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- extracting this package means it can be used in other components such as the asynchronous nats-queue-worker which may need to invoke functions which are scaled down to zero replicas. Ref: https://github.com/openfaas/nats-queue-worker/issues/32 Tested on Docker Swarm for scaling up, already scaled and not found error. Signed-off-by: Alex Ellis (VMware) <alexellis2@gmail.com>
64 lines
1.5 KiB
Go
64 lines
1.5 KiB
Go
// Copyright (c) OpenFaaS Author(s). All rights reserved.
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// Licensed under the MIT license. See LICENSE file in the project root for full license information.
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package scaling
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import (
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"sync"
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"time"
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)
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// FunctionMeta holds the last refresh and any other
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// meta-data needed for caching.
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type FunctionMeta struct {
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LastRefresh time.Time
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ServiceQueryResponse ServiceQueryResponse
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}
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// Expired find out whether the cache item has expired with
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// the given expiry duration from when it was stored.
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func (fm *FunctionMeta) Expired(expiry time.Duration) bool {
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return time.Now().After(fm.LastRefresh.Add(expiry))
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}
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// FunctionCache provides a cache of Function replica counts
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type FunctionCache struct {
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Cache map[string]*FunctionMeta
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Expiry time.Duration
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Sync sync.Mutex
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}
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// Set replica count for functionName
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func (fc *FunctionCache) Set(functionName string, serviceQueryResponse ServiceQueryResponse) {
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fc.Sync.Lock()
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defer fc.Sync.Unlock()
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if _, exists := fc.Cache[functionName]; !exists {
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fc.Cache[functionName] = &FunctionMeta{}
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}
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entry := fc.Cache[functionName]
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entry.LastRefresh = time.Now()
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entry.ServiceQueryResponse = serviceQueryResponse
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}
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// Get replica count for functionName
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func (fc *FunctionCache) Get(functionName string) (ServiceQueryResponse, bool) {
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fc.Sync.Lock()
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defer fc.Sync.Unlock()
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replicas := ServiceQueryResponse{
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AvailableReplicas: 0,
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}
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hit := false
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if val, exists := fc.Cache[functionName]; exists {
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replicas = val.ServiceQueryResponse
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hit = !val.Expired(fc.Expiry)
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}
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return replicas, hit
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}
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