// Write apply the given batch to the DB. The batch records will be applied
// sequentially. Write might be used concurrently, when used concurrently and
// batch is small enough, write will try to merge the batches. Set NoWriteMerge
// option to true to disable write merge.
//
// It is safe to modify the contents of the arguments after Write returns but
// not before. Write will not modify content of the batch.
func (db *DB) Write(batch *Batch, wo *opt.WriteOptions) error {
if err := db.ok(); err != nil || batch == nil || batch.Len() == 0 {
return err
}
// If the batch size is larger than write buffer, it may justified to write
// using transaction instead. Using transaction the batch will be written
// into tables directly, skipping the journaling.
if batch.internalLen > db.s.o.GetWriteBuffer() && !db.s.o.GetDisableLargeBatchTransaction() {
tr, err := db.OpenTransaction()
if err != nil {
return err
}
if err := tr.Write(batch, wo); err != nil {
tr.Discard()
return err
}
return tr.Commit()
}
merge := !wo.GetNoWriteMerge() && !db.s.o.GetNoWriteMerge()
sync := wo.GetSync() && !db.s.o.GetNoSync()
// Acquire write lock.
if merge {
select {
case db.writeMergeC <- writeMerge{sync: sync, batch: batch}:
if <-db.writeMergedC {
// Write is merged.
return <-db.writeAckC
}
// Write is not merged, the write lock is handed to us. Continue.
case db.writeLockC <- struct{}{}:
// Write lock acquired.
case err := <-db.compPerErrC:
// Compaction error.
return err
case <-db.closeC:
// Closed
return ErrClosed
}
} else {
select {
case db.writeLockC <- struct{}{}:
// Write lock acquired.
case err := <-db.compPerErrC:
// Compaction error.
return err
case <-db.closeC:
// Closed
return ErrClosed
}
}
return db.writeLocked(batch, nil, merge, sync)
}
func (db *DB) putRec(kt keyType, key, value []byte, wo *opt.WriteOptions) error {
if err := db.ok(); err != nil {
return err
}
merge := !wo.GetNoWriteMerge() && !db.s.o.GetNoWriteMerge()
sync := wo.GetSync() && !db.s.o.GetNoSync()
// Acquire write lock.
if merge {
select {
case db.writeMergeC <- writeMerge{sync: sync, keyType: kt, key: key, value: value}:
if <-db.writeMergedC {
// Write is merged.
return <-db.writeAckC
}
// Write is not merged, the write lock is handed to us. Continue.
case db.writeLockC <- struct{}{}:
// Write lock acquired.
case err := <-db.compPerErrC:
// Compaction error.
return err
case <-db.closeC:
// Closed
return ErrClosed
}
} else {
select {
case db.writeLockC <- struct{}{}:
// Write lock acquired.
case err := <-db.compPerErrC:
// Compaction error.
return err
case <-db.closeC:
// Closed
return ErrClosed
}
}
batch := db.batchPool.Get().(*Batch)
batch.Reset()
batch.appendRec(kt, key, value)
return db.writeLocked(batch, batch, merge, sync)
}
// Write apply the given batch to the DB. The batch will be applied
// sequentially.
//
// It is safe to modify the contents of the arguments after Write returns.
func (db *DB) Write(b *Batch, wo *opt.WriteOptions) (err error) {
err = db.ok()
if err != nil || b == nil || b.Len() == 0 {
return
}
b.init(wo.GetSync() && !db.s.o.GetNoSync())
if b.size() > db.s.o.GetWriteBuffer() && !db.s.o.GetDisableLargeBatchTransaction() {
// Writes using transaction.
tr, err1 := db.OpenTransaction()
if err1 != nil {
return err1
}
if err1 := tr.Write(b, wo); err1 != nil {
tr.Discard()
return err1
}
return tr.Commit()
}
// The write happen synchronously.
select {
case db.writeC <- b:
if <-db.writeMergedC {
return <-db.writeAckC
}
// Continue, the write lock already acquired by previous writer
// and handed out to us.
case db.writeLockC <- struct{}{}:
case err = <-db.compPerErrC:
return
case _, _ = <-db.closeC:
return ErrClosed
}
merged := 0
danglingMerge := false
defer func() {
for i := 0; i < merged; i++ {
db.writeAckC <- err
}
if danglingMerge {
// Only one dangling merge at most, so this is safe.
db.writeMergedC <- false
} else {
<-db.writeLockC
}
}()
mdb, mdbFree, err := db.flush(b.size())
if err != nil {
return
}
defer mdb.decref()
// Calculate maximum size of the batch.
m := 1 << 20
if x := b.size(); x <= 128<<10 {
m = x + (128 << 10)
}
m = minInt(m, mdbFree)
// Merge with other batch.
drain:
for b.size() < m && !b.sync {
select {
case nb := <-db.writeC:
if b.size()+nb.size() <= m {
b.append(nb)
db.writeMergedC <- true
merged++
} else {
danglingMerge = true
break drain
}
default:
break drain
}
}
// Set batch first seq number relative from last seq.
b.seq = db.seq + 1
// Write journal concurrently if it is large enough.
if b.size() >= (128 << 10) {
// Push the write batch to the journal writer
select {
case db.journalC <- b:
// Write into memdb
if berr := b.memReplay(mdb.DB); berr != nil {
panic(berr)
}
case err = <-db.compPerErrC:
return
case _, _ = <-db.closeC:
err = ErrClosed
return
}
// Wait for journal writer
select {
case err = <-db.journalAckC:
if err != nil {
// Revert memdb if error detected
if berr := b.revertMemReplay(mdb.DB); berr != nil {
panic(berr)
}
return
}
case _, _ = <-db.closeC:
err = ErrClosed
return
}
} else {
err = db.writeJournal(b)
if err != nil {
return
}
if berr := b.memReplay(mdb.DB); berr != nil {
panic(berr)
}
}
// Set last seq number.
db.addSeq(uint64(b.Len()))
if b.size() >= mdbFree {
db.rotateMem(0, false)
}
return
}
// Write apply the given batch to the DB. The batch will be applied
// sequentially.
//
// It is safe to modify the contents of the arguments after Write returns.
func (d *DB) Write(b *Batch, wo *opt.WriteOptions) (err error) {
err = d.ok()
if err != nil || b == nil || b.len() == 0 {
return
}
b.init(wo.GetSync())
// The write happen synchronously.
select {
case _, _ = <-d.closeCh:
return ErrClosed
case d.writeCh <- b:
return <-d.writeAckCh
case d.writeLockCh <- struct{}{}:
}
merged := 0
defer func() {
<-d.writeLockCh
for i := 0; i < merged; i++ {
d.writeAckCh <- err
}
}()
mem, err := d.flush()
if err != nil {
return
}
// Calculate maximum size of the batch.
m := 1 << 20
if x := b.size(); x <= 128<<10 {
m = x + (128 << 10)
}
// Merge with other batch.
drain:
for b.size() <= m && !b.sync {
select {
case nb := <-d.writeCh:
b.append(nb)
merged++
default:
break drain
}
}
// Set batch first seq number relative from last seq.
b.seq = d.seq + 1
// Write journal concurrently if it is large enough.
if b.size() >= (128 << 10) {
// Push the write batch to the journal writer
select {
case _, _ = <-d.closeCh:
err = ErrClosed
return
case d.journalCh <- b:
// Write into memdb
b.memReplay(mem)
}
// Wait for journal writer
select {
case _, _ = <-d.closeCh:
err = ErrClosed
return
case err = <-d.journalAckCh:
if err != nil {
// Revert memdb if error detected
b.revertMemReplay(mem)
return
}
}
} else {
err = d.doWriteJournal(b)
if err != nil {
return
}
b.memReplay(mem)
}
// Set last seq number.
d.addSeq(uint64(b.len()))
return
}
// Write apply the given batch to the DB. The batch will be applied
// sequentially.
//
// It is safe to modify the contents of the arguments after Write returns.
func (db *DB) Write(b *Batch, wo *opt.WriteOptions) (err error) {
err = db.ok()
if err != nil || b == nil || b.Len() == 0 {
return
}
b.init(wo.GetSync())
// The write happen synchronously.
select {
case db.writeC <- b:
if <-db.writeMergedC {
return <-db.writeAckC
}
case db.writeLockC <- struct{}{}:
case err = <-db.compPerErrC:
return
case _, _ = <-db.closeC:
return ErrClosed
}
merged := 0
danglingMerge := false
defer func() {
if danglingMerge {
db.writeMergedC <- false
} else {
<-db.writeLockC
}
for i := 0; i < merged; i++ {
db.writeAckC <- err
}
}()
mem, memFree, err := db.flush(b.size())
if err != nil {
return
}
defer mem.decref()
// Calculate maximum size of the batch.
m := 1 << 20
if x := b.size(); x <= 128<<10 {
m = x + (128 << 10)
}
m = minInt(m, memFree)
// Merge with other batch.
drain:
for b.size() < m && !b.sync {
select {
case nb := <-db.writeC:
if b.size()+nb.size() <= m {
b.append(nb)
db.writeMergedC <- true
merged++
} else {
danglingMerge = true
break drain
}
default:
break drain
}
}
// Set batch first seq number relative from last seq.
b.seq = db.seq + 1
// Write journal concurrently if it is large enough.
if b.size() >= (128 << 10) {
// Push the write batch to the journal writer
select {
case db.journalC <- b:
// Write into memdb
if berr := b.memReplay(mem.mdb); berr != nil {
panic(berr)
}
case err = <-db.compPerErrC:
return
case _, _ = <-db.closeC:
err = ErrClosed
return
}
// Wait for journal writer
select {
case err = <-db.journalAckC:
if err != nil {
// Revert memdb if error detected
if berr := b.revertMemReplay(mem.mdb); berr != nil {
panic(berr)
}
return
}
case _, _ = <-db.closeC:
err = ErrClosed
return
}
} else {
err = db.writeJournal(b)
if err != nil {
return
}
if berr := b.memReplay(mem.mdb); berr != nil {
panic(berr)
}
}
// Set last seq number.
db.addSeq(uint64(b.Len()))
if b.size() >= memFree {
db.rotateMem(0)
}
return
}