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    @fry/bits

    1.0.2 • Public • Published

    bits – Bits <3 Buffers

    A tool for twiddling bits in buffers

    Installation

    npm install --save @fry/bits

    Usage

    Create a 0-filled bit-buffer with a length of any given bit-length

    const { Bits } = require('bits');
    const bits = new Bits(15 * 8); // 15 bytes capacity

    Or reference an already exisiting Buffer

    const buffer = Buffer.from([0xff, 0x00, 0xff, 0x00]);
    const bits = new Bits(buffer);

    There are also convenience functions to create prefilled buffers (note that these use byte-length arguments)

    const bits = Bits.alloc(6, 0xaa); // 6 * 8 bits capacity, with 0b10101010... repeated for all bits
    const bits = Bits.from('Yml0YnVm', 'base64'); // 48 bits capacity prefilled with data

    After instantiating the bit-buffer you can begin manipulating the bits

    const bits = new Bits(2 * 8);
     
    // Write some bits, jump to the beginning of the buffer and read all bits
    const value = bits
        .write(7, 3)
        .write(0x55, 7)
        .write(0b10, 2)
        .seek(0)
        .read(12); // value = 0b111101010110
     
    // Turn on bit 4 and 5
    bits.insert(0b11, 2, 4);
     
    // Read the same 2 bits, not moving the offset
    bits.peek(2, 4); // 0b11
     
    // Get bit 4
    bits.getBit(4); // 0b1
     
    // Set bit 5 to 1
    bits.setBit(5);
     
    // Test if bit 5 is 1
    bits.testBit(5); // true
     
    // Clear bit 5 and flip bit 6
    bits
        .clearBit(5)
        .flipBit(6);
     
    // Stringify the buffer (e.g. ascii, utf8, ucs2, base64, binary, hex)
    bits.toString('hex'); // 'fb60'

    Install

    npm i @fry/bits

    DownloadsWeekly Downloads

    34

    Version

    1.0.2

    License

    MIT

    Unpacked Size

    11.6 kB

    Total Files

    5

    Last publish

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