git ssb

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const Buffer = require('safe-buffer').Buffer
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module.exports = class BufferPipe {
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  /**
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   * Creates a new instance of a pipe
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   * @param {Buffer} buf - an optional buffer to start with
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   */
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  constructor (buf = Buffer.from([])) {
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    this.buffer = buf
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    this._bytesRead = 0
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    this._bytesWrote = 0
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  }
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  /**
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   * read `num` number of bytes from the pipe
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   * @param {Number} num
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   * @return {Buffer}
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   */
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  read (num) {
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    this._bytesRead += num
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    const data = this.buffer.subarray(0, num)
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    this.buffer = this.buffer.subarray(num)
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    return data
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  }
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  /**
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   * Wites a buffer to the pipe
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   * @param {Buffer} buf
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   */
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  write (buf) {
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    buf = Buffer.from(buf)
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    this._bytesWrote += buf.length
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    this.buffer = Buffer.concat([this.buffer, buf])
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  }
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  /**
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   * Whether or not there is more data to read from the buffer
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   * returns {Boolean}
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   */
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  get end () {
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    return !this.buffer.length
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  }
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  /**
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   * returns the number of bytes read from the stream
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   * @return {Integer}
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   */
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  get bytesRead () {
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    return this._bytesRead
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  }
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  /**
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   * returns the number of bytes wrote to the stream
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   * @return {Integer}
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   */
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  get bytesWrote () {
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    return this._bytesWrote
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  }
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}
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