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50 lines
1.8 KiB
Markdown
50 lines
1.8 KiB
Markdown
# varint
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encode whole numbers to an array of [protobuf-style varint bytes](https://developers.google.com/protocol-buffers/docs/encoding#varints) and also decode them.
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```javascript
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var varint = require('varint')
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var bytes = varint.encode(300) // === [0xAC, 0x02]
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varint.decode(bytes) // 300
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varint.decode.bytesRead // 2 (the last decode() call required 2 bytes)
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```
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## api
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### varint = require('varint')
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### varint.encode(num[, output=[], offset=0]) -> array
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encodes `num` into either the array given by `offset` or a new array at `offset`
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and returns that array filled with integers.
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### varint.decode(data[, offset=0]) -> number
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decodes `data`, which can be either a buffer or array of integers, from position `offset` or default 0 and returns the decoded original integer.
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### varint.decode.bytesRead
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if you also require the length (number of bytes) that were required to decode the integer you can access it via `varint.decode.bytesRead`. this is an integer property that will tell you the number of bytes that the last .decode() call had to use to decode.
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### varint.encode.bytesWritten
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similar to `bytesRead` when encoding a number it can be useful to know how many bytes where written (especially if you pass an output array). you can access this via `varint.encode.bytesWritten` which holds the number of bytes written in the last encode.
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### varint.encodingLength(num)
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returns the number of bytes this number will be encoded as, up to a maximum of 8.
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## usage notes
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If varint is passed a buffer that does not contain a valid end
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byte, then `decode` will return undefined, and `decode.bytesRead`
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will be set to 0. If you are reading from a streaming source,
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it's okay to pass an incomplete buffer into `decode`, detect this
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case, and then concatenate the next buffer.
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# License
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MIT
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