From 00bd2bc65fa18dfe2fd6cbbeee4d7bb94f601b9c Mon Sep 17 00:00:00 2001
From: Asim Aslam <asim@aslam.me>
Date: Wed, 8 Jul 2020 11:08:59 +0100
Subject: [PATCH] cache interface (#1805)

---
 cache/cache.go         | 17 +++++++++++++
 cache/memory/memory.go | 56 ++++++++++++++++++++++++++++++++++++++++++
 2 files changed, 73 insertions(+)
 create mode 100644 cache/cache.go
 create mode 100644 cache/memory/memory.go

diff --git a/cache/cache.go b/cache/cache.go
new file mode 100644
index 00000000..872aacec
--- /dev/null
+++ b/cache/cache.go
@@ -0,0 +1,17 @@
+// Package cache is a caching interface
+package cache
+
+type Cache interface {
+	// Initialise options
+	Init(...Option) error
+	// Get a value
+	Get(key string) (interface{}, error)
+	// Set a value
+	Set(key string, val interface{}) error
+	// Delete a value
+	Delete(key string) error
+	// Name of the implementation
+	String() string
+}
+
+type Option struct{}
diff --git a/cache/memory/memory.go b/cache/memory/memory.go
new file mode 100644
index 00000000..d4246b77
--- /dev/null
+++ b/cache/memory/memory.go
@@ -0,0 +1,56 @@
+// Package memory is an in memory cache
+package memory
+
+import (
+	"sync"
+
+	"github.com/micro/go-micro/v2/cache"
+	"github.com/micro/go-micro/v2/errors"
+)
+
+type memoryCache struct {
+	// TODO: use a decent caching library
+	sync.RWMutex
+	values map[string]interface{}
+}
+
+func (m *memoryCache) Init(opts ...cache.Option) error {
+	// TODO: implement
+	return nil
+}
+
+func (m *memoryCache) Get(key string) (interface{}, error) {
+	m.RLock()
+	defer m.RUnlock()
+
+	v, ok := m.values[key]
+	if !ok {
+		return nil, errors.NotFound("go.micro.cache", key+" not found")
+	}
+
+	return v, nil
+}
+
+func (m *memoryCache) Set(key string, val interface{}) error {
+	m.Lock()
+	m.values[key] = val
+	m.Unlock()
+	return nil
+}
+
+func (m *memoryCache) Delete(key string) error {
+	m.Lock()
+	delete(m.values, key)
+	m.Unlock()
+	return nil
+}
+
+func (m *memoryCache) String() string {
+	return "memory"
+}
+
+func NewCache(opts ...cache.Option) cache.Cache {
+	return &memoryCache{
+		values: make(map[string]interface{}),
+	}
+}