frostfs-node/pkg/policy/grammar.ebnf

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EBNF
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Policy ::=
RepStmt, [RepStmt],
CbtStmt?,
[SelectStmt],
[FilterStmt],
;
RepStmt ::=
'REP', Number1, (* number of object replicas *)
('AS', Ident)? (* optional selector name *)
;
CbtStmt ::= 'CBF', Number1 (* container backup factor *)
;
SelectStmt ::=
'SELECT', Number1, (* number of nodes to select without container backup factor *)
('IN', Clause?, Ident)?, (* bucket name *)
FROM, (Ident | '*'), (* filter reference or whole netmap *)
('AS', Ident)? (* optional selector name *)
;
Clause ::=
'SAME' (* nodes from the same bucket *)
| 'DISTINCT' (* nodes from distinct buckets *)
;
FilterStmt ::=
'FILTER', AndChain, ['OR', AndChain],
'AS', Ident (* obligatory filter name *)
;
AndChain ::=
Expr, ['AND', Expr]
;
Expr ::=
'@' Ident (* filter reference *)
| Ident, Op, Value (* attribute filter *)
;
Op ::= 'EQ' | 'NE' | 'GE' | 'GT' | 'LT' | 'LE'
;
Value ::= Ident | Number | String
;
Number1 ::= Digit1 [Digit];
Number ::= Digit [Digit];
Digit1 ::= '1' | '2' | '3' | '4' | '5' | '6' | '7' | '8' | '9' ;
Digit ::= '0' | Digit1;