How do you optimize the performance and memory usage of cURLpp in C++?

2 Use the right handles

cURLpp uses handles to manage the network operations. There are two types of handles: easy handles and multi handles. Easy handles are used for single operations, while multi handles are used for concurrent operations. You should choose the right type of handle for your use case, and reuse them as much as possible. Reusing handles can improve the performance and memory usage of your program, because it avoids creating and destroying handles repeatedly, which can be costly and inefficient. To reuse a handle, you can either reset its options with the reset() method, or store it in a pool or a container and retrieve it when needed.

3 Use the right streams

cURLpp allows you to use streams to read and write data from and to the network. You can use standard C++ streams, such as std::cin, std::cout, and std::cerr, or custom streams, such as std::stringstream, std::fstream, and std::ostringstream. However, not all streams are created equal, and some of them may have better performance and memory usage than others. For example, std::stringstream is a memory-based stream, which means that it stores the data in memory, rather than in a file or a socket. This can be faster and more convenient, but it can also consume more memory and cause memory leaks if not handled properly. Therefore, you should use std::stringstream only for small or temporary data, and prefer std::fstream or std::ostringstream for large or persistent data.

4 Use the right callbacks

cURLpp allows you to use callbacks to handle the data transfer and the progress of your network operations. You can use lambda functions, function pointers, or function objects as callbacks, and pass them to the setOpt() method of your handle. However, some callbacks may have better performance and memory usage than others, depending on how they are defined and used. For example, lambda functions are anonymous functions that can capture variables from their surrounding scope, which can be convenient and expressive, but it can also introduce overhead and memory leaks if not used carefully. Therefore, you should use lambda functions only for simple or stateless callbacks, and prefer function pointers or function objects for complex or stateful callbacks.

5 Use the right exceptions

cURLpp uses exceptions to report errors and failures in your network operations. You can use the try-catch blocks to handle the exceptions, and use the what() method to get the error message. However, throwing and catching exceptions can be expensive and slow, especially if they occur frequently or in nested scopes. Therefore, you should use exceptions only for exceptional situations, and avoid them for normal or expected situations. For example, you should not use exceptions to check the status code or the content type of your HTTP response, but rather use the getOpt() method of your handle to get these information.

6 Use the right tools

cURLpp is a powerful and flexible library, but it is not the only tool that you can use for C++ network programming. Depending on your needs and preferences, you may find other tools that can offer better performance and memory usage, or more features and functionality. For example, you may consider using Boost.Asio, which is a cross-platform library that provides low-level access to sockets, timers, buffers, and protocols. Or you may consider using POCO, which is a framework that provides high-level abstractions for HTTP, FTP, SMTP, JSON, XML, and more. You should always compare and evaluate different tools before choosing the one that suits your project best.

7 Here’s what else to consider

This is a space to share examples, stories, or insights that don’t fit into any of the previous sections. What else would you like to add?