CalendarLib

OSCache is an open-source re-implementation of NSCache designed to be predictable and debuggable. It functions as an LRU (Least-Recently-Used) cache, meaning objects are discarded oldest-first based on their last access time.

Key behaviors:

• Automatic Eviction: It automatically empties itself when a memory warning occurs.
• NSCache Compatibility: It inherits from NSCache for easy drop-in replacement and implements all NSCache methods.
• Limitations: It does not support NSDiscardableContent; evictsObjectsWithDiscardedContent will always return NO regardless of its setting.

Thread safety behavior depends on which class you are using:

• OrderedDictionary: Inherently thread safe because it is immutable.
• MutableOrderedDictionary: Not thread safe. You must ensure that no thread attempts to read from the dictionary while another thread is writing to it.

OSCache performance depends on the cache capacity:

• When space is available: Reading, writing, and removing entries are constant time (O(1)).
• When the cache is full: Insertion time degrades to linear (O(n)), while reading and removal remain constant (O(1)).

Best Practice: Size your cache so it does not get full. If you must use a full cache, prefer a smaller size to avoid significant performance degradation during insertions.

The recommended way to install CalendarLib is using CocoaPods. Add the following line to your Podfile:

pod "CalendarLib"

OSCache requires ARC (Automatic Reference Counting). If your project does not use ARC, you must enable it specifically for the OSCache.m file:

1. Go to the Build Phases tab in your target settings.
2. Open the Compile Sources group.
3. Double-click OSCache.m.
4. Type -fobjc-arc into the popover.

If you are converting an entire project to ARC, comment out the #error line in OSCache.m before using Xcode's 'Convert to Objective-C ARC...' refactoring tool.

If you prefer not to use CocoaPods, you must manually copy the CalendarLib folder into your project. You are also required to include the source code for its two dependencies:

• OSCache
• OrderedDictionary

To use Apple's EventKit as your data source, instantiate or subclass MGCDayPlannerEKViewController or MGCMonthPlannerEKViewController.

Important: You must add the following frameworks to your Xcode project:

• EventKit.framework
• EventKitUI.framework

// Example: Using the EventKit Day Planner
let ekViewController = MGCDayPlannerEKViewController()
// Add to your view hierarchy

OSCache provides an OSCacheDelegate protocol, which is a superset of NSCacheDelegate. You can implement this protocol to gain control over the eviction process.

The optional method - (BOOL)cache:(OSCache *)cache shouldEvictObject:(id)entry; is called before an object is evicted (due to adding a new item or a memory warning). If you return NO, you can veto the eviction.

Note: This method is NOT called if you manually remove an object using -removeObjectForKey: or -removeAllObjects.

// Implementation example
- (BOOL)cache:(OSCache *)cache shouldEvictObject:(id)entry {
    // Return NO to prevent eviction of a specific object
    return YES;
}