1 files changed, 380 insertions, 0 deletions
diff --git a/common.go b/common.go
new file mode 100644
index 0000000..0676487
--- /dev/null
+++ b/common.go
@@ -0,0 +1,380 @@
+package main
+
+import (
+	"bufio"
+	"encoding/binary"
+	"net"
+	"os"
+	"strconv"
+	"strings"
+	"time"
+	"unicode"
+)
+
+// TReadBuffer
+// ==============================================================================
+type TReadBuffer struct {
+	Buffer   []byte
+	Position int
+}
+
+func (ReadBuffer *TReadBuffer) CanRead(Bytes int) bool {
+	return ReadBuffer.Position+Bytes <= len(ReadBuffer.Buffer)
+}
+
+func (ReadBuffer *TReadBuffer) Overflowed() bool {
+	return ReadBuffer.Position > len(ReadBuffer.Buffer)
+}
+
+func (ReadBuffer *TReadBuffer) ReadFlag() bool {
+	return ReadBuffer.Read8() != 0
+}
+
+func (ReadBuffer *TReadBuffer) Read8() uint8 {
+	Result := uint8(0)
+	if ReadBuffer.CanRead(1) {
+		Result = ReadBuffer.Buffer[ReadBuffer.Position]
+	}
+	ReadBuffer.Position += 1
+	return Result
+}
+
+func (ReadBuffer *TReadBuffer) Read16() uint16 {
+	Result := uint16(0)
+	if ReadBuffer.CanRead(2) {
+		Result = binary.LittleEndian.Uint16(ReadBuffer.Buffer[ReadBuffer.Position:])
+	}
+	ReadBuffer.Position += 2
+	return Result
+}
+
+func (ReadBuffer *TReadBuffer) Read16BE() uint16 {
+	Result := uint16(0)
+	if ReadBuffer.CanRead(2) {
+		Result = binary.BigEndian.Uint16(ReadBuffer.Buffer[ReadBuffer.Position:])
+	}
+	ReadBuffer.Position += 2
+	return Result
+}
+
+func (ReadBuffer *TReadBuffer) Read32() uint32 {
+	Result := uint32(0)
+	if ReadBuffer.CanRead(4) {
+		Result = binary.LittleEndian.Uint32(ReadBuffer.Buffer[ReadBuffer.Position:])
+	}
+	ReadBuffer.Position += 4
+	return Result
+}
+
+func (ReadBuffer *TReadBuffer) Read32BE() uint32 {
+	Result := uint32(0)
+	if ReadBuffer.CanRead(4) {
+		Result = binary.BigEndian.Uint32(ReadBuffer.Buffer[ReadBuffer.Position:])
+	}
+	ReadBuffer.Position += 4
+	return Result
+}
+
+func (ReadBuffer *TReadBuffer) ReadString() string {
+	Length := int(ReadBuffer.Read16())
+	if Length == 0xFFFF {
+		Length = int(ReadBuffer.Read32())
+	}
+
+	Result := ""
+	if ReadBuffer.CanRead(Length) {
+		Result = string(ReadBuffer.Buffer[ReadBuffer.Position:][:Length])
+	}
+	ReadBuffer.Position += Length
+	return Result
+}
+
+func (ReadBuffer *TReadBuffer) ReadBytes(Count int) []byte {
+	Result := []byte(nil)
+	if ReadBuffer.CanRead(Count) {
+		Result = ReadBuffer.Buffer[ReadBuffer.Position:][:Count]
+	}
+	ReadBuffer.Position += Count
+	return Result
+}
+
+// TWriteBuffer
+// ==============================================================================
+type TWriteBuffer struct {
+	Buffer   []byte
+	Position int
+}
+
+func (WriteBuffer *TWriteBuffer) CanWrite(Bytes int) bool {
+	return (WriteBuffer.Position + Bytes) <= len(WriteBuffer.Buffer)
+}
+
+func (WriteBuffer *TWriteBuffer) Overflowed() bool {
+	return WriteBuffer.Position > len(WriteBuffer.Buffer)
+}
+
+func (WriteBuffer *TWriteBuffer) WriteFlag(Value bool) {
+	Value8 := uint8(0)
+	if Value {
+		Value8 = uint8(1)
+	}
+	WriteBuffer.Write8(Value8)
+}
+
+func (WriteBuffer *TWriteBuffer) Write8(Value uint8) {
+	if WriteBuffer.CanWrite(1) {
+		WriteBuffer.Buffer[WriteBuffer.Position] = Value
+	}
+	WriteBuffer.Position += 1
+}
+
+func (WriteBuffer *TWriteBuffer) Write16(Value uint16) {
+	if WriteBuffer.CanWrite(2) {
+		binary.LittleEndian.PutUint16(WriteBuffer.Buffer[WriteBuffer.Position:], Value)
+	}
+	WriteBuffer.Position += 2
+}
+
+func (WriteBuffer *TWriteBuffer) Write16BE(Value uint16) {
+	if WriteBuffer.CanWrite(2) {
+		binary.BigEndian.PutUint16(WriteBuffer.Buffer[WriteBuffer.Position:], Value)
+	}
+	WriteBuffer.Position += 2
+}
+
+func (WriteBuffer *TWriteBuffer) Write32(Value uint32) {
+	if WriteBuffer.CanWrite(4) {
+		binary.LittleEndian.PutUint32(WriteBuffer.Buffer[WriteBuffer.Position:], Value)
+	}
+	WriteBuffer.Position += 4
+}
+
+func (WriteBuffer *TWriteBuffer) Write32BE(Value uint32) {
+	if WriteBuffer.CanWrite(4) {
+		binary.BigEndian.PutUint32(WriteBuffer.Buffer[WriteBuffer.Position:], Value)
+	}
+	WriteBuffer.Position += 4
+}
+
+func (WriteBuffer *TWriteBuffer) WriteString(String string) {
+	Length := len(String)
+	if Length < 0xFFFF {
+		WriteBuffer.Write16(uint16(Length))
+	} else {
+		WriteBuffer.Write16(0xFFFF)
+		WriteBuffer.Write32(uint32(Length))
+	}
+
+	if WriteBuffer.CanWrite(Length) {
+		copy(WriteBuffer.Buffer[WriteBuffer.Position:], String)
+	}
+	WriteBuffer.Position += Length
+}
+
+func (WriteBuffer *TWriteBuffer) WriteBytes(Bytes []byte) {
+	Count := len(Bytes)
+	if WriteBuffer.CanWrite(Count) {
+		copy(WriteBuffer.Buffer[WriteBuffer.Position:], Bytes)
+	}
+	WriteBuffer.Position += Count
+}
+
+func (WriteBuffer *TWriteBuffer) Rewrite16(Position int, Value uint16) {
+	if (Position+2) <= WriteBuffer.Position && !WriteBuffer.Overflowed() {
+		binary.LittleEndian.PutUint16(WriteBuffer.Buffer[Position:], Value)
+	}
+}
+
+func (WriteBuffer *TWriteBuffer) Insert32(Position int, Value uint32) {
+	if Position <= WriteBuffer.Position {
+		if WriteBuffer.CanWrite(4) {
+			copy(WriteBuffer.Buffer[Position+4:], WriteBuffer.Buffer[Position:])
+			binary.LittleEndian.PutUint32(WriteBuffer.Buffer[Position:], Value)
+		}
+		WriteBuffer.Position += 4
+	}
+}
+
+// Config
+// ==============================================================================
+func ParseBoolean(String string) bool {
+	return strings.EqualFold(String, "true")
+}
+
+func ParseInteger(String string) int {
+	Result, Err := strconv.Atoi(String)
+	if Err != nil {
+		g_LogErr.Printf("Failed to parse integer \"%v\": %v", String, Err)
+	}
+	return Result
+}
+
+func ParseIntegerSuffix(String string) (int, string) {
+	SuffixStart := -1
+	for Index, Rune := range String {
+		if !unicode.IsDigit(Rune) {
+			SuffixStart = Index
+			break
+		}
+	}
+
+	var Value, Suffix string
+	if SuffixStart != -1 {
+		Value = strings.TrimSpace(String[:SuffixStart])
+		Suffix = strings.TrimSpace(String[SuffixStart:])
+	} else {
+		Value = String
+		Suffix = ""
+	}
+
+	Result, Err := strconv.Atoi(Value)
+	if Err != nil {
+		g_LogErr.Printf("Failed to parse duration \"%v\": %v", String, Err)
+	}
+
+	return Result, Suffix
+}
+
+func ParseDuration(String string) time.Duration {
+	Value, Suffix := ParseIntegerSuffix(String)
+	Result := time.Duration(Value) * time.Millisecond
+	if len(Suffix) > 0 {
+		switch Suffix[0] {
+		case 'S', 's':
+			Result = time.Duration(Value) * time.Second
+		case 'M', 'm':
+			Result = time.Duration(Value) * time.Minute
+		case 'H', 'h':
+			Result = time.Duration(Value) * time.Hour
+		}
+	}
+	return Result
+}
+
+func ParseSize(String string) int {
+	Result, Suffix := ParseIntegerSuffix(String)
+	if len(Suffix) > 0 {
+		switch Suffix[0] {
+		case 'K', 'k':
+			Result *= 1024
+		case 'M', 'm':
+			Result *= (1024 * 1024)
+		}
+	}
+	return Result
+}
+
+func ParseString(String string) string {
+	if len(String) > 2 {
+		if String[0] == '"' && String[len(String)-1] == '"' ||
+			String[0] == '\'' && String[len(String)-1] == '\'' ||
+			String[0] == '`' && String[len(String)-1] == '`' {
+			String = String[1 : len(String)-1]
+		}
+	}
+	return String
+}
+
+func ReadConfig(FileName string, KVCallback func(string, string)) bool {
+	File, Err := os.Open(FileName)
+	if Err != nil {
+		g_LogErr.Print(Err)
+		return false
+	}
+	defer File.Close()
+
+	Scanner := bufio.NewScanner(File)
+	for LineNumber := 1; Scanner.Scan(); LineNumber += 1 {
+		Line := strings.TrimSpace(Scanner.Text())
+		if len(Line) == 0 || Line[0] == '#' {
+			continue
+		}
+
+		Key, Value, Ok := strings.Cut(Scanner.Text(), "=")
+		if !Ok {
+			g_LogErr.Printf("%v:%v: No assignment found on non empty line", FileName, LineNumber)
+			continue
+		}
+
+		Key = strings.TrimSpace(Key)
+		if len(Key) == 0 {
+			g_LogErr.Printf("%v:%v: Empty key", FileName, LineNumber)
+			continue
+		}
+
+		Value = strings.TrimSpace(Value)
+		if len(Value) == 0 {
+			g_LogErr.Printf("%v:%v: Empty value", FileName, LineNumber)
+			continue
+		}
+
+		KVCallback(Key, Value)
+	}
+
+	return true
+}
+
+// Utility
+// ==============================================================================
+func FileExists(FileName string) bool {
+	_, Err := os.Stat(FileName)
+	return Err == nil
+}
+
+func JoinHostPort(Host string, Port int) string {
+	PortString := strconv.Itoa(Port)
+	return net.JoinHostPort(Host, PortString)
+}
+
+func SplitDiscardEmpty(String string, Sep string) []string {
+	var Result []string
+	for String != "" {
+		SubStr := ""
+		Index := strings.Index(String, Sep)
+		if Index == -1 {
+			SubStr = String
+			String = ""
+		} else {
+			SubStr = String[:Index]
+			String = String[Index+1:]
+		}
+
+		if SubStr != "" {
+			Result = append(Result, SubStr)
+		}
+	}
+	return Result
+}
+
+func SwapAndPop[T any](Slice []T, Index int) []T {
+	if len(Slice) == 0 {
+		panic("slice is empty")
+	}
+
+	var Zero T
+	Slice[Index] = Slice[len(Slice)-1]
+	Slice[len(Slice)-1] = Zero
+	return Slice[:len(Slice)-1]
+}
+
+func WorldTypeString(Type int) string {
+	switch Type {
+	case 0:
+		return "Normal"
+	case 1:
+		return "Non-PvP"
+	case 2:
+		return "PvP-Enforced"
+	default:
+		return "Unknown"
+	}
+}
+
+func TimestampString(Timestamp int) string {
+	String := "Never"
+	if Timestamp > 0 {
+		Time := time.Unix(int64(Timestamp), 0)
+		String = Time.Format("Jan 02 2006, 15:04:05 MST")
+	}
+	return String
+}