Merge pull request 'ld' (#2) from ld into main

Reviewed-on: 10225501448/leveldb_proj2#2

.gitignore

@@ -9,4 +9,6 @@ out/
 
 # clangd
 .cache/
-compile_commands.json
+compile_commands.json
+
+benchmark-result/

3DB设计.md

@@ -16,14 +16,14 @@
 
 如果当前有正在创建（修改）的索引或者之前的对于同一个key的索引put，则判断本次put是否含有对应的索引，如果没有则按上面一段的操作进行。如果含有，则加入之前设计中的taskqueue，在索引创建完成后会进行处理。
 
-我觉得：索引put涉及到了indexDB和kvDB两者之间的原子性
+想法：索引put涉及到了indexDB和kvDB两者之间的原子性
 
 ## 创建（删除）索引
 在进行这个操作之前对metaDB写入一个标记`(field,creating/deleting)`，表示在field上创建（删除）索引操作的事务的开始。（注：这里的key是包含了时间戳或者seq的）。
 
 之后扫描kvDB，构建相应请求，对indexDB进行写入，这里也是通过writebatch写入的。写入完成之后，将之前的标记清除，表示当前的事务结束了。之后对于taskqueue里面的请求进行处理，完成之后，唤醒taskqueue中的请求。
 
-我觉得：创建（删除）索引这个操作实际上只对indexDB进行了写入请求，并不涉及indexDB和kvDB两者之间的一致性
+想法：创建（删除）索引这个操作实际上只对indexDB进行了写入请求，并不涉及indexDB和kvDB两者之间的一致性
 
 ## 索引get
 如果没有索引，则返回；如果索引正在创建，则存到taskqueue中，在索引创建完成之后进行处理（这里或许也可以直接返回）；如果存在索引则将请求发往indexDB。
@@ -63,10 +63,29 @@ indexDB的写入情况判断如下：扫描indexDB，如果是creating操作且
 不用时间戳，全部写入metaDB作为log，然后再写入kvDB和indexDB
 
 # 整体架构
-采用多线程架构
-由于二级索引理论上是幂等的操作,所以或许不用taskqueue来阻塞创建之后的写入？
-如果这么看的话，其实创建（删除）索引的操作也不需要
+基于request（类似于writer）来处理并发的请求。对于创建和删除索引操作，包含一个pending队列，来维护会受到影响的请求。
 
+# 有关实现的部分
+
+1. 对于metaDB中存入数据的编码部分放在了metakv文件中
+
+## TODO List
+1. index和kv的写入应该放在两个线程中同时写入，这里为了实现的方便，暂时先后完成
+
+2. 原版的env中的Schedule是使用单例模式，也就是所有的数据库都只有一个线程，我们这里
+需要所有的数据库都有属于自己的线程，且可能不止一个，因此需要实现类似于线程池的东西
+
+## 一些想法
+1. 根据对于某一个Field搜索的频率和耗时，自动的创建索引，且这个索引会在长时间不用后被清除
+
+# 有关KV分离的想法
+复用原有的log，将log信息加入到version信息中，需要更改version edit,version等内容
+log带上编号，从小到大的进行垃圾回收
+垃圾回收过程中形成的新的写入保留原有的seq放入L0
+
+KV分离核心的困难之一在于垃圾回收的并发控制。我的核心想法是在回收log的时候，不进行合并操作，将
+回收得到的东西直接保留seqno放进L0。由于L0本身就是无序的，如果在垃圾回收的过程中产生了并发写入，
+新的写入也只会写入到L0，这样只要等待下一次的合并就行了。
 
 
 

CMakeLists.txt

@@ -17,7 +17,7 @@ endif(NOT CMAKE_C_STANDARD)
 # C++ standard can be overridden when this is used as a sub-project.
 if(NOT CMAKE_CXX_STANDARD)
   # This project requires C++11.
-  set(CMAKE_CXX_STANDARD 11)
+  set(CMAKE_CXX_STANDARD 17)
   set(CMAKE_CXX_STANDARD_REQUIRED ON)
   set(CMAKE_CXX_EXTENSIONS OFF)
 endif(NOT CMAKE_CXX_STANDARD)
@@ -194,6 +194,12 @@ target_sources(leveldb
     "util/serialize_value.cc"
     "fielddb/field_db.cpp"
     "fielddb/field_db.h"
+    "fielddb/meta.cpp"
+    "fielddb/meta.h"
+    "fielddb/request.cpp"
+    "fielddb/request.h"
+    "testdb/testdb.cc"
+    "testdb/testdb.h"
 
   # Only CMake 3.3+ supports PUBLIC sources in targets exported by "install".
   $<$<VERSION_GREATER:CMAKE_VERSION,3.2>:PUBLIC>
@@ -443,6 +449,8 @@ if(LEVELDB_BUILD_BENCHMARKS)
 
   if(NOT BUILD_SHARED_LIBS)
     leveldb_benchmark("benchmarks/db_bench.cc")
+    leveldb_benchmark("benchmarks/db_bench_FieldDB.cc")
+    leveldb_benchmark("benchmarks/db_bench_testDB.cc")
   endif(NOT BUILD_SHARED_LIBS)
 
   check_library_exists(sqlite3 sqlite3_open "" HAVE_SQLITE3)
@@ -522,7 +530,17 @@ if(LEVELDB_INSTALL)
   )
 endif(LEVELDB_INSTALL)
 
-add_executable(lab1_test
+add_executable(basic_function_test
         "${PROJECT_SOURCE_DIR}/test/basic_function_test.cc"
 )
-target_link_libraries(lab1_test PRIVATE leveldb gtest)
+target_link_libraries(basic_function_test PRIVATE leveldb gtest)
+
+add_executable(parallel_test
+        "${PROJECT_SOURCE_DIR}/test/parallel_test.cc"
+)
+target_link_libraries(parallel_test PRIVATE leveldb gtest)
+
+add_executable(recover_test
+        "${PROJECT_SOURCE_DIR}/test/recover_test.cc"
+)
+target_link_libraries(recover_test PRIVATE leveldb gtest)

benchmarks/db_bench.cc

@@ -325,8 +325,8 @@ class Stats {
       // elapsed times.
       double elapsed = (finish_ - start_) * 1e-6;
       char rate[100];
-      std::snprintf(rate, sizeof(rate), "%6.1f MB/s",
-                    (bytes_ / 1048576.0) / elapsed);
+      std::snprintf(rate, sizeof(rate), "%6.1f MB/s Bytes:%6.1f elapsed(s):%6.1f seconds:%6.1f ",
+                    (bytes_ / 1048576.0) / elapsed,(bytes_ / 1048576.0),elapsed,seconds_);
       extra = rate;
     }
     AppendWithSpace(&extra, message_);
@@ -737,6 +737,10 @@ class Benchmark {
     }
     shared.mu.Unlock();
 
+    // for(int i = 0; i < n; i++) {
+    //   arg[i].thread->stats.Report(name.ToString() + "thread:" + std::to_string(i));
+    // }
+
     for (int i = 1; i < n; i++) {
       arg[0].thread->stats.Merge(arg[i].thread->stats);
     }
@@ -852,8 +856,20 @@ class Benchmark {
       for (int j = 0; j < entries_per_batch_; j++) {
         const int k = seq ? i + j : thread->rand.Uniform(FLAGS_num);
         key.Set(k);
-        batch.Put(key.slice(), gen.Generate(value_size_));
-        bytes += value_size_ + key.slice().size();
+
+        std::string name = "customer#" + std::to_string(k);
+        //这个字段用来查找
+        std::string age = std::to_string(thread->rand.Uniform(FLAGS_num) % 100); 
+        //这个字段填充长度
+        std::string tag = gen.Generate(value_size_).ToString(); 
+        FieldArray fields = {
+          {"name", name},
+          {"age", age},
+          {"tag", tag}
+        };
+        std::string value = SerializeValue(fields);
+        batch.Put(key.slice(), value);
+        bytes += value.size() + key.slice().size();
         thread->stats.FinishedSingleOp();
       }
       s = db_->Write(write_options_, &batch);
@@ -1123,6 +1139,8 @@ int main(int argc, char** argv) {
     }
   }
 
+  FLAGS_num /= FLAGS_threads;
+
   leveldb::g_env = leveldb::Env::Default();
 
   // Choose a location for the test database if none given with --db=<path>

db/db_impl.cc

@@ -1169,7 +1169,7 @@ Status DBImpl::GetFields(const ReadOptions& options, const Slice& key,
                    FieldArray* fields) {
   std::string value;
   Status s = DBImpl::Get(options, key, &value);
-  *fields = *ParseValue(value);
+  ParseValue(value,fields);
   return s;
 }
 
@@ -1183,6 +1183,7 @@ std::vector DBImpl::FindKeysByField(Field &field){
             result.push_back(iter->key().ToString());
         }
     }
+    delete iter;
     return result;
 }
 
@@ -1234,12 +1235,18 @@ Status DBImpl::Write(const WriteOptions& options, WriteBatch* updates) {
   w.sync = options.sync;
   w.done = false;
 
+  uint64_t start_ = env_->NowMicros();
   MutexLock l(&mutex_);
+  count ++;
   writers_.push_back(&w);
   while (!w.done && &w != writers_.front()) {
     w.cv.Wait();
   }
   if (w.done) {
+    Waiting_elapsed += env_->NowMicros() - start_;
+    waited_count ++;
+    Total_elapsed += env_->NowMicros() - start_;
+    // dumpStatistics();
     return w.status;
   }
 
@@ -1258,6 +1265,7 @@ Status DBImpl::Write(const WriteOptions& options, WriteBatch* updates) {
     // into mem_.
     {
       mutex_.Unlock();
+      uint64_t start_write = env_->NowMicros();
       status = log_->AddRecord(WriteBatchInternal::Contents(write_batch));
       bool sync_error = false;
       if (status.ok() && options.sync) {
@@ -1269,6 +1277,8 @@ Status DBImpl::Write(const WriteOptions& options, WriteBatch* updates) {
       if (status.ok()) {
         status = WriteBatchInternal::InsertInto(write_batch, mem_);
       }
+      BatchSize += write_batch->ApproximateSize();
+      write_elapsed += env_->NowMicros() - start_write;
       mutex_.Lock();
       if (sync_error) {
         // The state of the log file is indeterminate: the log record we
@@ -1297,7 +1307,10 @@ Status DBImpl::Write(const WriteOptions& options, WriteBatch* updates) {
   if (!writers_.empty()) {
     writers_.front()->cv.Signal();
   }
-
+  Total_elapsed += env_->NowMicros() - start_;
+  NoWaiting_elapsed += env_->NowMicros() - start_;
+  Nowaited_count ++;
+  // dumpStatistics();
   return status;
 }
 

db/db_impl.h

@@ -6,7 +6,10 @@
 #define STORAGE_LEVELDB_DB_DB_IMPL_H_
 
 #include <atomic>
+#include <cstdint>
+#include <cstdio>
 #include <deque>
+#include <ostream>
 #include <set>
 #include <string>
 
@@ -210,6 +213,33 @@ class DBImpl : public DB {
   Status bg_error_ GUARDED_BY(mutex_);
 
   CompactionStats stats_[config::kNumLevels] GUARDED_BY(mutex_);
+
+  int count = 0;
+  int waited_count = 0;
+  int Nowaited_count = 0;
+  uint64_t Total_elapsed = 0;
+  uint64_t Waiting_elapsed = 0;
+  uint64_t NoWaiting_elapsed = 0;
+  uint64_t write_elapsed = 0;
+  uint64_t BatchSize = 0;
+  const double MB = 1024 * 1024;
+  const double KB = 1024;
+  inline void dumpStatistics() {
+    if(count && count % 500000 == 0) {
+      printf("==================================\n");
+      printf("Count: Total:%d    Waited:%d    Nowaited:%d\n",count,waited_count,Nowaited_count);
+      printf("%ld %ld %ld\n",Total_elapsed,Waiting_elapsed,NoWaiting_elapsed);
+      printf("Average Total elapsed:   %lf ms\n",Total_elapsed * 1.0 / count);
+      printf("Average Waiting elapsed: %lf ms\n",Waiting_elapsed * 1.0 / count);
+      printf("For waiting request:     %lf ms\n",Waiting_elapsed * 1.0 / waited_count);
+      printf("For Nowait request:      %lf ms\n",NoWaiting_elapsed * 1.0 / Nowaited_count);
+      printf("Write elapsed:           %lf ms\n",write_elapsed * 1.0 / Nowaited_count);
+      printf("Average BatchSize:       %lfKB\n",BatchSize / KB / count);
+      printf("Average BatchSize per write:%lfKB\n",BatchSize / KB / Nowaited_count);
+      printf("==================================\n");
+      std::fflush(stdout);
+    }
+  }
 };
 
 // Sanitize db options.  The caller should delete result.info_log if

fielddb/SliceHashSet.h

@@ -0,0 +1,24 @@
+# ifndef SLICE_HASH_SET_H
+# define SLICE_HASH_SET_H
+
+#include "leveldb/slice.h"
+#include "util/hash.h"
+#include <unordered_set>
+using namespace leveldb;
+class SliceHash {
+public:
+    uint32_t operator()(const Slice &lhs) const {
+        return Hash(lhs.data(),lhs.size(),0x1234);
+    }
+};
+
+class SliceEq {
+public:
+    bool operator()(const Slice &lhs, const Slice &rhs) const {
+        return lhs == rhs;
+    }
+};
+
+using SliceHashSet = std::unordered_set<Slice,SliceHash,SliceEq>;
+
+#endif

fielddb/field_db.cpp

@@ -1,19 +1,30 @@
 #include "fielddb/field_db.h"
+#include <climits>
 #include <cstdint>
+#include <cstdio>
 #include <string>
+#include <sys/types.h>
+#include <utility>
 #include <vector>
 #include "leveldb/db.h"
 #include "leveldb/env.h"
+#include "leveldb/iterator.h"
 #include "leveldb/options.h"
+#include "leveldb/slice.h"
 #include "leveldb/status.h"
-#include "db/write_batch_internal.h"
+#include "leveldb/write_batch.h"
+#include "util/coding.h"
+#include "util/mutexlock.h"
 #include "util/serialize_value.h"
 #include "fielddb/encode_index.h"
+#include "fielddb/meta.h"
+#include "field_db.h"
+#include "fielddb/SliceHashSet.h"
 
 namespace fielddb {
 using namespace leveldb;
 //TODO:打开fieldDB
-Status FieldDB::OpenFieldDB(const Options& options,
+Status FieldDB::OpenFieldDB(Options& options,
                             const std::string& name, FieldDB** dbptr) {
     // options.env->CreateDir("./abc")
     if(*dbptr == nullptr){
@@ -23,11 +34,20 @@ Status FieldDB::OpenFieldDB(const Options& options,
     //
     Status status;
     DB *indexdb, *kvdb, *metadb;
+    // options.block_cache = NewLRUCache(ULONG_MAX);
+    // options.max_open_files = 1000;
+    // options.write_buffer_size = 512 * 1024 * 1024;
+
+    //这里是为了让3个数据库有独立的的Background thread
+    options.env = getPosixEnv();
     status = Open(options, name+"_indexDB", &indexdb);
     if(!status.ok()) return status;
-
+    
+    options.env = getPosixEnv();
     status = Open(options, name+"_kvDB", &kvdb);
     if(!status.ok()) return status;
+
+    options.env = getPosixEnv();
     status = Open(options, name+"_metaDB", &metadb);
     if(!status.ok()) return status;
 
@@ -37,38 +57,227 @@ Status FieldDB::OpenFieldDB(const Options& options,
     (*dbptr)->dbname_ = name;
 
     status = (*dbptr)->Recover();
+
+    (*dbptr)->options_ = &options;
+    (*dbptr)->env_ = options.env;
     return status;
 }
 
-// todo 
 Status FieldDB::Recover() {
-    //
+    //1. 遍历所有Index类型的meta，重建内存中的index_状态表
+    Iterator *Iter = indexDB_->NewIterator(ReadOptions());
+    std::string IndexKey;
+    Iter->SeekToFirst();
+    while(Iter->Valid()) {
+        IndexKey = Iter->key().ToString();
+        ParsedInternalIndexKey ParsedIndex;
+        ParseInternalIndexKey(Slice(IndexKey),&ParsedIndex);
+        index_[ParsedIndex.name_.ToString()] = {Exist,nullptr};
+
+        //构建下一个搜索的对象，在原来的fieldname的基础上加一个最大的ascii字符（不可见字符）
+        std::string Seek;
+        PutLengthPrefixedSlice(&Seek, ParsedIndex.name_);
+        Seek.push_back(0xff);
+        Iter->Seek(Slice(Seek));
+    }
+    delete Iter;
+    //2. 寻找所有KV类型的meta，再次提交一遍请求
+    Iter = metaDB_->NewIterator(ReadOptions());
+    Slice MetaValue;
+    Iter->SeekToFirst();
+    while (Iter->Valid()) {
+        MetaValue = Iter->key();
+        MetaType type = MetaType(DecodeFixed32(MetaValue.data()));
+        MetaValue.remove_prefix(4);//移除头上的metaType的部分
+        Slice extractKey;
+        GetLengthPrefixedSlice(&MetaValue, &extractKey);
+        if(type == KV_Creating) {
+            FieldArray fields;
+            ParseValue(Iter->value().ToString(), &fields);
+            PutFields(WriteOptions(), extractKey, fields);
+        } else if(type == KV_Deleting) {
+            Delete(WriteOptions(), extractKey);
+        } else {
+            assert(0 && "Invalid MetaType");
+        }
+        Iter->Next();
+    }
+    delete Iter;
+    //在所有的请求完成后，会自动把metaDB的内容清空。
+    Iter = metaDB_->NewIterator(ReadOptions());
+    Iter->SeekToFirst();
+    //std::cout << "Iter Valid : " << Iter->Valid() << std::endl; 
+    delete Iter;
+    //3. 等待所有请求完成
     return Status::OK();
 }
 
+Request *FieldDB::GetHandleInterval() {
+    mutex_.AssertHeld(); //保证队列是互斥访问的
+    Request *tail = taskqueue_.front();
+    for(auto *req_ptr : taskqueue_) {
+        if(req_ptr->isiDeleteReq() || req_ptr->isiCreateReq()) {
+            return tail;
+        }
+        tail = req_ptr;
+    }
+    return tail;
+}
+
+Status FieldDB::HandleRequest(Request &req, const WriteOptions &op) {
+    //uint64_t start_ = env_->NowMicros();
+    MutexLock L(&mutex_);
+    taskqueue_.push_back(&req);
+    while(true){
+        //uint64_t start_waiting = env_->NowMicros();
+        while(req.isPending() || !req.done && &req != taskqueue_.front()) {
+            req.cond_.Wait();
+        }
+        //waiting_elasped += env_->NowMicros() - start_waiting;
+        if(req.done) {
+            //elapsed += env_->NowMicros() - start_;
+            //count ++;
+            // dumpStatistics();
+            return req.s; //在返回时自动释放锁L
+        }
+        Request *tail = GetHandleInterval();
+        WriteBatch KVBatch,IndexBatch,MetaBatch;
+        SliceHashSet batchKeySet;
+        Status status;
+        if(!tail->isiCreateReq() && !tail->isiDeleteReq()) {
+            //表明这一个区间并没有涉及index的创建删除
+            {
+                //1. 构建各个Batch。构建的过程中要保证索引状态的一致性，需要上锁。
+                MutexLock iL(&index_mu);
+                //uint64_t start_construct = env_->NowMicros();
+                for(auto *req_ptr : taskqueue_) {
+                    req_ptr->ConstructBatch(KVBatch, IndexBatch, MetaBatch, this, batchKeySet);
+                    if(req_ptr == tail) break;
+                }
+                //construct_elapsed += env_->NowMicros() - start_construct;
+            }
+            //2. 首先写入meta，再并发写入index和kv，完成之后清除meta数据
+            //此处可以放锁是因为写入的有序性可以通过队列来保证
+            mutex_.Unlock();
+            //uint64_t start_write = env_->NowMicros();
+            if(MetaBatch.ApproximateSize() > 12) {
+                //uint64_t start_meta = env_->NowMicros();
+                status = metaDB_->Write(op, &MetaBatch);
+                //write_meta_elapsed += env_->NowMicros() - start_meta;
+                //write_bytes += MetaBatch.ApproximateSize();
+                assert(status.ok());
+            }
+            //TODO:index的写入需要在另外一个线程中同时完成
+            if(IndexBatch.ApproximateSize() > 12) {
+                //uint64_t start_index = env_->NowMicros();
+                status = indexDB_->Write(op, &IndexBatch);
+                //write_index_elapsed += env_->NowMicros() - start_index;
+                //write_bytes += IndexBatch.ApproximateSize();
+                assert(status.ok());
+            }
+            if(KVBatch.ApproximateSize() > 12) {
+                //uint64_t start_kv = env_->NowMicros();
+                status = kvDB_->Write(op, &KVBatch);
+                //write_kv_elapsed += env_->NowMicros() - start_kv;
+                //write_bytes += KVBatch.ApproximateSize();
+                assert(status.ok());
+            }
+            //3. 将meta数据清除
+            if(MetaBatch.ApproximateSize() > 12) {
+                //uint64_t start_clean = env_->NowMicros();
+                MetaCleaner cleaner;
+                cleaner.Collect(MetaBatch);
+                cleaner.CleanMetaBatch(metaDB_);
+                //write_clean_elapsed += env_->NowMicros() - start_clean;
+            }
+            //write_elapsed += env_->NowMicros() - start_write;
+            mutex_.Lock();
+        } else {
+            //对于创建和删除索引的请求，通过prepare完成索引状态的更新
+            MutexLock iL(&index_mu);
+            req.Prepare(this);
+        }
+        // {
+        //     static int count = 0;
+        //     if(count++ % 100000 == 0) {
+        //         std::cout << "TaskQueue Size : " << taskqueue_.size() << std::endl;
+        //     }
+        // }
+        while(true) {
+            Request *ready = taskqueue_.front();
+            // int debug = tail->type_;
+            taskqueue_.pop_front();
+            //当前ready不是队首，不是和index的创建有关
+            if(!ready->isPending() && !req.isiCreateReq() && !req.isiDeleteReq()) {
+                ready->s = status;
+                ready->done = true;
+                if (ready != &req)  ready->cond_.Signal();
+            }
+            if (ready == tail) break; 
+        }
+
+
+        if(!taskqueue_.empty()) {
+            taskqueue_.front()->cond_.Signal();
+        }
+        //如果done==true，那么就不会继续等待直接退出
+        //如果处于某个请求的pending list里面，那么就会继续等待重新入队
+    }
+}
+
+// 这里把一个空串作为常规put的name
 Status FieldDB::Put(const WriteOptions &options, const Slice &key, const Slice &value) {
-    return kvDB_->Put(options, key, value);
+    FieldArray FA = {{EMPTY,value.ToString()}};
+    return PutFields(options, key, FA);
+    // return kvDB_->Put(options, key, value);
 }
 
-// TODO：需要对是否进行index更新做处理
+// 需要对是否进行index更新做处理
 Status FieldDB::PutFields(const WriteOptions &Options, 
                         const Slice &key, const FieldArray &fields) {
-    //
-    return kvDB_->PutFields(Options, key, fields);  
+    // std::string key_ = key.ToString();
+    // FieldArray fields_ = fields;
+
+    FieldsReq req(key,fields,&mutex_);
+    
+    Status status = HandleRequest(req, Options);
+    return status;
 }
 
-// todo: 删除有索引的key时indexdb也要同步
+// 删除有索引的key时indexdb也要同步
 Status FieldDB::Delete(const WriteOptions &options, const Slice &key) {
-    //
-    return kvDB_->Delete(options, key);
+    
+    // std::string key_ = key.ToString();
+    DeleteReq req(key,&mutex_);
+    Status status = HandleRequest(req, options);
+    return status;
 }
-// TODO：根据updates里面的东西，要对是否需要更新index进行分别处理
+
+// 根据updates里面的东西，要对是否需要更新index进行分别处理
 Status FieldDB::Write(const WriteOptions &options, WriteBatch *updates) {
-    return Status::OK();
+    // {
+    //     uint64_t start_ = env_->NowMicros();
+    //     Status status = kvDB_->Write(options, updates);
+    //     temp_elapsed += env_->NowMicros() - start_;
+    //     count ++;
+    //     dumpStatistics();
+    //     return status;
+    // }
+    //uint64_t start_ = env_->NowMicros();
+    BatchReq req(updates,&mutex_);
+    //construct_BatchReq_init_elapsed += env_->NowMicros() - start_;
+    Status status = HandleRequest(req, options);
+    return status;
 }
-
+//由于常规put将空串作为name，这里也需要适当修改
 Status FieldDB::Get(const ReadOptions &options, const Slice &key, std::string *value) {
-    return kvDB_->Get(options, key, value);
+    FieldArray fields;
+    Status s = GetFields(options, key, &fields);
+    if(!s.ok()) {
+        return s;
+    }
+    *value = fields[0].second;
+    return s;
 }
 
 Status FieldDB::GetFields(const ReadOptions &options, const Slice &key, FieldArray *fields) {
@@ -81,63 +290,56 @@ std::vector FieldDB::FindKeysByField(Field &field) {
 }
 
 std::vector<std::pair<std::string, std::string>> FieldDB::FindKeysAndValByFieldName (
-                                                    const std::string &fieldName){
+                                                    const Slice fieldName){
     std::vector<std::pair<std::string, std::string>> result;
     auto iter = kvDB_->NewIterator(ReadOptions());
-    std::string val;
+    Slice val;
     for(iter->SeekToFirst();iter->Valid();iter->Next()) {
         InternalFieldArray fields(iter->value());
-        val = fields.ValOfName(fieldName);
+        val = fields.ValOfName(fieldName.ToString());
         if(!val.empty()) {
-            result.push_back(std::make_pair(iter->key().ToString(), val));
+            result.push_back(std::make_pair(iter->key().ToString(), val.ToString()));
         }
     }
+    delete iter;
     return result;                                                    
 }
 
-Status FieldDB::CreateIndexOnField(const std::string& field_name) {
-    //taskQueue相关
-    //写锁 是不是只需要给putfields设置一把锁就行
-
-    std::vector<std::pair<std::string, std::string>> keysAndVal = 
-                                            FindKeysAndValByFieldName(field_name);
-    WriteBatch writeBatch; 
-    Slice value = Slice();   
-    for (auto &kvPair : keysAndVal){
-        std::string indexKey;
-        AppendIndexKey(&indexKey, 
-                        ParsedInternalIndexKey(kvPair.first, field_name, kvPair.second));
-        writeBatch.Put(indexKey, value);
+Status FieldDB::CreateIndexOnField(const std::string& field_name, const WriteOptions &op) {
+    // std::string Field = field_name;
+    // iCreateReq req(&Field,&mutex_);
+    iCreateReq req(field_name,&mutex_);
+    HandleRequest(req, op);
+    //如果已经存在索引，那么直接返回
+    if(req.Existed) {
+        return req.s;
     }
-    Status s =  indexDB_->Write(WriteOptions(), &writeBatch);
-    if (!s.ok())    return s;
-
-    index_[field_name] = Exist;
-    //唤醒taskqueue
-
+    WriteBatch KVBatch,IndexBatch,MetaBatch;
+    SliceHashSet useless;
+    req.ConstructBatch(KVBatch, IndexBatch, MetaBatch, this, useless);
+    indexDB_->Write(op, &IndexBatch);
+    req.Finalize(this);
+    return req.s;
 }
 
-Status FieldDB::DeleteIndex(const std::string &field_name) {
-    //taskQueue相关
-    //写锁
-    std::vector<std::pair<std::string, std::string>> keysAndVal = 
-                                            FindKeysAndValByFieldName(field_name);
-    WriteBatch writeBatch;   
-    for (auto &kvPair : keysAndVal){
-        std::string indexKey;
-        AppendIndexKey(&indexKey, 
-                        ParsedInternalIndexKey(kvPair.first, field_name, kvPair.second));
-        writeBatch.Delete(indexKey);
+Status FieldDB::DeleteIndex(const std::string &field_name, const WriteOptions &op) {
+    // std::string Field = field_name;
+    iDeleteReq req(field_name,&mutex_);
+    HandleRequest(req, op);
+    //如果已经被删除或者不存在，那么可以直接返回
+    if(req.Deleted) {
+        return req.s;
     }
-    Status s =  indexDB_->Write(WriteOptions(), &writeBatch);
-    if (!s.ok())    return s;
-
-    index_.erase(field_name);
-    //唤醒taskqueue
+    WriteBatch KVBatch,IndexBatch,MetaBatch;
+    SliceHashSet useless;
+    req.ConstructBatch(KVBatch, IndexBatch, MetaBatch, this, useless);
+    indexDB_->Write(op, &IndexBatch);
+    req.Finalize(this);
+    return req.s;
 }
 
 std::vector<std::string> FieldDB::QueryByIndex(const Field &field, Status *s) {
-    if (index_.count(field.first) == 0 || index_[field.first] != Exist){
+    if (index_.count(field.first) == 0 || index_[field.first].first != Exist){
         *s = Status::NotFound(Slice());
         return std::vector<std::string>();
     }
@@ -158,11 +360,17 @@ std::vector FieldDB::QueryByIndex(const Field &field, Status *s) {
         }
         break;
     }                
-
+    delete indexIterator;
     *s = Status::OK();
     return result;
 }
 
+IndexStatus FieldDB::GetIndexStatus(const std::string &fieldName){
+    if (index_.count(fieldName) == 0) return IndexStatus::NotExist;
+    IndexStatus idxs =  index_[fieldName].first;
+    return idxs;
+}
+
 Iterator * FieldDB::NewIterator(const ReadOptions &options) {
     return kvDB_->NewIterator(options);
 }
@@ -191,4 +399,21 @@ void FieldDB::CompactRange(const Slice *begin, const Slice *end) {
     kvDB_->CompactRange(begin, end);
 }
 
-} // end of namespace
+Status DestroyDB(const std::string& name, const Options& options) {
+  Status s;
+  s = leveldb::DestroyDB(name+"_kvDB", options);
+  assert(s.ok());
+  s = leveldb::DestroyDB(name+"_indexDB", options);
+  assert(s.ok());
+  s = leveldb::DestroyDB(name+"_metaDB", options);
+  assert(s.ok());
+  return s;
+}
+
+FieldDB::~FieldDB() {
+    delete indexDB_;
+    delete kvDB_;
+    delete metaDB_;
+}
+
+}  // namespace fielddb

fielddb/field_db.h

@@ -1,25 +1,44 @@
-# ifndef FIELD_DB_H
-# define FIELD_DB_H
-
 #include "port/port_stdcxx.h"
 #include "db/db_impl.h"
+#include <cstdint>
+#include <cstdio>
 #include <deque>
 #include <map>
 #include <set>
 #include <string>
 #include "leveldb/db.h"
+#include "leveldb/env.h"
 #include "leveldb/options.h"
 #include "leveldb/slice.h"
 #include "leveldb/status.h"
-
 #include "fielddb/request.h"
-
+#include <shared_mutex>
+# ifndef FIELD_DB_H
+# define FIELD_DB_H
 namespace fielddb {
 using namespace leveldb;
+
+const char EMPTY[1] = {0};
+
+enum IndexStatus{
+        Creating,
+        Deleting,
+        Exist,
+        NotExist
+    };
+
 class FieldDB : DB {
 public:
+    friend class Request;
+    friend class FieldsReq;
+    friend class iCreateReq;
+    friend class iDeleteReq;
+    friend class DeleteReq;
+    friend class BatchReq;
+
     //用的时候必须FieldDB *db = new FieldDB()再open，不能像之前一样DB *db
     FieldDB() : indexDB_(nullptr), kvDB_(nullptr), metaDB_(nullptr) {};
+    ~FieldDB();
 /*lab1的要求，作为db派生类要实现的虚函数*/
     Status Put(const WriteOptions &options, const Slice &key, const Slice &value) override;
     Status PutFields(const WriteOptions &, const Slice &key, const FieldArray &fields) override;
@@ -35,34 +54,100 @@ public:
     void GetApproximateSizes(const Range *range, int n, uint64_t *sizes) override;
     void CompactRange(const Slice *begin, const Slice *end) override;
 /*与索引相关*/
-    Status CreateIndexOnField(const std::string& field_name);
-    Status DeleteIndex(const std::string &field_name);
+    Status CreateIndexOnField(const std::string& field_name, const WriteOptions &op);
+    Status DeleteIndex(const std::string &field_name, const WriteOptions &op);
     std::vector<std::string> QueryByIndex(const Field &field, Status *s);
+    //返回当前数据库中索引状态，用来测试，不过也可以作为一个功能？
+    IndexStatus GetIndexStatus(const std::string &fieldName);
 
-    static Status OpenFieldDB(const Options& options,const std::string& name,FieldDB** dbptr);
+    static Status OpenFieldDB(Options& options,const std::string& name,FieldDB** dbptr);
 
 private:
     //根据metaDB的内容进行恢复
     Status Recover(); 
 
 private:
-    std::string dbname_;
-
+    leveldb::DB *kvDB_;
     leveldb::DB *metaDB_;
     leveldb::DB *indexDB_;
-    leveldb::DB *kvDB_;
+    
+    std::string dbname_;
+    const Options *options_;
+    Env *env_;
+
+
+    using FieldName = std::string;
+    // 标记index的状态,如果是creating/deleting，则会附带相应的请求
+    std::map<FieldName, std::pair<IndexStatus,Request*>> index_; 
+    port::Mutex index_mu;
 
-    enum IndexStatus{
-        Creating,
-        Deleting,
-        Exist
-    };
-    std::map<std::string, int> index_;
     leveldb::port::Mutex mutex_; // mutex for taskqueue
     std::deque<Request *> taskqueue_;
 
     std::vector<std::pair<std::string, std::string>> FindKeysAndValByFieldName (
-                                                    const std::string &fieldName);
+                                                    const Slice fieldName);
+
+    /*For request handling*/
+    Status HandleRequest(Request &req, const WriteOptions &op); //每个请求自行构造请求后交由这个函数处理
+    Request *GetHandleInterval(); //获得任务队列中的待处理区间，区间划分规则和原因见文档
+
+// private:
+//     int count = 0;
+//     int count_Batch = 0;
+//     int count_Batch_Sub = 0;
+//     uint64_t elapsed = 0;
+
+//     uint64_t construct_elapsed = 0;
+//     uint64_t construct_BatchReq_init_elapsed = 0;
+//     uint64_t construct_BatchReq_elapsed = 0;
+//     uint64_t construct_BatchReq_Sub_elapsed = 0;
+//     uint64_t construct_BatchReq_perSub_elapsed = 0;
+//     uint64_t construct_FieldsReq_Read_elapsed = 0;
+
+//     uint64_t write_elapsed = 0;
+//     uint64_t write_meta_elapsed = 0;
+//     uint64_t write_index_elapsed = 0;
+//     uint64_t write_kv_elapsed = 0;
+//     uint64_t write_clean_elapsed = 0;
+
+//     uint64_t write_bytes = 0;
+//     uint64_t write_step = 500 * 1024 * 1024;
+//     uint64_t write_bytes_lim = write_step;
+
+//     uint64_t temp_elapsed = 0;
+
+//     uint64_t waiting_elasped = 0;
+
+//     inline void dumpStatistics() {
+//         if(count && count % 500000 == 0 || write_bytes && write_bytes > write_bytes_lim) {
+//             std::cout << "=====================================================\n";
+//             std::cout << "Total Count : " << count;
+//             std::cout << "\tTotal Write Bytes(MB) : " << write_bytes / 1048576.0 << std::endl;
+//             std::cout << "Average Time(ms) : " << elapsed * 1.0 / count;
+//             std::cout << "\tAverage Write rates(MB/s) : " << write_bytes / 1048576.0 / elapsed * 1000000 << std::endl;
+//             std::cout << "Construct Time(ms) : " << construct_elapsed * 1.0 / count << std::endl;
+//             std::cout << "\tConstruct BatchReq Init Time(ms) : " << construct_BatchReq_init_elapsed * 1.0 / count << std::endl;
+//             std::cout << "\tConstruct BatchReq Time(ms) : " << construct_BatchReq_elapsed * 1.0 / count << std::endl;
+//             std::cout << "\tConstruct BatchReq Sub Time(ms) : " << construct_BatchReq_Sub_elapsed * 1.0 / count << std::endl;
+//             std::cout << "\tConstruct BatchReq perSub Time(ms) : " << construct_BatchReq_perSub_elapsed * 1.0 / count_Batch_Sub << std::endl;
+//             std::cout << "\tConstruct FieldsReq Read Time(ms) : " << construct_FieldsReq_Read_elapsed * 1.0 / count << std::endl;
+//             std::cout << "Write Time(ms) : " << write_elapsed * 1.0 / count << std::endl;
+//             std::cout << "\tWrite Meta Time(ms) : " << write_meta_elapsed * 1.0 / count << std::endl;
+//             std::cout << "\tWrite Index Time(ms) : " << write_index_elapsed * 1.0 / count << std::endl;
+//             std::cout << "\tWrite KV Time(ms) : " << write_kv_elapsed * 1.0 / count << std::endl;
+//             std::cout << "\tWrite Clean Time(ms) : " << write_clean_elapsed * 1.0 / count << std::endl;
+//             std::cout << "TaskQueue Size : " << taskqueue_.size() << std::endl;
+//             std::cout << "temp_elased : " << temp_elapsed * 1.0 / count << std::endl;
+//             std::cout << "waiting elapsed : " << waiting_elasped * 1.0 / count << std::endl;
+//             // std::cout << MetaBatch.ApproximateSize() << " " << IndexBatch.ApproximateSize() << " " << KVBatch.ApproximateSize() << std::endl;
+//             std::cout << "=====================================================\n";
+//             write_bytes_lim = write_bytes + write_step;
+//             std::fflush(stdout);
+//         }
+//     }
 };
+
+Status DestroyDB(const std::string& name,
+                                const Options& options);
 } // end of namespace
 # endif

fielddb/meta.cpp

@@ -0,0 +1,69 @@
+#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/delete的meta编码为 (KV|Key,Value)
+void MetaKV::TransPut(std::string &MetaKey,std::string &MetaValue) {
+    MetaKey.clear();
+    MetaValue.clear();
+    //这里的改动是为了防止潜在的段错误。原来的写法中，slice(buf)对应的buf是局部的，在函数返回后，buf被销毁
+    //但是slice中的指针指向的是析构的string对象的部分内存
+    std::string &buf = MetaKey; 
+    PutFixed32(&buf, KV_Creating);
+    PutLengthPrefixedSlice(&buf, Slice(name));
+    // MetaKey = Slice(buf);
+    // MetaValue = Slice(*value);
+}
+
+void MetaKV::TransDelete(std::string &MetaKey) {
+    MetaKey.clear();
+    std::string &buf = MetaKey;
+    PutFixed32(&buf, KV_Deleting);
+    PutLengthPrefixedSlice(&buf, Slice(name));
+    // MetaKey = Slice(buf);
+}
+
+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) {
+    if(MetaBatch.ApproximateSize() <= 12) return;
+    CleanerHandler Handler;
+    Handler.NeedClean = &NeedClean;
+    MetaBatch.Iterate(&Handler);
+}
+
+void MetaCleaner::CleanMetaBatch(DB *metaDB) {
+    if(NeedClean.ApproximateSize() <= 12) return;
+    metaDB->Write(WriteOptions(), &NeedClean);
+}
+}

fielddb/meta.h

@@ -0,0 +1,56 @@
+#pragma once
+
+#include <cstdint>
+#include <cstdio>
+#include "leveldb/slice.h"
+#include "leveldb/write_batch.h"
+#include "util/serialize_value.h"
+#include "fielddb/field_db.h"
+namespace fielddb {
+using namespace leveldb;
+/*根据写入的流程可以推断，需要存在metaDB中的数据其实都是带索引的数据,也就是FieldArray*/
+// class MetaKV {
+//     MetaKV(Slice &Key,FieldArray Fields):
+//         Key(Key),Fields(Fields),tag(0),meta_seq(0) { }
+//     inline int get_seq() { return meta_seq; }
+//     inline void set_seq(int meta_seq) { this->meta_seq = meta_seq; }
+//     inline void setPut() { tag = PUT; }
+//     inline void setDelete() { tag = DELETE; }
+//     Slice metaKey();
+//     Slice metaValue();
+// private:
+//     enum {PUT = 0x0,DELETE = 0x1};
+//     uint64_t meta_seq;
+//     uint8_t tag;
+//     Slice &Key;
+//     FieldArray Fields;
+// };
+
+enum MetaType {
+    //Index, //记录index状态的meta
+    KV_Creating,  //记录含有index field的put的meta
+    KV_Deleting,
+};
+
+//将一对(field_name,field_value)转换到metaDB中的KV表示
+class MetaKV {
+public:
+    MetaKV(Slice field_name,Slice field_value = Slice()):
+        name(field_name),value(field_value) { }
+    void TransPut(std::string &MetaKey,std::string &MetaValue);
+    void TransDelete(std::string &MetaKey);
+private:
+    Slice name;
+    Slice value;
+};
+
+class MetaCleaner {
+public:
+    MetaCleaner() = default;
+    void Collect(WriteBatch &MetaBatch);
+    void CleanMetaBatch(DB *metaDB);
+private:
+    WriteBatch NeedClean;
+};
+
+}

fielddb/metakv.cpp

@@ -1,20 +0,0 @@
-#include "fielddb/metakv.h"
-#include "util/coding.h"
-#include <string>
-
-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));
-}
-
-}

fielddb/metakv.h

@@ -1,26 +0,0 @@
-#pragma once
-
-#include <cstdint>
-#include <cstdio>
-#include "leveldb/slice.h"
-#include "util/serialize_value.h"
-namespace fielddb {
-using namespace leveldb;
-/*根据写入的流程可以推断，需要存在metaDB中的数据其实都是带索引的数据,也就是FieldArray*/
-class MetaKV {
-    MetaKV(Slice &Key,FieldArray Fields):
-        Key(Key),Fields(Fields),tag(0),meta_seq(0) { }
-    inline int get_seq() { return meta_seq; }
-    inline void set_seq(int meta_seq) { this->meta_seq = meta_seq; }
-    inline void setPut() { tag = PUT; }
-    inline void setDelete() { tag = DELETE; }
-    Slice metaKey();
-    Slice metaValue();
-private:
-    enum {PUT = 0x0,DELETE = 0x1};
-    uint64_t meta_seq;
-    uint8_t tag;
-    Slice &Key;
-    FieldArray Fields;
-};
-}

fielddb/request.cpp

@@ -0,0 +1,439 @@
+#include "fielddb/request.h"
+#include <cassert>
+#include <cstdint>
+#include <deque>
+#include <string>
+#include <unordered_set>
+#include "leveldb/slice.h"
+#include "leveldb/status.h"
+#include "leveldb/write_batch.h"
+#include "port/port_stdcxx.h"
+#include "util/mutexlock.h"
+#include "util/serialize_value.h"
+#include "fielddb/encode_index.h"
+#include "fielddb/field_db.h"
+#include "fielddb/meta.h"
+#include "request.h"
+namespace fielddb {
+using namespace leveldb;
+
+//为虚函数提供最基本的实现
+void Request::PendReq(Request *req) {
+    assert(0);
+}
+
+//为虚函数提供最基本的实现
+void Request::ConstructBatch(WriteBatch &KVBatch,WriteBatch &IndexBatch,
+                WriteBatch &MetaBatch,fielddb::FieldDB *DB,
+                SliceHashSet &batchKeySet)
+{
+    assert(0);
+}
+
+void Request::Prepare(FieldDB *DB) {
+    assert(0);
+}
+
+void Request::Finalize(FieldDB *DB) {
+    assert(0);
+}
+
+//为虚函数提供最基本的实现
+bool Request::isPending() {
+    //pending中的请求的parent会指向所等待的请求（iCreate/iDelete）
+    return parent != this; 
+}
+
+
+/*******FieldsReq*******/
+void FieldsReq::ConstructBatch(WriteBatch &KVBatch,WriteBatch &IndexBatch,
+                    WriteBatch &MetaBatch,fielddb::FieldDB *DB,
+                    SliceHashSet &batchKeySet)
+{
+    if (batchKeySet.find(Key) != batchKeySet.end()){
+        return;//并发的被合并的put/delete请求只处理一次
+    } else {
+        batchKeySet.insert(Key);
+    }
+    std::string val_str;
+    //uint64_t start_ = DB->env_->NowMicros();
+    s = DB->kvDB_->Get(ReadOptions(), Key, &val_str);
+    //DB->construct_FieldsReq_Read_elapsed += DB->env_->NowMicros() - start_;
+    // FieldArray *oldFields;
+    FieldSliceArray oldFields;
+    if (s.IsNotFound()){
+        // oldFields = nullptr;
+    } else if (s.ok()) { //得到数据库之前key的fields, 判断需不需要删除其中潜在的索引
+        // oldFields = new FieldArray;
+        // oldFields = ParseValue(val_str,oldFields);        
+        Slice nameSlice, valSlice;
+        Slice Value(val_str);
+        while(GetLengthPrefixedSlice(&Value, &nameSlice)) {
+            if(GetLengthPrefixedSlice(&Value, &valSlice)) {
+                oldFields.push_back({nameSlice,valSlice});
+            } else {
+                std::cout << "name and val not match! From FieldsReq Init" << std::endl;
+            }
+            nameSlice.clear(), valSlice.clear();
+        }
+    } else {
+        assert(0);
+    }
+
+    bool HasIndex = false;
+    bool HasOldIndex = false;
+    {
+        // MutexLock L(&DB->index_mu); //互斥访问索引状态表
+        DB->index_mu.AssertHeld();
+        //1.将存在冲突的put pend到对应的请求
+        for(auto &[field_name,field_value] : SliceFields) {
+            if(field_name.data() == EMPTY) break;
+            if(DB->index_.count(field_name.ToString())) {
+                auto [index_status,parent_req] = DB->index_[field_name.ToString()];
+                if(index_status == IndexStatus::Creating || index_status == IndexStatus::Deleting) {
+                    parent_req->PendReq(this->parent);
+                    return;
+                } else if(index_status == IndexStatus::Exist) {
+                    HasIndex = true;
+                }
+                //assert(0);
+            }
+        }
+        //冲突也可能存在于，需要删除旧数据的索引，但该索引正在创删中
+        if (!oldFields.empty()){
+            for(auto &[field_name,field_value] : oldFields) {
+                if(field_name.data() == EMPTY) break;
+                if(DB->index_.count(field_name.ToString())) {
+                    auto [index_status,parent_req] = DB->index_[field_name.ToString()];
+                    if(index_status == IndexStatus::Creating || index_status == IndexStatus::Deleting) {
+                        parent_req->PendReq(this->parent);
+                        return;
+                    } else if(index_status == IndexStatus::Exist) {
+                        HasOldIndex = true;
+                    }
+                    //assert(0);
+                }
+            }
+        }
+        std::string scrach = SerializeValue(SliceFields);
+        KVBatch.Put(Slice(Key), Slice(scrach));
+        //2.对于没有冲突但含有索引操作的put，构建metaKV，这里直接将KV对简单编码后写入metaDB
+        if(HasIndex || HasOldIndex) {
+            std::string MetaKey,MetaValue;
+            std::string serialized = SerializeValue(SliceFields);
+            MetaKV MKV = MetaKV(Key,serialized);
+            MKV.TransPut(MetaKey, MetaValue);
+            MetaBatch.Put(MetaKey, serialized);
+            
+        
+        //3.1对于含有索引的oldfield删除索引
+            if (HasOldIndex) {
+                for(auto &[field_name,field_value] : oldFields) {
+                    if(field_name.data() == EMPTY) continue;
+                    if(DB->index_.count(field_name.ToString())) {
+                        std::string indexKey;
+                        AppendIndexKey(&indexKey, ParsedInternalIndexKey(
+                                                    Key,field_name,field_value));
+                        IndexBatch.Delete(indexKey);
+                    }
+                }
+            }
+
+        //3.2对于含有索引的field建立索引
+            if (HasIndex) {
+                for(auto &[field_name,field_value] : SliceFields) {
+                    if(field_name.data() == EMPTY) continue;
+                    if(DB->index_.count(field_name.ToString())) {
+                        std::string indexKey;
+                        AppendIndexKey(&indexKey, ParsedInternalIndexKey(
+                                                    Key,field_name,field_value));
+                        IndexBatch.Put(indexKey, Slice());
+                    }
+                }
+            }
+            
+        }
+        //优化：对于3.1，3.2中都有的索引只写一次
+    }
+
+    // if(oldFields) delete oldFields;
+}
+
+
+/*******DeleteReq*******/
+void DeleteReq::ConstructBatch(WriteBatch &KVBatch,WriteBatch &IndexBatch,
+        WriteBatch &MetaBatch,fielddb::FieldDB *DB,
+        SliceHashSet &batchKeySet)
+{
+    if (batchKeySet.find(Key) != batchKeySet.end()){
+        return;//并发的被合并的put/delete请求只处理一次
+    } else {
+        batchKeySet.insert(Key);
+    }
+    //1. 读取当前的最新的键值对，判断是否存在含有键值对的field
+    //2.1 如果无，则正常构造delete
+    //2.2 如果是有的field的索引状态都是exist，则在meta中写KV_Deleting类型的记录
+    //在kvDB和metaDB中写入对应的delete
+    //2.3 如果存在field的索引状态是Creating或者Deleting，那么在那个队列上面进行等待
+    std::string val_str;
+    Status s =  DB->kvDB_->Get(ReadOptions(), Key, &val_str);
+    if (s.IsNotFound()) return;
+    // FieldArray *Fields = new FieldArray;
+    // ParseValue(val_str,Fields); 
+    FieldSliceArray Fields;
+    Slice nameSlice, valSlice;
+    Slice Value(val_str);
+    while(GetLengthPrefixedSlice(&Value, &nameSlice)) {
+        if(GetLengthPrefixedSlice(&Value, &valSlice)) {
+            Fields.push_back({nameSlice,valSlice});
+        } else {
+            std::cout << "name and val not match! From FieldsReq Init" << std::endl;
+        }
+        nameSlice.clear(), valSlice.clear();
+    }
+    KVBatch.Delete(Slice(Key));
+    bool HasIndex = false;
+    {
+        // MutexLock L(&DB->index_mu); //互斥访问索引状态表
+        DB->index_mu.AssertHeld();
+        //1.将存在冲突的delete pend到对应的请求
+        for(auto &[field_name,field_value] : Fields) {
+            if(field_name.data() == EMPTY) break;
+            if(DB->index_.count(field_name.ToString())) {
+                auto [index_status,parent_req] = DB->index_[field_name.ToString()];
+                if(index_status == IndexStatus::Creating || index_status == IndexStatus::Deleting) {
+                    parent_req->PendReq(this->parent);
+                    return;
+                } else if(index_status == IndexStatus::Exist) {
+                    HasIndex = true;
+                }
+                //assert(0);
+            }
+        }
+        KVBatch.Delete(Slice(Key));
+        //2.对于没有冲突但含有索引操作的delete，构建metaKV，这里直接将KV对简单编码后写入metaDB
+        if(HasIndex) {
+            std::string MetaKey;
+            MetaKV MKV = MetaKV(Key);
+            MKV.TransDelete(MetaKey); //meta中写入一个delete不需要value
+            MetaBatch.Put(MetaKey, Slice());
+        //3.对于含有索引的field删除索引
+            for(auto &[field_name,field_value] : Fields) {
+                if(field_name.data() == EMPTY) continue;
+                if(DB->index_.count(field_name.ToString())) {
+                    std::string indexKey;
+                    AppendIndexKey(&indexKey, ParsedInternalIndexKey(
+                                                Key,field_name,field_value));
+                    IndexBatch.Delete(indexKey);
+                }
+            }
+        }
+    }
+    // delete Fields;
+}
+
+/*******iCreateReq*******/
+void iCreateReq::Prepare(FieldDB *DB) {
+    //在index_中完成索引状态更新,在这里可以避免重复创建
+    DB->index_mu.AssertHeld();
+    if(DB->index_.count(Field.ToString())) {
+        auto [istatus,parent] = DB->index_[Field.ToString()];
+        if(istatus == IndexStatus::Exist) {
+            //如果已经完成建立索引，则返回成功
+            done = true;
+            Existed = true;
+            s = Status::OK();
+        } else {
+            //如果正在创建或删除，那么进行等待
+            parent->PendReq(this->parent);
+        }
+        return;
+    }
+    //如果索引状态表中没有，则表示尚未创建，更新相应的状态
+    //这里将done设置为true表示在taskqueue中需要完成的部分已经完成，不需要pend
+    DB->index_[Field.ToString()] = {IndexStatus::Creating,this};
+    done = true;
+}
+
+void iCreateReq::PendReq(Request *req) {
+    req->parent = this;
+    pending_list.push_back(req);
+}
+
+void iCreateReq::ConstructBatch(WriteBatch &KVBatch,WriteBatch &IndexBatch,
+        WriteBatch &MetaBatch,fielddb::FieldDB *DB,
+        SliceHashSet &batchKeySet)
+{
+    //遍历数据库，构建二级索引到indexbatch，(更新metaDB中的元数据为Index类型的（Field,Creating）)
+    //一个indexwritebatch写入，那么索引创建删除应该和metadb没有交互
+    std::vector<std::pair<std::string, std::string>> keysAndVal = 
+                                            DB->FindKeysAndValByFieldName(Field.ToString());
+    Slice value = Slice();   
+    for (auto &kvPair : keysAndVal){
+        std::string indexKey;
+        AppendIndexKey(&indexKey, 
+                        ParsedInternalIndexKey(kvPair.first, Field, kvPair.second));
+        IndexBatch.Put(indexKey, value);
+    }
+}
+
+void iCreateReq::Finalize(FieldDB *DB) {
+    //1. 写入完成后，更新index状态表，(并将metaDB的值改为Index类型的（Field，Existing）)
+    MutexLock iL(&DB->index_mu);
+    DB->index_[Field.ToString()] = {IndexStatus::Exist, nullptr};   
+    DB->index_mu.Unlock(); 
+
+    if (pending_list.empty())   return;
+    //2. 将所有的pendinglist重新入队    
+    MutexLock L(&DB->mutex_);
+    for (auto req : pending_list){
+        DB->taskqueue_.push_back(req);
+        req->parent = req; //解绑
+    }
+    if (pending_list[0] == DB->taskqueue_.front()) {
+        pending_list[0]->cond_.Signal();
+    }
+    this->s = Status::OK();
+}
+
+/*******iDeleteReq*******/
+void iDeleteReq::Prepare(FieldDB *DB) {
+    DB->index_mu.AssertHeld();
+    if(DB->index_.count(Field.ToString()) == 0) {
+        done = true;
+        Deleted = true;
+        s = Status::OK();
+        return ;
+    }
+    auto [istatus,parent] = DB->index_[Field.ToString()];
+    if(istatus == IndexStatus::Exist) {
+        DB->index_[Field.ToString()] = {IndexStatus::Deleting,this};
+        done = true;
+    } else {
+        //如果正在创建或者删除，那么pend到对应的请求上
+        parent->PendReq(this->parent);
+    }
+}
+
+void iDeleteReq::PendReq(Request* req) {
+    req->parent = this;
+    pending_list.push_back(req);
+}
+
+void iDeleteReq::ConstructBatch(WriteBatch &KVBatch,WriteBatch &IndexBatch,
+        WriteBatch &MetaBatch,fielddb::FieldDB *DB,SliceHashSet &batchKeySet)
+{
+    std::vector<std::pair<std::string, std::string>> keysAndVal = 
+                                            DB->FindKeysAndValByFieldName(Field);
+    Slice value = Slice();   
+    for (auto &kvPair : keysAndVal){
+        std::string indexKey;
+        AppendIndexKey(&indexKey, 
+                        ParsedInternalIndexKey(kvPair.first, Field, kvPair.second));
+        IndexBatch.Delete(indexKey);
+    }
+}
+
+void iDeleteReq::Finalize(FieldDB *DB) {
+    MutexLock iL(&DB->index_mu);
+    DB->index_.erase(Field.ToString());   
+    DB->index_mu.Unlock(); 
+
+    if (pending_list.empty())   return;
+    //2. 将所有的pendinglist重新入队    
+    MutexLock L(&DB->mutex_);
+    for (auto req : pending_list){
+        DB->taskqueue_.push_back(req);
+        req->parent = req; //解绑
+    }
+    if (pending_list[0] == DB->taskqueue_.front()) {
+        pending_list[0]->cond_.Signal();
+    }
+    this->s = Status::OK();
+}
+
+BatchReq::BatchReq(WriteBatch *Batch,port::Mutex *mu):
+    Batch(Batch),Request(BatchReq_t, mu) {
+
+    struct BatchHandler : WriteBatch::Handler {
+        void Put(const Slice &key, const Slice &value) override {
+            //为key和value构造存储的地方，防止由于string的析构造成可能得内存访问错误
+            // str_buf->push_back(key.ToString());
+            // FieldArray *field = new FieldArray;
+            // field = ParseValue(value.ToString(), field);
+            // if (field->empty()){ //batch中的value没有field
+            //     fa_buf->push_back({{EMPTY,value.ToString()}});
+            // } else {
+            //     fa_buf->push_back(*field);                
+            // }
+            //默认所有WriteBatch中的东西都是有Field的!!!!!
+            sub_requests->emplace_back(new FieldsReq(key,value,mu));
+            sub_requests->back()->parent = req;
+            // delete field;
+        }
+        void Delete(const Slice &key) override {
+            // str_buf->push_back(key.ToString());
+            sub_requests->emplace_back(new DeleteReq(key,mu));
+            sub_requests->back()->parent = req;
+        }
+
+        BatchReq *req;
+        port::Mutex *mu;
+        // std::deque<std::string> *str_buf;
+        // std::deque<FieldArray> *fa_buf;
+        std::deque<Request*> *sub_requests;
+    };
+
+    BatchHandler Handler;
+    Handler.req = this;
+    Handler.mu = mu;
+    // Handler.str_buf = &str_buf;
+    // Handler.fa_buf = &fa_buf;
+    Handler.sub_requests = &sub_requests;
+
+    Batch->Iterate(&Handler);
+}
+
+BatchReq::~BatchReq() {
+    while(!sub_requests.empty()) {
+        Request *req = sub_requests.front();
+        sub_requests.pop_front();
+        delete req;
+    }
+}
+
+void BatchReq::ConstructBatch(WriteBatch &KVBatch,WriteBatch &IndexBatch,
+        WriteBatch &MetaBatch,fielddb::FieldDB *DB,SliceHashSet &batchKeySet)
+{
+    WriteBatch Sub_KVBatch,Sub_IndexBatch,Sub_MetaBatch;
+    SliceHashSet Sub_batchKeySet;
+    //由于batch是有顺序的，根据我们现在的一个key只处理最开始的算法，这里需要反向迭代
+    //uint64_t start_ = DB->env_->NowMicros();
+    for(auto subreq = sub_requests.rbegin(); subreq != sub_requests.rend(); subreq++ ) {
+        //uint64_t start_sub = DB->env_->NowMicros();
+        (*subreq)->ConstructBatch(Sub_KVBatch, Sub_IndexBatch, Sub_MetaBatch, DB, Sub_batchKeySet);
+        // (*subreq)->ConstructBatch(KVBatch, IndexBatch, MetaBatch, DB, batchKeySet);
+        //DB->construct_BatchReq_perSub_elapsed += DB->env_->NowMicros() - start_sub;
+        //DB->count_Batch_Sub ++;
+        //所有的对于pendreq的调用传入的参数被改成了this->parent，因此，对于subrequests来说，
+        //pendreq的传参为对应的Batchreq，因此，此处判断batchreq是否pending可以得到subreq是否有冲突
+        if(isPending()) {
+            return;
+        }        
+    }
+    //DB->construct_BatchReq_Sub_elapsed += DB->env_->NowMicros() - start_;
+    if(Sub_KVBatch.ApproximateSize() > 12) {
+        KVBatch.Append(Sub_KVBatch);
+    }
+    if(Sub_IndexBatch.ApproximateSize() > 12) {
+        IndexBatch.Append(Sub_IndexBatch);
+    }
+    if(Sub_MetaBatch.ApproximateSize() > 12) {
+        MetaBatch.Append(Sub_MetaBatch);
+    }
+    batchKeySet.insert(Sub_batchKeySet.begin(),Sub_batchKeySet.end());
+    //DB->construct_BatchReq_elapsed += DB->env_->NowMicros() - start_;
+}
+
+
+}  // namespace fielddb

fielddb/request.h

@@ -1,25 +1,171 @@
+#include <deque>
 #include <string>
+#include "leveldb/slice.h"
+#include "leveldb/status.h"
+#include "leveldb/write_batch.h"
 #include "port/port_stdcxx.h"
+#include "util/coding.h"
 #include "util/mutexlock.h"
 #include "util/serialize_value.h"
+#include <unordered_set>
+// #include "fielddb/field_db.h"
+#include "fielddb/SliceHashSet.h"
+
+#ifndef REQUEST_H
+#define REQUEST_H
 namespace fielddb {
 using namespace leveldb;
 // 在taskqueue中的Request，由taskqueue最开始的线程处理一批Request
 // 这个思路与write写入的思路类似
+class FieldDB;
 class Request {
 public:
-    Request(std::string *Key,std::string *Value,port::Mutex *mu):
-        Key(Key),Value(Value),hasFields(false),_cond(mu) { }
-    Request(std::string *Key,FieldArray *Fields,port::Mutex *mu):
-        Key(Key),Fields(Fields),hasFields(false),_cond(mu) { }
+    friend class FieldDB;
+    enum RequestType {
+        FieldsReq_t,
+        //ValueReq_t,
+        iCreateReq_t,
+        iDeleteReq_t,
+        DeleteReq_t,
+        BatchReq_t,
+    };
+
+public:
+    // Request(std::string *Key,std::string *Value,port::Mutex *mu):
+    //     Key(Key),Value(Value),hasFields(false),cond_(mu) { }
+    // Request(std::string *Key,FieldArray *Fields,port::Mutex *mu):
+    //     Key(Key),Fields(Fields),hasFields(true),cond_(mu) { }
+    Request(RequestType type,port::Mutex *mu):
+        type_(type),cond_(mu),done(false) { parent = this; };
+
+    //virtual ~Request();
+
+    inline bool isFieldsReq() { return type_ == FieldsReq_t; }
+    // inline bool isValueReq() { return type_ == ValueReq_t; }
+    inline bool isiCreateReq() { return type_ == iCreateReq_t; }
+    inline bool isiDeleteReq() { return type_ == iDeleteReq_t; }
+    inline bool isDeleteReq() { return type_ == DeleteReq_t; }
+    inline bool isBatchReq() { return type_ == BatchReq_t; }
 
-private:
+    //用于含有Fields的
+    virtual void ConstructBatch(WriteBatch &KVBatch,WriteBatch &IndexBatch,
+                WriteBatch &MetaBatch,fielddb::FieldDB *DB,SliceHashSet &batchKeySet);
+    //主要用于icreate和idelete在队列中的注册当前状态
+    virtual void Prepare(FieldDB *DB);
+    virtual void Finalize(FieldDB *DB);
+
+    virtual void PendReq(Request *req);
+    bool isPending();
+// protected:
     bool done;
-    port::CondVar _cond;
+    Status s;
+    port::CondVar cond_;
+    RequestType type_;
+    Request *parent;
+};
+
+//含有field的put
+class FieldsReq : public Request {
+public:
+    FieldsReq(Slice Key,const FieldArray &Fields,port::Mutex *mu):
+        Key(Key),Request(FieldsReq_t,mu) {
+            for(auto &[name,value] : Fields) {
+                SliceFields.push_back({name,value});
+            }
+        };
+
+    FieldsReq(Slice Key, Slice Value,port::Mutex *mu):
+        Key(Key),Request(FieldsReq_t,mu) {
+            Slice nameSlice, valSlice;
+            while(GetLengthPrefixedSlice(&Value, &nameSlice)) {
+                if(GetLengthPrefixedSlice(&Value, &valSlice)) {
+                    SliceFields.push_back({nameSlice,valSlice});
+                } else {
+                    std::cout << "name and val not match! From FieldsReq Init" << std::endl;
+                }
+                nameSlice.clear(), valSlice.clear();
+            }
+        }
+
+    void ConstructBatch(WriteBatch &KVBatch,WriteBatch &IndexBatch,
+        WriteBatch &MetaBatch,fielddb::FieldDB *DB,SliceHashSet &batchKeySet) override;
+
+    Slice Key;
+    FieldSliceArray SliceFields;
+};
+
+//不含有field的put，但是计划被弃用了
+// class ValueReq : public Request {
+// public:
+//     ValueReq(std::string *Key,std::string *Value,port::Mutex *mu):
+//         Key(Key),Value(Value),Request(ValueReq_t,mu) { };
+
+//     std::string *Key;
+//     std::string *Value;
+// };
+
+//TODO:下面的Field什么的可能通过传引用的方式会更加好？
+
+//创建索引的request
+class iCreateReq : public Request {
+public:
+    iCreateReq(Slice Field,port::Mutex *mu):
+        Field(Field),Request(iCreateReq_t, mu),Existed(false) { };
 
-    bool hasFields;
-    std::string *Key;
-    std::string *Value;
-    FieldArray *Fields;
+    void ConstructBatch(WriteBatch &KVBatch,WriteBatch &IndexBatch,
+        WriteBatch &MetaBatch,fielddb::FieldDB *DB,SliceHashSet &batchKeySet) override;
+    void Prepare(FieldDB *DB) override;
+    void Finalize(FieldDB *DB) override;
+    void PendReq(Request *req) override;
+        
+    bool Existed;
+    Slice Field;
+    std::deque<Request *> pending_list;
 };
-}
+
+//删除索引的request
+class iDeleteReq : public Request {
+public:
+    iDeleteReq(Slice Field,port::Mutex *mu):
+        Field(Field),Request(iDeleteReq_t, mu),Deleted(false) { };
+
+    void ConstructBatch(WriteBatch &KVBatch,WriteBatch &IndexBatch,
+        WriteBatch &MetaBatch,fielddb::FieldDB *DB,SliceHashSet &batchKeySet) override;
+    void Prepare(FieldDB *DB) override;
+    void Finalize(FieldDB *DB) override;
+    void PendReq(Request *req) override;
+
+    bool Deleted;
+    Slice Field;
+    std::deque<Request *> pending_list;
+};
+
+//删除key的request
+class DeleteReq : public Request {
+public:
+    DeleteReq(Slice Key,port::Mutex *mu):
+        Key(Key),Request(DeleteReq_t,mu) { };
+
+    void ConstructBatch(WriteBatch &KVBatch,WriteBatch &IndexBatch,
+        WriteBatch &MetaBatch,fielddb::FieldDB *DB,SliceHashSet &batchKeySet) override;
+
+    Slice Key;
+};
+
+class BatchReq : public Request {
+public:
+    BatchReq(WriteBatch *Batch,port::Mutex *mu);
+    ~BatchReq();
+
+    void ConstructBatch(WriteBatch &KVBatch,WriteBatch &IndexBatch,
+        WriteBatch &MetaBatch,fielddb::FieldDB *DB,SliceHashSet &batchKeySet) override;
+
+    WriteBatch *Batch;
+    std::deque<Request *> sub_requests;
+    // std::deque<std::string> str_buf;
+    // std::deque<FieldArray> fa_buf;
+};
+
+}
+
+#endif

include/leveldb/env.h

@@ -218,6 +218,8 @@ class LEVELDB_EXPORT Env {
   virtual void SleepForMicroseconds(int micros) = 0;
 };
 
+Env* getPosixEnv();
+
 // A file abstraction for reading sequentially through a file
 class LEVELDB_EXPORT SequentialFile {
  public:

test/basic_function_test.cc

@@ -2,139 +2,63 @@
 // #include "leveldb/env.h"
 // #include "leveldb/db.h"
 #include "fielddb/field_db.h"
+#include "test/helper.cc"
 using namespace fielddb;
 
-constexpr int value_size = 2048;
-constexpr int data_size = 128 << 20;
-std::vector<std::string> cities = {
-        "Beijing", "Shanghai", "Guangzhou", "Shenzhen", "Hangzhou", 
-        "Chengdu", "Chongqing", "Wuhan", "Suzhou", "Tianjin"
-    };
-std::vector<std::string> shanghaiKeys;
-
-Status OpenDB(std::string dbName, FieldDB **db) {
-  Options options;
-  options.create_if_missing = true;
-  return FieldDB::OpenFieldDB(options, dbName, db);
-}
-
-void ClearDB(FieldDB *db){ 
-  //destroy和恢复没做前先用这个清理数据库，否则跑不同的数据多做几次测试会污染
-  WriteOptions writeOptions;
-  int key_num = data_size / value_size;
-  for (int i = 0; i < key_num; i++) {
-    int key_ = i+1;
-    std::string key = std::to_string(key_);
-    Status s =  db->Delete(WriteOptions(), key);
-    ASSERT_TRUE(s.ok());
-  }
-} 
-
-void InsertFieldData(FieldDB *db) {
-  WriteOptions writeOptions;
-  int key_num = data_size / value_size;
-  srand(0);
-
-  for (int i = 0; i < key_num; i++) {
-    int randThisTime = rand(); //确保读写一个循环只rand一次，否则随机序列会不一致
-    int key_ = randThisTime % key_num+1;
-    std::string key = std::to_string(key_);
-
-    std::string name = "customer#" + std::to_string(key_);
-    std::string address = cities[randThisTime % cities.size()]; 
-    FieldArray fields = {
-        {"name", name},
-        {"address", address}
-    };
-    if (address == "Shanghai")  {
-      shanghaiKeys.push_back(key);
-    }
-    Status s =  db->PutFields(WriteOptions(), key, fields);
-    ASSERT_TRUE(s.ok());
-  }
-}
-
-void GetFieldData(FieldDB *db) {
-  ReadOptions readOptions;
-  int key_num = data_size / value_size;
-  
-  // 点查
-  srand(0);
-  for (int i = 0; i < 100; i++) {
-    int randThisTime = rand();
-    int key_ = randThisTime % key_num+1;
-    std::string key = std::to_string(key_);
-    FieldArray fields_ret;
-    Status s = db->GetFields(readOptions, key, &fields_ret);
-    ASSERT_TRUE(s.ok());
-    for (const Field& pairs : fields_ret) {
-      if (pairs.first == "name"){
-
-      } else if (pairs.first == "address"){
-          std::string city = pairs.second;
-          ASSERT_NE(std::find(cities.begin(), cities.end(), city), cities.end());          
-      } else assert(false);
-    }
-  }
-}
-
-void findKeysByCity(FieldDB *db) {
-  Field field = {"address", "Shanghai"};
-  std::vector<std::string> resKeys = db->FindKeysByField(field);
-  std::cout << shanghaiKeys.size() << " " << resKeys.size() << std::endl;
-  for (const std::string &key : resKeys){
-    ASSERT_NE(std::find(shanghaiKeys.begin(), shanghaiKeys.end(), key), shanghaiKeys.end());
-  }
-}
-
-void findKeysByCityIndex(FieldDB *db, bool expect) {
-  Field field = {"address", "Shanghai"};
-  Status s;
-  std::vector<std::string> resKeys = db->QueryByIndex(field, &s);
-  if (expect) ASSERT_TRUE(s.ok());
-  else {
-    ASSERT_TRUE(s.IsNotFound());
-    return;
-  }
-  std::cout << shanghaiKeys.size() << " " << resKeys.size() << std::endl;
-  for (const std::string &key : resKeys){
-    ASSERT_NE(std::find(shanghaiKeys.begin(), shanghaiKeys.end(), key), shanghaiKeys.end());
-  }
-}
 
 TEST(TestLab1, Basic) {
-    // DestroyDB("testdb",Options());
+    fielddb::DestroyDB("testdb1.1",Options()); //每个测试前，先把对应名称的之前的数据库删了
     FieldDB *db = new FieldDB();
 
-    if(OpenDB("testdb", &db).ok() == false) {
+    if(OpenDB("testdb1.1", &db).ok() == false) {
         std::cerr << "open db failed" << std::endl;
         abort();
     }
     // ClearDB(db);
     InsertFieldData(db);
-    GetFieldData(db);    
+    bool allowNotFound = false;
+    GetFieldData(db, allowNotFound);    
     findKeysByCity(db);
+
+    DeleteFieldData(db);
+    GetDeleteData(db);
+
     delete db;
 }
 
 TEST(TestLab2, Basic) {
-    //destroy
+    fielddb::DestroyDB("testdb1.2",Options());
     FieldDB *db = new FieldDB();
 
-    if(OpenDB("testdb2", &db).ok() == false) {
+    if(OpenDB("testdb1.2", &db).ok() == false) {
         std::cerr << "open db failed" << std::endl;
         abort();
     }
-    // ClearDB(db);
     shanghaiKeys.clear();
+    age20Keys.clear();
     InsertFieldData(db);
     // GetFieldData(db);    
     // findKeysByCity(db);
-    db->CreateIndexOnField("address");
+    db->CreateIndexOnField("address", op);
+    db->CreateIndexOnField("age", op);
     findKeysByCityIndex(db, true);
-    db->DeleteIndex("address");
-    findKeysByCityIndex(db, false);
+    findKeysByAgeIndex(db, true);
 
+    db->DeleteIndex("address", op);
+    findKeysByCityIndex(db, false);
+    findKeysByAgeIndex(db, true);
+
+    DeleteFieldData(db);
+    // GetDeleteData(db);
+    //helper太长不再封装函数了，这里因为数据都被delete了，但索引还在，所以能QueryByIndex但返回key数量0
+    Field field = {"age", "20"};
+    Status s;
+    std::vector<std::string> resKeys = db->QueryByIndex(field, &s);
+    ASSERT_EQ(resKeys.size(), 0);
+
+    WriteFieldData(db);
+    GetFieldData(db, false);
+    findKeysByAgeIndex(db, true);
     delete db;
 }
 

test/helper.cc

@@ -0,0 +1,284 @@
+#include "gtest/gtest.h"
+// #include "leveldb/env.h"
+// #include "leveldb/db.h"
+#include "fielddb/field_db.h"
+#include <random>
+#include "helper.h"
+using namespace fielddb;
+
+constexpr int value_size = 2048;
+constexpr int data_size = 128 << 20;
+#define AGE_RANGE 100
+std::vector<std::string> cities = {
+        "Beijing", "Shanghai", "Guangzhou", "Shenzhen", "Hangzhou", 
+        "Chengdu", "Chongqing", "Wuhan", "Suzhou", "Tianjin"
+    };
+//检查insert和queryByIndex的数据是否对应
+//封装了一个线程安全的全局set
+
+ThreadSafeSet shanghaiKeys; 
+ThreadSafeSet age20Keys;
+//复杂的测试要注意这两个全局变量，
+//目前只有InsertFieldData和InsertOneField和writeFieldData会往里加，
+//DeleteFieldData和InsertOneField会删除，
+//其他测试之间有必要手动clear
+const WriteOptions op;
+
+Status OpenDB(std::string dbName, FieldDB **db) {
+  Options options;
+  options.create_if_missing = true;
+  return FieldDB::OpenFieldDB(options, dbName, db);
+}
+
+// void ClearDB(FieldDB *db){ 
+//   //destroy和恢复没做前先用这个清理数据库，否则跑不同的数据多做几次测试会污染
+//   WriteOptions writeOptions;
+//   int key_num = data_size / value_size;
+//   for (int i = 0; i < key_num; i++) {
+//     int key_ = i+1;
+//     std::string key = std::to_string(key_);
+//     Status s =  db->Delete(WriteOptions(), key);
+//     ASSERT_TRUE(s.ok());
+//   }
+// } 
+
+//只插一条特定数据的测试
+void InsertOneField(FieldDB *db, std::string key = "0") {
+    WriteOptions writeOptions;
+        FieldArray fields = {
+        {"name", "special#" + key},
+        {"address", "Shanghai"},
+        {"age", "20"}
+    };
+    Status s =  db->PutFields(WriteOptions(), key, fields);
+    ASSERT_TRUE(s.ok());
+    shanghaiKeys.insert(key);
+    age20Keys.insert(key);
+}
+
+//只删一条特定数据的测试
+void DeleteOneField(FieldDB *db, std::string key = "0") {
+    WriteOptions writeOptions;
+    Status s =  db->Delete(WriteOptions(), key);
+    ASSERT_TRUE(s.ok());
+    shanghaiKeys.erase(key);
+    age20Keys.erase(key);
+}
+
+//与上面对应
+void GetOneField(FieldDB *db, std::string key = "0") {
+    ReadOptions readOptions;
+    FieldArray fields_ret;
+    Status s = db->GetFields(readOptions, key, &fields_ret);
+    ASSERT_TRUE(s.ok());
+    for (const Field& pairs : fields_ret) {
+      if (pairs.first == "name"){
+        ASSERT_EQ(pairs.second, "special#" + key);
+      } else if (pairs.first == "address"){
+        ASSERT_EQ(pairs.second, "Shanghai");
+      } else if (pairs.first == "age"){
+        ASSERT_EQ(pairs.second, "20");
+      } else assert(false);
+    }
+}
+
+void InsertFieldData(FieldDB *db, int seed = 0/*随机种子*/) {
+  std::cout << "-------inserting-------" << std::endl;
+  WriteOptions writeOptions;
+  int key_num = data_size / value_size;
+  // srand线程不安全，这种可以保证多线程时随机序列也一致
+  std::mt19937 rng(seed);
+
+  for (int i = 0; i < key_num; i++) {
+    int randThisTime = rng(); //确保读写一个循环只rand一次，否则随机序列会不一致
+    //让批量写入的key>0, 单独写入的key<=0,方便测试观察
+    int key_ = std::abs(randThisTime) % key_num + 1; 
+    std::string key = std::to_string(key_);
+
+    std::string name = "customer#" + std::to_string(key_);
+    std::string address = cities[randThisTime % cities.size()];
+    std::string age = std::to_string(std::abs(randThisTime) % AGE_RANGE); 
+    FieldArray fields = {
+        {"name", name},
+        {"address", address},
+        {"age", age}
+    };
+    if (address == "Shanghai") {
+      shanghaiKeys.insert(key);
+    }
+    if (age == "20") {
+      age20Keys.insert(key);
+    }
+    Status s =  db->PutFields(WriteOptions(), key, fields);
+    ASSERT_TRUE(s.ok());
+  }
+}
+
+void DeleteFieldData(FieldDB *db, int seed = 0/*随机种子*/) {
+  std::cout << "-------deleting-------" << std::endl;
+  WriteOptions writeOptions;
+  int key_num = data_size / value_size;
+  // srand线程不安全，这种可以保证多线程时随机序列也一致
+  std::mt19937 rng(seed);
+
+  shanghaiKeys.clear();
+  age20Keys.clear();
+  for (int i = 0; i < key_num; i++) {
+    int randThisTime = rng(); //确保读写一个循环只rand一次，否则随机序列会不一致
+    int key_ = std::abs(randThisTime) % key_num + 1; 
+    std::string key = std::to_string(key_);
+
+    Status s =  db->Delete(WriteOptions(), key);
+    ASSERT_TRUE(s.ok());
+  }
+}
+
+void WriteFieldData(FieldDB *db, int seed = 0/*随机种子*/) {
+  std::cout << "-------writing-------" << std::endl;
+  WriteOptions writeOptions;
+  int key_num = data_size / value_size;
+  // srand线程不安全，这种可以保证多线程时随机序列也一致
+  std::mt19937 rng(seed);
+
+  WriteBatch wb;
+  for (int i = 0; i < key_num; i++) {
+    int randThisTime = rng(); //确保读写一个循环只rand一次，否则随机序列会不一致
+    //让批量写入的key>0, 单独写入的key<=0,方便测试观察
+    int key_ = std::abs(randThisTime) % key_num + 1; 
+    std::string key = std::to_string(key_);
+
+    std::string name = "customer#" + std::to_string(key_);
+    std::string address = cities[randThisTime % cities.size()];
+    std::string age = std::to_string(std::abs(randThisTime) % AGE_RANGE); 
+    FieldArray fields = {
+        {"name", name},
+        {"address", address},
+        {"age", age}
+    };
+    if (address == "Shanghai") {
+      shanghaiKeys.insert(key);
+    }
+    if (age == "20") {
+      age20Keys.insert(key);
+    }
+    wb.Put(key, SerializeValue(fields));
+
+  }
+  Status s =  db->Write(writeOptions, &wb);
+  ASSERT_TRUE(s.ok());  
+}
+
+//并发时不一定能读到，加个参数控制
+void GetFieldData(FieldDB *db, bool allowNotFound, int seed = 0) {
+  std::cout << "-------getting-------" << std::endl;
+  ReadOptions readOptions;
+  int key_num = data_size / value_size;
+  
+  // 点查
+  std::mt19937 rng(seed);
+  for (int i = 0; i < 100; i++) {
+    int randThisTime = rng();
+    int key_ = std::abs(randThisTime) % key_num + 1;
+    std::string key = std::to_string(key_);
+    FieldArray fields_ret;
+    Status s = db->GetFields(readOptions, key, &fields_ret);
+    if (!allowNotFound){ //必须读到
+        // if (!s.ok()){
+        //   std::cout << key << std::endl;
+        // }
+        ASSERT_TRUE(s.ok());
+    } else { //不必须读到，但只要读到address必须正确
+        if(s.IsNotFound()) continue;
+    }
+    for (const Field& pairs : fields_ret) {
+      if (pairs.first == "name"){
+
+      } else if (pairs.first == "address"){
+          std::string city = pairs.second;
+          ASSERT_NE(std::find(cities.begin(), cities.end(), city), cities.end());  
+
+      } else if (pairs.first == "age"){
+        int age = std::stoi(pairs.second);
+        ASSERT_TRUE(age >= 0 && age < AGE_RANGE);
+
+      } else assert(false);
+    }
+  }
+}
+
+//检查对应种子有没有删除干净
+//删除期间即使其他种子也不能并发写，因为即使种子不同，随机出的key可能相同
+void GetDeleteData(FieldDB *db, int seed = 0) {
+  std::cout << "-------getting-------" << std::endl;
+  ReadOptions readOptions;
+  int key_num = data_size / value_size;
+  
+  std::mt19937 rng(seed);
+  for (int i = 0; i < 100; i++) {
+    int randThisTime = rng();
+    int key_ = std::abs(randThisTime) % key_num + 1;
+    std::string key = std::to_string(key_);
+    FieldArray fields_ret;
+    Status s = db->GetFields(readOptions, key, &fields_ret);
+    ASSERT_TRUE(s.IsNotFound());
+  }
+}
+
+void findKeysByCity(FieldDB *db) {
+  std::cout << "-------getting field address-------" << std::endl;
+  Field field = {"address", "Shanghai"};
+  std::vector<std::string> resKeys = db->FindKeysByField(field);
+  //打印比较，因为shanghaikey可能被后写入的、其他address的key覆盖，打印出的后一个数应该小于前一个数
+  //如果随机种子相同，每次打印出的两个数也应该相同
+  std::cout << "address: " << shanghaiKeys.size() << " " << resKeys.size() << std::endl;
+  for (const std::string &key : resKeys){
+    ASSERT_TRUE(shanghaiKeys.haveKey(key));
+  }
+}
+
+// haveIndex表明数据库有没有该索引（address）
+void findKeysByCityIndex(FieldDB *db, bool haveIndex) {
+  std::cout << "-------getting field address by index-------" << std::endl;
+  Field field = {"address", "Shanghai"};
+  Status s;
+  std::vector<std::string> resKeys = db->QueryByIndex(field, &s);
+  if (haveIndex) ASSERT_TRUE(s.ok());
+  else {
+    ASSERT_TRUE(s.IsNotFound());
+    return;
+  }
+  std::cout << "address: " << shanghaiKeys.size() << " " << resKeys.size() << std::endl;//打印比较
+  for (const std::string &key : resKeys){
+    ASSERT_TRUE(shanghaiKeys.haveKey(key));
+  }
+}
+
+void findKeysByAgeIndex(FieldDB *db, bool haveIndex) {
+  std::cout << "-------getting field age by index-------" << std::endl;
+  Field field = {"age", "20"};
+  Status s;
+  std::vector<std::string> resKeys = db->QueryByIndex(field, &s);
+  if (haveIndex) ASSERT_TRUE(s.ok());
+  else {
+    ASSERT_TRUE(s.IsNotFound());
+    return;
+  } 
+  std::cout << "age: " << age20Keys.size() << " " << resKeys.size() << std::endl;
+  for (const std::string &key : resKeys){
+    ASSERT_TRUE(age20Keys.haveKey(key));
+  }
+}
+
+void checkDataInKVAndIndex(FieldDB *db, std::string fieldName = "address") {
+  Field field;
+  if (fieldName == "address") field = {"address", "Shanghai"};
+  else if (fieldName == "age") field = {"age", "20"};
+  else  assert(0);//只支持这两个字段检查
+  Status s;
+  std::vector<std::string> resKeys1 = db->QueryByIndex(field, &s); //indexdb根据索引查到的数据
+  std::vector<std::string> resKeys2 = db->FindKeysByField(field); //kvdb强行遍历查到的数据
+  std::sort(resKeys1.begin(), resKeys1.end());
+  std::sort(resKeys2.begin(), resKeys2.end());
+  std::cout << resKeys1.size() << " "  << resKeys2.size() << std::endl;
+  ASSERT_EQ(resKeys1, resKeys2);
+}

test/helper.h

@@ -0,0 +1,34 @@
+#include "fielddb/field_db.h"
+using namespace fielddb;
+class ThreadSafeSet
+{
+private:
+  std::set<std::string> keys;
+  std::mutex setMutex;
+public:
+  ThreadSafeSet(){}
+
+  void insert(std::string key){
+    std::lock_guard<std::mutex> lock(setMutex);
+    keys.insert(key);
+  }
+
+  void erase(std::string key){
+    std::lock_guard<std::mutex> lock(setMutex);
+    keys.erase(key);
+  }
+
+  void clear(){
+    std::lock_guard<std::mutex> lock(setMutex);
+    keys.clear();
+  }
+
+  size_t size(){
+    std::lock_guard<std::mutex> lock(setMutex);
+    return keys.size();
+  }
+
+  bool haveKey(std::string key){
+    return std::find(keys.begin(), keys.end(), key) != keys.end();
+  }
+};

test/parallel_test.cc

@@ -0,0 +1,302 @@
+#include "gtest/gtest.h"
+#include <thread>
+// #include "leveldb/env.h"
+// #include "leveldb/db.h"
+#include "fielddb/field_db.h"
+#include "test/helper.cc"
+using namespace fielddb;
+
+// 测试中read/write都表示带索引的读写
+
+//读写有索引数据的并发
+TEST(TestReadPut, Parallel) {
+    fielddb::DestroyDB("testdb2.1",Options());
+    FieldDB *db = new FieldDB();
+
+    if(OpenDB("testdb2.1", &db).ok() == false) {
+        std::cerr << "open db failed" << std::endl;
+        abort();
+    }
+    // ClearDB(db);
+    db->CreateIndexOnField("address", op);
+    db->CreateIndexOnField("age", op);
+    int thread_num_ = 5;
+    std::vector<std::thread> threads(thread_num_);
+    //二写三读
+    for (size_t i = 0; i < thread_num_; i++)
+    {
+        if (i == 0) {//写随机序列0
+            threads[i] = std::thread(InsertFieldData, db, 0);
+        } else if (i == 1)
+        {//写随机序列1
+            threads[i] = std::thread(InsertFieldData, db, 1);
+        } else {//读
+        bool allowNotFound = true;
+            threads[i] = std::thread(GetFieldData, db, allowNotFound, 0);
+        }
+    }
+    
+    for (auto& t : threads) {
+        if (t.joinable()) {
+            t.join();
+        }
+    }    
+
+    // 此时写已完成，一定能读到两次写
+    bool allowNotFound = false;
+    GetFieldData(db, allowNotFound); 
+    GetFieldData(db, allowNotFound, 1); 
+    findKeysByCity(db);
+    checkDataInKVAndIndex(db);
+    delete db;
+}
+
+//创建索引与写有该索引数据的并发
+TEST(TestPutCreatei, Parallel) {
+    fielddb::DestroyDB("testdb2.2",Options());
+    FieldDB *db = new FieldDB();
+
+    if(OpenDB("testdb2.2", &db).ok() == false) {
+        std::cerr << "open db failed" << std::endl;
+        abort();
+    }
+
+    // ClearDB(db);
+    shanghaiKeys.clear();
+    InsertFieldData(db);
+    int thread_num_ = 2;
+    std::vector<std::thread> threads(thread_num_);
+    for (size_t i = 0; i < thread_num_; i++)
+    {
+        if (i == 0) {//创建索引
+            threads[i] = std::thread([db](){
+                db->CreateIndexOnField("address", op);
+                std::cout << "finish create index\n";
+            });
+        } else {//写
+            threads[i] = std::thread([db](){
+                while (db->GetIndexStatus("address") == NotExist){
+                    continue; //开始创建了再并发的写
+                }
+                InsertOneField(db); //先插一条
+            });
+        }
+    }
+    
+    for (auto& t : threads) {
+        if (t.joinable()) {
+            t.join();
+        }
+    }
+    //检查索引是否创建成功
+    bool haveIndex = true;
+    findKeysByCityIndex(db, haveIndex);
+    //检查写入是否成功
+    GetOneField(db);
+    checkDataInKVAndIndex(db);
+
+    delete db;
+}
+
+//创建删除不同索引的并发
+TEST(TestCreateiCreatei, Parallel) {
+    fielddb::DestroyDB("testdb2.3",Options());
+    FieldDB *db = new FieldDB();
+
+    if(OpenDB("testdb2.3", &db).ok() == false) {
+        std::cerr << "open db failed" << std::endl;
+        abort();
+    }
+
+    // ClearDB(db);
+    shanghaiKeys.clear();
+    age20Keys.clear();
+    InsertFieldData(db);
+    int thread_num_ = 3;
+    std::vector<std::thread> threads(thread_num_);
+    for (size_t i = 0; i < thread_num_; i++)
+    {
+        //3线程并发创建索引address
+            threads[i] = std::thread([db](){
+                db->CreateIndexOnField("address", op);
+                std::cout << "finish create index address\n";
+            });
+    }
+    
+    for (auto& t : threads) {
+        if (t.joinable()) {
+            t.join();
+        }
+    }
+    //检查索引是否创建成功
+    bool haveIndex = true;
+    findKeysByCityIndex(db, haveIndex);
+    findKeysByAgeIndex(db, false);
+    checkDataInKVAndIndex(db);
+
+
+    for (size_t i = 0; i < thread_num_; i++)
+    {
+        if (i == 0 || i == 1) {//2线程删除索引address
+            threads[i] = std::thread([db](){
+                db->DeleteIndex("address", op);
+                std::cout << "finish delete index address\n";
+            });
+        } else {//1线程创建索引age
+            threads[i] = std::thread([db](){
+                db->CreateIndexOnField("age", op);
+                std::cout << "finish create index age\n";
+            });
+        }
+    }
+    
+    for (auto& t : threads) {
+        if (t.joinable()) {
+            t.join();
+        }
+    }
+    //检查
+    findKeysByCityIndex(db, false);
+    findKeysByAgeIndex(db, true);
+
+    delete db;
+}
+
+//有索引时，大量并发put与delete相同key，确保kvdb和indexdb的一致性
+TEST(TestPutDeleteOne, Parallel) {
+    fielddb::DestroyDB("testdb2.4",Options());
+    FieldDB *db = new FieldDB();
+
+    if(OpenDB("testdb2.4", &db).ok() == false) {
+        std::cerr << "open db failed" << std::endl;
+        abort();
+    }
+
+    // ClearDB(db);
+    shanghaiKeys.clear();
+    age20Keys.clear();
+    db->CreateIndexOnField("address", op);
+    db->CreateIndexOnField("age", op);
+    int thread_num_ = 20;
+    std::vector<std::thread> threads(thread_num_);
+    for (size_t i = 0; i < thread_num_; i++)
+    {
+        if (i % 2 == 0) {//2线程删除索引address
+            threads[i] = std::thread([db](){
+                for (size_t j = 0; j < 100; j++)
+                {
+                    InsertOneField(db, std::to_string(j));
+                }
+            });
+        } else {//1线程创建索引age
+            threads[i] = std::thread([db](){
+                for (size_t j = 0; j < 100; j++)
+                {
+                    DeleteOneField(db, std::to_string(j));
+                }
+            });
+        }
+    }
+    
+    for (auto& t : threads) {
+        if (t.joinable()) {
+            t.join();
+        }
+    }
+    
+    //检查
+    checkDataInKVAndIndex(db);
+    delete db;
+}
+
+//有索引时，put与delete的并发，确保kvdb和indexdb的一致性
+TEST(TestPutDelete, Parallel) {
+    fielddb::DestroyDB("testdb2.5",Options());
+    FieldDB *db = new FieldDB();
+
+    if(OpenDB("testdb2.5", &db).ok() == false) {
+        std::cerr << "open db failed" << std::endl;
+        abort();
+    }
+
+    // ClearDB(db);
+    shanghaiKeys.clear();
+    age20Keys.clear();
+    db->CreateIndexOnField("address", op);
+    db->CreateIndexOnField("age", op);
+    int thread_num_ = 4;
+    std::vector<std::thread> threads(thread_num_);
+    threads[0] = std::thread([db](){InsertFieldData(db);});
+    threads[1] = std::thread([db](){InsertFieldData(db, 1);});
+    threads[2] = std::thread([db](){DeleteFieldData(db);});
+    threads[3] = std::thread([db](){DeleteFieldData(db, 1);});
+    
+    for (auto& t : threads) {
+        if (t.joinable()) {
+            t.join();
+        }
+    }
+    
+    //检查
+    checkDataInKVAndIndex(db);
+    delete db;
+}
+
+//write和其他功能的并发（大杂烩
+TEST(TestWrite, Parallel) {
+    fielddb::DestroyDB("testdb2.6",Options());
+    FieldDB *db = new FieldDB();
+
+    if(OpenDB("testdb2.6", &db).ok() == false) {
+        std::cerr << "open db failed" << std::endl;
+        abort();
+    }
+
+    // ClearDB(db);
+    shanghaiKeys.clear();
+    age20Keys.clear();
+    db->CreateIndexOnField("address", op);
+    InsertFieldData(db, 2); //先填点数据，让创建索引的时间久一点
+    int thread_num_ = 5;
+    std::vector<std::thread> threads(thread_num_);
+    threads[0] = std::thread([db](){db->CreateIndexOnField("age", op);});
+    threads[1] = std::thread([db](){
+                while (db->GetIndexStatus("age") == NotExist){
+                    continue; //开始创建了再并发的写
+                }
+                InsertFieldData(db);});
+    threads[2] = std::thread([db](){
+                while (db->GetIndexStatus("age") == NotExist){
+                    continue; 
+                }
+                WriteFieldData(db, 1);});
+    threads[3] = std::thread([db](){
+                while (db->GetIndexStatus("age") == NotExist){
+                    continue; 
+                }
+                DeleteFieldData(db, 0);});
+    threads[4] = std::thread([db](){
+                while (db->GetIndexStatus("age") == NotExist){
+                    continue; 
+                }
+                db->DeleteIndex("age", op);});
+    
+    for (auto& t : threads) {
+        if (t.joinable()) {
+            t.join();
+        }
+    }
+    
+    //检查
+    checkDataInKVAndIndex(db);    
+    ASSERT_EQ(db->GetIndexStatus("age"), NotExist); //删除索引的请求应该被pend在创建之上
+    //删掉最后一个线程，可以测试创建age索引时并发的写入能不能保持age的一致性
+    //checkDataInKVAndIndex(db, "age");
+    delete db;
+}
+
+int main(int argc, char** argv) {
+  // All tests currently run with the same read-only file limits.
+  testing::InitGoogleTest(&argc, argv);
+  return RUN_ALL_TESTS();
+}

test/recover_test.cc

@@ -0,0 +1,90 @@
+#include "gtest/gtest.h"
+// #include "leveldb/env.h"
+// #include "leveldb/db.h"
+#include "fielddb/field_db.h"
+#include "test/helper.cc"
+#include <thread>
+#include <csignal>
+#include <exception>
+using namespace fielddb;
+
+TEST(TestNormalRecover, Recover) {
+    fielddb::DestroyDB("testdb3.1",Options());
+    FieldDB *db = new FieldDB();
+
+    if(OpenDB("testdb3.1", &db).ok() == false) {
+        std::cerr << "open db failed" << std::endl;
+        abort();
+    }
+    db->CreateIndexOnField("address", op);
+    db->CreateIndexOnField("age", op);
+    InsertFieldData(db);
+    bool allowNotFound = false;
+    GetFieldData(db, allowNotFound);   
+    findKeysByCityIndex(db, true);
+    findKeysByAgeIndex(db, true); 
+
+    delete db;
+    db = new FieldDB();
+    if(OpenDB("testdb3.1", &db).ok() == false) {
+        std::cerr << "open db failed" << std::endl;
+        abort();
+    }
+    //仍然能读到之前写入的数据和索引
+    GetFieldData(db, allowNotFound);
+    findKeysByCityIndex(db, true);
+    findKeysByAgeIndex(db, true); 
+}
+
+TEST(TestParalRecover, Recover) {
+    //第一次运行
+    // fielddb::DestroyDB("testdb3.2",Options());
+    // FieldDB *db = new FieldDB();
+
+    // if(OpenDB("testdb3.2", &db).ok() == false) {
+    //     std::cerr << "open db failed" << std::endl;
+    //     abort();
+    // }
+    // db->CreateIndexOnField("address", op);
+    // db->CreateIndexOnField("age", op);
+    // int thread_num_ = 4;
+    // std::vector<std::thread> threads(thread_num_);
+    // threads[0] = std::thread([db](){
+    //     InsertFieldData(db);
+    // });
+    // threads[1] = std::thread([db](){
+    //     WriteFieldData(db);
+    // });
+    // threads[2] = std::thread([db](){
+    //     DeleteFieldData(db);
+    // });
+    // threads[3] = std::thread([db](){
+    //     InsertOneField(db);
+    //     delete db;
+    // });
+    //     for (auto& t : threads) {
+    //     if (t.joinable()) {
+    //         t.join();
+    //     }
+    // }
+    //线程3导致了其他线程错误，测试会终止（模拟数据库崩溃）
+    //这会导致各线程在各种奇怪的时间点崩溃
+    //第二次运行注释掉上面的代码，运行下面的代码测试恢复
+
+
+    //第二次运行
+    FieldDB *db = new FieldDB();
+    if(OpenDB("testdb3.2", &db).ok() == false) {
+        std::cerr << "open db failed" << std::endl;
+        abort();
+    }
+    GetOneField(db);
+    checkDataInKVAndIndex(db);
+    //这里会出现两个数字，如果>1说明除了线程3插入的一条数据，其他线程也有数据在崩溃前被正确恢复了
+}
+
+int main(int argc, char** argv) {
+  // All tests currently run with the same read-only file limits.
+  testing::InitGoogleTest(&argc, argv);
+  return RUN_ALL_TESTS();
+}

testdb/testdb.cc

@@ -0,0 +1,112 @@
+#include "testdb/testdb.h"
+#include "db/db_impl.h"
+#include <memory>
+#include "leveldb/status.h"
+#include "testdb.h"
+using namespace testdb;
+
+Status testDB::OpentestDB(Options& options,
+                            const std::string& name, testDB** dbptr) {
+    // options.env->CreateDir("./abc")
+    if(*dbptr == nullptr){
+        return Status::NotSupported(name, "new a testDb first\n");
+    }
+
+    //
+    Status status;
+    DB *indexdb, *kvdb, *metadb;
+    // options.block_cache = NewLRUCache(ULONG_MAX);
+    // options.max_open_files = 1000;
+    // options.write_buffer_size = 512 * 1024 * 1024;
+    // options.env = getPosixEnv();
+    // status = Open(options, name+"_indexDB", &indexdb);
+    // if(!status.ok()) return status;
+    // (*dbptr)->indexDB_ = indexdb;
+    
+    // options.env = getPosixEnv();
+    status = DB::Open(options, name+"_kvDB", &kvdb);
+    if(!status.ok()) return status;
+    (*dbptr)->kvDB_ = kvdb;
+
+    // options.env = getPosixEnv();
+    // status = Open(options, name+"_metaDB", &metadb);
+    // if(!status.ok()) return status;
+    // (*dbptr)->metaDB_ = metadb;
+
+    (*dbptr)->dbname_ = name;
+
+    // status = (*dbptr)->Recover();
+
+    (*dbptr)->options_ = &options;
+    (*dbptr)->env_ = options.env;
+    return status;
+}
+
+Status testDB::Put(const WriteOptions &options, const Slice &key, const Slice &value) {
+    return kvDB_->Put(options, key, value);
+}
+
+Status testDB::PutFields(const WriteOptions &, const Slice &key, const FieldArray &tests) {
+    return Status::OK();
+}
+
+Status testDB::Delete(const WriteOptions &options, const Slice &key) {
+    return kvDB_->Delete(options, key);
+}
+
+Status testDB::Write(const WriteOptions &options, WriteBatch *updates) {
+    return kvDB_->Write(options, updates);
+}
+
+Status testDB::Get(const ReadOptions &options, const Slice &key, std::string *value) {
+    return kvDB_->Get(options, key, value);
+}
+
+Status testDB::GetFields(const ReadOptions &options, const Slice &key, FieldArray *tests) {
+    return Status::OK();
+}
+
+std::vector<std::string> testDB::FindKeysByField(Field &test) {
+    return std::vector<std::string>();
+}
+
+Iterator * testDB::NewIterator(const ReadOptions &options) {
+    return kvDB_->NewIterator(options);
+}
+
+const Snapshot * testDB::GetSnapshot() {
+    return kvDB_->GetSnapshot();
+}
+
+void testDB::ReleaseSnapshot(const Snapshot *snapshot) {
+    kvDB_->ReleaseSnapshot(snapshot);
+}
+
+bool testDB::GetProperty(const Slice &property, std::string *value) {
+    return kvDB_->GetProperty(property, value);
+}
+
+void testDB::GetApproximateSizes(const Range *range, int n, uint64_t *sizes) {
+    kvDB_->GetApproximateSizes(range, n, sizes);
+}
+
+void testDB::CompactRange(const Slice *begin, const Slice *end) {
+    kvDB_->CompactRange(begin, end);
+}
+
+Status testdb::DestroyDB(const std::string& name, const Options& options) {
+  Status s;
+  s = leveldb::DestroyDB(name+"_kvDB", options);
+  assert(s.ok());
+//   s = leveldb::DestroyDB(name+"_indexDB", options);
+//   assert(s.ok());
+//   s = leveldb::DestroyDB(name+"_metaDB", options);
+//   assert(s.ok());
+  return s;
+}
+
+testDB::~testDB() {
+    delete kvDB_;
+    // delete indexDB_;
+    // delete metaDB_;
+}

testdb/testdb.h

@@ -0,0 +1,72 @@
+#include "port/port_stdcxx.h"
+#include "db/db_impl.h"
+#include <cstdint>
+#include <cstdio>
+#include <deque>
+#include <map>
+#include <set>
+#include <string>
+#include "leveldb/db.h"
+#include "leveldb/env.h"
+#include "leveldb/options.h"
+#include "leveldb/slice.h"
+#include "leveldb/status.h"
+#include <shared_mutex>
+# ifndef test_DB_H
+# define test_DB_H
+namespace testdb {
+using namespace leveldb;
+
+enum IndexStatus{
+        Creating,
+        Deleting,
+        Exist,
+        NotExist
+    };
+
+class testDB {
+private:
+    leveldb::DB *kvDB_;
+    // leveldb::DB *metaDB_;
+    // leveldb::DB *indexDB_;
+    
+    std::string dbname_;
+    const Options *options_;
+    Env *env_;
+public:
+    friend class Request;
+    friend class testsReq;
+    friend class iCreateReq;
+    friend class iDeleteReq;
+    friend class DeleteReq;
+    friend class BatchReq;
+
+    //用的时候必须testDB *db = new testDB()再open，不能像之前一样DB *db
+    // testDB() : indexDB_(nullptr), kvDB_(nullptr), metaDB_(nullptr) {};
+    testDB() : kvDB_(nullptr) { }
+    ~testDB();
+/*lab1的要求，作为db派生类要实现的虚函数*/
+    Status Put(const WriteOptions &options, const Slice &key, const Slice &value) ;
+    Status PutFields(const WriteOptions &, const Slice &key, const FieldArray &tests) ;
+    Status Delete(const WriteOptions &options, const Slice &key) ;
+    Status Write(const WriteOptions &options, WriteBatch *updates) ;
+    Status Get(const ReadOptions &options, const Slice &key, std::string *value) ;
+    Status GetFields(const ReadOptions &options, const Slice &key, FieldArray *tests) ;
+    std::vector<std::string> FindKeysByField(Field &test) ;
+    Iterator * NewIterator(const ReadOptions &options) ;
+    const Snapshot * GetSnapshot() ;
+    void ReleaseSnapshot(const Snapshot *snapshot) ;
+    bool GetProperty(const Slice &property, std::string *value) ;
+    void GetApproximateSizes(const Range *range, int n, uint64_t *sizes) ;
+    void CompactRange(const Slice *begin, const Slice *end) ;
+
+    static Status OpentestDB(Options& options,const std::string& name,testDB** dbptr);
+
+
+
+};
+
+Status DestroyDB(const std::string& name,
+                                const Options& options);
+} // end of namespace
+# endif

util/env_posix.cc

@@ -923,4 +923,8 @@ Env* Env::Default() {
   return env_container.env();
 }
 
+Env* getPosixEnv() {
+  return new PosixEnv;
+}
+
 }  // namespace leveldb

util/serialize_value.cc

@@ -3,6 +3,7 @@
 #include <string>
 #include "util/coding.h"
 #include <iostream>
+#include "leveldb/slice.h"
 
 namespace leveldb{
 bool compareByFirst(const Field& a, const Field& b) {
@@ -20,9 +21,25 @@ std::string SerializeValue(const FieldArray& fields){
     return result;
 }
 
-FieldArray *ParseValue(const std::string& value_str){
+std::string SerializeValue(const FieldSliceArray& fields) {
+    using pss = std::pair<Slice,Slice>;
+    FieldSliceArray sortFields = fields;
+    std::sort(sortFields.begin(), sortFields.end(),
+    [&](const pss &lhs, const pss &rhs) {
+        return lhs.first.compare(rhs.first);
+    });
+    std::string result;
+    for (const pss& pairs : sortFields) {
+        PutLengthPrefixedSlice(&result, pairs.first);
+        PutLengthPrefixedSlice(&result, pairs.second);
+    }
+    return result;
+}
+
+FieldArray *ParseValue(const std::string& value_str,FieldArray *fields){
     Slice valueSlice(value_str);
-    FieldArray *res = new FieldArray;
+    // FieldArray *res = new FieldArray;
+    FieldArray *res = fields;
     Slice nameSlice = Slice();
     Slice valSlice = Slice();
     std::string nameStr;
@@ -34,7 +51,8 @@ FieldArray *ParseValue(const std::string& value_str){
             valStr = valSlice.ToString();
             res->emplace_back(nameStr, valStr);
         } else {
-            std::cout << "name and val not match!" << std::endl;
+            std::cout << "name and val not match! From ParseValue" << std::endl;
+            assert(0);
         }
         nameSlice.clear();
         valSlice.clear();
@@ -73,22 +91,22 @@ bool InternalFieldArray::HasField(const Field& field) {
     return std::find(fields.begin(),fields.end(),field) != fields.end();
 }
 
-std::string InternalFieldArray::ValOfName(const std::string &name) {
+Slice InternalFieldArray::ValOfName(const std::string &name) {
     if(isMapped) {
         if(map.count(name)) {
             return map[name];
         }
-        return std::string();
+        return Slice();
     }
     
     for (auto iter = fields.begin(); iter != fields.end(); iter++){
         if (iter->first == name) {
             return iter->second;
         } else if (iter->first > name) {
-            return std::string();
+            return Slice();
         }
     }
-    return std::string();
+    return Slice();
 }
 
 }

util/serialize_value.h

@@ -3,6 +3,7 @@
 
 #include <iostream>
 #include <string>
+#include <utility>
 #include <vector>
 #include <map>
 #include "leveldb/slice.h"
@@ -10,13 +11,15 @@
 namespace leveldb{
 using Field = std::pair<std::string, std::string>;	  // field_name:field_value
 using FieldArray = std::vector<std::pair<std::string, std::string>>;
+using FieldSliceArray = std::vector<std::pair<Slice, Slice>>;
 
 std::string SerializeValue(const FieldArray& fields);
-FieldArray *ParseValue(const std::string& value_str);
+std::string SerializeValue(const FieldSliceArray& fields);
+FieldArray *ParseValue(const std::string& value_str, FieldArray *fields);
 
 class InternalFieldArray {
 public:
-    using FieldMap = std::map<std::string,std::string>;
+    using FieldMap = std::map<std::string,Slice>;
 
     InternalFieldArray(const FieldArray &fields, bool to_map = false):
                         fields(fields),isMapped(false) {
@@ -29,9 +32,9 @@ public:
         Slice nameSlice, valSlice;
         while(GetLengthPrefixedSlice(&valueSlice, &nameSlice)) {
             if(GetLengthPrefixedSlice(&valueSlice, &valSlice)) {
-                map[nameSlice.ToString()] = valSlice.ToString();
+                map[nameSlice.ToString()] = valSlice;
             } else {
-                std::cout << "name and val not match!" << std::endl;
+                std::cout << "name and val not match! From InternalFieldArray" << std::endl;
             }
             nameSlice.clear();
             valSlice.clear();
@@ -48,7 +51,7 @@ public:
     std::string Serialize();
 
     bool HasField(const Field& field);
-    std::string ValOfName(const std::string& name);
+    Slice ValOfName(const std::string& name);
 
 private:
     bool isMapped;