/// <summary>
/// Memoizes provided function. Function should provide deterministic results.
/// For the same input it should return the same result.
/// Memoized function for the specific input will be called once, further calls will use cache.
/// </summary>
/// <param name="func">function to be memoized</param>
/// <param name="options">memoize options</param>
/// <typeparam name="TInput">Type of the function input value</typeparam>
/// <typeparam name="TResult">Type of the function result</typeparam>
/// <returns></returns>
public static Func <TInput, TResult> MemoizeWithDictionary <TInput, TResult>(this Func <TInput, TResult> func, MemoizeOptions options = null)
{
// create cache ("memo")
var memo = new ConcurrentDictionary <TInput, TResult>();
// wrap provided function with cache handling
// get a value from cache if it exists
// if not, call factory method
// ConcurrentDictionary will handle that internally
return(input => memo.GetOrAdd(input, func));
}
public static Func <TInput, TResult> MemoizeWithMemoryCache <TInput, TResult>(this Func <TInput, TResult> func, MemoizeOptions options = null)
{
var memCacheOptions = new MemoryCacheOptions();
options?.MemoryCacheOptions?.Invoke(memCacheOptions);
// create cache ("memo")
var memo = new MemoryCache(memCacheOptions);
// wrap provided function with cache handling
// get a value from cache if it exists
// if not, call factory method
// MemCache will handle that internally
return(input => memo.GetOrCreate(input, entry =>
{
options?.CacheEntryOptions?.Invoke(entry);
return func(input);
}));
}
/// <summary>
/// Memoizes provided function. Function should provide deterministic results.
/// For the same input it should return the same result.
/// Memoized function for the specific input will be called once, further calls will use cache.
/// </summary>
/// <param name="func">function to be memoized</param>
/// <typeparam name="TInput">Type of the function input value</typeparam>
/// <typeparam name="TResult">Type of the function result</typeparam>
/// <returns></returns>
public static Func <TInput, TResult> Memoize <TInput, TResult>(this Func <TInput, TResult> func, MemoizeOptions options = null)
{
return((options?.Type == MemoizeType.MemoryCache) ? MemoizeWithMemoryCache(func, options) : MemoizeWithDictionary(func, options));
}
