[C++] Add C++ single file logger factory (apache#10712)

* Add SampleFileLogger C++ example

* Expose SingleFileLoggerFactory as the public interface

* Make logger factory public

* Change logger factory's name

* Use PImpl idiom for LoggerFactory classes

pulsar-client-cpp/examples/CMakeLists.txt

@@ -37,6 +37,10 @@ set(SAMPLE_PRODUCER_SOURCES
   SampleProducer.cc
 )
 
+set(SAMPLE_FILE_LOGGER_SOURCES
+  SampleFileLogger.cc
+)
+
 set(SAMPLE_PRODUCER_C_SOURCES
     SampleProducerCApi.c
 )
@@ -57,6 +61,7 @@ add_executable(SampleAsyncProducer    ${SAMPLE_ASYNC_PRODUCER_SOURCES})
 add_executable(SampleConsumer         ${SAMPLE_CONSUMER_SOURCES})
 add_executable(SampleConsumerListener ${SAMPLE_CONSUMER_LISTENER_SOURCES})
 add_executable(SampleProducer         ${SAMPLE_PRODUCER_SOURCES})
+add_executable(SampleFileLogger       ${SAMPLE_FILE_LOGGER_SOURCES})
 add_executable(SampleProducerCApi         ${SAMPLE_PRODUCER_C_SOURCES})
 add_executable(SampleConsumerCApi         ${SAMPLE_CONSUMER_C_SOURCES})
 add_executable(SampleConsumerListenerCApi         ${SAMPLE_CONSUMER_LISTENER_C_SOURCES})
@@ -66,6 +71,7 @@ target_link_libraries(SampleAsyncProducer    ${CLIENT_LIBS} pulsarShared)
 target_link_libraries(SampleConsumer         ${CLIENT_LIBS} pulsarShared)
 target_link_libraries(SampleConsumerListener ${CLIENT_LIBS} pulsarShared)
 target_link_libraries(SampleProducer         ${CLIENT_LIBS} pulsarShared)
+target_link_libraries(SampleFileLogger       ${CLIENT_LIBS} pulsarShared)
 target_link_libraries(SampleProducerCApi     ${CLIENT_LIBS} pulsarShared)
 target_link_libraries(SampleConsumerCApi     ${CLIENT_LIBS} pulsarShared)
 target_link_libraries(SampleConsumerListenerCApi     ${CLIENT_LIBS} pulsarShared)

pulsar-client-cpp/examples/SampleAsyncProducer.cc

@@ -35,7 +35,7 @@ int main() {
     Client client("pulsar://localhost:6650");
 
     Producer producer;
-    Result result = client.createProducer("persistent://prop/r1/ns1/my-topic", producer);
+    Result result = client.createProducer("persistent://public/default/my-topic", producer);
     if (result != ResultOk) {
         LOG_ERROR("Error creating producer: " << result);
         return -1;

pulsar-client-cpp/examples/SampleConsumer.cc

@@ -30,7 +30,7 @@ int main() {
     Client client("pulsar://localhost:6650");
 
     Consumer consumer;
-    Result result = client.subscribe("persistent://prop/r1/ns1/my-topic", "consumer-1", consumer);
+    Result result = client.subscribe("persistent://public/default/my-topic", "consumer-1", consumer);
     if (result != ResultOk) {
         LOG_ERROR("Failed to subscribe: " << result);
         return -1;

pulsar-client-cpp/examples/SampleConsumerListener.cc

@@ -38,7 +38,7 @@ int main() {
     Consumer consumer;
     ConsumerConfiguration config;
     config.setMessageListener(listener);
-    Result result = client.subscribe("persistent://prop/r1/ns1/my-topic", "consumer-1", config, consumer);
+    Result result = client.subscribe("persistent://public/default/my-topic", "consumer-1", config, consumer);
     if (result != ResultOk) {
         LOG_ERROR("Failed to subscribe: " << result);
         return -1;

pulsar-client-cpp/examples/SampleFileLogger.cc

@@ -0,0 +1,33 @@
+/**
+ * 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.
+ */
+#include <pulsar/Client.h>
+
+using namespace pulsar;
+
+int main(int argc, char* argv[]) {
+    ClientConfiguration clientConf;
+    // The logs whose level is >= INFO will be written to pulsar-cpp-client.log
+    clientConf.setLogger(new FileLoggerFactory(Logger::Level::LEVEL_INFO, "pulsar-cpp-client.log"));
+
+    Client client("pulsar://localhost:6650", clientConf);
+    Producer producer;
+    client.createProducer("my-topic", producer);  // just to create some logs
+    client.close();
+    return 0;
+}

pulsar-client-cpp/examples/SampleProducer.cc

@@ -30,7 +30,7 @@ int main() {
     Client client("pulsar://localhost:6650");
 
     Producer producer;
-    Result result = client.createProducer("persistent://prop/r1/ns1/my-topic", producer);
+    Result result = client.createProducer("persistent://public/default/my-topic", producer);
     if (result != ResultOk) {
         LOG_ERROR("Error creating producer: " << result);
         return -1;

pulsar-client-cpp/include/pulsar/Client.h

@@ -28,6 +28,8 @@
 #include <pulsar/MessageBuilder.h>
 #include <pulsar/ClientConfiguration.h>
 #include <pulsar/Schema.h>
+#include <pulsar/ConsoleLoggerFactory.h>
+#include <pulsar/FileLoggerFactory.h>
 #include <string>
 
 namespace pulsar {

pulsar-client-cpp/include/pulsar/SimpleLoggerFactory.h → pulsar-client-cpp/include/pulsar/ConsoleLoggerFactory.h

@@ -23,6 +23,8 @@
 
 namespace pulsar {
 
+class ConsoleLoggerFactoryImpl;
+
 /**
  * The default LoggerFactory of Client if `USE_LOG4CXX` macro was not defined during compilation.
  *
@@ -37,22 +39,23 @@ namespace pulsar {
  * level simply.
  *
  * ```c++
- * #include <pulsar/SimpleLoggerFactory.h>
+ * #include <pulsar/ConsoleLoggerFactory.h>
  *
  * ClientConfiguration conf;
- * conf.setLogger(new SimpleLoggerFactory(Logger::LEVEL_DEBUG));
+ * conf.setLogger(new ConsoleLoggerFactory(Logger::LEVEL_DEBUG));
  * Client client("pulsar://localhost:6650", conf);
  * ```
  */
-class SimpleLoggerFactory : public LoggerFactory {
+class PULSAR_PUBLIC ConsoleLoggerFactory : public LoggerFactory {
    public:
-    explicit SimpleLoggerFactory() = default;
-    explicit SimpleLoggerFactory(Logger::Level level) : level_(level) {}
+    explicit ConsoleLoggerFactory(Logger::Level level = Logger::LEVEL_INFO);
+
+    ~ConsoleLoggerFactory();
 
     Logger* getLogger(const std::string& fileName) override;
 
    private:
-    Logger::Level level_{Logger::LEVEL_INFO};
+    std::unique_ptr<ConsoleLoggerFactoryImpl> impl_;
 };
 
 }  // namespace pulsar

pulsar-client-cpp/include/pulsar/FileLoggerFactory.h

@@ -0,0 +1,65 @@
+/**
+ * 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.
+ */
+
+#pragma once
+
+#include <pulsar/Logger.h>
+
+namespace pulsar {
+
+class FileLoggerFactoryImpl;
+
+/**
+ * A logger factory that is appending logs to a single file.
+ *
+ * The log format is "yyyy-mm-dd hh:MM:ss.xxx <level> <thread-id> <file>:<line> | <msg>", like
+ *
+ * ```
+ * 2021-03-24 17:35:46.571 INFO  [0x10a951e00] ConnectionPool:85 | Created connection for ...
+ * ```
+ *
+ * Example:
+ *
+ * ```c++
+ * #include <pulsar/FileLoggerFactory.h>
+ *
+ * ClientConfiguration conf;
+ * conf.setLogger(new FileLoggerFactory(Logger::LEVEL_DEBUG, "pulsar-client-cpp.log"));
+ * Client client("pulsar://localhost:6650", conf);
+ * ```
+ */
+class PULSAR_PUBLIC FileLoggerFactory : public pulsar::LoggerFactory {
+   public:
+    /**
+     * Create a FileLoggerFactory instance.
+     *
+     * @param level the log level
+     * @param logFilePath the log file's path
+     */
+    FileLoggerFactory(Logger::Level level, const std::string& logFilePath);
+
+    ~FileLoggerFactory();
+
+    pulsar::Logger* getLogger(const std::string& filename) override;
+
+   private:
+    std::unique_ptr<FileLoggerFactoryImpl> impl_;
+};
+
+}  // namespace pulsar

pulsar-client-cpp/lib/ClientImpl.cc

@@ -26,7 +26,7 @@
 #include "PartitionedConsumerImpl.h"
 #include "MultiTopicsConsumerImpl.h"
 #include "PatternMultiTopicsConsumerImpl.h"
-#include <pulsar/SimpleLoggerFactory.h>
+#include <pulsar/ConsoleLoggerFactory.h>
 #include <boost/algorithm/string/predicate.hpp>
 #include <sstream>
 #include <lib/HTTPLookupService.h>
@@ -101,11 +101,11 @@ ClientImpl::ClientImpl(const std::string& serviceUrl, const ClientConfiguration&
             loggerFactory = Log4CxxLoggerFactory::create(clientConfiguration_.getLogConfFilePath());
         } else {
             // Use default simple console logger
-            loggerFactory.reset(new SimpleLoggerFactory);
+            loggerFactory.reset(new ConsoleLoggerFactory);
         }
 #else
         // Use default simple console logger
-        loggerFactory.reset(new SimpleLoggerFactory);
+        loggerFactory.reset(new ConsoleLoggerFactory);
 #endif
     }
     LogUtils::setLoggerFactory(std::move(loggerFactory));

pulsar-client-cpp/lib/ConsoleLoggerFactory.cc

@@ -0,0 +1,32 @@
+/**
+ * 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.
+ */
+
+#include <pulsar/ConsoleLoggerFactory.h>
+#include "lib/ConsoleLoggerFactoryImpl.h"
+
+namespace pulsar {
+
+ConsoleLoggerFactory::ConsoleLoggerFactory(Logger::Level level)
+    : impl_(new ConsoleLoggerFactoryImpl(level)) {}
+
+ConsoleLoggerFactory::~ConsoleLoggerFactory() {}
+
+Logger* ConsoleLoggerFactory::getLogger(const std::string& fileName) { return impl_->getLogger(fileName); }
+
+}  // namespace pulsar

pulsar-client-cpp/lib/ConsoleLoggerFactoryImpl.h

@@ -0,0 +1,37 @@
+/**
+ * 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.
+ */
+
+#pragma once
+
+#include <pulsar/Logger.h>
+#include "lib/SimpleLogger.h"
+
+namespace pulsar {
+
+class ConsoleLoggerFactoryImpl {
+   public:
+    ConsoleLoggerFactoryImpl(Logger::Level level) : level_(level) {}
+
+    Logger* getLogger(const std::string& fileName) { return new SimpleLogger(std::cout, fileName, level_); }
+
+   private:
+    Logger::Level level_;
+};
+
+}  // namespace pulsar

pulsar-client-cpp/lib/FileLoggerFactory.cc

@@ -0,0 +1,31 @@
+/**
+ * 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.
+ */
+#include <pulsar/FileLoggerFactory.h>
+#include "lib/FileLoggerFactoryImpl.h"
+
+namespace pulsar {
+
+FileLoggerFactory::FileLoggerFactory(Logger::Level level, const std::string& logFilePath)
+    : impl_(new FileLoggerFactoryImpl(level, logFilePath)) {}
+
+FileLoggerFactory::~FileLoggerFactory() {}
+
+Logger* FileLoggerFactory::getLogger(const std::string& filename) { return impl_->getLogger(filename); }
+
+}  // namespace pulsar

pulsar-client-cpp/lib/FileLoggerFactoryImpl.h

@@ -0,0 +1,44 @@
+/**
+ * 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.
+ */
+#pragma once
+
+#include <fstream>
+#include <ios>
+#include <string>
+#include <pulsar/Logger.h>
+
+#include "lib/SimpleLogger.h"
+
+namespace pulsar {
+
+class FileLoggerFactoryImpl {
+   public:
+    FileLoggerFactoryImpl(Logger::Level level, const std::string& logFilePath)
+        : level_(level), os_(logFilePath, std::ios_base::out | std::ios_base::app) {}
+
+    ~FileLoggerFactoryImpl() { os_.close(); }
+
+    Logger* getLogger(const std::string& filename) { return new SimpleLogger(os_, filename, level_); }
+
+   private:
+    const Logger::Level level_;
+    std::ofstream os_;
+};
+
+}  // namespace pulsar

pulsar-client-cpp/lib/LogUtils.cc

@@ -20,7 +20,7 @@
 
 #include <atomic>
 #include <iostream>
-#include <pulsar/SimpleLoggerFactory.h>
+#include <pulsar/ConsoleLoggerFactory.h>
 
 #include "Log4CxxLogger.h"
 
@@ -50,7 +50,7 @@ void LogUtils::setLoggerFactory(std::unique_ptr<LoggerFactory> loggerFactory) {
 
 LoggerFactory* LogUtils::getLoggerFactory() {
     if (s_loggerFactory.load() == nullptr) {
-        std::unique_ptr<LoggerFactory> newFactory(new SimpleLoggerFactory());
+        std::unique_ptr<LoggerFactory> newFactory(new ConsoleLoggerFactory());
         setLoggerFactory(std::move(newFactory));
     }
     return s_loggerFactory.load();