ledisdb/store/leveldb/batch.go

102 lines
1.7 KiB
Go

// +build leveldb
package leveldb
// #cgo LDFLAGS: -lleveldb
// #include "leveldb/c.h"
import "C"
import (
"github.com/siddontang/goleveldb/leveldb"
"unsafe"
)
/*
It's not easy to let leveldb support Data() function like rocksdb,
so here, we will use goleveldb batch instead
later optimize
*/
type WriteBatch struct {
db *DB
wbatch *C.leveldb_writebatch_t
gbatch *leveldb.Batch
}
func newWriteBatch(db *DB) *WriteBatch {
w := new(WriteBatch)
w.db = db
w.wbatch = C.leveldb_writebatch_create()
w.gbatch = new(leveldb.Batch)
return w
}
func (w *WriteBatch) Close() error {
C.leveldb_writebatch_destroy(w.wbatch)
w.wbatch = nil
w.gbatch = nil
return nil
}
func (w *WriteBatch) Put(key, value []byte) {
w.gbatch.Put(key, value)
var k, v *C.char
if len(key) != 0 {
k = (*C.char)(unsafe.Pointer(&key[0]))
}
if len(value) != 0 {
v = (*C.char)(unsafe.Pointer(&value[0]))
}
lenk := len(key)
lenv := len(value)
C.leveldb_writebatch_put(w.wbatch, k, C.size_t(lenk), v, C.size_t(lenv))
}
func (w *WriteBatch) Delete(key []byte) {
w.gbatch.Delete(key)
C.leveldb_writebatch_delete(w.wbatch,
(*C.char)(unsafe.Pointer(&key[0])), C.size_t(len(key)))
}
func (w *WriteBatch) Commit() error {
w.gbatch.Reset()
return w.commit(w.db.writeOpts)
}
func (w *WriteBatch) SyncCommit() error {
w.gbatch.Reset()
return w.commit(w.db.syncOpts)
}
func (w *WriteBatch) Rollback() error {
C.leveldb_writebatch_clear(w.wbatch)
w.gbatch.Reset()
return nil
}
func (w *WriteBatch) commit(wb *WriteOptions) error {
var errStr *C.char
C.leveldb_write(w.db.db, wb.Opt, w.wbatch, &errStr)
if errStr != nil {
return saveError(errStr)
}
return nil
}
func (w *WriteBatch) Data() []byte {
return w.gbatch.Dump()
}