Display median time instead of average (fixes #3399)

src/engine/server/databases/connection.h

@@ -21,7 +21,7 @@ public:
 	virtual IDbConnection *Copy() = 0;
 
 	// returns the database prefix
-	const char *GetPrefix() { return m_aPrefix; }
+	const char *GetPrefix() const { return m_aPrefix; }
 	virtual const char *BinaryCollate() const = 0;
 	// can be inserted into queries to convert a timestamp variable to the unix timestamp
 	virtual void ToUnixTimestamp(const char *pTimestamp, char *aBuf, unsigned int BufferSize) = 0;
@@ -35,6 +35,8 @@ public:
 	virtual const char *InsertIgnore() const = 0;
 	// ORDER BY RANDOM()/RAND()
 	virtual const char *Random() const = 0;
+	// Get Median Map Time from l.Map
+	virtual const char *MedianMapTime(char *pBuffer, int BufferSize) const = 0;
 
 	enum Status
 	{

src/engine/server/databases/mysql.cpp

@@ -309,6 +309,18 @@ int CMysqlConnection::GetBlob(int Col, unsigned char *pBuffer, int BufferSize) c
 #endif
 }
 
+const char *CMysqlConnection::MedianMapTime(char *pBuffer, int BufferSize) const
+{
+	str_format(pBuffer, BufferSize,
+		"SELECT MEDIAN(Time) "
+		"OVER (PARTITION BY Map) "
+		"FROM %s_race "
+		"GROUP BY Map "
+		"HAVING Map = l.Map",
+		GetPrefix());
+	return pBuffer;
+}
+
 void CMysqlConnection::AddPoints(const char *pPlayer, int Points)
 {
 	char aBuf[512];

src/engine/server/databases/mysql.h

@@ -35,6 +35,7 @@ public:
 	virtual const char *CollateNocase() const { return "CONVERT(? USING utf8mb4) COLLATE utf8mb4_general_ci"; }
 	virtual const char *InsertIgnore() const { return "INSERT IGNORE"; };
 	virtual const char *Random() const { return "RAND()"; };
+	virtual const char *MedianMapTime(char *pBuffer, int BufferSize) const;
 
 	virtual Status Connect();
 	virtual void Disconnect();

src/engine/server/databases/sqlite.cpp

@@ -214,6 +214,23 @@ int CSqliteConnection::GetBlob(int Col, unsigned char *pBuffer, int BufferSize)
 	return Size;
 }
 
+const char *CSqliteConnection::MedianMapTime(char *pBuffer, int BufferSize) const
+{
+	str_format(pBuffer, BufferSize,
+		"SELECT AVG("
+		"  CASE counter %% 2 "
+		"    WHEN 0 THEN CASE WHEN rn IN (counter / 2, counter / 2 + 1) THEN Time END "
+		"    WHEN 1 THEN CASE WHEN rn = counter / 2 + 1 THEN Time END END) "
+		"  OVER (PARTITION BY Map) AS Median "
+		"FROM ("
+		"  SELECT *, ROW_NUMBER() "
+		"  OVER (PARTITION BY Map ORDER BY Time) rn, COUNT(*) "
+		"  OVER (PARTITION BY Map) counter "
+		"  FROM %s_race where Map = l.Map) as r",
+		GetPrefix());
+	return pBuffer;
+}
+
 bool CSqliteConnection::Execute(const char *pQuery)
 {
 	char *pErrorMsg;

src/engine/server/databases/sqlite.h

@@ -22,6 +22,7 @@ public:
 	virtual const char *CollateNocase() const { return "? COLLATE NOCASE"; }
 	virtual const char *InsertIgnore() const { return "INSERT OR IGNORE"; };
 	virtual const char *Random() const { return "RANDOM()"; };
+	virtual const char *MedianMapTime(char *pBuffer, int BufferSize) const;
 
 	virtual Status Connect();
 	virtual void Disconnect();

src/game/server/score.cpp

@@ -355,12 +355,13 @@ bool CScore::MapInfoThread(IDbConnection *pSqlServer, const ISqlData *pGameData)
 	char aTimestamp[512];
 	pSqlServer->ToUnixTimestamp("l.Timestamp", aTimestamp, sizeof(aTimestamp));
 
-	char aBuf[1024];
+	char aMedianMapTime[2048];
+	char aBuf[4096];
 	str_format(aBuf, sizeof(aBuf),
 		"SELECT l.Map, l.Server, Mapper, Points, Stars, "
 		"  (SELECT COUNT(Name) FROM %s_race WHERE Map = l.Map) AS Finishes, "
 		"  (SELECT COUNT(DISTINCT Name) FROM %s_race WHERE Map = l.Map) AS Finishers, "
-		"  (SELECT ROUND(AVG(Time)) FROM %s_race WHERE Map = l.Map) AS Average, "
+		"  (%s) AS Median, "
 		"  %s AS Stamp, "
 		"  %s-%s AS Ago, "
 		"  (SELECT MIN(Time) FROM %s_race WHERE Map = l.Map AND Name = ?) AS OwnTime "
@@ -374,7 +375,8 @@ bool CScore::MapInfoThread(IDbConnection *pSqlServer, const ISqlData *pGameData)
 		"    Map "
 		"  LIMIT 1"
 		") as l;",
-		pSqlServer->GetPrefix(), pSqlServer->GetPrefix(), pSqlServer->GetPrefix(),
+		pSqlServer->GetPrefix(), pSqlServer->GetPrefix(),
+		pSqlServer->MedianMapTime(aMedianMapTime, sizeof(aMedianMapTime)),
 		aTimestamp, aCurrentTimestamp, aTimestamp,
 		pSqlServer->GetPrefix(), pSqlServer->GetPrefix(),
 		pSqlServer->CollateNocase());
@@ -396,7 +398,7 @@ bool CScore::MapInfoThread(IDbConnection *pSqlServer, const ISqlData *pGameData)
 		int Stars = pSqlServer->GetInt(5);
 		int Finishes = pSqlServer->GetInt(6);
 		int Finishers = pSqlServer->GetInt(7);
-		int Average = pSqlServer->GetInt(8);
+		float Median = pSqlServer->GetInt(8);
 		int Stamp = pSqlServer->GetInt(9);
 		int Ago = pSqlServer->GetInt(10);
 		float OwnTime = pSqlServer->GetFloat(11);
@@ -409,11 +411,11 @@ bool CScore::MapInfoThread(IDbConnection *pSqlServer, const ISqlData *pGameData)
 			str_format(aReleasedString, sizeof(aReleasedString), ", released %s ago", aAgoString);
 		}
 
-		char aAverageString[60] = "\0";
+		char aMedianString[60] = "\0";
-		if(Average > 0)
+		if(Median > 0)
 		{
-			str_time((int64)Average * 100, TIME_HOURS, aBuf, sizeof(aBuf));
+			str_time((int64)Median * 100, TIME_HOURS, aBuf, sizeof(aBuf));
-			str_format(aAverageString, sizeof(aAverageString), " in %s average", aBuf);
+			str_format(aMedianString, sizeof(aMedianString), " in %s median", aBuf);
 		}
 
 		char aStars[20];
@@ -443,7 +445,7 @@ bool CScore::MapInfoThread(IDbConnection *pSqlServer, const ISqlData *pGameData)
 			aReleasedString,
 			Finishes, Finishes == 1 ? "finish" : "finishes",
 			Finishers, Finishers == 1 ? "tee" : "tees",
-			aAverageString, aOwnFinishesString);
+			aMedianString, aOwnFinishesString);
 	}
 	else
 	{