feat: write stream

src/core/streams/buffer.ts

@@ -71,3 +71,76 @@ export class ReadStream {
     return this.buffer.readUInt8(this.increment(1)) === 1;
   }
 }
+
+export class WriteStream {
+  private array: number[] = [];
+
+  get buffer() {
+    return Buffer.from(this.array);
+  }
+
+  constructor(buffer?: Buffer) {
+    if (buffer) this.array = Array.from(buffer);
+  }
+
+  byte(value: Uint8Array) {
+    this.array.push(...value);
+    return this;
+  }
+
+  ascii(value: string) {
+    for (let index = 0; index < value.length; index++) {
+      this.array.push(value.charCodeAt(index));
+    }
+    return this;
+  }
+
+  private uintN(bytes: number, value: number) {
+    for (let index = 0; index < bytes; index++) {
+      this.array.push((value >>> (8 * index)) & 0xff);
+    }
+    return this;
+  }
+  uint8(value: number) {
+    this.uintN(1, value);
+    return this;
+  }
+  uint16(value: number) {
+    this.uintN(2, value);
+    return this;
+  }
+  uint32(value: number) {
+    this.uintN(4, value);
+    return this;
+  }
+  uint64(value: bigint) {
+    for (let index = 0n; index < 8n; index++) {
+      this.uint8(Number((value >> (8n * index)) & 0xffn));
+    }
+    return this;
+  }
+  private intN(bytes: number, value: number) {
+    for (let index = 0; index < bytes; index++) {
+      this.array.push((value >> (8 * index)) & 0xff);
+    }
+    return this;
+  }
+  int8(value: number) {
+    this.intN(1, value);
+    return this;
+  }
+  int16(value: number) {
+    this.intN(2, value);
+    return this;
+  }
+  int32(value: number) {
+    this.intN(4, value);
+    return this;
+  }
+  int64(value: bigint) {
+    for (let index = 0n; index < 8n; index++) {
+      this.int8(Number((value >> (8n * index)) & 0xffn));
+    }
+    return this;
+  }
+}