You can not select more than 25 topics
Topics must start with a letter or number, can include dashes ('-') and can be up to 35 characters long.
226 lines
4.2 KiB
226 lines
4.2 KiB
package db
|
|
|
|
import (
|
|
"fmt"
|
|
"sort"
|
|
"sync"
|
|
)
|
|
|
|
func init() {
|
|
registerDBCreator(MemDBBackendStr, func(name string, dir string) (DB, error) {
|
|
return NewMemDB(), nil
|
|
}, false)
|
|
}
|
|
|
|
var _ DB = (*MemDB)(nil)
|
|
|
|
type MemDB struct {
|
|
mtx sync.Mutex
|
|
db map[string][]byte
|
|
}
|
|
|
|
func NewMemDB() *MemDB {
|
|
database := &MemDB{
|
|
db: make(map[string][]byte),
|
|
}
|
|
return database
|
|
}
|
|
|
|
func (db *MemDB) Get(key []byte) []byte {
|
|
db.mtx.Lock()
|
|
defer db.mtx.Unlock()
|
|
panicNilKey(key)
|
|
return db.db[string(key)]
|
|
}
|
|
|
|
func (db *MemDB) Has(key []byte) bool {
|
|
db.mtx.Lock()
|
|
defer db.mtx.Unlock()
|
|
panicNilKey(key)
|
|
_, ok := db.db[string(key)]
|
|
return ok
|
|
}
|
|
|
|
func (db *MemDB) Set(key []byte, value []byte) {
|
|
db.mtx.Lock()
|
|
defer db.mtx.Unlock()
|
|
panicNilKey(key)
|
|
db.SetNoLock(key, value)
|
|
}
|
|
|
|
func (db *MemDB) SetSync(key []byte, value []byte) {
|
|
db.mtx.Lock()
|
|
defer db.mtx.Unlock()
|
|
panicNilKey(key)
|
|
db.SetNoLock(key, value)
|
|
}
|
|
|
|
// NOTE: Implements atomicSetDeleter
|
|
func (db *MemDB) SetNoLock(key []byte, value []byte) {
|
|
if value == nil {
|
|
value = []byte{}
|
|
}
|
|
panicNilKey(key)
|
|
db.db[string(key)] = value
|
|
}
|
|
|
|
func (db *MemDB) Delete(key []byte) {
|
|
db.mtx.Lock()
|
|
defer db.mtx.Unlock()
|
|
panicNilKey(key)
|
|
delete(db.db, string(key))
|
|
}
|
|
|
|
func (db *MemDB) DeleteSync(key []byte) {
|
|
db.mtx.Lock()
|
|
defer db.mtx.Unlock()
|
|
panicNilKey(key)
|
|
delete(db.db, string(key))
|
|
}
|
|
|
|
// NOTE: Implements atomicSetDeleter
|
|
func (db *MemDB) DeleteNoLock(key []byte) {
|
|
panicNilKey(key)
|
|
delete(db.db, string(key))
|
|
}
|
|
|
|
func (db *MemDB) Close() {
|
|
// Close is a noop since for an in-memory
|
|
// database, we don't have a destination
|
|
// to flush contents to nor do we want
|
|
// any data loss on invoking Close()
|
|
// See the discussion in https://github.com/tendermint/tmlibs/pull/56
|
|
}
|
|
|
|
func (db *MemDB) Print() {
|
|
db.mtx.Lock()
|
|
defer db.mtx.Unlock()
|
|
|
|
for key, value := range db.db {
|
|
fmt.Printf("[%X]:\t[%X]\n", []byte(key), value)
|
|
}
|
|
}
|
|
|
|
func (db *MemDB) Stats() map[string]string {
|
|
db.mtx.Lock()
|
|
defer db.mtx.Unlock()
|
|
|
|
stats := make(map[string]string)
|
|
stats["database.type"] = "memDB"
|
|
stats["database.size"] = fmt.Sprintf("%d", len(db.db))
|
|
return stats
|
|
}
|
|
|
|
func (db *MemDB) NewBatch() Batch {
|
|
db.mtx.Lock()
|
|
defer db.mtx.Unlock()
|
|
|
|
return &memBatch{db, nil}
|
|
}
|
|
|
|
func (db *MemDB) Mutex() *sync.Mutex {
|
|
return &(db.mtx)
|
|
}
|
|
|
|
//----------------------------------------
|
|
|
|
func (db *MemDB) Iterator(start, end []byte) Iterator {
|
|
it := newMemDBIterator(db, start, end)
|
|
|
|
db.mtx.Lock()
|
|
defer db.mtx.Unlock()
|
|
|
|
// We need a copy of all of the keys.
|
|
// Not the best, but probably not a bottleneck depending.
|
|
it.keys = db.getSortedKeys(start, end)
|
|
return it
|
|
}
|
|
|
|
func (db *MemDB) ReverseIterator(start, end []byte) Iterator {
|
|
it := newMemDBIterator(db, start, end)
|
|
|
|
db.mtx.Lock()
|
|
defer db.mtx.Unlock()
|
|
|
|
// We need a copy of all of the keys.
|
|
// Not the best, but probably not a bottleneck depending.
|
|
it.keys = db.getSortedKeys(end, start)
|
|
// reverse the order
|
|
l := len(it.keys) - 1
|
|
for i, v := range it.keys {
|
|
it.keys[i] = it.keys[l-i]
|
|
it.keys[l-i] = v
|
|
}
|
|
return nil
|
|
}
|
|
|
|
func (db *MemDB) getSortedKeys(start, end []byte) []string {
|
|
keys := []string{}
|
|
for key, _ := range db.db {
|
|
if IsKeyInDomain(key, start, end) {
|
|
keys = append(keys, key)
|
|
}
|
|
}
|
|
sort.Strings(keys)
|
|
return keys
|
|
}
|
|
|
|
var _ Iterator = (*memDBIterator)(nil)
|
|
|
|
type memDBIterator struct {
|
|
cur int
|
|
keys []string
|
|
db DB
|
|
start, end []byte
|
|
}
|
|
|
|
func newMemDBIterator(db DB, start, end []byte) *memDBIterator {
|
|
return &memDBIterator{
|
|
db: db,
|
|
start: start,
|
|
end: end,
|
|
}
|
|
}
|
|
|
|
func (it *memDBIterator) Domain() ([]byte, []byte) {
|
|
return it.start, it.end
|
|
}
|
|
|
|
func (it *memDBIterator) Valid() bool {
|
|
return 0 <= it.cur && it.cur < len(it.keys)
|
|
}
|
|
|
|
func (it *memDBIterator) Next() {
|
|
if !it.Valid() {
|
|
panic("memDBIterator Next() called when invalid")
|
|
}
|
|
it.cur++
|
|
}
|
|
|
|
func (it *memDBIterator) Prev() {
|
|
if !it.Valid() {
|
|
panic("memDBIterator Next() called when invalid")
|
|
}
|
|
it.cur--
|
|
}
|
|
|
|
func (it *memDBIterator) Key() []byte {
|
|
if !it.Valid() {
|
|
panic("memDBIterator Key() called when invalid")
|
|
}
|
|
return []byte(it.keys[it.cur])
|
|
}
|
|
|
|
func (it *memDBIterator) Value() []byte {
|
|
if !it.Valid() {
|
|
panic("memDBIterator Value() called when invalid")
|
|
}
|
|
return it.db.Get(it.Key())
|
|
}
|
|
|
|
func (it *memDBIterator) Close() {
|
|
it.db = nil
|
|
it.keys = nil
|
|
}
|
|
|
|
func (it *memDBIterator) Release() {}
|