[Request] Resizable buffers

[jonbarrow]

Currently this library seems to only work with fixed size buffers, with no way to expand them. Creating a new stream with a larger buffer and copying the old data can work, but in some comtexts this isn't viable (such as if the stream is passed around to many functions by reference, and those functions need to possibly grow the size of the buffer)

I'm currently using this implementation and it seems to work well for my use case:

ensureSize(size) {
	const bitsNeeded = size * 8;
	const bitsAvailable = this.remaining;
	
	if (bitsAvailable >= bitsNeeded) {
		return;
	}

	const bitsToAdd = bitsNeeded - bitsAvailable;
	const bytesToAdd = Math.ceil(bitsToAdd / 8);

	const oldBuffer = this.#view.buffer;
	const oldView = new Uint8Array(oldBuffer);
	const oldLength = oldView.length;

	const newBuffer = new ArrayBuffer(oldLength + bytesToAdd);
	const newView = new Uint8Array(newBuffer);

	newView.set(oldView);

	this.#view = new BitView(newBuffer);
	this.#view.bigEndian = this.bigEndian;
}

Which only adds the required number of bytes such that size will fit

[rain1]

Since you already have functional example in your repository, you could make pull request to help those guys get the functionality faster.

[inolen]

We don't support resizing because ArrayBuffers can't be resized. If you want to create a new, larger buffer and then wrap it with another BitView, that's a perfectly fine solution but not something that needs to be a part of the BitView.

[jonbarrow]

If you want to create a new, larger buffer and then wrap it with another BitView, that's a perfectly fine solution but not something that needs to be a part of the BitView

The problem with this is that you still run into the issue of running out of room at some point unless you create a massive buffer to begin with, which wastes resources

because ArrayBuffers can't be resized

Yes they can

After making this issue and the PoC fix, I have since learned about ArrayBuffer.resize() which lets you resize an ArrayBuffer up to maxByteLength, and is supported by all major browsers/runtimes

Allowing BitBuffer/BitView to take in the maxByteLength and then supporting resize sounds more idiomatic than not supporting it at all imo

[inolen]

Ah, I wasn't aware that was added. So what's needed to support that exactly? It looks like if you create a resizeable ArrayBuffer, and then create the BitView with an undefined length, the internal typed array we create will auto-resize - but then I assume the writeBits function would want to honor the max byte length property instead of length for checking available space. Is there much more to it than that? That seems reasonable if so, sorry, I hadn't seen they were now somewhat resizeable.

…

On Thu, Dec 25, 2025, 3:57 PM Jonathan Barrow ***@***.***> wrote: *jonbarrow* left a comment (inolen/bit-buffer#34) <#34 (comment)> If you want to create a new, larger buffer and then wrap it with another BitView, that's a perfectly fine solution but not something that needs to be a part of the BitView The problem with this is that you still run into the issue of running out of room at some point unless you create a massive buffer to begin with, which wastes resources because ArrayBuffers can't be resized Yes they can After making this issue and the PoC fix, I have since learned about ArrayBuffer.resize() <https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/ArrayBuffer/resize> which lets you resize an ArrayBuffer up to maxByteLength, and is supported by all major browsers/runtimes — Reply to this email directly, view it on GitHub <#34 (comment)>, or unsubscribe <https://github.com/notifications/unsubscribe-auth/AADQMCGEOXWGHYZDHJWUNEL4DP3N7AVCNFSM6AAAAACOM7BJZGVHI2DSMVQWIX3LMV43OSLTON2WKQ3PNVWWK3TUHMZTMOJRGUYTKMZUHA> . You are receiving this because you modified the open/close state.Message ID: ***@***.***>