- // Delete deletes the specified key. It is allowed to delete a nonexistent
- // key.
- func (n NamespacedKV) Delete(key string) {
- keyBs := append(n.prefix, []byte(key)...)
- n.db.Delete(keyBs, nil)
- }
|