Nelze vybrat více než 25 témat
Téma musí začínat písmenem nebo číslem, může obsahovat pomlčky („-“) a může být dlouhé až 35 znaků.
148 řádky
3.7 KiB
148 řádky
3.7 KiB
// Copyright (c) 2011 The LevelDB Authors. All rights reserved.
|
|
// Use of this source code is governed by a BSD-style license that can be
|
|
// found in the LICENSE file. See the AUTHORS file for names of contributors.
|
|
//
|
|
// WriteBatch::rep_ :=
|
|
// sequence: fixed64
|
|
// count: fixed32
|
|
// data: record[count]
|
|
// record :=
|
|
// kTypeValue varstring varstring |
|
|
// kTypeDeletion varstring
|
|
// varstring :=
|
|
// len: varint32
|
|
// data: uint8[len]
|
|
|
|
#include "leveldb/write_batch.h"
|
|
|
|
#include "leveldb/db.h"
|
|
#include "db/dbformat.h"
|
|
#include "db/memtable.h"
|
|
#include "db/write_batch_internal.h"
|
|
#include "util/coding.h"
|
|
|
|
namespace leveldb {
|
|
|
|
WriteBatch::WriteBatch() {
|
|
Clear();
|
|
}
|
|
|
|
WriteBatch::~WriteBatch() { }
|
|
|
|
void WriteBatch::Clear() {
|
|
rep_.clear();
|
|
rep_.resize(12);
|
|
}
|
|
|
|
int WriteBatchInternal::Count(const WriteBatch* b) {
|
|
return DecodeFixed32(b->rep_.data() + 8);
|
|
}
|
|
|
|
void WriteBatchInternal::SetCount(WriteBatch* b, int n) {
|
|
EncodeFixed32(&b->rep_[8], n);
|
|
}
|
|
|
|
SequenceNumber WriteBatchInternal::Sequence(const WriteBatch* b) {
|
|
return SequenceNumber(DecodeFixed64(b->rep_.data()));
|
|
}
|
|
|
|
void WriteBatchInternal::SetSequence(WriteBatch* b, SequenceNumber seq) {
|
|
EncodeFixed64(&b->rep_[0], seq);
|
|
}
|
|
|
|
void WriteBatch::Put(const Slice& key, const Slice& value) {
|
|
WriteBatchInternal::SetCount(this, WriteBatchInternal::Count(this) + 1);
|
|
rep_.push_back(static_cast<char>(kTypeValue));
|
|
PutLengthPrefixedSlice(&rep_, key);
|
|
PutLengthPrefixedSlice(&rep_, value);
|
|
}
|
|
|
|
void WriteBatch::Delete(const Slice& key) {
|
|
WriteBatchInternal::SetCount(this, WriteBatchInternal::Count(this) + 1);
|
|
rep_.push_back(static_cast<char>(kTypeDeletion));
|
|
PutLengthPrefixedSlice(&rep_, key);
|
|
}
|
|
|
|
Status WriteBatchInternal::InsertInto(const WriteBatch* b,
|
|
MemTable* memtable) {
|
|
const int count = WriteBatchInternal::Count(b);
|
|
int found = 0;
|
|
Iterator it(*b);
|
|
for (; !it.Done(); it.Next()) {
|
|
switch (it.op()) {
|
|
case kTypeDeletion:
|
|
memtable->Add(it.sequence_number(), kTypeDeletion, it.key(), Slice());
|
|
break;
|
|
case kTypeValue:
|
|
memtable->Add(it.sequence_number(), kTypeValue, it.key(), it.value());
|
|
break;
|
|
}
|
|
found++;
|
|
}
|
|
if (!it.status().ok()) {
|
|
return it.status();
|
|
} else if (found != count) {
|
|
return Status::Corruption("wrong count in WriteBatch");
|
|
}
|
|
return Status::OK();
|
|
}
|
|
|
|
void WriteBatchInternal::SetContents(WriteBatch* b, const Slice& contents) {
|
|
assert(contents.size() >= 12);
|
|
b->rep_.assign(contents.data(), contents.size());
|
|
}
|
|
|
|
WriteBatchInternal::Iterator::Iterator(const WriteBatch& batch)
|
|
: input_(WriteBatchInternal::Contents(&batch)),
|
|
done_(false) {
|
|
if (input_.size() < 12) {
|
|
done_ = true;
|
|
} else {
|
|
seq_ = WriteBatchInternal::Sequence(&batch),
|
|
input_.remove_prefix(12);
|
|
GetNextEntry();
|
|
}
|
|
}
|
|
|
|
void WriteBatchInternal::Iterator::Next() {
|
|
assert(!done_);
|
|
seq_++;
|
|
GetNextEntry();
|
|
}
|
|
|
|
void WriteBatchInternal::Iterator::GetNextEntry() {
|
|
if (input_.empty()) {
|
|
done_ = true;
|
|
return;
|
|
}
|
|
char tag = input_[0];
|
|
input_.remove_prefix(1);
|
|
switch (tag) {
|
|
case kTypeValue:
|
|
if (GetLengthPrefixedSlice(&input_, &key_) &&
|
|
GetLengthPrefixedSlice(&input_, &value_)) {
|
|
op_ = static_cast<ValueType>(tag);
|
|
} else {
|
|
status_ = Status::Corruption("bad WriteBatch Put");
|
|
done_ = true;
|
|
input_.clear();
|
|
}
|
|
break;
|
|
case kTypeDeletion:
|
|
if (GetLengthPrefixedSlice(&input_, &key_)) {
|
|
op_ = kTypeDeletion;
|
|
} else {
|
|
status_ = Status::Corruption("bad WriteBatch Delete");
|
|
done_ = true;
|
|
input_.clear();
|
|
}
|
|
break;
|
|
default:
|
|
status_ = Status::Corruption("unknown WriteBatch tag");
|
|
done_ = true;
|
|
input_.clear();
|
|
break;
|
|
}
|
|
}
|
|
|
|
}
|