Clean code

CMakeLists.txt

@@ -225,11 +225,11 @@ target_sources(leveldb
         rdma/nova_msg_parser.h
         novalsm/nic_server.cpp
         novalsm/nic_server.h
-        novalsm/conn_worker.cpp
-        novalsm/conn_worker.h
+        novalsm/client_req_worker.cpp
+        novalsm/client_req_worker.h
         common/nova_common.cpp
         common/nova_common.h
-        rdma/nova_msg_callback.h
+        rdma/rdma_msg_callback.h
         rdma/nova_rdma_rc_broker.cpp
         rdma/nova_rdma_rc_broker.h
         rdma/nova_rdma_broker.h

benchmarks/rdma_write_client.h

@@ -7,12 +7,12 @@
 #ifndef LEVELDB_RDMA_WRITE_CLIENT_H
 #define LEVELDB_RDMA_WRITE_CLIENT_H
 
-#include "rdma/nova_msg_callback.h"
+#include "rdma/rdma_msg_callback.h"
 #include "rdma/nova_rdma_broker.h"
 #include "common/nova_mem_manager.h"
 
 namespace nova {
-    class RDMAWRITEClient : public NovaMsgCallback {
+    class RDMAWRITEClient : public RDMAMsgCallback {
     public:
         RDMAWRITEClient(uint32_t write_size_kb,
                         uint32_t my_server_id);

benchmarks/rdma_write_server_worker.h

@@ -9,7 +9,7 @@
 
 #include <semaphore.h>
 
-#include "rdma/nova_msg_callback.h"
+#include "rdma/rdma_msg_callback.h"
 #include "rdma/nova_rdma_broker.h"
 #include "stoc/persistent_stoc_file.h"
 #include "common/nova_mem_manager.h"
@@ -34,7 +34,7 @@ namespace nova {
 
     class RDMAWRITEDiskWorker;
 
-    class RDMAWRITEServerWorker : public NovaMsgCallback {
+    class RDMAWRITEServerWorker : public RDMAMsgCallback {
     public:
         RDMAWRITEServerWorker(uint32_t max_run_time, uint32_t write_size_kb,
                               bool is_local_disk_bench, bool eval_disk_horizontal_scalability, uint32_t server_id);

common/nova_common.h

@@ -205,30 +205,30 @@ namespace nova {
 /* Initial power multiplier for the hash table */
 #define HASHPOWER_DEFAULT 16
 
-    class Semaphore {
-    public:
-        Semaphore(int count_ = 0)
-                : count(count_) {}
-
-        inline void notify() {
-            std::unique_lock<std::mutex> lock(mtx);
-            count++;
-            cv.notify_all();
-        }
-
-        inline void wait() {
-            std::unique_lock<std::mutex> lock(mtx);
-            while (count == 0) {
-                cv.wait(lock);
-            }
-            count--;
-        }
-
-    private:
-        std::mutex mtx;
-        std::condition_variable cv;
-        int count = 0;
-    };
+//    class Semaphore {
+//    public:
+//        Semaphore(int count_ = 0)
+//                : count(count_) {}
+//
+//        inline void notify() {
+//            std::unique_lock<std::mutex> lock(mtx);
+//            count++;
+//            cv.notify_all();
+//        }
+//
+//        inline void wait() {
+//            std::unique_lock<std::mutex> lock(mtx);
+//            while (count == 0) {
+//                cv.wait(lock);
+//            }
+//            count--;
+//        }
+//
+//    private:
+//        std::mutex mtx;
+//        std::condition_variable cv;
+//        int count = 0;
+//    };
 
 
     uint32_t fastrand();
@@ -431,47 +431,6 @@ namespace nova {
         }
     };
 
-    enum LeaseType : uint8_t {
-        ILEASE = 1,
-        QLEASE = 2
-    };
-
-    struct LeaseEntry {
-        uint8_t type = 0;
-        // worker_id | lease_id.
-        uint64_t lease_id = 0;
-        // client_id | session_id.
-        uint64_t session_id = 0;
-
-        bool empty() {
-            return lease_id == 0;
-        }
-
-        static uint64_t size() {
-            return sizeof(uint8_t) + sizeof(uint64_t) + sizeof(uint64_t);
-        }
-
-        static LeaseEntry chars_to_leaseitem(char *buf) {
-            LeaseEntry it{};
-            char *tmp = buf;
-            memcpy(&it.type, tmp, sizeof(uint8_t));
-            tmp += sizeof(uint8_t);
-            memcpy(&it.lease_id, tmp, sizeof(uint64_t));
-            tmp += sizeof(uint64_t);
-            memcpy(&it.session_id, tmp, sizeof(uint64_t));
-            return it;
-        }
-
-        static void leaseitem_to_chars(char *_base, const LeaseEntry &entry) {
-            char *buf = _base;
-            memcpy(buf, &entry.type, sizeof(uint8_t));
-            buf += sizeof(uint8_t);
-            memcpy(buf, &entry.lease_id, sizeof(uint64_t));
-            buf += sizeof(uint64_t);
-            memcpy(buf, &entry.session_id, sizeof(uint64_t));
-        }
-    };
-
 // Memory layout:
 // stale, refs, nkey, key, nval (string representation + 1), 'h', val, checksum.
 // data points to the beginning of the backing array.
@@ -627,19 +586,6 @@ namespace nova {
         }
     };
 
-//    inline uint32_t
-//    LogRecordsSize(const leveldb::LevelDBLogRecord &log_record);
-//
-//    inline uint32_t
-//    LogRecordsSize(const std::vector<leveldb::LevelDBLogRecord> &log_records);
-//
-//    inline uint32_t
-//    EncodeLogRecord(char *buf,
-//                    const leveldb::LevelDBLogRecord &log_record);
-//
-//    inline uint32_t DecodeLogRecord(char *buf,
-//                             leveldb::LevelDBLogRecord *log_record);
-
     inline uint32_t
     LogRecordSize(const leveldb::LevelDBLogRecord &record) {
         uint32_t size = 0;

common/nova_config.h

@@ -146,7 +146,7 @@ namespace nova {
         uint64_t log_buf_size;
         uint64_t max_stoc_file_size;
         uint64_t sstable_size;
-        std::string stoc_file_path;
+        std::string stoc_files_path;
 
         bool use_local_disk;
         bool enable_subrange;
@@ -185,7 +185,6 @@ namespace nova {
         int level;
 
         int block_cache_mb;
-        int row_cache_mb;
         bool enable_lookup_index;
         bool enable_range_index;
         uint32_t num_memtables;

common/nova_mem_manager.h

@@ -2,7 +2,7 @@
 //
 // Created by Haoyu Huang on 4/8/19.
 // Copyright (c) 2019 University of Southern California. All rights reserved.
-//
+// A slabclass memory manager.
 
 #ifndef NOVA_MEM_MANAGER_H
 #define NOVA_MEM_MANAGER_H

db/db_impl.cc

@@ -2634,15 +2634,15 @@ namespace leveldb {
                                    uint32_t memtable_id) {
         if (nova::NovaConfig::config->log_record_mode ==
             nova::NovaLogRecordMode::LOG_RDMA && !options.local_write) {
-            auto dc = reinterpret_cast<leveldb::StoCBlockClient *>(options.stoc_client);
-            NOVA_ASSERT(dc);
-            dc->set_dbid(dbid_);
+            auto stoc = reinterpret_cast<leveldb::StoCBlockClient *>(options.stoc_client);
+            NOVA_ASSERT(stoc);
+            stoc->set_dbid(dbid_);
             options.stoc_client->InitiateReplicateLogRecords(
                     nova::LogFileName(server_id_, dbid_, memtable_id),
                     options.thread_id, dbid_, memtable_id,
                     options.rdma_backing_mem, log_records,
                     options.replicate_log_record_states);
-            dc->Wait();
+            stoc->Wait();
         }
     }
 
@@ -2652,9 +2652,9 @@ namespace leveldb {
                                    uint32_t memtable_id) {
         if (nova::NovaConfig::config->log_record_mode ==
             nova::NovaLogRecordMode::LOG_RDMA && !options.local_write) {
-            auto dc = reinterpret_cast<leveldb::StoCBlockClient *>(options.stoc_client);
-            NOVA_ASSERT(dc);
-            dc->set_dbid(dbid_);
+            auto stoc = reinterpret_cast<leveldb::StoCBlockClient *>(options.stoc_client);
+            NOVA_ASSERT(stoc);
+            stoc->set_dbid(dbid_);
             LevelDBLogRecord log_record = {};
             log_record.sequence_number = last_sequence;
             log_record.key = key;
@@ -2666,7 +2666,7 @@ namespace leveldb {
                     options.thread_id, dbid_, memtable_id,
                     options.rdma_backing_mem, {log_record},
                     options.replicate_log_record_states);
-            dc->Wait();
+            stoc->Wait();
         }
     }
 

db/lookup_index.h

@@ -2,7 +2,8 @@
 //
 // Created by Haoyu Huang on 5/19/20.
 // Copyright (c) 2020 University of Southern California. All rights reserved.
-//
+// It assumes a fixed size lookup index. One may swap it with any implementation of concurrent hash map.
+// TODO: Support cleaning up the lookup index to remove entries that point to obsolete memtable ids.
 
 #ifndef LEVELDB_LOOKUP_INDEX_H
 #define LEVELDB_LOOKUP_INDEX_H
@@ -29,12 +30,12 @@ namespace leveldb {
         uint32_t Encode(char *buf);
 
         void Decode(Slice *buf);
+
     private:
         uint32_t size_ = 0;
         TableLocation *table_locator_ = nullptr;
     };
 }
 
 
-
 #endif //LEVELDB_LOOKUP_INDEX_H

db/range_index.h

@@ -15,8 +15,6 @@
 #include "leveldb/slice.h"
 #include "version_set.h"
 
-#define MAX_LIVE_VERSIONS 100000
-
 namespace leveldb {
     struct RangeTables {
         std::set<uint32_t> memtable_ids;

db/subrange.cpp

@@ -2,6 +2,7 @@
 //
 // Created by Haoyu Huang on 5/4/20.
 // Copyright (c) 2020 University of Southern California. All rights reserved.
+// It assumes keys are integers.
 //
 
 #include "leveldb/subrange.h"

db/subrange_manager.h

@@ -2,6 +2,7 @@
 //
 // Created by Haoyu Huang on 5/4/20.
 // Copyright (c) 2020 University of Southern California. All rights reserved.
+// It assumes keys are integers.
 //
 
 #ifndef LEVELDB_SUBRANGE_MANAGER_H

db/version_set.h

@@ -29,6 +29,8 @@
 #include "table_cache.h"
 #include "range_index.h"
 
+// Maintain this many live memtables.
+// The program exits when the number of memtables exceeds this threshold.
 #define MAX_LIVE_MEMTABLES 100000
 
 namespace leveldb {
@@ -216,6 +218,7 @@ namespace leveldb {
         uint32_t Encode(char *buf);
 
         void Decode(Slice *buf);
+
         int refs_ = 0;          // Number of live refs to this version
 
     private: