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dataproxy: added caching of datasources when doing data proxy requests, #9078

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This commit is contained in:
Torkel Ödegaard
2017-08-23 13:31:26 +02:00
parent bcb3dfac9f
commit 4f9fbcc211
12 changed files with 155 additions and 107 deletions
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vendor/github.com/patrickmn/go-cache/CONTRIBUTORS
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@@ -6,3 +6,4 @@ code was contributed.)
Dustin Sallings <dustin@spy.net>
Jason Mooberry <jasonmoo@me.com>
Sergey Shepelev <temotor@gmail.com>
Alex Edwards <ajmedwards@gmail.com>
vendor/github.com/patrickmn/go-cache/LICENSE
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+1 -1
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@@ -1,4 +1,4 @@
Copyright (c) 2012-2016 Patrick Mylund Nielsen and the go-cache contributors
Copyright (c) 2012-2017 Patrick Mylund Nielsen and the go-cache contributors
Permission is hereby granted, free of charge, to any person obtaining a copy
of this software and associated documentation files (the "Software"), to deal
vendor/github.com/patrickmn/go-cache/README.md
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@@ -20,86 +20,62 @@ one) to recover from downtime quickly. (See the docs for `NewFrom()` for caveats
### Usage
```go
import (
"fmt"
"github.com/patrickmn/go-cache"
"time"
)
import (
"fmt"
"github.com/patrickmn/go-cache"
"time"
)
func main() {
func main() {
// Create a cache with a default expiration time of 5 minutes, and which
// purges expired items every 10 minutes
c := cache.New(5*time.Minute, 10*time.Minute)
// Create a cache with a default expiration time of 5 minutes, and which
// purges expired items every 30 seconds
c := cache.New(5*time.Minute, 30*time.Second)
// Set the value of the key "foo" to "bar", with the default expiration time
c.Set("foo", "bar", cache.DefaultExpiration)
// Set the value of the key "foo" to "bar", with the default expiration time
c.Set("foo", "bar", cache.DefaultExpiration)
// Set the value of the key "baz" to 42, with no expiration time
// (the item won't be removed until it is re-set, or removed using
// c.Delete("baz")
c.Set("baz", 42, cache.NoExpiration)
// Get the string associated with the key "foo" from the cache
foo, found := c.Get("foo")
if found {
fmt.Println(foo)
}
// Since Go is statically typed, and cache values can be anything, type
// assertion is needed when values are being passed to functions that don't
// take arbitrary types, (i.e. interface{}). The simplest way to do this for
// values which will only be used once--e.g. for passing to another
// function--is:
foo, found := c.Get("foo")
if found {
MyFunction(foo.(string))
}
// This gets tedious if the value is used several times in the same function.
// You might do either of the following instead:
if x, found := c.Get("foo"); found {
foo := x.(string)
// ...
}
// or
var foo string
if x, found := c.Get("foo"); found {
foo = x.(string)
}
// ...
// foo can then be passed around freely as a string
// Want performance? Store pointers!
c.Set("foo", &MyStruct, cache.DefaultExpiration)
if x, found := c.Get("foo"); found {
foo := x.(*MyStruct)
// ...
}
// If you store a reference type like a pointer, slice, map or channel, you
// do not need to run Set if you modify the underlying data. The cached
// reference points to the same memory, so if you modify a struct whose
// pointer you've stored in the cache, retrieving that pointer with Get will
// point you to the same data:
foo := &MyStruct{Num: 1}
c.Set("foo", foo, cache.DefaultExpiration)
// ...
x, _ := c.Get("foo")
foo := x.(*MyStruct)
fmt.Println(foo.Num)
// ...
foo.Num++
// ...
x, _ := c.Get("foo")
foo := x.(*MyStruct)
foo.Println(foo.Num)
// will print:
// 1
// 2
// Set the value of the key "baz" to 42, with no expiration time
// (the item won't be removed until it is re-set, or removed using
// c.Delete("baz")
c.Set("baz", 42, cache.NoExpiration)
// Get the string associated with the key "foo" from the cache
foo, found := c.Get("foo")
if found {
fmt.Println(foo)
}
// Since Go is statically typed, and cache values can be anything, type
// assertion is needed when values are being passed to functions that don't
// take arbitrary types, (i.e. interface{}). The simplest way to do this for
// values which will only be used once--e.g. for passing to another
// function--is:
foo, found := c.Get("foo")
if found {
MyFunction(foo.(string))
}
// This gets tedious if the value is used several times in the same function.
// You might do either of the following instead:
if x, found := c.Get("foo"); found {
foo := x.(string)
// ...
}
// or
var foo string
if x, found := c.Get("foo"); found {
foo = x.(string)
}
// ...
// foo can then be passed around freely as a string
// Want performance? Store pointers!
c.Set("foo", &MyStruct, cache.DefaultExpiration)
if x, found := c.Get("foo"); found {
foo := x.(*MyStruct)
// ...
}
}
```
### Reference
vendor/github.com/patrickmn/go-cache/cache.go
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@@ -135,6 +135,36 @@ func (c *cache) Get(k string) (interface{}, bool) {
return item.Object, true
}
// GetWithExpiration returns an item and its expiration time from the cache.
// It returns the item or nil, the expiration time if one is set (if the item
// never expires a zero value for time.Time is returned), and a bool indicating
// whether the key was found.
func (c *cache) GetWithExpiration(k string) (interface{}, time.Time, bool) {
c.mu.RLock()
// "Inlining" of get and Expired
item, found := c.items[k]
if !found {
c.mu.RUnlock()
return nil, time.Time{}, false
}
if item.Expiration > 0 {
if time.Now().UnixNano() > item.Expiration {
c.mu.RUnlock()
return nil, time.Time{}, false
}
// Return the item and the expiration time
c.mu.RUnlock()
return item.Object, time.Unix(0, item.Expiration), true
}
// If expiration <= 0 (i.e. no expiration time set) then return the item
// and a zeroed time.Time
c.mu.RUnlock()
return item.Object, time.Time{}, true
}
func (c *cache) get(k string) (interface{}, bool) {
item, found := c.items[k]
if !found {
@@ -1044,7 +1074,6 @@ type janitor struct {
}
func (j *janitor) Run(c *cache) {
j.stop = make(chan bool)
ticker := time.NewTicker(j.Interval)
for {
select {
@@ -1064,6 +1093,7 @@ func stopJanitor(c *Cache) {
func runJanitor(c *cache, ci time.Duration) {
j := &janitor{
Interval: ci,
stop: make(chan bool),
}
c.janitor = j
go j.Run(c)