blackbull.protocol.field_grammar

blackbull.protocol.field_grammar

Shared HTTP field, authority and URI scheme grammar.

authority_is_valid = lru_cache(maxsize=256)(authority_is_valid) module-attribute

Whether value is a URI authority host [":" port] (RFC 3986 §3.2): ASCII, no userinfo, a reg-name, IPv4 or bracketed IPv6 host.

FieldError

Bases: ValueError

A field section that breaks the field grammar; the request gets 400.

field_line(line, *, check=True)

Split one HTTP/1.1 field line (no CRLF) into its lowercase tchar name and its value without edge SP/HTAB (RFC 9112 §5).

The value carries no CTL unless check is false because the caller has already proved the octets clean. Raises FieldError for obs-fold, a missing colon, whitespace before the colon, a name outside tchar, or a CTL.

field_value(raw, *, check=True)

Return raw without its edge SP/HTAB.

The result carries no CTL: raises FieldError for one, unless check is false because the caller has already proved the octets clean.

host_field_value(fields)

Return the value of the one host field in fields, or None when there is none.

fields are (name, value) pairs whose values carry no edge SP/HTAB. Raises FieldError for more than one field, an empty value, or a value that is not an authority.

if_none_match_hit(value, etag)

Whether an If-None-Match value matches etag by weak comparison: *, or any listed entity-tag with W/ ignored (RFC 9110 §13.1.2).

list_members(value)

Return the lowercase members of a comma-separated list value without OWS, empty members dropped (RFC 9110 §5.6.1). Not for case-sensitive members such as entity-tags.

media_type(value)

Return the lowercase type/subtype of a media type or media range, without its parameters (RFC 9110 §8.3.1); b'' for an empty value.

method_token_is_valid(value)

RFC 9110 §9.1 method = token (§5.6.2 token = 1*tchar).

Both transports grade their method with this — HTTP/1.1 its request line, HTTP/2 :method — so a method one of them refuses cannot run on the other.

normalized_fields(pairs)

Return pairs with every name lowercased and every value's edge SP/HTAB removed, in order.

Every returned name is lowercase tchar and every value is free of CTL. Raises FieldError for a pair that is not two bytes, a name outside tchar, or a value with a CTL.