osc-js/src/bundle.ts

import { messageFromBuffer, messageToBuffer } from "./message";
import { OSCBundle } from "./models";
import { oscTypeConverterMap } from "./osc-types";

export function bundleFromBuffer(bytes: Buffer): OSCBundle | undefined {
    if (bytes.length < 8) {
      throw new Error('bundle has to be at least 20 bytes');
    }
  
    if (bytes.subarray(0, 7).toString('ascii') !== '#bundle') {
      throw new Error('bundle must start with #bundle');
    }
  
    const [bundleHeader, bytesAfterHeader] = oscTypeConverterMap.s.fromBuffer(bytes);
    let [timeTag, bytesAfterTimeTag] = oscTypeConverterMap.t.fromBuffer(bytesAfterHeader);
  
    if (!Array.isArray(timeTag)) {
      throw new Error('problem getting bundle time tag');
    }
  
    const bundleContents = [];
  
    let endOfBundle = false;
  
    let [contentSize, remainingBytes] = oscTypeConverterMap.i.fromBuffer(bytesAfterTimeTag);
    if (typeof contentSize === 'number') {
      while (!endOfBundle) {
        if (remainingBytes.length < contentSize) {
          throw new Error('bundle does not contain enough data');
        }
  
        const bundleContentBytes = remainingBytes.subarray(0, contentSize);
  
        if (bundleContentBytes[0] === 35) {
          // # character indicating contents is a bundle
          const content = bundleFromBuffer(bundleContentBytes);
          if (content) {
            bundleContents.push(content);
          }
        } else if (bundleContentBytes[0] === 47) {
          const content = messageFromBuffer(bundleContentBytes);
          if (content) {
            bundleContents.push(content);
          }
        } else {
          throw new Error('bundle contents does not look like a OSC message or bundle');
        }
  
        remainingBytes = remainingBytes.subarray(contentSize);
        if (remainingBytes.length === 0) {
          endOfBundle = true;
        }
      }
    }
  
    return {
      timeTag,
      contents: bundleContents,
    };
  }
  
  export function bundleToBuffer(bundle: OSCBundle): Buffer {
    const headerBuffer = oscTypeConverterMap.s.toBuffer('#bundle');
  
    if (headerBuffer === undefined) {
      throw new Error('problem encoding buffer header');
    }
  
    const timeTagBuffer = oscTypeConverterMap.t.toBuffer(bundle.timeTag);
  
    if (timeTagBuffer === undefined) {
      throw new Error('problem encoding buffer time tag');
    }
  
    const contentsBuffers: Buffer[] = [];
  
    bundle.contents.forEach((bundleContent) => {
      if ('address' in bundleContent) {
        const contentBuffer = messageToBuffer(bundleContent);
        const contentSizeBuffer = oscTypeConverterMap.i.toBuffer(contentBuffer.length);
  
        if (contentBuffer && contentSizeBuffer) {
          contentsBuffers.push(Buffer.concat([contentSizeBuffer, contentBuffer]));
        }
      }
    });
  
    return Buffer.concat([headerBuffer, timeTagBuffer, ...contentsBuffers]);
  }