Compresses messages according to the selected algorithm. Supported compression algorithms are: gzip, zlib, flate.
compress:algorithm: gziplevel: -1
The 'level' field might not apply to all algorithms.
string The compression algorithm to use.
number The level of compression to use. May not be applicable to all algorithms.
array An optional array of message indexes of a batch that the processor should apply to.
If left empty all messages are processed. This field is only applicable when
batching messages at the input level.
Indexes can be negative, and if so the part will be selected from the end counting backwards starting from -1.