Initial commit of the TCP helper backend that we'll need for the next-gen chat

src/menu-fn/progs.src

@@ -14,6 +14,7 @@ colors.cpp
 master.cpp
 servers.cpp
 modserver.cpp
+tcp.cpp
 
 widgets.cpp
 w_checkbox.cpp

src/menu-fn/tcp.cpp

@@ -0,0 +1,126 @@
+/*
+ * Copyright (c) 2016-2020 Marco Hladik <marco@icculus.org>
+ *
+ * Permission to use, copy, modify, and distribute this software for any
+ * purpose with or without fee is hereby granted, provided that the above
+ * copyright notice and this permission notice appear in all copies.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
+ * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
+ * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
+ * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
+ * WHATSOEVER RESULTING FROM LOSS OF MIND, USE, DATA OR PROFITS, WHETHER
+ * IN AN ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING
+ * OUT OF OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
+ */
+
+#define TCP_BUFFER_LENGTH 32
+
+typedef struct
+{
+	filestream m_fSocket;
+	string m_strBuffer[TCP_BUFFER_LENGTH];
+	int m_iBufferLines;
+	int m_iState;
+} tcpinfo_t;
+
+enum
+{
+	STATE_DISCONNECTED,
+	STATE_CONNECTING,
+	STATE_CONNECTED
+};
+
+int
+TCP_Connect(tcpinfo_t *in, string path)
+{
+	in.m_fSocket = fopen(path, -1);
+
+	if (in.m_fSocket < 0) {
+		dprint(sprintf("^1TCP_Connect^7: Unable to access %s\n", path));
+	}
+
+	/* we got at least this far */
+	in.m_iState = STATE_CONNECTING;
+	return (int)in.m_fSocket;
+}
+
+void
+TCP_Disconnect(tcpinfo_t *in)
+{
+	if (in.m_iState == STATE_DISCONNECTED)
+		return;
+
+	in.m_iState = STATE_DISCONNECTED;
+	fclose(in.m_fSocket);
+}
+
+int
+TCP_Send(tcpinfo_t *in, string msg)
+{
+	if (in.m_iState == STATE_DISCONNECTED) {
+		dprint("^1TCP_Send^7: Can't send, we're disconnected\n");
+		return 0;
+	}
+
+	/* the buffer is full. we've been unable to send messages for a while */
+	if (in.m_iBufferLines >= (TCP_BUFFER_LENGTH - 1)) {
+		dprint("^1TCP_Send^7: Buffer full.\n");
+		return 0;
+	}
+
+	in.m_strBuffer[in.m_iBufferLines] = msg;
+	in.m_iBufferLines++;
+	return 1;
+}
+
+string
+TCP_Receive(tcpinfo_t *in)
+{
+	/* not even open */
+	if (in.m_fSocket <= 0)
+		return "";
+
+	return fgets(in.m_fSocket);
+}
+
+/* you want to run this every frame */
+void
+TCP_Frame(tcpinfo_t *in)
+{
+	string data;
+
+	/* not even open */
+	if (in.m_iState == STATE_DISCONNECTED)
+		return;
+
+	data = in.m_strBuffer[0];
+
+	/* got nothing worth sending */
+	if (data == "" || in.m_iBufferLines <= 0)
+		return;
+
+	/* if the send was unsuccessful, try next frame */
+	if (fwrite(in.m_fSocket, data, strlen(data)) <= 0) {
+		dprint("^1TCP_Frame^7: Unsuccessful frame\n");
+		return;
+	}
+
+	print(sprintf("^1TCP_Frame^7: Sent %s", data));
+
+	/* at least one successful write went through */
+	in.m_iState = STATE_CONNECTED;
+
+	/* a send was successful after here */
+	for (int i = 0; i < (TCP_BUFFER_LENGTH - 1); i++) {
+		in.m_strBuffer[i] = in.m_strBuffer[i+1];
+	}
+
+	in.m_iBufferLines--;
+}
+
+int
+TCP_GetState(tcpinfo_t *in)
+{
+	return in.m_iState;
+}