Merge pull request #137 from willson556/master

Add bytesAvailable() method.

Author: pengyunchou

Sources/TCPClient.swift

@@ -32,14 +32,14 @@ import Foundation
 
 @_silgen_name("ytcpsocket_connect") private func c_ytcpsocket_connect(_ host:UnsafePointer<Byte>,port:Int32,timeout:Int32) -> Int32
 @_silgen_name("ytcpsocket_close") private func c_ytcpsocket_close(_ fd:Int32) -> Int32
+@_silgen_name("ytcpsocket_bytes_available") private func c_ytcpsocket_bytes_available(_ fd:Int32) -> Int32
 @_silgen_name("ytcpsocket_send") private func c_ytcpsocket_send(_ fd:Int32,buff:UnsafePointer<Byte>,len:Int32) -> Int32
 @_silgen_name("ytcpsocket_pull") private func c_ytcpsocket_pull(_ fd:Int32,buff:UnsafePointer<Byte>,len:Int32,timeout:Int32) -> Int32
 @_silgen_name("ytcpsocket_listen") private func c_ytcpsocket_listen(_ address:UnsafePointer<Int8>,port:Int32)->Int32
 @_silgen_name("ytcpsocket_accept") private func c_ytcpsocket_accept(_ onsocketfd:Int32,ip:UnsafePointer<Int8>,port:UnsafePointer<Int32>,timeout:Int32) -> Int32
 @_silgen_name("ytcpsocket_port") private func c_ytcpsocket_port(_ fd:Int32) -> Int32
 
 open class TCPClient: Socket {
-  
     /*
      * connect to server
      * return success or fail with message
@@ -62,7 +62,7 @@ open class TCPClient: Socket {
             }
         }
     }
-  
+
     /*
     * close socket
     * return success or fail with message
@@ -136,6 +136,21 @@ open class TCPClient: Socket {
 
         return data
     }
+
+    /*
+    * gets byte available for reading
+    */
+    open func bytesAvailable() -> Int32? {
+        guard let fd:Int32 = self.fd else { return nil }
+
+        let bytesAvailable = c_ytcpsocket_bytes_available(fd);
+
+        if (bytesAvailable < 0) {
+            return nil
+        }
+
+        return bytesAvailable
+    }
 }
 
 open class TCPServer: Socket {

Sources/ytcpsocket.c

@@ -44,6 +44,7 @@
 #include <fcntl.h>
 #include <signal.h>
 #include <sys/select.h>
+#include <sys/ioctl.h>
 
 void ytcpsocket_set_block(int socket, int on) {
     int flags;
@@ -130,6 +131,17 @@ int ytcpsocket_pull(int socketfd, char *data, int len, int timeout_sec) {
     return datalen;
 }
 
+int ytcpsocket_bytes_available(int socketfd) {
+    int count;
+    int callResult = ioctl(socketfd, FIONREAD, &count);
+
+    if (callResult < 0) {
+        return callResult;
+    }
+
+    return count;
+}
+
 int ytcpsocket_send(int socketfd, const char *data, int len){
     int byteswrite = 0;
     while (len - byteswrite > 0) {