Codec → Compress

Compress

Compress a string with LZ77 or LZH (Deflate), and check whether a buffer is already compressed before compressing again.

Algorithms

Algorithm	Access	Notes
LZ77	`Codec.LZ77`	Sliding window. Fast, good ratio on repetitive data.
LZH / Deflate	`Codec.LZH`	LZ77 + Huffman coding. Better ratio, slightly more CPU. Added in v2.3.

API

Codec.LZ77:Compress(data: string) → string

Codec.LZH:Compress(data: string) → string

Codec:IsCompressed(data: string) → boolean

Manual compression

local Codec  = RoExpress.Codec
local json   = game:GetService("HttpService"):JSONEncode(bigTable)
local packed = Codec.LZH:Compress(json)

print(#json, "→", #packed)  -- original vs compressed size

Checking before compress

Use Codec:IsCompressed to avoid double-compressing a buffer that was already compressed elsewhere:

if not Codec:IsCompressed(data) then
    data = Codec.LZH:Compress(data)
end

Manual vs route opt-in

Manual compression is useful when you need fine-grained control — for example, compressing data before storing it, or compressing only part of a payload. For route-level compression handled automatically by App, see Route Integration.

Size advice

Scenario	Recommendation
Large repeated-structure data (map tiles, inventories)	LZH — better ratio
High-frequency small updates	Don't compress — overhead not worth it
Binary buffer data	Use Stream instead

Compression only helps when the data has enough repetition to exploit. Always log #original vs #compressed during development to verify you're actually saving bytes.