Will Hawkins
65 lines
2.0 KiB
Swift
65 lines
2.0 KiB
Swift
// p4rse, Copyright 2026, Will Hawkins
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//
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// This file is part of p4rse.
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//
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// This file is free software: you can redistribute it and/or modify
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// it under the terms of the GNU General Public License as published by
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// the Free Software Foundation, either version 3 of the License, or
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// (at your option) any later version.
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//
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// This program is distributed in the hope that it will be useful,
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// but WITHOUT ANY WARRANTY; without even the implied warranty of
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// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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// GNU General Public License for more details.
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//
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// You should have received a copy of the GNU General Public License
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// along with this program. If not, see <https://www.gnu.org/licenses/>.
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import Common
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import Lang
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/// The runtime for a parser
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public class ParserRuntime: CustomStringConvertible {
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public var parser: ParserInstance
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init(execution: ParserInstance) {
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self.parser = execution
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}
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/// Create a parser runtime from a P4 program
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public static func create(program: Lang.Program) -> Result<ParserRuntime> {
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return switch program.starting_parser() {
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case .Ok(let parser):
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switch ParserInstance.compile(parser) {
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case .Ok(let execution): .Ok(Runtime.ParserRuntime(execution: execution))
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case .Error(let error): .Error(error)
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}
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case .Error(let error): .Error(error)
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}
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}
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/// Run the P4 parser on a given packet
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public func run() -> Result<(ParserState, ProgramExecution)> {
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return .Ok(parser.execute())
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}
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public var description: String {
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return "Runtime:\nExecution: \(parser)"
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}
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}
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/// Instances of parsers are executable
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extension ParserInstance: ParserExecution {
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public func execute() -> (ParserState, ProgramExecution) {
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var execution = self as ProgramExecution
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var c = self.start_state
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// Evaluate until the state is either accept or reject.
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while !c.done() && !execution.hasError() {
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(c, execution) = c.execute(program: execution)
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}
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return (c.current(), execution)
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}
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}
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