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author | Wim <wim@42.be> | 2017-12-03 01:24:05 +0100 |
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committer | Wim <wim@42.be> | 2017-12-03 01:24:05 +0100 |
commit | ed9118b34620f1ecd5f28506328d4ffe1b04793d (patch) | |
tree | 442998012f6779446a463e402fa7c0836edcac91 /vendor/github.com/shazow/rateio/limiter.go | |
parent | 59e55cfbd5cc3c82236c5e8b95e5baff256f7143 (diff) | |
download | matterbridge-msglm-ed9118b34620f1ecd5f28506328d4ffe1b04793d.tar.gz matterbridge-msglm-ed9118b34620f1ecd5f28506328d4ffe1b04793d.tar.bz2 matterbridge-msglm-ed9118b34620f1ecd5f28506328d4ffe1b04793d.zip |
Add sshchat dependencies in vendor
Diffstat (limited to 'vendor/github.com/shazow/rateio/limiter.go')
-rw-r--r-- | vendor/github.com/shazow/rateio/limiter.go | 62 |
1 files changed, 62 insertions, 0 deletions
diff --git a/vendor/github.com/shazow/rateio/limiter.go b/vendor/github.com/shazow/rateio/limiter.go new file mode 100644 index 00000000..db5ae76c --- /dev/null +++ b/vendor/github.com/shazow/rateio/limiter.go @@ -0,0 +1,62 @@ +package rateio + +import ( + "errors" + "time" +) + +const minInt = -int(^uint(0)>>1) - 1 + +// The error returned when the read rate exceeds our specification. +var ErrRateExceeded = errors.New("Read rate exceeded.") + +// Limiter is an interface for a rate limiter. +// There are a few example limiters included in the package, but feel free to go wild with your own. +type Limiter interface { + // Apply this many bytes to the limiter, return ErrRateExceeded if the defined rate is exceeded. + Count(int) error +} + +// simpleLimiter is a rate limiter that restricts Amount bytes in Frequency duration. +type simpleLimiter struct { + Amount int + Frequency time.Duration + + numRead int + timeRead time.Time +} + +// NewSimpleLimiter creates a Limiter that restricts a given number of bytes per frequency. +func NewSimpleLimiter(amount int, frequency time.Duration) Limiter { + return &simpleLimiter{ + Amount: amount, + Frequency: frequency, + } +} + +// NewGracefulLimiter returns a Limiter that is the same as a +// SimpleLimiter but adds a grace period at the start of the rate +// limiting where it allows unlimited bytes to be read during that +// period. +func NewGracefulLimiter(amount int, frequency time.Duration, grace time.Duration) Limiter { + return &simpleLimiter{ + Amount: amount, + Frequency: frequency, + numRead: minInt, + timeRead: time.Now().Add(grace), + } +} + +// Count applies n bytes to the limiter. +func (limit *simpleLimiter) Count(n int) error { + now := time.Now() + if now.After(limit.timeRead) { + limit.numRead = 0 + limit.timeRead = now.Add(limit.Frequency) + } + limit.numRead += n + if limit.numRead > limit.Amount { + return ErrRateExceeded + } + return nil +} |