Glossary

Some words in these docs carry more than one meaning. Each entry says which sense applies where, and links to the page that explains it.

data model

A Data subclass, or an instance of one: a protocol’s fields as parsed values, which Protocol.info returns, as against the raw octets of Protocol.data. Its base, Info, models the library’s other records too, such as the reassembly ones; New Protocol explains data models.

default engine

The engine that engine='default' (also spelled 'pcapkit') selects, and the one an unknown or unavailable engine falls back to: the built-in PCAP and PCAPNG readers, picked by the input’s magic number (Built-in Engines).

info

On a protocol, Protocol.info: its data model, stored in the enclosing layer’s data model under Protocol.info_name (Root Protocol). Elsewhere, an Info instance, such as the reasm.tcp.packet record that reassembly takes as info (Info Class).

registry

One of these, told apart by context:

• an upstream registry, such as an IANA protocol number registry, that the crawlers fetch (Vendor Crawlers);

• the pcapkit.const enumeration generated from one, such as EtherType (Constant Enumerations);

• a dispatch table from a code or name to the class that handles it, such as Protocol.__proto__ or Extractor.__engine__, and the registration functions that write to one (Registry Management);

• EnumMeta.registry, the mapping from an enumeration member to the schema that parses it.

schema

A Schema subclass, which lays out a protocol header’s fields as they sit on the wire, or an instance of one: the header as read or built, which Protocol.schema returns. It is not the data model; New Protocol explains the pair.