VOL-3202: Include port capability in the port create message.
Change-Id: I7d8fbafb2db2834def1903f13a1af25eb57500e3
diff --git a/vendor/github.com/uber/jaeger-client-go/utils/rate_limiter.go b/vendor/github.com/uber/jaeger-client-go/utils/rate_limiter.go
new file mode 100644
index 0000000..bf2f131
--- /dev/null
+++ b/vendor/github.com/uber/jaeger-client-go/utils/rate_limiter.go
@@ -0,0 +1,112 @@
+// Copyright (c) 2017 Uber Technologies, Inc.
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+// http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package utils
+
+import (
+ "sync"
+ "time"
+)
+
+// RateLimiter is a filter used to check if a message that is worth itemCost units is within the rate limits.
+//
+// TODO (breaking change) remove this interface in favor of public struct below
+//
+// Deprecated, use ReconfigurableRateLimiter.
+type RateLimiter interface {
+ CheckCredit(itemCost float64) bool
+}
+
+// ReconfigurableRateLimiter is a rate limiter based on leaky bucket algorithm, formulated in terms of a
+// credits balance that is replenished every time CheckCredit() method is called (tick) by the amount proportional
+// to the time elapsed since the last tick, up to max of creditsPerSecond. A call to CheckCredit() takes a cost
+// of an item we want to pay with the balance. If the balance exceeds the cost of the item, the item is "purchased"
+// and the balance reduced, indicated by returned value of true. Otherwise the balance is unchanged and return false.
+//
+// This can be used to limit a rate of messages emitted by a service by instantiating the Rate Limiter with the
+// max number of messages a service is allowed to emit per second, and calling CheckCredit(1.0) for each message
+// to determine if the message is within the rate limit.
+//
+// It can also be used to limit the rate of traffic in bytes, by setting creditsPerSecond to desired throughput
+// as bytes/second, and calling CheckCredit() with the actual message size.
+//
+// TODO (breaking change) rename to RateLimiter once the interface is removed
+type ReconfigurableRateLimiter struct {
+ lock sync.Mutex
+
+ creditsPerSecond float64
+ balance float64
+ maxBalance float64
+ lastTick time.Time
+
+ timeNow func() time.Time
+}
+
+// NewRateLimiter creates a new ReconfigurableRateLimiter.
+func NewRateLimiter(creditsPerSecond, maxBalance float64) *ReconfigurableRateLimiter {
+ return &ReconfigurableRateLimiter{
+ creditsPerSecond: creditsPerSecond,
+ balance: maxBalance,
+ maxBalance: maxBalance,
+ lastTick: time.Now(),
+ timeNow: time.Now,
+ }
+}
+
+// CheckCredit tries to reduce the current balance by itemCost provided that the current balance
+// is not lest than itemCost.
+func (rl *ReconfigurableRateLimiter) CheckCredit(itemCost float64) bool {
+ rl.lock.Lock()
+ defer rl.lock.Unlock()
+
+ // if we have enough credits to pay for current item, then reduce balance and allow
+ if rl.balance >= itemCost {
+ rl.balance -= itemCost
+ return true
+ }
+ // otherwise check if balance can be increased due to time elapsed, and try again
+ rl.updateBalance()
+ if rl.balance >= itemCost {
+ rl.balance -= itemCost
+ return true
+ }
+ return false
+}
+
+// updateBalance recalculates current balance based on time elapsed. Must be called while holding a lock.
+func (rl *ReconfigurableRateLimiter) updateBalance() {
+ // calculate how much time passed since the last tick, and update current tick
+ currentTime := rl.timeNow()
+ elapsedTime := currentTime.Sub(rl.lastTick)
+ rl.lastTick = currentTime
+ // calculate how much credit have we accumulated since the last tick
+ rl.balance += elapsedTime.Seconds() * rl.creditsPerSecond
+ if rl.balance > rl.maxBalance {
+ rl.balance = rl.maxBalance
+ }
+}
+
+// Update changes the main parameters of the rate limiter in-place, while retaining
+// the current accumulated balance (pro-rated to the new maxBalance value). Using this method
+// instead of creating a new rate limiter helps to avoid thundering herd when sampling
+// strategies are updated.
+func (rl *ReconfigurableRateLimiter) Update(creditsPerSecond, maxBalance float64) {
+ rl.lock.Lock()
+ defer rl.lock.Unlock()
+
+ rl.updateBalance() // get up to date balance
+ rl.balance = rl.balance * maxBalance / rl.maxBalance
+ rl.creditsPerSecond = creditsPerSecond
+ rl.maxBalance = maxBalance
+}