aememcache

Documentation

Overview

Package aememcache handles Put, Get etc to Datastore and provides caching by AppEngine's Memcache. How the cache is used is explained in the storagecache package's document.

Related document.

https://cloud.google.com/appengine/docs/standard/go/memcache/ https://godoc.org/go.mercari.io/datastore/dsmiddleware/storagecache

Example (HowToUse)

package main

import (
	"context"

	"go.mercari.io/datastore/aedatastore"
	"go.mercari.io/datastore/dsmiddleware/aememcache"
	"google.golang.org/appengine"
	"google.golang.org/appengine/aetest"
)

func appengineContext() (ctx context.Context, cancelFn func() error) {
	inst, err := aetest.NewInstance(&aetest.Options{StronglyConsistentDatastore: true, SuppressDevAppServerLog: true})
	if err != nil {
		panic(err)
	}
	cancelFn = inst.Close
	r, err := inst.NewRequest("GET", "/", nil)
	if err != nil {
		panic(err)
	}
	ctx = appengine.NewContext(r)

	return
}

func main() {
	ctx, cancelFn := appengineContext()
	go cancelFn()

	client, err := aedatastore.FromContext(ctx)
	if err != nil {
		panic(err)
	}
	defer client.Close()

	mw := aememcache.New()
	client.AppendMiddleware(mw)
}

Index

• func New(opts ...CacheOption) interface{ ... }
• type CacheOption
  • func WithCacheKey(f func(key datastore.Key) string) CacheOption
  • func WithExcludeKinds(kinds ...string) CacheOption
  • func WithExpireDuration(d time.Duration) CacheOption
  • func WithIncludeKinds(kinds ...string) CacheOption
  • func WithKeyFilter(f storagecache.KeyFilter) CacheOption
  • func WithLogger(logf func(ctx context.Context, format string, args ...interface{})) CacheOption

Examples

• Package (HowToUse)

Functions

func New

func New(opts ...CacheOption) interface {
	datastore.Middleware
	storagecache.Storage
}

New AE Memcache middleware creates & returns.

Types

type CacheOption

type CacheOption interface {
	Apply(*cacheHandler)
}

A CacheOption is an cache option for a AE Memcache middleware.

func WithCacheKey

func WithCacheKey(f func(key datastore.Key) string) CacheOption

WithCacheKey creates a ClientOption that specifies how to generate a cache key from datastore.Key.

func WithExcludeKinds

func WithExcludeKinds(kinds ...string) CacheOption

WithExcludeKinds creates a ClientOption that selects the Kind unspecified as the cache target.

func WithExpireDuration

func WithExpireDuration(d time.Duration) CacheOption

WithExpireDuration creates a ClientOption to expire at a specified time.

func WithIncludeKinds

func WithIncludeKinds(kinds ...string) CacheOption

WithIncludeKinds creates a ClientOption that selects the Kind specified as the cache target.

func WithKeyFilter

func WithKeyFilter(f storagecache.KeyFilter) CacheOption

WithKeyFilter creates a ClientOption that selects the Keys specified as the cache target.

func WithLogger

func WithLogger(logf func(ctx context.Context, format string, args ...interface{})) CacheOption

WithLogger creates a ClientOption that uses the specified logger.