stream-reader-async

stream-reader-async

Wraps a readable stream with a bunch of helper buffer-like methods that can be used asynchronously with async/await.

This results in an interesting blend between streams, buffers and promises that's very useful when parsing binary data.

The reader position is updated along with how many bytes you read.

API Reference

AsyncStreamReader(stream)

Constructs a new stream reader from a stream.

closed

Returns whether the stream has finished reading. This property may be removed in a future release.

read(byteCount)

Returns a new buffer of size byteCount and advances the stream position that same amount.

readByte()

Returns the next byte and advances the stream position by one. Equal to calling read(1)[0]

readBoolean()

Reads the next byte and returns whether it's not equal to 0.

read7BitEncodedInt()

Reads a 7-bit encoded integer. This is not the same as a varint, as the order is not reversed before the final binary is added.

A byte is read, if its most significant bit is a 1, there is another byte to be consumed. The other 7 bits are added to the number.

1111111 11100010 11111011 01110101
 111111  1100010  1111011  1110101

111111110001011110111110101 // 133742069

readString(strlen, encoding = utf8)

Reads a string of strlen. Both parameters are optional. The default encoding is utf8.

If you omit strlen, a first 7-bit integer wil be read, and it will be used as the string length to return.

Buffer methods

These methods behave exactly how Node Buffers would, except they return a promise, and don't require an offset as it will always be zero.

readInt8()

readInt16BE() / readInt16LE()

readInt32BE() / readInt32LE()

readBigInt64BE() / readBigInt64LE()

readIntBE(byteLength) / readIntLE(byteLength)

readUInt8()

readUInt16BE() / readUInt16LE()

readUInt32BE() / readUInt32LE()

readBigUInt64BE() / readBigUInt64LE()

readUIntBE(byteLength) / readUIntLE(byteLength)

readDoubleBE() / readDoubleLE()

readFloatBE() / readFloatLE()