overall improvements + support STATUS requests

1 files changed, 222 insertions, 0 deletions

diff --git a/src/status.cc b/src/status.cc
new file mode 100644
index 0000000..cb960b8
--- /dev/null
+++ b/src/status.cc
@@ -0,0 +1,222 @@
+#include "common.hh"
+
+// IMPORTANT(fusion): We want connections to use the status string directly for
+// output, but because it could be refreshed while connections are still using
+// it, we need to have them buffered, to allow old versions to remain valid, at
+// least for a couple refreshes. Note that `
+
+static int g_LastStatusRefresh = 0;
+static int g_StatusStringIndex = 0;
+static char g_StatusString[3][KB(2)];
+
+struct XMLBuffer{
+	char *Data;
+	int Size;
+	int Position;
+};
+
+static void XMLNullTerminate(XMLBuffer *Buffer){
+	ASSERT(Buffer->Size > 0);
+	if(Buffer->Position < Buffer->Size){
+		Buffer->Data[Buffer->Position] = 0;
+	}else{
+		Buffer->Data[Buffer->Size - 1] = 0;
+	}
+}
+
+static void XMLAppendChar(XMLBuffer *Buffer, char Ch){
+	if(Buffer->Position < Buffer->Size){
+		Buffer->Data[Buffer->Position] = Ch;
+	}
+	Buffer->Position += 1;
+}
+
+static void XMLAppendNumber(XMLBuffer *Buffer, int64 Num){
+	if(Num == 0){
+		XMLAppendChar(Buffer, '0');
+		return;
+	}
+
+	if(Num < 0){
+		XMLAppendChar(Buffer, '-');
+		Num = -Num;
+	}
+
+	char String[64] = {};
+	int StringLen = 0;
+	while(Num > 0){
+		ASSERT(StringLen < (int)sizeof(String));
+		String[StringLen] = (Num % 10) + '0';
+		Num = (Num / 10);
+		StringLen += 1;
+	}
+
+	for(int i = 0; i < StringLen; i += 1){
+		XMLAppendChar(Buffer, String[(StringLen - 1) - i]);
+	}
+}
+
+static void XMLAppendString(XMLBuffer *Buffer, const char *String){
+	const char *P = String;
+	while(P[0]){
+		XMLAppendChar(Buffer, P[0]);
+		P += 1;
+	}
+}
+
+static void XMLAppendStringEscaped(XMLBuffer *Buffer, const char *String){
+	const char *P = String;
+	while(P[0]){
+		switch(P[0]){
+			case '\t': XMLAppendString(Buffer, "&#9;"); break;
+			case '\n': XMLAppendString(Buffer, "&#10;"); break;
+			case '"':  XMLAppendString(Buffer, "&quot;"); break;
+			case '&':  XMLAppendString(Buffer, "&amp;"); break;
+			case '\'': XMLAppendString(Buffer, "&apos;"); break;
+			case '<':  XMLAppendString(Buffer, "&lt;"); break;
+			case '>':  XMLAppendString(Buffer, "&gt;"); break;
+			default:   XMLAppendChar(Buffer, P[0]); break;
+		}
+		P += 1;
+	}
+}
+
+static void XMLAppendStringFV(XMLBuffer *Buffer, const char *Format, va_list Args){
+	const char *P = Format;
+	while(P[0]){
+		// IMPORTANT(fusion): This function only implements a small subset of
+		// the printf syntax.
+		if(P[0] == '%'){
+			P += 1;
+
+			// IMPORTANT(fusion): Small integral parameters such as char and short
+			// are promoted to int, similar to how they're promoted in arithmetic
+			// operations. This means there are only really 4 and 8 bytes integers.
+			int Length = 4;
+			if(P[0] == 'h' && P[1] == 'h'){
+				P += 2;
+			}else if(P[0] == 'l' && P[1] == 'l'){
+				Length = 8;
+				P += 2;
+			}else if(P[0] == 'h'){
+				P += 1;
+			}else if(P[0] == 'l'){
+				Length = 8;
+				P += 1;
+			}
+
+			switch(P[0]){
+				case '%':{
+					XMLAppendChar(Buffer, '%');
+					break;
+				}
+
+				case 'c':{
+					int Ch = va_arg(Args, int);
+					XMLAppendChar(Buffer, (char)Ch);
+					break;
+				}
+
+				case 'd':{
+					int64 Num = (Length == 4 ? va_arg(Args, int) : va_arg(Args, int64));
+					XMLAppendNumber(Buffer, Num);
+					break;
+				}
+
+				case 's':{
+					const char *String = va_arg(Args, const char*);
+					XMLAppendStringEscaped(Buffer, String);
+					break;
+				}
+
+				default:{
+					LOG_ERR("Invalid XML format specifier \"%c\"", P[0]);
+					break;
+				}
+			}
+
+			if(P[0]){
+				P += 1;
+			}
+
+		}else{
+			XMLAppendChar(Buffer, P[0]);
+			P += 1;
+		}
+	}
+}
+
+static void XMLAppendStringF(XMLBuffer *Buffer, const char *Format, ...){
+	va_list Args;
+	va_start(Args, Format);
+	XMLAppendStringFV(Buffer, Format, Args);
+	va_end(Args);
+}
+
+const char *GetStatusString(void){
+	int TimeNow = (int)time(NULL);
+	if((TimeNow - g_LastStatusRefresh) >= g_Config.MinStatusInterval){
+		const char *WorldName = "";
+		int Uptime = 0;
+		int NumPlayers = 0;
+		int MaxPlayers = 0;
+		int OnlinePeak = 0;
+
+		TWorld World = {};
+		if(GetWorld(g_Config.StatusWorld, &World) == 0){
+			WorldName = World.Name;
+			if(World.LastStartup != 0 && World.LastStartup > World.LastShutdown){
+				Uptime = (int)time(NULL) - World.LastStartup;
+			}
+			NumPlayers = World.NumPlayers;
+			MaxPlayers = World.MaxPlayers;
+			OnlinePeak = World.OnlinePeak;
+
+			// IMPORTANT(fusion): This could be a common behaviour but, on OTSERVLIST,
+			// the server will show as OFFLINE if the the online peak is less than
+			// the number of online players. This shouldn't usually be a problem since
+			// the online character list and online peak are updated together in the
+			// same CREATE_PLAYERLIST query, but is something to keep in mind.
+			if(OnlinePeak < NumPlayers){
+				OnlinePeak = NumPlayers;
+			}
+		}else{
+			LOG_ERR("Failed to query world data...");
+		}
+
+		// NOTE(fusion): Skip line with MOTD hash.
+		const char *Motd = g_Config.Motd;
+		while(Motd[0]){
+			if(Motd[0] == '\n'){
+				Motd += 1;
+				break;
+			}
+			Motd += 1;
+		}
+
+		g_StatusStringIndex = (g_StatusStringIndex + 1) % NARRAY(g_StatusString);
+		XMLBuffer Buffer = {};
+		Buffer.Data = g_StatusString[g_StatusStringIndex];
+		Buffer.Size = sizeof(g_StatusString[g_StatusStringIndex]);
+		XMLAppendString(&Buffer, "<?xml version=\"1.0\" encoding=\"UTF-8\"?>");
+		XMLAppendString(&Buffer, "<tsqp version=\"1.0\">");
+		XMLAppendStringF(&Buffer,
+				"<serverinfo servername=\"%s\" uptime=\"%d\" url=\"%s\""
+					" location=\"%s\" server=\"%s\" version=\"%s\""
+					" client=\"%s\"/>",
+				WorldName, Uptime, g_Config.Url, g_Config.Location,
+				g_Config.ServerType, g_Config.ServerVersion,
+				g_Config.ClientVersion);
+		XMLAppendStringF(&Buffer,
+				"<players online=\"%d\" max=\"%d\" peak=\"%d\"/>",
+				NumPlayers, MaxPlayers, OnlinePeak);
+		XMLAppendStringF(&Buffer, "<motd>%s</motd>", Motd);
+		XMLAppendString(&Buffer, "</tsqp>");
+		XMLNullTerminate(&Buffer);
+
+		g_LastStatusRefresh = TimeNow;
+	}
+
+	return g_StatusString[g_StatusStringIndex];
+}
+