# `ExCodecs.Compression.Snappy`
[🔗](https://github.com/AnimaLogica/codecs/blob/v0.2.4/lib/ex_codecs/compression/snappy.ex#L1)

Standalone Snappy compression codec.

This is the **registry codec** `:snappy`. It is independent of Blosc2.
Do not confuse with `ExCodecs.encode(:blosc2, data, cname: :snappy)`, which
is rejected (Snappy is not a standard C-Blosc2 inner compressor here).

## Options

  * `:max_output_size` — Maximum allowed decompressed size in bytes
    (default: 256 MiB).

## Security

Do not decompress untrusted inputs without a tight `:max_output_size`.

## Examples

    iex> {:ok, compressed} = ExCodecs.encode(:snappy, "hello world")
    iex> {:ok, decompressed} = ExCodecs.decode(:snappy, compressed)
    iex> decompressed
    "hello world"

# `__codec_info__`

Returns the registry metadata for the standalone Snappy codec.

## Arguments

This function takes no arguments.

## Returns

An `ExCodecs.Codec.t()` with these Snappy-specific fields:

  * `name: :snappy` and `category: :compression`
  * `module: ExCodecs.Compression.Snappy`
  * `native?: true` because compression runs in a NIF
  * `streaming?: false` because only complete buffers are supported
  * `configurable?: false` because this codec has no options
  * `version: "snap-1.1"` for the backend implementation

## Raises / Exceptions

This function does not invoke the NIF and does not raise.

## Examples

    iex> ExCodecs.Compression.Snappy.__codec_info__()
    %ExCodecs.Codec{
      name: :snappy,
      category: :compression,
      module: ExCodecs.Compression.Snappy,
      native?: true,
      streaming?: false,
      configurable?: false,
      version: "snap-1.1"
    }

# `decode`

Decompresses Snappy data.

## Arguments

  * `data` (`binary()`) — a standalone Snappy block, normally produced by
    `encode/2`
  * `opts` (`keyword()`) — optional `:max_output_size` (positive integer
    bytes, default 256 MiB)

## Returns

  * `{:ok, decompressed :: binary()}` on success
  * `{:error, %ExCodecs.Error{reason: :invalid_data}}` when `data` is not a
    binary, `opts` is not a list, or the NIF raises an argument error
  * `{:error, %ExCodecs.Error{reason: :invalid_options}}` when
    `:max_output_size` is not a positive integer
  * `{:error, %ExCodecs.Error{reason: :output_limit_exceeded}}` when the
    decompressed size would exceed `:max_output_size`
  * `{:error, %ExCodecs.Error{reason: :decompression_failed}}` when `data`
    is corrupt, truncated, or not a Snappy block
  * `{:error, %ExCodecs.Error{reason: :nif_not_loaded}}` when the native
    library is unavailable

## Raises / Exceptions

Guard failures and `ErlangError`/`ArgumentError` exceptions from the NIF
call are converted to error tuples. Unexpected exception classes may
propagate.

## Examples

    iex> payload = <<10, 20, 30, 40>>
    iex> {:ok, compressed} = ExCodecs.Compression.Snappy.encode(payload, [])
    iex> ExCodecs.Compression.Snappy.decode(compressed, [])
    {:ok, <<10, 20, 30, 40>>}

    iex> {:error, error} = ExCodecs.Compression.Snappy.decode("not snappy", [])
    iex> error.reason
    :decompression_failed

# `encode`

Compresses a binary with Snappy.

## Arguments

  * `data` (`binary()`) — uncompressed bytes
  * `opts` (`term()`) — ignored by this direct function; callers using the
    codec behaviour or registry API should pass the keyword list `[]`

## Returns

  * `{:ok, compressed :: binary()}` containing a standalone Snappy block
  * `{:error, %ExCodecs.Error{reason: :invalid_data}}` when `data` is not a
    binary or the NIF raises an argument error
  * `{:error, %ExCodecs.Error{reason: :compression_failed}}` when the native
    compressor fails
  * `{:error, %ExCodecs.Error{reason: :nif_not_loaded}}` when the native
    library is unavailable

## Raises / Exceptions

Data guard failures and `ErlangError`/`ArgumentError` exceptions from the NIF
call are converted to error tuples. Because `opts` is ignored, this direct
function also accepts non-list option terms. Unexpected exception classes
may propagate.

## Examples

    iex> payload = :binary.copy("event,", 25)
    iex> {:ok, compressed} = ExCodecs.Compression.Snappy.encode(payload, [])
    iex> is_binary(compressed)
    true
    iex> ExCodecs.Compression.Snappy.decode(compressed, [])
    {:ok, payload}

---

*Consult [api-reference.md](api-reference.md) for complete listing*