javascript - Send text and binary via websocket - Stack Overflow

Is there any way to send text and binary in one request via websocket? For example: file name (text) and file content (binary)

I can send them as string like:

JSON.stringify({filename: "test.dat", filecontent: data});

But it is a lot slower than sending only file content as binary (arraybuffer).

Is there any way to send text and binary in one request via websocket? For example: file name (text) and file content (binary)

I can send them as string like:

JSON.stringify({filename: "test.dat", filecontent: data});

But it is a lot slower than sending only file content as binary (arraybuffer).

• javascript
• websocket

Share Improve this question Follow asked Jun 24, 2016 at 22:01 potenterpotenter 5511 silver badge99 bronze badges 3

• Maybe you want to look at a different data interchange format that has native support for binary data, such as MsgPack. – mpen Commented Jun 24, 2016 at 22:05
• @mpen - webSocket supports binary data. – jfriend00 Commented Jun 24, 2016 at 22:36
• @jfriend00 Right.. I'm saying instead of using JSON.stringify use msgpack.encode. – mpen Commented Jun 24, 2016 at 23:21

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1 Answer 1

Sorted by: Reset to default 7

Remember that binary is just encoded data. This is less a JavaScript question and more an encoding question. Here's how I would do it.

Set aside 32 bits (representing one integer) at the beginning of your request to specify the bit length of test.dat. Then bine this with your two data sources. Your payload will look like this:

TEXT_LENGTH + TEST.DAT AS BINARY + FILECONTENT AS BINARY

Then get back the data as an array buffer. Use

textLengthBits = parseInt(arrBuffer.slice(0,32), 2);

To get the length of the text. Then slice again,

textBits = arrBuffer.slice(32, 32 + textLengthBits)

To get the text. The remaining bits are your file.

fileBits = arrBuffer.slice(32 + textLengthBits);