Refactoring Status Menu

baRSS/Core Data/FeedMeta+Ext.m

@@ -0,0 +1,89 @@
+//
+//  The MIT License (MIT)
+//  Copyright (c) 2018 Oleg Geier
+//
+//  Permission is hereby granted, free of charge, to any person obtaining a copy of
+//  this software and associated documentation files (the "Software"), to deal in
+//  the Software without restriction, including without limitation the rights to
+//  use, copy, modify, merge, publish, distribute, sublicense, and/or sell copies
+//  of the Software, and to permit persons to whom the Software is furnished to do
+//  so, subject to the following conditions:
+//
+//  The above copyright notice and this permission notice shall be included in all
+//  copies or substantial portions of the Software.
+//
+//  THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+//  IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+//  FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+//  AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+//  LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+//  OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+//  SOFTWARE.
+
+#import "FeedMeta+Ext.h"
+#import "Feed+Ext.h"
+#import "FeedGroup+Ext.h"
+
+@implementation FeedMeta (Ext)
+
+#pragma mark - HTTP response
+
+/// Increment @c errorCount and set new @c scheduled date (2^N minutes, max. 5.7 days).
+- (void)setErrorAndPostponeSchedule {
+	if (self.errorCount < 0)
+		self.errorCount = 0;
+	int16_t n = self.errorCount + 1; // always increment errorCount (can be used to indicate bad feeds)
+	// TODO: remove logging
+	NSLog(@"ERROR: Feed download failed: %@ (errorCount: %d)", self.url, n);
+	if ([self.scheduled timeIntervalSinceNow] > 30) // forced, early update. Scheduled is still in the futute.
+		return; // Keep error counter low. Not enough time has passed (e.g., temporary server outage)
+	NSTimeInterval retryWaitTime = pow(2, (n > 13 ? 13 : n)) * 60; // 2^N (between: 2 minutes and 5.7 days)
+	self.errorCount = n;
+	[self scheduleNow:retryWaitTime];
+}
+
+- (void)setSucessfulWithResponse:(NSHTTPURLResponse*)response {
+	self.errorCount = 0; // reset counter
+	NSDictionary *header = [response allHeaderFields];
+	[self setEtag:header[@"Etag"] modified:header[@"Date"]]; // @"Expires", @"Last-Modified"
+	[self scheduleNow:self.refresh];
+}
+
+#pragma mark - Setter
+
+/// Set @c url attribute but only if value differs.
+- (void)setUrlIfChanged:(NSString*)url {
+	if (![self.url isEqualToString:url]) self.url = url;
+}
+
+/// Set @c etag and @c modified attributes. Only values that differ will be updated.
+- (void)setEtag:(NSString*)etag modified:(NSString*)modified {
+	if (![self.etag isEqualToString:etag])         self.etag = etag;
+	if (![self.modified isEqualToString:modified]) self.modified = modified;
+}
+
+/**
+ Set @c refresh and calculate new @c scheduled date.
+
+ @return @c YES if refresh interval has changed
+ */
+- (BOOL)setRefreshAndSchedule:(int32_t)refresh {
+	if (self.refresh != refresh) {
+		self.refresh = refresh;
+		[self scheduleNow:self.refresh];
+		return YES;
+	}
+	return NO;
+}
+
+/// Set next scheduled feed update or @c nil if @c refresh @c <= @c 0.
+- (void)scheduleNow:(NSTimeInterval)future {
+	if (self.refresh <= 0) { // update deactivated; manually update with force update all
+		if (self.scheduled != nil) // already nil? Avoid unnecessary core data edits
+			self.scheduled = nil;
+	} else {
+		self.scheduled = [NSDate dateWithTimeIntervalSinceNow:future];
+	}
+}
+
+@end