From 5cd22318f1d0f9ed84e9fae98d6f332e15f70f41 Mon Sep 17 00:00:00 2001
From: Lukasz Raczylo <lukasz@raczylo.com>
Date: Fri, 3 Dec 2021 09:12:59 +0000
Subject: [PATCH] Add environment variables to steer the query cache.

---
 README.md |  5 ++++-
 gql.go    | 31 +++++++++++++++++++++++++++++--
 2 files changed, 33 insertions(+), 3 deletions(-)

diff --git a/README.md b/README.md
index 628eb7d..175c09a 100644
--- a/README.md
+++ b/README.md
@@ -23,12 +23,15 @@ Therefore, I present you the simple client to which you can copy & paste your gr
 * Executing GraphQL queries as they are, without types declaration
 * HTTP2 support!
 * Support for additional headers
+* Query cache
 
 ## Usage example
 
 ### Environment variables
 
 * `GRAPHQL_ENDPOINT` - Your GraphQL endpoint. Default: `http://127.0.0.1:9090/v1/graphql`
+* `GRAPHQL_CACHE` -  Should the query cache be enabled? Default: `false`
+* `GRAPHQL_CACHE_TTL` -  Cache TTL in seconds for SELECT type of queries. Default: `5`
 * `LOG_LEVEL` - Logging level. Default: `info`
 
 ### Example reader code
@@ -37,7 +40,7 @@ Therefore, I present you the simple client to which you can copy & paste your gr
 ```go
 import (
   fmt
-  gql "github.com/lukaszraczylo/simple-gql-client"
+  gql "github.com/lukaszraczylo/go-simple-graphql"
 )
 
 headers := map[string]interface{}{
diff --git a/gql.go b/gql.go
index 9b07225..e7da315 100644
--- a/gql.go
+++ b/gql.go
@@ -18,6 +18,7 @@ import (
 	"net"
 	"net/http"
 	"os"
+	"strconv"
 	"time"
 
 	"github.com/allegro/bigcache/v3"
@@ -49,6 +50,32 @@ func pickGraphqlEndpoint() (graphqlEndpoint string) {
 	return graphqlEndpoint
 }
 
+func setCacheTTL() int {
+	value, present := os.LookupEnv("GRAPHQL_CACHE_TTL")
+	if present && value != "" {
+		i, err := strconv.Atoi(value)
+		if err != nil {
+			panic("Invalid value for query cache ttl")
+		}
+		return int(i)
+	} else {
+		return 5
+	}
+}
+
+func setCacheEnabled() bool {
+	value, present := os.LookupEnv("GRAPHQL_CACHE")
+	if present && value != "" {
+		b, err := strconv.ParseBool(value)
+		if err != nil {
+			panic("Invalid value for query cache")
+		}
+		return b
+	} else {
+		return false
+	}
+}
+
 func NewConnection() *GraphQL {
 	return &GraphQL{
 		Endpoint: pickGraphqlEndpoint(),
@@ -63,13 +90,13 @@ func NewConnection() *GraphQL {
 			},
 		},
 		Log:        logging.NewLogger(),
-		Cache:      false,
+		Cache:      setCacheEnabled(),
 		CacheStore: setupCache(),
 	}
 }
 
 func setupCache() *bigcache.BigCache {
-	cache, err := bigcache.NewBigCache(bigcache.DefaultConfig(10 * time.Second))
+	cache, err := bigcache.NewBigCache(bigcache.DefaultConfig(time.Duration(setCacheTTL()) * time.Second))
 	if err != nil {
 		panic("Error creating cache: " + err.Error())
 	}