crypt.lz4decompress

Decompresses compressed and returns exactly expectedSize bytes.

crypt.lz4decompress(compressed: string, expectedSize: number): string

Input must be LZ4 Block format - see the page entry crypt.lz4compress to learn more.
expectedSize is the length of the original plaintext in bytes, not the length of the compressed input - you have to track and pass it yourself.

There is no integrity check - if the bytes are damaged or expectedSize is wrong,
the function still returns a string of that length without raising an error.

Parameters

Parameter	Type	Description
compressed	string	An LZ4 Block-format payload.
expectedSize	number	The desired output length in bytes (size of the original plaintext).

Returns

string - the decompressed bytes, padded or truncated to exactly expectedSize characters.
When expectedSize matches the original length, the result is the full plaintext.

Aliases

• lz4decompress

Example

In a chat-event-based Roblox game, stream Bad Apple as ASCII video over a remote at 30fps.
Reason: storing >1800 frames and parsing them would be a lot more easier if you compress the data beforehand.

Example 1

<<<<<<< HEAD
local lz4decompress = crypt.lz4decompress("test", 10)
=======
-- crypt.lz4decompress(compressed: string, expectedSize: number): string
>>>>>>> 50e30f53759b0538759af25c9b271514aa2c9290

There is no built-in integrity check. If the compressed string is malformed, or expectedSize is wrong, you get back a string that looks valid, but actually isn’t. For any data, store a hash alongside the payload (crypt.hash works) and verify after decompressing.