1  const emptyBuffer = Buffer.allocUnsafe(0)
 2  
 3  export class BufferReader {
 4    private buffer: Buffer = emptyBuffer
 5  
 6    // TODO(bmc): support non-utf8 encoding?
 7    private encoding: string = 'utf-8'
 8  
 9    constructor(private offset: number = 0) {}
10  
11    public setBuffer(offset: number, buffer: Buffer): void {
12      this.offset = offset
13      this.buffer = buffer
14    }
15  
16    public int16(): number {
17      const result = this.buffer.readInt16BE(this.offset)
18      this.offset += 2
19      return result
20    }
21  
22    public byte(): number {
23      const result = this.buffer[this.offset]
24      this.offset++
25      return result
26    }
27  
28    public int32(): number {
29      const result = this.buffer.readInt32BE(this.offset)
30      this.offset += 4
31      return result
32    }
33  
34    public uint32(): number {
35      const result = this.buffer.readUInt32BE(this.offset)
36      this.offset += 4
37      return result
38    }
39  
40    public string(length: number): string {
41      const result = this.buffer.toString(this.encoding, this.offset, this.offset + length)
42      this.offset += length
43      return result
44    }
45  
46    public cstring(): string {
47      const start = this.offset
48      let end = start
49      // eslint-disable-next-line no-empty
50      while (this.buffer[end++] !== 0) {}
51      this.offset = end
52      return this.buffer.toString(this.encoding, start, end - 1)
53    }
54  
55    public bytes(length: number): Buffer {
56      const result = this.buffer.slice(this.offset, this.offset + length)
57      this.offset += length
58      return result
59    }
60  }