From 7727b359c88e6be8ffbfe94429efd97de07b47e7 Mon Sep 17 00:00:00 2001
From: Asim Aslam <asim@aslam.me>
Date: Tue, 11 Jun 2019 17:49:34 +0100
Subject: [PATCH] Add memory data store

---
 data/data.go          |  6 +--
 data/memory/memory.go | 97 +++++++++++++++++++++++++++++++++++++++++++
 2 files changed, 100 insertions(+), 3 deletions(-)
 create mode 100644 data/memory/memory.go

diff --git a/data/data.go b/data/data.go
index 004c5160..1744c5dc 100644
--- a/data/data.go
+++ b/data/data.go
@@ -28,7 +28,7 @@ type Data interface {
 
 // Record represents a data record
 type Record struct {
-	Key        string
-	Value      []byte
-	Expiration time.Duration
+	Key    string
+	Value  []byte
+	Expiry time.Duration
 }
diff --git a/data/memory/memory.go b/data/memory/memory.go
new file mode 100644
index 00000000..12a529af
--- /dev/null
+++ b/data/memory/memory.go
@@ -0,0 +1,97 @@
+// Package memory is a in-memory data store
+package memory
+
+import (
+	"sync"
+	"time"
+
+	"github.com/micro/go-micro/data"
+	"github.com/micro/go-micro/options"
+)
+
+type memoryData struct {
+	options.Options
+
+	sync.RWMutex
+	values map[string]*memoryRecord
+}
+
+type memoryRecord struct {
+	r *data.Record
+	c time.Time
+}
+
+func (m *memoryData) Dump() ([]*data.Record, error) {
+	m.RLock()
+	defer m.RUnlock()
+
+	var values []*data.Record
+
+	for _, v := range m.values {
+		// get expiry
+		d := v.r.Expiry
+		t := time.Since(v.c)
+
+		// expired
+		if d > time.Duration(0) && t > d {
+			continue
+		}
+		values = append(values, v.r)
+	}
+
+	return values, nil
+}
+
+func (m *memoryData) Read(key string) (*data.Record, error) {
+	m.RLock()
+	defer m.RUnlock()
+
+	v, ok := m.values[key]
+	if !ok {
+		return nil, data.ErrNotFound
+	}
+
+	// get expiry
+	d := v.r.Expiry
+	t := time.Since(v.c)
+
+	// expired
+	if d > time.Duration(0) && t > d {
+		return nil, data.ErrNotFound
+	}
+
+	return v.r, nil
+}
+
+func (m *memoryData) Write(r *data.Record) error {
+	m.Lock()
+	defer m.Unlock()
+
+	// set the record
+	m.values[r.Key] = &memoryRecord{
+		r: r,
+		c: time.Now(),
+	}
+
+	return nil
+}
+
+func (m *memoryData) Delete(key string) error {
+	m.Lock()
+	defer m.Unlock()
+
+	// delete the value
+	delete(m.values, key)
+
+	return nil
+}
+
+// NewData returns a new data.Data
+func NewData(opts ...options.Option) data.Data {
+	options := options.NewOptions(opts...)
+
+	return &memoryData{
+		Options: options,
+		values:  make(map[string]*memoryRecord),
+	}
+}