refactor: hide leveldb interface into leveldb_wrapper

project-tsurugi · Jun 6, 2023 · 3f307c7 · 3f307c7
1 parent 464246a
commit 3f307c7
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Showing 2 changed files with 31 additions and 20 deletions.
diff --git a/src/limestone/datastore_snapshot.cpp b/src/limestone/datastore_snapshot.cpp
@@ -71,7 +71,7 @@ epoch_id_type datastore::last_durable_epoch_in_dir() noexcept {
 
 void datastore::create_snapshot() noexcept {
     auto& from_dir = location_;
-    auto lvldb = std::make_unique<leveldb_wrapper>(from_dir);
+    auto db = std::make_unique<leveldb_wrapper>(from_dir);
 
     epoch_id_type ld_epoch = last_durable_epoch_in_dir();
     epoch_id_switched_.store(ld_epoch + 1);
@@ -100,8 +100,7 @@ void datastore::create_snapshot() noexcept {
                         e.write_version(write_version);
 
                         // skip older entry than already inserted
-                        leveldb::ReadOptions read_options;
-                        if (auto status = lvldb->db()->Get(read_options, e.key_sid(), &value); status.ok()) {
+                        if (db->get(e.key_sid(), &value)) {
                             if (write_version < write_version_type(value.substr(1))) {
                                 need_write = false;
                             }
@@ -110,8 +109,7 @@ void datastore::create_snapshot() noexcept {
                             std::string db_value;
                             db_value.append(1, static_cast<char>(e.type()));
                             db_value.append(e.value_etc());
-                            leveldb::WriteOptions write_options;
-                            lvldb->db()->Put(write_options, e.key_sid(), db_value);
+                            db->put(e.key_sid(), db_value);
                         }
                     }
                     break;
@@ -125,8 +123,7 @@ void datastore::create_snapshot() noexcept {
                         e.write_version(write_version);
 
                         // skip older entry than already inserted
-                        leveldb::ReadOptions read_options;
-                        if (auto status = lvldb->db()->Get(read_options, e.key_sid(), &value); status.ok()) {
+                        if (db->get(e.key_sid(), &value)) {
                             if (write_version < write_version_type(value.substr(1))) {
                                 need_write = false;
                             }
@@ -135,8 +132,7 @@ void datastore::create_snapshot() noexcept {
                             std::string db_value;
                             db_value.append(1, static_cast<char>(e.type()));
                             db_value.append(e.value_etc());
-                            leveldb::WriteOptions write_options;
-                            lvldb->db()->Put(write_options, e.key_sid(), db_value);
+                            db->put(e.key_sid(), db_value);
                         }
                     }
                     break;
@@ -167,25 +163,22 @@ void datastore::create_snapshot() noexcept {
         LOG_LP(ERROR) << "cannot create snapshot file (" << snapshot_file << ")";
         std::abort();
     }
-    leveldb::Iterator* it = lvldb->db()->NewIterator(leveldb::ReadOptions());  // NOLINT (typical usage of leveldb)
-    for (it->SeekToFirst(); it->Valid(); it->Next()) {
-        leveldb::Slice db_value = it->value();
+    db->each([&ostrm](std::string_view db_key, std::string_view db_value) {
         static_assert(sizeof(log_entry::entry_type) == 1);
         auto entry_type = static_cast<log_entry::entry_type>(db_value[0]);
         db_value.remove_prefix(1);
         switch (entry_type) {
         case log_entry::entry_type::normal_entry:
-            log_entry::write(ostrm, it->key().ToString(), db_value.ToString());
+            log_entry::write(ostrm, db_key, db_value);
             break;
         case log_entry::entry_type::remove_entry:
             break;  // skip
         default:
             LOG_LP(ERROR) << "never reach " << static_cast<int>(entry_type);
             std::abort();
         }
-    }
+    });
     ostrm.close();
-    delete it;  // NOLINT (typical usage of leveldb)
 }
 
 } // namespace limestone::api
diff --git a/src/limestone/leveldb_wrapper.h b/src/limestone/leveldb_wrapper.h
@@ -17,8 +17,8 @@
 // #include <boost/foreach.hpp>
 #include <leveldb/db.h>
 
-// #include <glog/logging.h>
-// #include <limestone/logging.h>
+#include <glog/logging.h>
+#include <limestone/logging.h>
 
 // #include <limestone/api/datastore.h>
 // #include "log_entry.h"
@@ -58,10 +58,28 @@ class leveldb_wrapper {
     leveldb_wrapper(leveldb_wrapper&& other) noexcept = delete;
     leveldb_wrapper& operator=(leveldb_wrapper&& other) noexcept = delete;
 
-    [[nodiscard]] leveldb::DB* db() const noexcept {
-        return lvldb_;
+    bool put(const std::string& key, const std::string& value) {
+        leveldb::WriteOptions write_options{};
+        auto status = lvldb_->Put(write_options, key, value);
+        return status.ok();
     }
-
+
+    bool get(const std::string& key, std::string* value) {
+        leveldb::ReadOptions read_options{};
+        auto status = lvldb_->Get(read_options, key, value);
+        return status.ok();
+    }
+
+    void each(std::function<void(std::string_view, std::string_view)> fun) {
+        leveldb::Iterator* it = lvldb_->NewIterator(leveldb::ReadOptions());  // NOLINT (typical usage of leveldb)
+        for (it->SeekToFirst(); it->Valid(); it->Next()) {
+            leveldb::Slice key = it->key();
+            leveldb::Slice value = it->value();
+            fun(std::string_view(key.data(), key.size()), std::string_view(value.data(), value.size()));
+        }
+        delete it;  // NOLINT (typical usage of leveldb)
+    }
+
 private:
     leveldb::DB* lvldb_{};
     boost::filesystem::path lvldb_path_;