doc-en.md

#handy yedongfu

A C++11 non-blocking network library

Example
EventBase events dispatcher
tcp connection
tcp server
http server
half sync half async server

example--echo

```c #include

using namespace std; using namespace handy;

int main(int argc, const char* argv[]) { EventBase base; //handle ctrl+c Signal::signal(SIGINT, [&]{ base.exit(); }); TcpServer echo(&base); int r = echo.bind("", 99); exitif(r, "bind failed %d %s", errno, strerror(errno)); echo.onConnRead([](const TcpConnPtr& con) { con->send(con->getInput()); }); base.loop(); //enter events loop }

<h2 id="event-base">EventBase: events dispatcher</h2>
EventBase is an events dispatcher，use epoll/kqueue to handle non-blocking I/O
```c
EventBase base;

###events loop

//call epoll_wait repeatedly, handle I/O events
base.loop();

###exit events loop

//exit events loop, can be called from other threads
base.exit();

###is events loop exited?

bool exited();

###add tcp connection

TcpConnPtr con = TcpConn::createConnection(&base, host, port);

###add listen fd, and will add all socket return by accept(listen_fd)

TcpServer echo(&base);

###perform tasks in I/O thread Some tasks must be called from I/O thread, for example writing some data to connection. In order to avoid conflicting read/write, the operation should be performed in a single thread.

void safeCall(const Task& task);

base.safeCall([](con){con->send("OK");});

###manage timeout tasks EventBase will make itself return by setting a wait time form epoll_wait/kevent. It will check and call timeout tasks. The precision rely on epoll_wait/kevent

//interval: 0：once task；>0：repeated task, task will be execute every interval milliseconds
TimerId runAfter(int64_t milli, const Task& task, int64_t interval=0);
//runAt will specify the absolute time
TimerId runAt(int64_t milli, const Task& task, int64_t interval=0)
//cancel Task, Ignore if task is already removed or expired.
bool cancel(TimerId timerid);

TimerId tid = base.runAfter(1000, []{ info("a second passed"); });
base.cancel(tid);

TcpConn tcp connection

use shared_ptr to manage connection, no need to release manually ###reference count ```c typedef std::shared_ptr TcpConnPtr; ``` ###state ```c enum State { Invalid=1, Handshaking, Connected, Closed, Failed, }; ``` ###example ```c TcpConnPtr con = TcpConn::createConnection(base, host, port); con->onState([=](const TcpConnPtr& con) { info("onState called state: %d", con->getState()); }); con->onRead([](const TcpConnPtr& con){ info("recv %lu bytes", con->getInput().size()); con->send("ok"); con->getInput().clear(); }); ``` ###reconnect setting ```c //set reconnect. -1: no reconnect; 0 :reconnect now; other: wait millisecond; default -1 void setReconnectInterval(int milli); ``` ###callback for idle ```c void addIdleCB(int idle, const TcpCallBack& cb);

//close connection if idle for 30 seconds con->addIdleCB(30, [](const TcpConnPtr& con)) { con->close(); });

###Message mode
you can onRead or onMsg to handle message
```c
//message callback, confict with onRead callback. You should set only one of these
//codec will be released when connection destroyed
void onMsg(CodecBase* codec, const MsgCallBack& cb);
//send message
void sendMsg(Slice msg);

con->onMsg(new LineCodec, [](const TcpConnPtr& con, Slice msg) {
    info("recv msg: %.*s", (int)msg.size(), msg.data());
    con->sendMsg("hello");
});

###store you own data

template<class T> T& context();

con->context<std::string>() = "user defined data";

TcpServer

###example ```c TcpServer echo(&base); int r = echo.bind("", 99); exitif(r, "bind failed %d %s", errno, strerror(errno)); echo.onConnRead([](const TcpConnPtr& con) { con->send(con->getInput()); // echo data read }); ``` ###customize your connection when TcpServer accept a connection, it will call this to create an TcpConn ``` void onConnCreate(const std::function& cb);

chat.onConnCreate([&]{ TcpConnPtr con(new TcpConn); con->onState([&](const TcpConnPtr& con) { if (con->getState() == TcpConn::Connected) { con->context() = 1; } } return con; });

<h2 id="http-server">HttpServer</h2>
```c
//example
HttpServer sample(&base);
int r = sample.bind("", 8081);
exitif(r, "bind failed %d %s", errno, strerror(errno));
sample.onGet("/hello", [](const HttpConnPtr& con) {
   HttpResponse resp;
   resp.body = Slice("hello world");
   con.sendResponse(resp);
});

half sync half async server

```c // empty string indicates unfinished handling of request. You may operate on con as you like. void onMsg(CodecBase* codec, const RetMsgCallBack& cb);

hsha.onMsg(new LineCodec, [](const TcpConnPtr& con, const string& input){ int ms = rand() % 1000; info("processing a msg"); usleep(ms * 1000); return util::format("%s used %d ms", input.c_str(), ms); });

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