include/SPTDataLoader/SPTDataLoaderRateLimiter.h

/*
 Copyright Spotify AB.
 SPDX-License-Identifier: Apache-2.0
 */

#import <Foundation/Foundation.h>

@class SPTDataLoaderRequest;

NS_ASSUME_NONNULL_BEGIN

/**
 A rate limiter for configuring custom rates on a per service basis
 @discussion A service is defined as the scheme, host and first path component of the URL
 */
@interface SPTDataLoaderRateLimiter : NSObject

/**
 Class constructor
 @param requestsPerSecond The number of requests per second as a default to allow for a service
 */
+ (instancetype)rateLimiterWithDefaultRequestsPerSecond:(double)requestsPerSecond;

/**
 Finds the earliest time until a request can be executed
 @param request The request pending for execution
 @discussion A result of 0.0 means the request can be executed immediately
 */
- (NSTimeInterval)earliestTimeUntilRequestCanBeExecuted:(SPTDataLoaderRequest *)request;
/**
 Tells the rate limiter a request is currently being executed
 @param request The request being executed
 */
- (void)executedRequest:(SPTDataLoaderRequest *)request;
/**
 The amount of requests per second that are allowed to be executed on a URL
 @param URL The URL to check the requests per second for
 */
- (double)requestsPerSecondForURL:(NSURL *)URL;
/**
 Set the requests per second that are allowed to be executed on a URL
 @param requestsPerSecond The number of requests per second to accept
 @param URL The URL to check the requests per second for
 */
- (void)setRequestsPerSecond:(double)requestsPerSecond forURL:(NSURL *)URL;
/**
 Set the amount of time to wait until retrying for a given URL
 @param absoluteTime The time when the retry after can be realised
 @param URL The URL to set the retry after
 */
- (void)setRetryAfter:(NSTimeInterval)absoluteTime forURL:(NSURL *)URL;

@end

NS_ASSUME_NONNULL_END