bserializer/dist/bufferWriter.js

A TypeScript-based serialization/deserialization library built for exploration and learning.

const DEFAULT_CHUNK_SIZE = 8192 * 8; // 64KB
export class BufferWriter {
    chunks = [];
    current;
    offset = 0;
    constructor(initialSize = DEFAULT_CHUNK_SIZE) {
        this.current = Buffer.allocUnsafe(initialSize);
    }
    ensure(size) {
        if (this.offset + size > this.current.length)
            this.flush(size);
    }
    get getChunks() {
        return this.chunks;
    }
    flush(size = 0) {
        this.chunks.push(this.current.subarray(0, this.offset));
        this.offset = 0;
        this.current = Buffer.allocUnsafe(Math.max(size, DEFAULT_CHUNK_SIZE));
    }
    writeUInt8(val) {
        this.ensure(1);
        this.current.writeUInt8(val, this.offset++);
    }
    writeUInt32LE(val) {
        this.ensure(4);
        this.current.writeUInt32LE(val, this.offset);
        this.offset += 4;
    }
    writeDoubleLE(val) {
        this.ensure(8);
        this.current.writeDoubleLE(val, this.offset);
        this.offset += 8;
    }
    writeBigInt64LE(val) {
        this.ensure(8);
        this.current.writeBigInt64LE(val, this.offset);
        this.offset += 8;
    }
    writeString(str) {
        const strBuf = Buffer.from(str, "utf8");
        this.writeBuffer(strBuf);
    }
    writeBuffer(buf) {
        this.ensure(buf.length);
        buf.copy(this.current, this.offset);
        this.offset += buf.length;
    }
    concat(buffer) {
        buffer.flush();
        this.flush();
        this.chunks.push(...buffer.getChunks);
    }
    toBuffer() {
        if (this.offset > 0)
            this.flush(); // Always flush final buffer
        if (this.chunks.length === 1)
            return this.chunks[0];
        return Buffer.concat(this.chunks);
    }
}