data_buffers

data_buffers

DataBuffer and DataBitBuffer built on top of ArrayBuffers that grows when needed.

github: https://github.com/jbluepolarbear/data_buffers npm: https://www.npmjs.com/package/data_buffers

ArrayBufferProvider

Provides a pool of reusable ArrayBuffers and provides the functionality to convert an ArrayBuffer to and from a base 64 string.

DataBuffer

A lightweight wrapper around DataView with the ability to grow the buffer as needed.

DataBitBuffer

A Data Bit Buffer View built on top of DataBuffer. Allows reading and writing values of 1-32 bits.

Usage:

const arrayBufferProvider = new ArrayBufferProvider();
const dataBuffer = new DataBuffer(arrayBufferProvider);
const sut = new DataBitBuffer(dataBuffer);
let i: number;
let value: number;

let testValues = [];
// input
for (i = 0; i < 7; ++i) {
  value = 1 << i;
  sut.setInt8(value);
  testValues.push(value);
}

for (i = 0; i < 7; ++i) {
  value = 1 << (i + 7);
  sut.setInt16(value);
  testValues.push(value);
}

for (i = 0; i < 15; ++i) {
  value = 1 << (i + 15 - 1);
  sut.setInt32(value);
  testValues.push(value);
}

for (i = 1; i < 15; ++i) {
  value = 1 << (i - 1);
  sut.setBits(i, value);
  testValues.push(value);
}

var packed = arrayBufferProvider.arrayBufferToTransportString({
  buffer: sut.getArrayBuffer(),
  length: sut.getArrayBufferOffset(),
});

var result = arrayBufferProvider.transportStringToArrayBuffer(packed);
sut.loadBuffer(result);
arrayBufferProvider.giveArrayBufferBack(result.buffer);
sut.setOffset(0);

for (i = 0; i < 7; ++i) {
  console.log(sut.getInt8());
  testValues.shift();
}

for (i = 0; i < 7; ++i) {
  console.log(sut.getInt16());
  testValues.shift();
}

for (i = 0; i < 15; ++i) {
  console.log(sut.getInt32());
  testValues.shift();
}

for (i = 1; i < 15; ++i) {
  console.log(sut.getBits(i));
  testValues.shift();
}