ExCodecs (ex_codecs v0.2.3)

Extensible BEAM-native codec framework for Elixir.

One framework, specialized category APIs

Binary→binary registry codecs use:

ExCodecs.encode(codec_atom, binary, opts \\ [])
ExCodecs.decode(codec_atom, binary, opts \\ [])

All implementations are registered in the shared ExCodecs.CodecRegistry catalog. Category modules provide entry points suited to their data:

ExCodecs.Compression — compress/3 / decompress/3 aliases of the registry API, plus listing codecs in the compression category
ExCodecs.Spatial — domain types and formats for point clouds / Gaussians (struct↔format). Call ExCodecs.Spatial.encode/2 and ExCodecs.Spatial.decode/2

The APIs belong to one framework and share tagged results and %ExCodecs.Error{} conventions. They are not overloaded because their input shapes differ. Registry encoding and decoding keep the codec atom first:

{:ok, compressed} = ExCodecs.encode(:zstd, data)
{:ok, decoded} = ExCodecs.decode(:zstd, compressed)

Registry codecs

Codec	Notes
`:zstd`	Pure-Rust Zstd (`structured-zstd`)
`:lz4`	Size-prepended `lz4_flex` blocks
`:snappy`	Standalone Snappy codec
`:bzip2`	Pure-Rust bzip2
`:blosc2`	C-Blosc2 chunk (not super-chunk / B2ND / `.b2frame`)

Snappy vs Blosc2 `cname: :snappy`

ExCodecs.encode(:snappy, data) — supported (standalone codec).
ExCodecs.encode(:blosc2, data, cname: :snappy) — rejected (:invalid_options). Snappy is not a standard C-Blosc2 inner compressor in this build; use :lz4, :blosclz, :zstd, :lz4hc, or :zlib inside Blosc2.

Blosc2 “chunk only”

:blosc2 compresses one buffer → one Blosc2 chunk. That matches normal ExCodecs use (and python-blosc2 compress/decompress on a single buffer). It does not open .b2frame files, append super-chunks, or slice B2ND arrays. For large data, chunk yourself and store multiple blobs.

Quick start

# Registry compression
{:ok, c} = ExCodecs.encode(:zstd, "hello")
{:ok, "hello"} = ExCodecs.decode(:zstd, c)

# Category alias
{:ok, c} = ExCodecs.Compression.compress(:lz4, data)

# Spatial category
alias ExCodecs.Spatial.{Point, PointCloud}
cloud = PointCloud.new([Point.new(0.0, 0.0, 0.0)])
{:ok, ply} = ExCodecs.Spatial.encode(cloud, format: :ply)
{:ok, cloud} = ExCodecs.Spatial.decode(ply, format: :ply)

ExCodecs.available_codecs()
#=> [:blosc2, :bzip2, :gsplat, :lz4, :ply, :snappy, :spatial_binary, :zstd]

Error policy

Public encode/decode paths return {:ok, _} or {:error, %ExCodecs.Error{}}. They do not raise for invalid codecs, bad options, or compression failure. (NIF load failure is converted to {:error, %Error{reason: :nif_not_loaded}}.)

Summary

Functions

available_codecs()

Lists registered codec atoms that are available at runtime.

available_codecs(category)

Lists available codec names in one category.

codec_info(codec)

Returns metadata for a registered codec.

decode(codec, data, opts \\ [])

Decodes a binary with a registered codec.

encode(codec, data, opts \\ [])

Encodes a binary with a registered codec.

stream_decode(source, opts)

Lazily enumerates spatial primitives from a file path or binary.

stream_encode(enumerable, opts)

Encodes an enumerable of spatial %Point{} / %Gaussian{} values.

supports?(codec)

Returns whether a shared-catalog codec is available.

Functions

available_codecs()

@spec available_codecs() :: [atom()]

Lists registered codec atoms that are available at runtime.

Arguments

None.

Returns

A sorted [atom()] containing every shared-catalog entry whose implementation module is non-nil, including binary and spatial codecs.

Raises

May raise ArgumentError if the registry ETS table has not been started.

Examples

iex> :blosc2 in ExCodecs.available_codecs()
true

available_codecs(category)

@spec available_codecs(atom()) :: [atom()]

Lists available codec names in one category.

Arguments

category — category atom such as :compression or :spatial

Returns

A sorted list of available names in that category.

Raises

Raises FunctionClauseError for a non-atom category and may raise ArgumentError if the shared catalog has not started.

Examples

iex> ExCodecs.available_codecs(:spatial)
[:gsplat, :ply, :spatial_binary]

codec_info(codec)

@spec codec_info(atom()) :: {:ok, ExCodecs.Codec.t()} | {:error, :unsupported_codec}

Returns metadata for a registered codec.

Arguments

codec (atom()) — registry key whose metadata is requested

Returns

{:ok, ExCodecs.Codec.t()} — name, category, interface, module, capability flags, and backend version; unavailable codecs are returned with module: nil
{:error, :unsupported_codec} — not registered (note: bare atom, not %Error{})

Raises

Raises FunctionClauseError if codec is not an atom. May raise ArgumentError if the registry ETS table has not been started.

Examples

iex> {:ok, info} = ExCodecs.codec_info(:zstd)
iex> info.name
:zstd

iex> {:ok, info} = ExCodecs.codec_info(:zstd)
iex> info.category
:compression

decode(codec, data, opts \\ [])

@spec decode(atom(), binary(), keyword()) ::
  {:ok, binary()} | {:error, ExCodecs.Error.t()}

Decodes a binary with a registered codec.

First argument is always a codec atom. For spatial formats use ExCodecs.Spatial.decode/2 with format:.

Arguments

codec (atom()) — registry key, such as :zstd
data (binary()) — encoded payload
opts (keyword()) — codec-specific decoding options; defaults to []

Returns

{:ok, binary()} — decoded payload
{:error, %ExCodecs.Error{reason: :unsupported_codec}} — codec is not registered
{:error, %ExCodecs.Error{reason: :codec_unavailable}} — codec has no implementation module
{:error, %ExCodecs.Error{reason: :invalid_data}} — arguments have the wrong shape or the codec rejects the input
{:error, %ExCodecs.Error{reason: :invalid_options}} — options are invalid, including the mistaken decode(binary, format: format) shape
{:error, %ExCodecs.Error{reason: :decompression_failed}} — payload is corrupt or the native decoder failed
{:error, %ExCodecs.Error{reason: :nif_not_loaded}} — native library is unavailable

Raises

Does not raise for the documented failure modes. It may raise ArgumentError if the registry has not been started, or propagate an unexpected exception from a third-party registered codec.

Examples

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

encode(codec, data, opts \\ [])

@spec encode(atom(), binary(), keyword()) ::
  {:ok, binary()} | {:error, ExCodecs.Error.t()}

Encodes a binary with a registered codec.

Primary framework entry point. First argument is always a codec atom (:zstd, :lz4, …). For spatial structs use ExCodecs.Spatial.encode/2.

Arguments

codec (atom()) — registry key, such as :zstd
data (binary()) — unencoded bytes
opts (keyword()) — codec-specific options; defaults to []

Returns

{:ok, binary()} — encoded payload
{:error, %ExCodecs.Error{reason: :unsupported_codec}} — codec is not registered
{:error, %ExCodecs.Error{reason: :codec_unavailable}} — codec is registered without an implementation module
{:error, %ExCodecs.Error{reason: :invalid_data}} — data is not a binary, arguments do not have the documented shape, or the codec rejects the input
{:error, %ExCodecs.Error{reason: :invalid_options}} — codec-specific option validation failed
{:error, %ExCodecs.Error{reason: :compression_failed}} — native encoder failed
{:error, %ExCodecs.Error{reason: :nif_not_loaded}} — native library is unavailable

Raises

Does not raise for the documented failure modes, including malformed public arguments. It may raise ArgumentError if the registry has not been started, or propagate an unexpected exception from a third-party registered codec.

Examples

iex> {:ok, compressed} = ExCodecs.encode(:zstd, "hello world")
iex> is_binary(compressed)
true

iex> {:ok, compressed} = ExCodecs.encode(:zstd, "hello world", level: 3)
iex> is_binary(compressed)
true

iex> {:error, %ExCodecs.Error{reason: :unsupported_codec}} =
...>   ExCodecs.encode(:not_a_codec, "x")
iex> true
true

stream_decode(source, opts)

@spec stream_decode(
  Path.t() | binary(),
  keyword()
) :: Enumerable.t()

Lazily enumerates spatial primitives from a file path or binary.

Delegates to ExCodecs.Spatial.stream_decode/2. Not used for registry compression codecs. File sources stream record-by-record; in-memory binaries materialize through decode/2 (or use chunked Rust unpack when the spatial NIF is loaded).

Arguments

source (Path.t() | binary()) — filesystem path or encoded binary; use the :source option to disambiguate a binary that is also a path
opts (keyword()) — requires :format (:ply, :spatial_binary, or :gsplat); optionally accepts :source (:auto, :file, or :binary) and format-specific options

Returns

An Enumerable.t() yielding %ExCodecs.Spatial.Point{} or %ExCodecs.Spatial.Gaussian{} values. On failure it yields exactly one {:error, %ExCodecs.Error{}} element with one of these reasons:

:invalid_options — required :format is absent
:unsupported_codec — the format is not stream-decodable
:io_error — a file source cannot be read
:invalid_data — the encoded payload is malformed or truncated

Raises

Missing or invalid format values and file read errors are yielded as error tuples. Passing non-keyword opts raises FunctionClauseError; enumeration may propagate unexpected exceptions from the source enumerable or runtime.

Examples

iex> alias ExCodecs.Spatial.{Point, PointCloud}
iex> {:ok, bin} = ExCodecs.Spatial.encode(PointCloud.new([Point.new(1.0, 2.0, 3.0)]), format: :ply)
iex> [%Point{x: x} | _] = ExCodecs.stream_decode(bin, format: :ply) |> Enum.to_list()
iex> x == 1.0
true

stream_encode(enumerable, opts)

@spec stream_encode(
  Enumerable.t(),
  keyword()
) :: {:ok, binary()} | {:error, ExCodecs.Error.t()}

Encodes an enumerable of spatial %Point{} / %Gaussian{} values.

Delegates to ExCodecs.Spatial.stream_encode/2. Collects the enumerable (format headers need a count). Not for registry compression codecs.

Arguments

enumerable (Enumerable.t()) — points or Gaussians, all of one type
opts (keyword()) — requires :format (:ply, :spatial_binary, or :gsplat) and may contain format-specific options

Returns

{:ok, binary()} — encoded spatial payload
{:error, %ExCodecs.Error{reason: :invalid_options}} — required format is absent or a format option is invalid
{:error, %ExCodecs.Error{reason: :unsupported_codec}} — format is unknown
{:error, %ExCodecs.Error{reason: :invalid_data}} — items are mixed, malformed, unsupported, or include an error tuple

Raises

Returns error tuples for documented format, option, and item failures. Passing non-keyword opts raises FunctionClauseError. A value that does not implement Enumerable raises Protocol.UndefinedError, and exceptions raised while enumerating propagate.

Examples

iex> alias ExCodecs.Spatial.Point
iex> {:ok, bin} = ExCodecs.stream_encode([Point.new(0.0, 0.0, 0.0)], format: :ply)
iex> is_binary(bin)
true

supports?(codec)

@spec supports?(atom()) :: boolean()

Returns whether a shared-catalog codec is available.

Arguments

codec (atom()) — registry key to test

Returns

true if codec is registered with a non-nil implementation module; otherwise false.

Raises

Raises FunctionClauseError if codec is not an atom. May raise ArgumentError if the registry ETS table has not been started.

Examples

iex> ExCodecs.supports?(:zstd)
true

iex> ExCodecs.supports?(:nonexistent)
false

ExCodecs (ex_codecs v0.2.3)

One framework, specialized category APIs

Registry codecs

Snappy vs Blosc2 cname: :snappy

Blosc2 “chunk only”

Quick start

Error policy

Summary

Functions

Functions

available_codecs()

Arguments

Returns

Raises

Examples

available_codecs(category)

Arguments

Returns

Raises

Examples

codec_info(codec)

Arguments

Returns

Raises

Examples

decode(codec, data, opts \\ [])

Arguments

Returns

Raises

Examples

encode(codec, data, opts \\ [])

Arguments

Returns

Raises

Examples

stream_decode(source, opts)

Arguments

Returns

Raises

Examples

stream_encode(enumerable, opts)

Arguments

Returns

Raises

Examples

supports?(codec)

Arguments

Returns

Raises

Examples

Snappy vs Blosc2 `cname: :snappy`