lib/token-bucket.h

   1 /*
   2  * Copyright (c) 2012 Nicira, Inc.
   3  *
   4  * Licensed under the Apache License, Version 2.0 (the "License");
   5  * you may not use this file except in compliance with the License.
   6  * You may obtain a copy of the License at:
   7  *
   8  *     http://www.apache.org/licenses/LICENSE-2.0
   9  *
  10  * Unless required by applicable law or agreed to in writing, software
  11  * distributed under the License is distributed on an "AS IS" BASIS,
  12  * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
  13  * See the License for the specific language governing permissions and
  14  * limitations under the License.
  15  */
  16
  17 #ifndef TOKEN_BUCKET_H
  18 #define TOKEN_BUCKET_H 1
  19
  20 #include <limits.h>
  21 #include <stdbool.h>
  22
  23 struct token_bucket {
  24     /* Configuration settings. */
  25     unsigned int rate;          /* Tokens added per millisecond. */
  26     unsigned int burst;         /* Max cumulative tokens credit. */
  27
  28     /* Current status. */
  29     unsigned int tokens;        /* Current number of tokens. */
  30     long long int last_fill;    /* Last time tokens added. */
  31 };
  32
  33 #define TOKEN_BUCKET_INIT(RATE, BURST) { RATE, BURST, 0, LLONG_MIN }
  34
  35 void token_bucket_init(struct token_bucket *,
  36                        unsigned int rate, unsigned int burst);
  37 void token_bucket_set(struct token_bucket *,
  38                        unsigned int rate, unsigned int burst);
  39 bool token_bucket_withdraw(struct token_bucket *, unsigned int n);
  40 void token_bucket_wait(struct token_bucket *, unsigned int n);
  41
  42 #endif /* token-bucket.h */