Move modules to Modules folder.

Modules/RSWeb/Sources/RSWeb/HTTPConditionalGetInfo.swift

@@ -0,0 +1,46 @@
+//
+//  HTTPConditionalGetInfo.swift
+//  RSWeb
+//
+//  Created by Brent Simmons on 4/11/16.
+//  Copyright © 2016 Ranchero Software, LLC. All rights reserved.
+//
+
+import Foundation
+
+public struct HTTPConditionalGetInfo: Codable, Equatable {
+	
+	public let lastModified: String?
+	public let etag: String?
+	
+	public init?(lastModified: String?, etag: String?) {
+		if lastModified == nil && etag == nil {
+			return nil
+		}
+		self.lastModified = lastModified
+		self.etag = etag
+	}
+	
+	public init?(urlResponse: HTTPURLResponse) {
+		let lastModified = urlResponse.valueForHTTPHeaderField(HTTPResponseHeader.lastModified)
+		let etag = urlResponse.valueForHTTPHeaderField(HTTPResponseHeader.etag)
+		self.init(lastModified: lastModified, etag: etag)
+	}
+
+	public init?(headers: [AnyHashable : Any]) {
+		let lastModified = headers[HTTPResponseHeader.lastModified] as? String
+		let etag = headers[HTTPResponseHeader.etag] as? String
+		self.init(lastModified: lastModified, etag: etag)
+	}
+	
+	public func addRequestHeadersToURLRequest(_ urlRequest: inout URLRequest) {
+		// Bug seen in the wild: lastModified with last possible 32-bit date, which is in 2038. Ignore those.
+		// TODO: drop this check in late 2037.
+		if let lastModified = lastModified, !lastModified.contains("2038") {
+			urlRequest.addValue(lastModified, forHTTPHeaderField: HTTPRequestHeader.ifModifiedSince)
+		}
+		if let etag = etag {
+			urlRequest.addValue(etag, forHTTPHeaderField: HTTPRequestHeader.ifNoneMatch)
+		}
+	}
+}