From 5ebc282bf96950789e1ccaf9f6721c4856fdfc1a Mon Sep 17 00:00:00 2001
From: NatureFreshMilk <naturefreshmilk@github.com>
Date: Fri, 11 Jan 2019 09:07:31 +0100
Subject: [PATCH] accessor cache

---
 go.mod                               |  1 +
 go.sum                               |  2 ++
 mapblockaccessor/mapblockaccessor.go | 28 ++++++++++++++++++++++++++--
 3 files changed, 29 insertions(+), 2 deletions(-)

diff --git a/go.mod b/go.mod
index 545d048..115778f 100644
--- a/go.mod
+++ b/go.mod
@@ -2,5 +2,6 @@ module mapserver
 
 require (
 	github.com/mattn/go-sqlite3 v1.10.0
+	github.com/patrickmn/go-cache v2.1.0+incompatible
 	github.com/sirupsen/logrus v1.3.0
 )
diff --git a/go.sum b/go.sum
index 84060a0..a10de16 100644
--- a/go.sum
+++ b/go.sum
@@ -3,6 +3,8 @@ github.com/davecgh/go-spew v1.1.1/go.mod h1:J7Y8YcW2NihsgmVo/mv3lAwl/skON4iLHjSs
 github.com/konsorten/go-windows-terminal-sequences v1.0.1/go.mod h1:T0+1ngSBFLxvqU3pZ+m/2kptfBszLMUkC4ZK/EgS/cQ=
 github.com/mattn/go-sqlite3 v1.10.0 h1:jbhqpg7tQe4SupckyijYiy0mJJ/pRyHvXf7JdWK860o=
 github.com/mattn/go-sqlite3 v1.10.0/go.mod h1:FPy6KqzDD04eiIsT53CuJW3U88zkxoIYsOqkbpncsNc=
+github.com/patrickmn/go-cache v2.1.0+incompatible h1:HRMgzkcYKYpi3C8ajMPV8OFXaaRUnok+kx1WdO15EQc=
+github.com/patrickmn/go-cache v2.1.0+incompatible/go.mod h1:3Qf8kWWT7OJRJbdiICTKqZju1ZixQ/KpMGzzAfe6+WQ=
 github.com/pmezard/go-difflib v1.0.0 h1:4DBwDE0NGyQoBHbLQYPwSUPoCMWR5BEzIk/f1lZbAQM=
 github.com/pmezard/go-difflib v1.0.0/go.mod h1:iKH77koFhYxTK1pcRnkKkqfTogsbg7gZNVY4sRDYZ/4=
 github.com/sirupsen/logrus v1.3.0 h1:hI/7Q+DtNZ2kINb6qt/lS+IyXnHQe9e90POfeewL/ME=
diff --git a/mapblockaccessor/mapblockaccessor.go b/mapblockaccessor/mapblockaccessor.go
index 28947a6..5afb7fe 100644
--- a/mapblockaccessor/mapblockaccessor.go
+++ b/mapblockaccessor/mapblockaccessor.go
@@ -4,30 +4,54 @@ import (
 	"mapserver/coords"
 	"mapserver/db"
 	"mapserver/mapblockparser"
+	"github.com/patrickmn/go-cache"
+	"time"
+	"fmt"
 )
 
 type MapBlockAccessor struct {
 	accessor db.DBAccessor
+	c *cache.Cache
+}
+
+func getKey(pos coords.MapBlockCoords) string {
+	return fmt.Sprintf("Coord %d/%d/%d", pos.X, pos.Y, pos.Z)
 }
 
 func NewMapBlockAccessor(accessor db.DBAccessor) *MapBlockAccessor {
-	return &MapBlockAccessor{accessor: accessor}
+	c := cache.New(5*time.Minute, 10*time.Minute)
+
+	return &MapBlockAccessor{accessor: accessor, c: c}
 }
 
 func (a *MapBlockAccessor) Update(pos coords.MapBlockCoords, mb *mapblockparser.MapBlock) {
-	//TODO: cache
+	key := getKey(pos)
+	a.c.Set(key, mb, cache.DefaultExpiration)
 }
 
 func (a *MapBlockAccessor) GetMapBlock(pos coords.MapBlockCoords) (*mapblockparser.MapBlock, error) {
+	key := getKey(pos)
+
+	cachedblock, found := a.c.Get(key)
+	if found {
+		return cachedblock.(*mapblockparser.MapBlock), nil
+	}
+
 	block, err := a.accessor.GetBlock(pos)
 	if err != nil {
 		return nil, err
 	}
 
+	if block == nil {
+		return nil, nil
+	}
+
 	mapblock, err := mapblockparser.Parse(block.Data)
 	if err != nil {
 		return nil, err
 	}
 
+	a.c.Set(key, mapblock, cache.DefaultExpiration)
+
 	return mapblock, nil
 }