simpletokenbucket.h (1481B)
1 /* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 2 -*- */ 2 /* vim: set ts=2 et sw=2 tw=80: */ 3 /* This Source Code Form is subject to the terms of the Mozilla Public 4 * License, v. 2.0. If a copy of the MPL was not distributed with this file, 5 * You can obtain one at http://mozilla.org/MPL/2.0/. */ 6 7 /* Original author: bcampen@mozilla.com */ 8 9 /* 10 * This file defines a dirt-simple token bucket class. 11 */ 12 13 #ifndef simpletokenbucket_h__ 14 #define simpletokenbucket_h__ 15 16 #include <stdint.h> 17 18 #include "m_cpp_utils.h" 19 #include "prinrval.h" 20 21 namespace mozilla { 22 23 class SimpleTokenBucket { 24 public: 25 /* 26 * Create a SimpleTokenBucket with a given maximum size and 27 * token replenishment rate. 28 * (eg; if you want a maximum rate of 5 per second over a 7 second 29 * period, call SimpleTokenBucket b(5*7, 5);) 30 */ 31 SimpleTokenBucket(size_t bucket_size, size_t tokens_per_second); 32 33 /* 34 * Attempt to acquire a number of tokens. If successful, returns 35 * |num_tokens|, otherwise returns the number of tokens currently 36 * in the bucket. 37 * Note: To get the number of tokens in the bucket, pass something 38 * like UINT32_MAX. 39 */ 40 size_t getTokens(size_t num_tokens); 41 42 protected: // Allow testing to touch these. 43 uint64_t max_tokens_; 44 uint64_t num_tokens_; 45 size_t tokens_per_second_; 46 PRIntervalTime last_time_tokens_added_; 47 48 DISALLOW_COPY_ASSIGN(SimpleTokenBucket); 49 }; 50 51 } // namespace mozilla 52 53 #endif // simpletokenbucket_h__