hyparquet-compressors/src/brotliStreams.js

/**
 * @param {Uint8Array} buffer
 */
export function BrotliInput(buffer) {
  this.buffer = buffer
  this.pos = 0
}

/**
 * @param {Uint8Array} buf
 * @param {number} i
 * @param {number} count
 * @returns {number}
 */
BrotliInput.prototype.read = function(buf, i, count) {
  if (this.pos + count > this.buffer.length) {
    count = this.buffer.length - this.pos
  }

  for (let p = 0; p < count; p++)
    buf[i + p] = this.buffer[this.pos + p]

  this.pos += count
  return count
}

/**
 * @param {Uint8Array} buf
 */
export function BrotliOutput(buf) {
  this.buffer = buf
  this.pos = 0
}

/**
 * @param {Uint8Array} buf
 * @param {number} count
 * @returns {number}
 */
BrotliOutput.prototype.write = function(buf, count) {
  if (this.pos + count > this.buffer.length) throw new Error('brotli output buffer is not large enough')

  this.buffer.set(buf.subarray(0, count), this.pos)
  this.pos += count
  return count
}