| /** |
| * Licensed to the Apache Software Foundation (ASF) under one |
| * or more contributor license agreements. See the NOTICE file |
| * distributed with this work for additional information |
| * regarding copyright ownership. The ASF licenses this file |
| * to you under the Apache License, Version 2.0 (the |
| * "License"); you may not use this file except in compliance |
| * with the License. You may obtain a copy of the License at |
| * |
| * http://www.apache.org/licenses/LICENSE-2.0 |
| * |
| * Unless required by applicable law or agreed to in writing, software |
| * distributed under the License is distributed on an "AS IS" BASIS, |
| * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. |
| * See the License for the specific language governing permissions and |
| * limitations under the License. |
| */ |
| #ifndef DISABLE_WARNINGS |
| |
| #include "singa/io/reader.h" |
| #include "singa/utils/logging.h" |
| |
| #ifdef USE_LMDB |
| |
| namespace singa { |
| namespace io { |
| bool LMDBReader::Open(const std::string& path) { |
| path_ = path; |
| MDB_CHECK(mdb_env_create(&mdb_env_)); |
| int flags = MDB_RDONLY | MDB_NOTLS; |
| int rc = mdb_env_open(mdb_env_, path_.c_str(), flags, 0664); |
| #ifndef ALLOW_LMDB_NOLOCK |
| MDB_CHECK(rc); |
| #else |
| if (rc == EACCES) { |
| LOG(WARNING) << "Permission denied. Trying with MDB_NOLOCK ..."; |
| // Close and re-open environment handle |
| mdb_env_close(mdb_env_); |
| MDB_CHECK(mdb_env_create(&mdb_env_)); |
| // Try again with MDB_NOLOCK |
| flags |= MDB_NOLOCK; |
| MDB_CHECK(mdb_env_open(mdb_env_, source.c_str(), flags, 0664)); |
| } else { |
| MDB_CHECK(rc); |
| } |
| #endif |
| MDB_CHECK(mdb_txn_begin(mdb_env_, NULL, MDB_RDONLY, &mdb_txn_)); |
| MDB_CHECK(mdb_dbi_open(mdb_txn_, NULL, 0, &mdb_dbi_)); |
| MDB_CHECK(mdb_cursor_open(mdb_txn_, mdb_dbi_, &mdb_cursor_)); |
| SeekToFirst(); |
| return true; |
| } |
| |
| void LMDBReader::Close() { |
| if (mdb_env_ != nullptr) { |
| mdb_cursor_close(mdb_cursor_); |
| mdb_txn_abort(mdb_txn_); |
| mdb_dbi_close(mdb_env_, mdb_dbi_); |
| mdb_env_close(mdb_env_); |
| mdb_env_ = nullptr; |
| mdb_txn_ = nullptr; |
| mdb_cursor_ = nullptr; |
| } |
| } |
| |
| bool LMDBReader::Read(std::string* key, std::string* value) { |
| if (first_ != true) |
| Seek(MDB_NEXT); |
| if (valid_ == false) return false; |
| *key = string(static_cast<const char*>(mdb_key_.mv_data), mdb_key_.mv_size); |
| *value = |
| string(static_cast<const char*>(mdb_value_.mv_data), mdb_value_.mv_size); |
| first_ = false; |
| return true; |
| } |
| |
| int LMDBReader::Count() { |
| MDB_env* env; |
| MDB_dbi dbi; |
| MDB_txn* txn; |
| MDB_cursor* cursor; |
| int flags = MDB_RDONLY | MDB_NOTLS | MDB_NOLOCK; |
| MDB_CHECK(mdb_env_create(&env)); |
| MDB_CHECK(mdb_env_open(env, path_.c_str(), flags, 0664)); |
| MDB_CHECK(mdb_txn_begin(env, NULL, MDB_RDONLY, &txn)); |
| MDB_CHECK(mdb_dbi_open(txn, NULL, 0, &dbi)); |
| MDB_CHECK(mdb_cursor_open(txn, dbi, &cursor)); |
| int status = MDB_SUCCESS; |
| int count = 0; |
| MDB_val key, value; |
| while (true) { |
| status = mdb_cursor_get(cursor, &key, &value, MDB_NEXT); |
| if (status == MDB_NOTFOUND) break; |
| count++; |
| } |
| mdb_cursor_close(cursor); |
| mdb_txn_abort(txn); |
| mdb_dbi_close(env, dbi); |
| mdb_env_close(env); |
| return count; |
| } |
| |
| void LMDBReader::SeekToFirst() { Seek(MDB_FIRST); first_ = true; } |
| |
| void LMDBReader::Seek(MDB_cursor_op op) { |
| int mdb_status = mdb_cursor_get(mdb_cursor_, &mdb_key_, &mdb_value_, op); |
| if (mdb_status == MDB_NOTFOUND) { |
| valid_ = false; |
| } else { |
| MDB_CHECK(mdb_status); |
| valid_ = true; |
| } |
| } |
| |
| inline void LMDBReader::MDB_CHECK(int mdb_status) { |
| CHECK_EQ(mdb_status, MDB_SUCCESS) << mdb_strerror(mdb_status); |
| } |
| } // namespace io |
| } // namespace singa |
| #endif // USE_LMDB |
| |
| #endif |