Demo recording for the frontend library
authorMedo <smaxein@googlemail.com>
Sat, 02 Jun 2012 14:26:52 +0200
changeset 7162 fe76d24a25d7
parent 7160 c42949cfdd92
child 7166 8d1d6adf5f82
Demo recording for the frontend library
frontlib/frontlib.c
frontlib/frontlib.h
frontlib/ipcconn.c
frontlib/ipcconn.h
frontlib/logging.c
frontlib/logging.h
frontlib/nonblocksockets.c
frontlib/nonblocksockets.h
project_files/frontlib/buffer.c
project_files/frontlib/buffer.h
project_files/frontlib/events.c
project_files/frontlib/events.h
project_files/frontlib/frontlib.c
project_files/frontlib/ipcconn.c
project_files/frontlib/ipcconn.h
project_files/frontlib/logging.c
--- a/frontlib/frontlib.c	Thu May 31 18:54:40 2012 +0200
+++ /dev/null	Thu Jan 01 00:00:00 1970 +0000
@@ -1,65 +0,0 @@
-#include "frontlib.h"
-#include "logging.h"
-#include "nonblocksockets.h"
-#include "ipcconn.h"
-
-#include <SDL.h>
-#include <SDL_net.h>
-#include <stdio.h>
-#include <stdint.h>
-#include <stdlib.h>
-
-static int flib_initflags;
-
-int flib_init(int flags) {
-	flib_initflags = flags;
-
-	if(!(flib_initflags | FRONTLIB_SDL_ALREADY_INITIALIZED)) {
-		if(SDL_Init(0)==-1) {
-		    flib_log_e("Error in SDL_Init: %s", SDL_GetError());
-		    return -1;
-		}
-	}
-
-	if(SDLNet_Init()==-1) {
-		flib_log_e("Error in SDLNet_Init: %s", SDLNet_GetError());
-		if(!(flib_initflags | FRONTLIB_SDL_ALREADY_INITIALIZED)) {
-			SDL_Quit();
-		}
-		return -1;
-	}
-
-	flib_ipcconn_init();
-	return 0;
-}
-
-void flib_quit() {
-	flib_ipcconn_quit();
-
-	SDLNet_Quit();
-	if(!(flib_initflags | FRONTLIB_SDL_ALREADY_INITIALIZED)) {
-		SDL_Quit();
-	}
-}
-
-int main(int argc, char *argv[]) {
-	flib_init(0);
-	int port = flib_ipcconn_listen();
-	printf("%i\n", port);
-	fflush(stdout);
-	char data[256];
-	while(flib_ipcconn_state() != IPC_NOT_CONNECTED) {
-		flib_ipcconn_tick();
-		int size = flib_ipcconn_recv_message(data);
-		if(size>0) {
-			data[size]=0;
-			flib_log_i("IPC IN: %s", data);
-			if(data[0]=='?') {
-				flib_log_i("IPC OUT: !");
-				flib_ipcconn_send_message("!", 1);
-			}
-		}
-	}
-	flib_log_i("IPC connection lost.");
-	return 0;
-}
--- a/frontlib/frontlib.h	Thu May 31 18:54:40 2012 +0200
+++ /dev/null	Thu Jan 01 00:00:00 1970 +0000
@@ -1,31 +0,0 @@
-/*
- * Public header file for the hedgewars frontent networking library.
- *
- * This is the only header you should need to include from frontend code.
- */
-
-#ifndef FRONTLIB_H_
-#define FRONTLIB_H_
-
-#define FRONTLIB_SDL_ALREADY_INITIALIZED 1
-
-/**
- * Call this function before anything else in this library.
- *
- * If the calling program uses SDL, it needs to call SDL_Init before initializing
- * this library and then pass FRONTLIB_SDL_ALREADY_INITIALIZED as flag to this function.
- *
- * Otherwise, pass 0 to let this library handle SDL_Init an SDL_Quit itself.
- *
- * Returns 0 on success, -1 on error.
- */
-int flib_init(int flags);
-
-/**
- * Free resources associated with the library. Call this function once
- * the library is no longer needed. You can re-initialize the library by calling
- * flib_init again.
- */
-void flib_quit();
-
-#endif /* FRONTLIB_H_ */
--- a/frontlib/ipcconn.c	Thu May 31 18:54:40 2012 +0200
+++ /dev/null	Thu Jan 01 00:00:00 1970 +0000
@@ -1,134 +0,0 @@
-#include "ipcconn.h"
-#include "logging.h"
-#include "nonblocksockets.h"
-
-#include <SDL_net.h>
-#include <time.h>
-static TCPsocket ipcListenSocket;
-static NonBlockSocket ipcConnSocket;
-
-static uint8_t ipcReadBuffer[256];
-static int ipcReadBufferSize;
-
-void flib_ipcconn_init() {
-	ipcListenSocket = NULL;
-	ipcConnSocket = NULL;
-	ipcReadBufferSize = 0;
-}
-
-void flib_ipcconn_quit() {
-	flib_ipcconn_close();
-}
-
-int flib_ipcconn_listen() {
-	if(ipcListenSocket || ipcConnSocket) {
-		flib_log_e("flib_ipcconn_listen: Already listening or connected.");
-		return -1;
-	}
-	IPaddress addr;
-	addr.host = INADDR_ANY;
-
-	/* SDL_net does not seem to have a way to listen on a random unused port
-	   and find out which port that is, so let's try to find one ourselves. */
-	// TODO: Is socket binding fail-fast on all platforms?
-	srand(time(NULL));
-	rand();
-	for(int i=0; i<1000; i++) {
-		// IANA suggests using ports in the range 49152-65535 for things like this
-		int ipcPort = 49152+(rand()%(65535-49152));
-		SDLNet_Write16(ipcPort, &addr.port);
-		ipcListenSocket = SDLNet_TCP_Open(&addr);
-		if(!ipcListenSocket) {
-			flib_log_w("Failed to start an IPC listening socket on port %i: %s", ipcPort, SDLNet_GetError());
-		} else {
-			flib_log_i("Listening for IPC connections on port %i.", ipcPort);
-			return ipcPort;
-		}
-	}
-	flib_log_e("Unable to find a free port for IPC.");
-	return -1;
-}
-
-void flib_ipcconn_close() {
-	if(ipcListenSocket) {
-		SDLNet_TCP_Close(ipcListenSocket);
-		ipcListenSocket = NULL;
-	}
-	flib_nbsocket_close(&ipcConnSocket);
-	ipcReadBufferSize = 0;
-}
-
-IpcConnState flib_ipcconn_state() {
-	if(ipcConnSocket) {
-		return IPC_CONNECTED;
-	} else if(ipcListenSocket) {
-		return IPC_LISTENING;
-	} else {
-		return IPC_NOT_CONNECTED;
-	}
-}
-
-/**
- * Receive a single message and copy it into the data buffer.
- * Returns the length of the received message, -1 when nothing is received.
- */
-int flib_ipcconn_recv_message(void *data) {
-	flib_ipcconn_tick();
-
-	if(ipcConnSocket) {
-		int size = flib_nbsocket_recv(ipcConnSocket, ipcReadBuffer+ipcReadBufferSize, sizeof(ipcReadBuffer)-ipcReadBufferSize);
-		if(size>=0) {
-			ipcReadBufferSize += size;
-		} else {
-			flib_nbsocket_close(&ipcConnSocket);
-		}
-	}
-
-	int msgsize = ipcReadBuffer[0];
-	if(ipcReadBufferSize > msgsize) {
-		memcpy(data, ipcReadBuffer+1, msgsize);
-		memmove(ipcReadBuffer, ipcReadBuffer+msgsize+1, ipcReadBufferSize-(msgsize+1));
-		ipcReadBufferSize -= (msgsize+1);
-		return msgsize;
-	} else if(!ipcConnSocket && ipcReadBufferSize>0) {
-		flib_log_w("Last message from engine data stream is incomplete (received %u of %u bytes)", ipcReadBufferSize-1, msgsize);
-		ipcReadBufferSize = 0;
-		return -1;
-	} else {
-		return -1;
-	}
-}
-
-int flib_ipcconn_send_message(void *data, size_t len) {
-	flib_ipcconn_tick();
-
-	if(!ipcConnSocket) {
-		flib_log_w("flib_ipcconn_send_message: Not connected.");
-		return -1;
-	}
-	if(len>255) {
-		flib_log_e("Attempt to send too much data to the engine in a single message.");
-		return -1;
-	}
-
-	uint8_t sendbuf[256];
-	sendbuf[0] = len;
-	memcpy(sendbuf+1, data, len);
-	if(flib_nbsocket_blocksend(ipcConnSocket, sendbuf, len+1) < len+1) {
-		flib_log_w("Failed or incomplete ICP write: engine connection lost.");
-		flib_nbsocket_close(&ipcConnSocket);
-		return -1;
-	} else {
-		return 0;
-	}
-}
-
-void flib_ipcconn_tick() {
-	if(!ipcConnSocket && ipcListenSocket) {
-		ipcConnSocket = flib_nbsocket_accept(ipcListenSocket, true);
-		if(ipcConnSocket) {
-			SDLNet_TCP_Close(ipcListenSocket);
-			ipcListenSocket = NULL;
-		}
-	}
-}
--- a/frontlib/ipcconn.h	Thu May 31 18:54:40 2012 +0200
+++ /dev/null	Thu Jan 01 00:00:00 1970 +0000
@@ -1,67 +0,0 @@
-/*
- * Low-level protocol support for the IPC connection to the engine.
- */
-
-#ifndef IPCCONN_H_
-#define IPCCONN_H_
-
-#include <stddef.h>
-
-typedef enum {IPC_NOT_CONNECTED, IPC_LISTENING, IPC_CONNECTED} IpcConnState;
-
-/**
- * Called by flib_init(). Initialize everything related to ipc.
- */
-void flib_ipcconn_init();
-
-/**
- * Called by flib_quit(). Free resources and shut down.
- */
-void flib_ipcconn_quit();
-
-/**
- * Start listening for a connection from the engine. The system has to be in state
- * IPC_NOT_CONNECTED when calling this function.
- *
- * Returns the port we started listening on, or a negative value if there is an error.
- *
- * We stop listening once a connection has been established, so if you want to start
- * the engine again and talk to it you need to call this function again after the old
- * connection is closed.
- */
-int flib_ipcconn_listen();
-
-/**
- * Close the current IPC connection and/or stop listening for an incoming one.
- * This also discards all unread messages.
- */
-void flib_ipcconn_close();
-
-/**
- * Determine the current connection state
- */
-IpcConnState flib_ipcconn_state();
-
-/**
- * Receive a single message (up to 255 bytes) and copy it into the data buffer.
- * Returns the length of the received message, a negative value if no message could
- * be read.
- */
-int flib_ipcconn_recv_message(void *data);
-
-/**
- * Write a single message (up to 255 bytes) to the engine. This call blocks until the
- * message is completely written or the connection is closed or an error occurs.
- *
- * Calling this function in a state other than IPC_CONNECTED will fail immediately.
- * Returns a negative value on failure.
- */
-int flib_ipcconn_send_message(void *data, size_t len);
-
-/**
- * Call regularly to allow background work to proceed
- */
-void flib_ipcconn_tick();
-
-#endif /* IPCCONN_H_ */
-
--- a/frontlib/logging.c	Thu May 31 18:54:40 2012 +0200
+++ /dev/null	Thu Jan 01 00:00:00 1970 +0000
@@ -1,51 +0,0 @@
-#include "logging.h"
-
-#include <time.h>
-#include <stdio.h>
-#include <stdarg.h>
-
-char* flib_format_ip(uint32_t numip) {
-	static char ip[16];
-	snprintf(ip, 16, "%u.%u.%u.%u", numip>>24, (numip>>16)&0xff, (numip>>8)&0xff, numip&0xff);
-	return ip;
-}
-
-static void log_time(FILE *file) {
-    time_t timer;
-    char buffer[25];
-    struct tm* tm_info;
-
-    time(&timer);
-    tm_info = localtime(&timer);
-
-    strftime(buffer, 25, "%Y-%m-%d %H:%M:%S", tm_info);
-    fprintf(file, "%s", buffer);
-}
-
-static void flib_vflog(FILE *file, const char *prefix, const char *fmt, va_list args) {
-	log_time(file);
-	fprintf(file, " [%s]", prefix);
-	vfprintf(file, fmt, args);
-	fprintf(file, "\n");
-}
-
-void flib_log_e(const char *fmt, ...) {
-	va_list argp;
-	va_start(argp, fmt);
-	flib_vflog(stderr, "E", fmt, argp);
-	va_end(argp);
-}
-
-void flib_log_w(const char *fmt, ...) {
-	va_list argp;
-	va_start(argp, fmt);
-	flib_vflog(stdout, "W", fmt, argp);
-	va_end(argp);
-}
-
-void flib_log_i(const char *fmt, ...) {
-	va_list argp;
-	va_start(argp, fmt);
-	flib_vflog(stdout, "I", fmt, argp);
-	va_end(argp);
-}
--- a/frontlib/logging.h	Thu May 31 18:54:40 2012 +0200
+++ /dev/null	Thu Jan 01 00:00:00 1970 +0000
@@ -1,16 +0,0 @@
-/*
- *
- */
-
-#ifndef LOGGING_H_
-#define LOGGING_H_
-
-#include<stdint.h>
-
-char* flib_format_ip(uint32_t numip);
-
-void flib_log_e(const char *fmt, ...);
-void flib_log_w(const char *fmt, ...);
-void flib_log_i(const char *fmt, ...);
-
-#endif /* LOGGING_H_ */
--- a/frontlib/nonblocksockets.c	Thu May 31 18:54:40 2012 +0200
+++ /dev/null	Thu Jan 01 00:00:00 1970 +0000
@@ -1,76 +0,0 @@
-#include "nonblocksockets.h"
-#include "logging.h"
-#include <stdlib.h>
-
-static uint32_t get_peer_ip(TCPsocket sock) {
-	IPaddress *addr = SDLNet_TCP_GetPeerAddress(sock);
-	return SDLNet_Read32(&addr->host);
-}
-
-static bool connection_is_local(TCPsocket sock) {
-	return get_peer_ip(sock) == (uint32_t)((127UL<<24)+1); // 127.0.0.1
-}
-
-void flib_nbsocket_close(NonBlockSocket *nbsockptr) {
-	NonBlockSocket nbsock = *nbsockptr;
-	if(nbsock!=NULL) {
-		SDLNet_DelSocket(nbsock->sockset, (SDLNet_GenericSocket)nbsock->sock);
-		SDLNet_TCP_Close(nbsock->sock);
-		SDLNet_FreeSocketSet(nbsock->sockset);
-	}
-	free(nbsock);
-	*nbsockptr = NULL;
-}
-
-NonBlockSocket flib_nbsocket_accept(TCPsocket listensocket, bool localOnly) {
-	NonBlockSocket result = NULL;
-	if(!listensocket) {
-		flib_log_e("Attempt to accept a connection on a NULL socket.");
-		return NULL;
-	}
-	while(result==NULL) {
-		TCPsocket sock = SDLNet_TCP_Accept(listensocket);
-		if(!sock) {
-			// No incoming connections
-			return NULL;
-		}
-		if(localOnly && !connection_is_local(sock)) {
-			flib_log_i("Rejected nonlocal connection attempt from %s", flib_format_ip(get_peer_ip(sock)));
-			SDLNet_TCP_Close(sock);
-		} else {
-			result = malloc(sizeof(_NonBlockSocket));
-			if(result==NULL) {
-				flib_log_e("Out of memory!");
-				SDLNet_TCP_Close(sock);
-				return NULL;
-			}
-			result->sock = sock;
-			result->sockset = SDLNet_AllocSocketSet(1);
-			if(result->sockset==NULL) {
-				flib_log_e("Out of memory!");
-				SDLNet_TCP_Close(sock);
-				free(result);
-				return NULL;
-			}
-			SDLNet_AddSocket(result->sockset, (SDLNet_GenericSocket)result->sock);
-		}
-	}
-	return result;
-}
-
-int flib_nbsocket_recv(NonBlockSocket sock, void *data, int maxlen) {
-	if(!sock) {
-		flib_log_e("Attempt to receive on a NULL socket.");
-		return -1;
-	}
-	int readySockets = SDLNet_CheckSockets(sock->sockset, 0);
-	if(readySockets>0) {
-		int size = SDLNet_TCP_Recv(sock->sock, data, maxlen);
-		return size>0 ? size : -1;
-	} else if(readySockets==0) {
-		return 0;
-	} else {
-		flib_log_e("Error in select system call: %s", SDLNet_GetError());
-		return -1;
-	}
-}
--- a/frontlib/nonblocksockets.h	Thu May 31 18:54:40 2012 +0200
+++ /dev/null	Thu Jan 01 00:00:00 1970 +0000
@@ -1,51 +0,0 @@
-/*
- * nonblocksockets.h
- *
- *  Created on: 31.05.2012
- *      Author: simmax
- */
-
-#ifndef NONBLOCKSOCKETS_H_
-#define NONBLOCKSOCKETS_H_
-
-#include <SDL_net.h>
-#include <stdbool.h>
-
-typedef struct {
-	TCPsocket sock;
-	SDLNet_SocketSet sockset;
-} _NonBlockSocket;
-
-typedef _NonBlockSocket *NonBlockSocket;
-
-/**
- * Close the indicated socket, free its memory and set it to NULL.
- * If the socket is already NULL, nothing happens.
- */
-void flib_nbsocket_close(NonBlockSocket *socket);
-
-/**
- * Try to accept a connection from a listening socket.
- * if localOnly is true, this will only accept connections which came from 127.0.0.1
- * Returns NULL if nothing can be accepted.
- */
-NonBlockSocket flib_nbsocket_accept(TCPsocket listensocket, bool localOnly);
-
-/**
- * Attempt to receive up to maxlen bytes from the socket, but does not
- * block if nothing is available.
- * Returns the ammount of data received, 0 if there was nothing to receive,
- * or a negative number if the connection was closed or an error occurred.
- */
-int flib_nbsocket_recv(NonBlockSocket sock, void *data, int maxlen);
-
-/**
- * We can't do a nonblocking send over SDL_net, so this function just forwards
- * to SDLNet_TCP_Send for convenience, which blocks until all data is sent or an
- * error occurs. The ammount of data actually sent is returned, negative value on error.
- */
-static inline int flib_nbsocket_blocksend(NonBlockSocket sock, void *data, int len) {
-	return SDLNet_TCP_Send(sock->sock, data, len);
-}
-
-#endif /* NONBLOCKSOCKETS_H_ */
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/project_files/frontlib/buffer.c	Sat Jun 02 14:26:52 2012 +0200
@@ -0,0 +1,90 @@
+#include "buffer.h"
+#include "logging.h"
+
+#include <stdlib.h>
+#include <limits.h>
+#include <string.h>
+
+typedef struct _flib_vector {
+	void *data;
+	size_t size;
+	size_t capacity;
+} _flib_vector;
+
+flib_vector flib_vector_create() {
+	flib_vector result = malloc(sizeof(_flib_vector));
+	if(result == NULL) {
+		return NULL;
+	}
+	result->data = malloc(16);
+	if(result->data == NULL) {
+		free(result);
+		return NULL;
+	}
+	result->size = 0;
+	result->capacity = 16;
+	return result;
+}
+
+void flib_vector_destroy(flib_vector *vec) {
+	if(vec && *vec) {
+		free((*vec)->data);
+		free(*vec);
+		*vec = NULL;
+	}
+}
+
+static void try_realloc(flib_vector vec, size_t newCapacity) {
+	void *newData = realloc(vec->data, newCapacity);
+	if(newData) {
+		vec->data = newData;
+		vec->capacity = newCapacity;
+	}
+}
+
+static size_t getFreeCapacity(flib_vector vec) {
+	return vec->capacity - vec->size;
+}
+
+int flib_vector_append(flib_vector vec, const void *data, size_t len) {
+	if(getFreeCapacity(vec) < len) {
+		// Resize exponentially for constant amortized time,
+		// But at least by as much as we need of course,
+		// and be extra careful with integer overflows...
+		size_t extraCapacity = (vec->capacity)/2;
+
+		size_t minExtraCapacity = len - getFreeCapacity(vec);
+		if(extraCapacity < minExtraCapacity) {
+			extraCapacity = minExtraCapacity;
+		}
+
+		if(extraCapacity <= SIZE_MAX - vec->capacity) {
+			try_realloc(vec, vec->capacity+extraCapacity);
+		}
+
+		// Check if we were able to resize.
+		// If not, try to allocate at least what we need...
+		if(getFreeCapacity(vec) < len) {
+			try_realloc(vec, vec->capacity+minExtraCapacity);
+
+			// Still not working? Then we fail.
+			if(getFreeCapacity(vec) < len) {
+				return 0;
+			}
+		}
+	}
+
+	memmove(vec->data + vec->size, data, len);
+	vec->size += len;
+	return len;
+}
+
+flib_buffer flib_vector_as_buffer(flib_vector vec) {
+	flib_buffer result = {vec->data, vec->size};
+	return result;
+}
+
+flib_constbuffer flib_vector_as_constbuffer(flib_vector vec) {
+	flib_constbuffer result = {vec->data, vec->size};
+	return result;
+}
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/project_files/frontlib/buffer.h	Sat Jun 02 14:26:52 2012 +0200
@@ -0,0 +1,58 @@
+#ifndef BUFFER_H_
+#define BUFFER_H_
+
+#include <stdint.h>
+#include <stddef.h>
+
+/**
+ * A simple struct to hold both the pointer to an array and its size,
+ * for e.g. conveniently returning it from a function.
+ *
+ * Convention: Size is zero iff data is a NULL pointer.
+ */
+typedef struct {
+	void *data;
+	size_t size;
+} flib_buffer;
+
+/**
+ * Just like flib_buffer, but the contents are not supposed to be modified.
+ */
+typedef struct {
+	const void *data;
+	size_t size;
+} flib_constbuffer;
+
+/**
+ * Simple variable-capacity data structure (opaque type).
+ */
+struct _flib_vector;
+typedef struct _flib_vector *flib_vector;
+
+/**
+ * Create a new vector. Needs to be destroyed again later with flib_vector_destroy.
+ * May return NULL if memory runs out.
+ */
+flib_vector flib_vector_create();
+
+/**
+ * Free the memory of this vector and set it to NULL.
+ */
+void flib_vector_destroy(flib_vector *vec);
+
+/**
+ * Append the provided data to the end of the vector, enlarging it as required.
+ * Returns the ammount of data appended, which is either len (success) or 0 (out of memory).
+ * The vector remains unchanged if an out of memory situation occurs.
+ */
+int flib_vector_append(flib_vector vec, const void *data, size_t len);
+
+/**
+ * Return a buffer or constbuffer pointing to the current contents of the vector.
+ * These will become invalid if the vector size or capacity is changed.
+ */
+flib_buffer flib_vector_as_buffer(flib_vector vec);
+flib_constbuffer flib_vector_as_constbuffer(flib_vector vec);
+
+
+#endif
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/project_files/frontlib/events.c	Sat Jun 02 14:26:52 2012 +0200
@@ -0,0 +1,2 @@
+#include "events.h"
+
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/project_files/frontlib/events.h	Sat Jun 02 14:26:52 2012 +0200
@@ -0,0 +1,14 @@
+/*
+ * events.h
+ *
+ *  Created on: 01.06.2012
+ *      Author: simmax
+ */
+
+#ifndef EVENTS_H_
+#define EVENTS_H_
+
+
+
+
+#endif /* EVENTS_H_ */
--- a/project_files/frontlib/frontlib.c	Thu May 31 18:54:40 2012 +0200
+++ b/project_files/frontlib/frontlib.c	Sat Jun 02 14:26:52 2012 +0200
@@ -43,10 +43,8 @@
 }
 
 int main(int argc, char *argv[]) {
-	flib_init(0);
-	int port = flib_ipcconn_listen();
-	printf("%i\n", port);
-	fflush(stdout);
+	flib_init(FRONTLIB_SDL_ALREADY_INITIALIZED);
+	flib_ipcconn_start(true);
 	char data[256];
 	while(flib_ipcconn_state() != IPC_NOT_CONNECTED) {
 		flib_ipcconn_tick();
@@ -54,12 +52,36 @@
 		if(size>0) {
 			data[size]=0;
 			flib_log_i("IPC IN: %s", data);
-			if(data[0]=='?') {
-				flib_log_i("IPC OUT: !");
-				flib_ipcconn_send_message("!", 1);
+			switch(data[0]) {
+			case 'C':
+				flib_log_i("Sending config...");
+				flib_ipcconn_send_messagestr("TL");
+				flib_ipcconn_send_messagestr("eseed loremipsum");
+				flib_ipcconn_send_messagestr("escript Missions/Training/Basic_Training_-_Bazooka.lua");
+				break;
+			case '?':
+				flib_log_i("Sending pong...");
+				flib_ipcconn_send_messagestr("!");
+				break;
+			case 'Q':
+				flib_log_i("Game interrupted.");
+				break;
+			case 'q':
+				flib_log_i("Game finished.");
+				flib_constbuffer demobuf = flib_ipcconn_getdemo();
+				flib_log_i("Writing demo (%u bytes)...", demobuf.size);
+				FILE *file = fopen("testdemo.dem", "w");
+				fwrite(demobuf.data, 1, demobuf.size, file);
+				fclose(file);
+				file = NULL;
+				break;
+			case 'H':
+				flib_log_i("Game halted.");
+				break;
 			}
 		}
 	}
 	flib_log_i("IPC connection lost.");
+	flib_quit();
 	return 0;
 }
--- a/project_files/frontlib/ipcconn.c	Thu May 31 18:54:40 2012 +0200
+++ b/project_files/frontlib/ipcconn.c	Sat Jun 02 14:26:52 2012 +0200
@@ -4,23 +4,32 @@
 
 #include <SDL_net.h>
 #include <time.h>
+#include <string.h>
+#include <stdbool.h>
+
 static TCPsocket ipcListenSocket;
 static NonBlockSocket ipcConnSocket;
 
 static uint8_t ipcReadBuffer[256];
 static int ipcReadBufferSize;
 
+static flib_vector demoBuffer;
+static char localPlayerName[255];
+
 void flib_ipcconn_init() {
 	ipcListenSocket = NULL;
 	ipcConnSocket = NULL;
 	ipcReadBufferSize = 0;
+	demoBuffer=NULL;
+	strncpy(localPlayerName, "Local Player", 255);
 }
 
 void flib_ipcconn_quit() {
+	flib_vector_destroy(&demoBuffer);
 	flib_ipcconn_close();
 }
 
-int flib_ipcconn_listen() {
+int flib_ipcconn_start(bool recordDemo) {
 	if(ipcListenSocket || ipcConnSocket) {
 		flib_log_e("flib_ipcconn_listen: Already listening or connected.");
 		return -1;
@@ -42,6 +51,10 @@
 			flib_log_w("Failed to start an IPC listening socket on port %i: %s", ipcPort, SDLNet_GetError());
 		} else {
 			flib_log_i("Listening for IPC connections on port %i.", ipcPort);
+			if(recordDemo) {
+				flib_vector_destroy(&demoBuffer);
+				demoBuffer = flib_vector_create();
+			}
 			return ipcPort;
 		}
 	}
@@ -68,6 +81,44 @@
 	}
 }
 
+static void demo_record(const void *data, size_t len) {
+	if(demoBuffer) {
+		if(flib_vector_append(demoBuffer, data, len) < len) {
+			// Out of memory, fail demo recording
+			flib_vector_destroy(&demoBuffer);
+		}
+	}
+}
+
+static void demo_record_from_engine(const uint8_t *message) {
+	if(!demoBuffer || message[0]==0) {
+		return;
+	}
+	if(strchr("?CEiQqHb", message[1])) {
+		// Those message types are not recorded in a demo.
+		return;
+	}
+
+	if(message[1] == 's') {
+		if(message[0] >= 3) {
+			// Chat messages get a special once-over to make them look as if they were received, not sent.
+			// Get the actual chat message as c string
+			char chatMsg[256];
+			memcpy(chatMsg, message+2, message[0]-3);
+			chatMsg[message[0]-3] = 0;
+
+			char converted[257];
+			bool memessage = message[0] >= 7 && !memcmp(message+2, "/me ", 4);
+			const char *template = memessage ? "s\x02* %s %s  " : "s\x01%s: %s  ";
+			int size = snprintf(converted+1, 256, template, localPlayerName, chatMsg);
+			converted[0] = size>255 ? 255 : size;
+			demo_record(converted, converted[0]+1);
+		}
+	} else {
+		demo_record(message, message[0]+1);
+	}
+}
+
 /**
  * Receive a single message and copy it into the data buffer.
  * Returns the length of the received message, -1 when nothing is received.
@@ -86,6 +137,7 @@
 
 	int msgsize = ipcReadBuffer[0];
 	if(ipcReadBufferSize > msgsize) {
+		demo_record_from_engine(ipcReadBuffer);
 		memcpy(data, ipcReadBuffer+1, msgsize);
 		memmove(ipcReadBuffer, ipcReadBuffer+msgsize+1, ipcReadBufferSize-(msgsize+1));
 		ipcReadBufferSize -= (msgsize+1);
@@ -114,15 +166,20 @@
 	uint8_t sendbuf[256];
 	sendbuf[0] = len;
 	memcpy(sendbuf+1, data, len);
-	if(flib_nbsocket_blocksend(ipcConnSocket, sendbuf, len+1) < len+1) {
+	if(flib_nbsocket_blocksend(ipcConnSocket, sendbuf, len+1) == len+1) {
+		demo_record(sendbuf, len+1);
+		return 0;
+	} else {
 		flib_log_w("Failed or incomplete ICP write: engine connection lost.");
 		flib_nbsocket_close(&ipcConnSocket);
 		return -1;
-	} else {
-		return 0;
 	}
 }
 
+int flib_ipcconn_send_messagestr(char *data) {
+	return flib_ipcconn_send_message(data, strlen(data));
+}
+
 void flib_ipcconn_tick() {
 	if(!ipcConnSocket && ipcListenSocket) {
 		ipcConnSocket = flib_nbsocket_accept(ipcListenSocket, true);
@@ -132,3 +189,32 @@
 		}
 	}
 }
+
+static void replace_gamemode(flib_buffer buf, char gamemode) {
+	size_t msgStart = 0;
+	char *data = (char*)buf.data;
+	while(msgStart+2 < buf.size) {
+		if(!memcmp(data+msgStart, "\x02T", 2)) {
+			data[msgStart+2] = gamemode;
+		}
+		msgStart += (uint8_t)data[msgStart]+1;
+	}
+}
+
+flib_constbuffer flib_ipcconn_getdemo() {
+	if(!demoBuffer) {
+		flib_constbuffer result = {NULL, 0};
+		return result;
+	}
+	replace_gamemode(flib_vector_as_buffer(demoBuffer), 'D');
+	return flib_vector_as_constbuffer(demoBuffer);
+}
+
+flib_constbuffer flib_ipcconn_getsave() {
+	if(!demoBuffer) {
+		flib_constbuffer result = {NULL, 0};
+		return result;
+	}
+	replace_gamemode(flib_vector_as_buffer(demoBuffer), 'S');
+	return flib_vector_as_constbuffer(demoBuffer);
+}
--- a/project_files/frontlib/ipcconn.h	Thu May 31 18:54:40 2012 +0200
+++ b/project_files/frontlib/ipcconn.h	Sat Jun 02 14:26:52 2012 +0200
@@ -5,7 +5,10 @@
 #ifndef IPCCONN_H_
 #define IPCCONN_H_
 
+#include "buffer.h"
+
 #include <stddef.h>
+#include <stdbool.h>
 
 typedef enum {IPC_NOT_CONNECTED, IPC_LISTENING, IPC_CONNECTED} IpcConnState;
 
@@ -21,7 +24,11 @@
 
 /**
  * Start listening for a connection from the engine. The system has to be in state
- * IPC_NOT_CONNECTED when calling this function.
+ * IPC_NOT_CONNECTED when calling this function, and will be in state IPC_LISTENING
+ * if the function returns successfully.
+ *
+ * The parameter "recordDemo" can be used to control whether demo recording should
+ * be enabled for this connection.
  *
  * Returns the port we started listening on, or a negative value if there is an error.
  *
@@ -29,7 +36,7 @@
  * the engine again and talk to it you need to call this function again after the old
  * connection is closed.
  */
-int flib_ipcconn_listen();
+int flib_ipcconn_start(bool recordDemo);
 
 /**
  * Close the current IPC connection and/or stop listening for an incoming one.
@@ -46,6 +53,10 @@
  * Receive a single message (up to 255 bytes) and copy it into the data buffer.
  * Returns the length of the received message, a negative value if no message could
  * be read.
+ *
+ * Note: When a connection is closed, you probably want to call this function until
+ * no further message is returned, to ensure you see all messages that were sent
+ * before the connection closed.
  */
 int flib_ipcconn_recv_message(void *data);
 
@@ -59,9 +70,40 @@
 int flib_ipcconn_send_message(void *data, size_t len);
 
 /**
+ * Convenience function for sending a 0-delimited string.
+ */
+int flib_ipcconn_send_messagestr(char *data);
+
+/**
  * Call regularly to allow background work to proceed
  */
 void flib_ipcconn_tick();
 
+/**
+ * Get a demo record of the last connection. This should be called after
+ * the connection is closed and all messages have been received.
+ *
+ * If demo recording was not enabled in the last call to flib_ipcconn_start(),
+ * or if the recording failed for some reason, the buffer will be empty.
+ *
+ * The buffer is only valid until the next call to flib_ipcconn_start() or
+ * a call to flib_ipcconn_getsave() (save and demo records have some minor
+ * differences, and those are performed directly on the buffer before returning it).
+ */
+flib_constbuffer flib_ipcconn_getdemo();
+
+/**
+ * Get a savegame record of the last connection. This should be called after
+ * the connection is closed and all messages have been received.
+ *
+ * If demo recording was not enabled in the last call to flib_ipcconn_start(),
+ * or if the recording failed for some reason, the buffer will be empty.
+ *
+ * The buffer is only valid until the next call to flib_ipcconn_start() or
+ * a call to flib_ipcconn_getdemo() (save and demo records have some minor
+ * differences, and those are performed directly on the buffer before returning it).
+ */
+flib_constbuffer flib_ipcconn_getsave();
+
 #endif /* IPCCONN_H_ */
 
--- a/project_files/frontlib/logging.c	Thu May 31 18:54:40 2012 +0200
+++ b/project_files/frontlib/logging.c	Sat Jun 02 14:26:52 2012 +0200
@@ -3,6 +3,7 @@
 #include <time.h>
 #include <stdio.h>
 #include <stdarg.h>
+#include <stdlib.h>
 
 char* flib_format_ip(uint32_t numip) {
 	static char ip[16];
@@ -27,6 +28,7 @@
 	fprintf(file, " [%s]", prefix);
 	vfprintf(file, fmt, args);
 	fprintf(file, "\n");
+	fflush(file);
 }
 
 void flib_log_e(const char *fmt, ...) {