Implement C# 7 varint writing/reading

base/ReaderBase.ts

@@ -82,4 +82,26 @@ export class ReaderBase {
 
 		return text;
 	}
+
+	public readVarint() {
+		let total = 0;
+		let shift = 0;
+		let byte = this.readUByte();
+
+		if (!(byte & 0x80)) {
+			return (byte & 0x7F);
+		} else {
+			let end = false;
+			while (!end) {
+				if (shift) {
+					byte = this.readUByte();
+				}
+				total |= ((byte & 0x7F) << shift);
+				end = !(byte & 0x80);
+				shift += 7;
+			}
+		}
+
+		return total;
+	}
 }

base/WriterBase.ts

@@ -112,4 +112,17 @@ export class WriterBase {
 
 		return this;
 	}
+
+	public writeVarint(value: number) {
+		let temp: number;
+		while (value > 0) {
+			temp = value & 0x7F;
+			if (!!(value >>= 7)) {
+				temp |= 0xB4;
+			}
+			this.writeUByte(temp);
+		}
+
+		return this;
+	}
 }

readers/IReader.ts

@@ -12,6 +12,7 @@ export interface IReader {
 	readUShortString(): string,
 	readShortString(): string,
 	readBytesAsString(bytesToRead:number): string,
+	readVarint(): number,
 	readShort(): number,
 	readUShort(): number,
 	readInt(): number,
@@ -25,4 +26,6 @@ export interface IReader {
 	readShortsAsString(shortsToRead:number): string,
 	readUString16(): string,
 	readString16(): string,
+	readArbInt(length: number): number,
+	readArbUInt(length: number): number,
 }

readers/ReaderBE.ts

@@ -106,4 +106,16 @@ export class ReaderBE extends ReaderBase implements IReader {
 
 		return text;
 	}
+
+	public readArbInt(length: number) {
+		const value = this.buffer.readIntBE(this.offset, length);
+		this.offset += length;
+		return value;
+	}
+
+	public readArbUInt(length: number) {
+		const value = this.buffer.readUIntBE(this.offset, length);
+		this.offset += length;
+		return value;
+	}
 }

readers/ReaderLE.ts

@@ -106,4 +106,16 @@ export class ReaderLE extends ReaderBase implements IReader {
 
 		return text;
 	}
+
+	public readArbInt(length: number) {
+		const value = this.buffer.readIntLE(this.offset, length);
+		this.offset += length;
+		return value;
+	}
+
+	public readArbUInt(length: number) {
+		const value = this.buffer.readUIntLE(this.offset, length);
+		this.offset += length;
+		return value;
+	}
 }

writers/IWriter.ts

@@ -12,6 +12,7 @@ export interface IWriter {
 	writeUByte(value:number): IWriter,
 	writeBool(value:boolean|number): IWriter,
 	writeStringAsBytes(text:string): IWriter,
+	writeVarint(value: number): IWriter,
 	writeShort(value:number): IWriter,
 	writeUShort(value:number): IWriter,
 	writeInt(value:number): IWriter,

writers/WriterBE.ts

@@ -173,6 +173,8 @@ export class WriterBE extends WriterBase implements IWriter {
 		return this;
 	}
 
+	// ! TODO: Implement this properly. This was a quick, hacky implementation for mc-beta-server
+	// !       as it is used in one single place in the whole game's protocol.
 	public writeJavaUTF(text: string) {
 		const dataWriter = new WriterBE();