10225501448 李度 10225101546 陈胤遒 10215501422 高宇菲
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58 rader
1.4 KiB

#include "fielddb/meta.h"
#include "util/coding.h"
#include <string>
#include "leveldb/options.h"
#include "leveldb/slice.h"
#include "leveldb/write_batch.h"
namespace fielddb {
using namespace leveldb;
// Slice MetaKV::metaKey() {
// std::string buf;
// PutLengthPrefixedSlice(&buf, Key);
// PutFixed64(&buf, meta_seq);
// PutFixed32(&buf, tag);
// return Slice(buf);
// }
// Slice MetaKV::metaValue() {
// return Slice(SerializeValue(Fields));
// }
//对于含有index field的put的meta编码为 (KV|Key,Value)
void MetaKV::Trans(Slice &MetaKey,Slice &MetaValue) {
MetaKey.clear();
MetaValue.clear();
std::string buf;
PutFixed32(&buf, KV_Creating);
PutLengthPrefixedSlice(&buf, Slice(*name));
MetaKey = Slice(buf);
MetaValue = Slice(*value);
}
class CleanerHandler : public WriteBatch::Handler {
public:
WriteBatch *NeedClean;
void Put(const Slice& key, const Slice& value) override {
//将所有之前put的meta数据进行delete
NeedClean->Delete(key);
}
void Delete(const Slice& key) override {
//所有的传入的MetaBatch都是Put的
assert(0);
}
};
void MetaCleaner::Collect(WriteBatch &MetaBatch) {
CleanerHandler Handler;
Handler.NeedClean = &NeedClean;
MetaBatch.Iterate(&Handler);
}
void MetaCleaner::CleanMetaBatch(DB *metaDB) {
if(NeedClean.ApproximateSize() == 0) return;
metaDB->Write(WriteOptions(), &NeedClean);
}
}