am-c-p-p commented on a change in pull request #709: MINIFICPP-1088 - clean up minifiexe and MINIFI_HOME logic URL: https://github.com/apache/nifi-minifi-cpp/pull/709#discussion_r367268177
########## File path: libminifi/src/utils/Environment.cpp ########## @@ -0,0 +1,192 @@ +/** + * 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 "utils/Environment.h" + +#ifdef WIN32 +#include <Windows.h> +#else +#include <cstdlib> +#include <cerrno> +#include <unistd.h> +#endif +#include <mutex> +#include <vector> +#include <iostream> + +namespace org { +namespace apache { +namespace nifi { +namespace minifi { +namespace utils { + +bool Environment::runningAsService_(false); + +void Environment::accessEnvironment(const std::function<void(void)>& func) { + static std::recursive_mutex environmentMutex; + std::lock_guard<std::recursive_mutex> lock(environmentMutex); + func(); +} + +std::pair<bool, std::string> Environment::getEnvironmentVariable(const char* name) { + bool exists = false; + std::string value; + + Environment::accessEnvironment([&exists, &value, name](){ +#ifdef WIN32 + std::vector<char> buffer(32767U); // https://docs.microsoft.com/en-gb/windows/win32/api/processenv/nf-processenv-getenvironmentvariablea + // GetEnvironmentVariableA does not set last error to 0 on success, so an error from a pervious API call would influence the GetLastError() later, + // so we set the last error to 0 before calling + SetLastError(ERROR_SUCCESS); + uint32_t ret = GetEnvironmentVariableA(name, buffer.data(), buffer.size()); + if (ret > 0U) { + exists = true; + value = std::string(buffer.data(), ret); + } else if (GetLastError() == ERROR_SUCCESS) { + // Exists, but empty + exists = true; + } +#else + char* ret = getenv(name); + if (ret != nullptr) { + exists = true; + value = ret; + } +#endif + }); + + return std::make_pair(exists, std::move(value)); +} + +bool Environment::setEnvironmentVariable(const char* name, const char* value, bool overwrite /*= true*/) { + bool success = false; + + Environment::accessEnvironment([&success, name, value, overwrite](){ +#ifdef WIN32 + if (!overwrite && Environment::getEnvironmentVariable(name).first) { + success = true; + } else { + success = SetEnvironmentVariableA(name, value); + } +#else + int ret = setenv(name, value, static_cast<int>(overwrite)); + success = ret == 0; +#endif + }); + + return success; +} + +bool Environment::unsetEnvironmentVariable(const char* name) { + bool success = false; + + Environment::accessEnvironment([&success, name](){ +#ifdef WIN32 + success = SetEnvironmentVariableA(name, nullptr); +#else + int ret = unsetenv(name); + success = ret == 0; +#endif + }); + + return success; +} + +std::string Environment::getCurrentWorkingDirectory() { + std::string cwd; + + Environment::accessEnvironment([&cwd](){ +#ifdef WIN32 + uint32_t len = 0U; + std::vector<char> buffer; + // https://docs.microsoft.com/en-us/windows/win32/api/winbase/nf-winbase-getcurrentdirectory + // "If the buffer that is pointed to by lpBuffer is not large enough, + // the return value specifies the required size of the buffer, + // in characters, including the null-terminating character." + while (true) { + len = GetCurrentDirectoryA(buffer.size(), buffer.data()); Review comment: nit - can be used GetCurrentDirectory. ---------------------------------------------------------------- This is an automated message from the Apache Git Service. To respond to the message, please log on to GitHub and use the URL above to go to the specific comment. For queries about this service, please contact Infrastructure at: us...@infra.apache.org With regards, Apache Git Services
