# deflate.raw

> A module of deflate's API.

Raw DEFLATE (RFC 1951) — `inflate` and `deflate`, in pure Mojo.

*Raw* DEFLATE is the compressed stream on its own: no zlib (RFC 1950) header,
no gzip (RFC 1952) wrapper, no trailing checksum. A caller that needs one of
those framings parses it itself and hands the body here — Avro's `deflate`
block codec is raw already, and Parquet's `GZIP` codec is this plus a gzip
header and trailer.

Implementing it rather than binding zlib keeps the tin free of FFI and of any
sibling dependency, so a consumer needs nothing but `-I ../deflate.mojo/src`.

`inflate` handles all three block types (stored, fixed-Huffman,
dynamic-Huffman). `deflate` emits fixed-Huffman blocks from a single-slot
hash-chain LZ77 matcher — the same "fast" strategy `snappy.mojo` uses —
which keeps the encoder small.

## Functions

### `inflate`

```mojo
def inflate(data: Span[UInt8]) -> List[UInt8]
```

Decompress a raw DEFLATE stream.

### `inflate_at`

```mojo
def inflate_at(data: Span[UInt8], mut end: Int) -> List[UInt8]
```

Decompress a DEFLATE stream, and report where it ended.

`end` is set to the offset of the first byte *after* the stream, rounded
up to a byte boundary. Callers with several streams back to back —
concatenated gzip members, for instance — need it to find the next one;
callers that do not can use `inflate`.

### `deflate`

```mojo
def deflate(data: Span[UInt8]) -> List[UInt8]
```

Compress to a raw DEFLATE stream (one fixed-Huffman block).