Zarr Extensions

Appearance

Vlen-bytes codec ​

Defines an array -> bytes codec that serializes variable-length byte string arrays.

Codec name ​

The value of the name member in the codec object MUST be vlen-bytes.

Configuration parameters ​

None.

Example ​

For example, the array metadata below specifies that the array contains variable-length byte strings:

json
{
    "data_type": "bytes",
    "codecs": [{
        "name": "vlen-bytes"
    }],
}

Format and algorithm ​

This is a array -> bytes codec.

This codec is only compatible with the "bytes" data type.

In the encoded format, each chunk is prefixed with a 32-bit little-endian unsigned integer (u32le) that specifies the number of elements in the chunk. This prefix is followed by a sequence of encoded elements in lexicographical order. Each element in the sequence is encoded by a u32le representing the number of bytes followed by the bytes themselves.

See https://numcodecs.readthedocs.io/en/stable/other/vlen.html#vlenbytes for details about the encoding.

Change log ​

No changes yet.

Current maintainers ​