[C++] Add C++ single file logger factory

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 +1,111 @@
+/**
+ * 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 <string.h>
+
+#include <chrono>
+#include <ctime>
+#include <fstream>
+#include <sstream>
+#include <thread>
+
+#include <pulsar/Client.h>
+
+class FileLogger : public pulsar::Logger {
+   public:
+    FileLogger(std::ofstream& os, Level level, const std::string& filename)
+        : os_(os), level_(level), filename_(filename) {}
+
+    bool isEnabled(Level level) override { return level >= level_; }
+
+    void log(Level level, int line, const std::string& message) override {
+        std::ostringstream oss;
+        auto now = std::chrono::system_clock::to_time_t(std::chrono::system_clock::now());
+        oss << currentTime() << " " << convertLevelToString(level) << " [" << std::this_thread::get_id()
+            << "] " << filename_ << ":" << line << " " << message << "\n";
+        os_ << oss.str();
+        os_.flush();
+    }
+
+   private:
+    std::ostream& os_;
+    const Level level_;
+    const std::string filename_;
+
+    static const char* currentTime() {
+        auto now = std::chrono::system_clock::to_time_t(std::chrono::system_clock::now());
+        char* s = ctime(&now);  // ctime() returns a string with a newline at the end
+        auto newLinePos = strlen(s) - 1;
+        s[newLinePos] = '\0';
+        return s;
+    }
+
+    static const char* convertLevelToString(Level level) {
+        switch (level) {
+            case Level::LEVEL_DEBUG:
+                return "DEBUG";
+            case Level::LEVEL_INFO:
+                return "INFO";
+            case Level::LEVEL_WARN:
+                return "WARN";
+            case Level::LEVEL_ERROR:
+                return "ERROR";
+            default:
+                return "???";
+        }
+    }
+};
+
+/**
+ * A logger factory that is appending logs to a single file.
+ */
+class SingleFileLoggerFactory : public pulsar::LoggerFactory {
+   public:
+    /**
+     * Create a SingleFileLoggerFactory instance.
+     *
+     * @param level the log level
+     * @param logFilePath the log file's path
+     */
+    SingleFileLoggerFactory(pulsar::Logger::Level level, const std::string& logFilePath)
+        : level_(level), os_(logFilePath, std::ios_base::out | std::ios_base::app) {}
+
+    ~SingleFileLoggerFactory() { os_.close(); }
+
+    virtual pulsar::Logger* getLogger(const std::string& filename) override {
+        return new FileLogger(os_, level_, filename);
+    }
+
+   private:
+    const pulsar::Logger::Level level_;
+    std::ofstream os_;
+};
+
+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 SingleFileLoggerFactory(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;