From e5314fd75d63d56911769f636fdd1d91bfbfaff3 Mon Sep 17 00:00:00 2001
From: Julien Dessaux
Date: Sun, 4 Apr 2021 00:22:35 +0200
Subject: Added 60 seconds caching to navitia api departures requests

---
 go.mod                                |  2 ++
 go.sum                                |  8 +++++++-
 navitia_api_client/client.go          | 10 ++++++++++
 navitia_api_client/client_test.go     |  1 +
 navitia_api_client/departures.go      | 16 +++++++++++++++-
 navitia_api_client/departures_test.go |  9 +++++++++
 6 files changed, 44 insertions(+), 2 deletions(-)

diff --git a/go.mod b/go.mod
index 6b55e17..c7ec694 100644
--- a/go.mod
+++ b/go.mod
@@ -3,6 +3,8 @@ module git.adyxax.org/adyxax/trains
 go 1.16
 
 require (
+	github.com/kr/pretty v0.2.1 // indirect
 	github.com/pkg/errors v0.9.1
+	gopkg.in/check.v1 v1.0.0-20180628173108-788fd7840127 // indirect
 	gopkg.in/yaml.v3 v3.0.0-20210107192922-496545a6307b
 )
diff --git a/go.sum b/go.sum
index 51a261f..ba9b6cd 100644
--- a/go.sum
+++ b/go.sum
@@ -1,6 +1,12 @@
+github.com/kr/pretty v0.2.1 h1:Fmg33tUaq4/8ym9TJN1x7sLJnHVwhP33CNkpYV/7rwI=
+github.com/kr/pretty v0.2.1/go.mod h1:ipq/a2n7PKx3OHsz4KJII5eveXtPO4qwEXGdVfWzfnI=
+github.com/kr/pty v1.1.1/go.mod h1:pFQYn66WHrOpPYNljwOMqo10TkYh1fy3cYio2l3bCsQ=
+github.com/kr/text v0.1.0 h1:45sCR5RtlFHMR4UwH9sdQ5TC8v0qDQCHnXt+kaKSTVE=
+github.com/kr/text v0.1.0/go.mod h1:4Jbv+DJW3UT/LiOwJeYQe1efqtUx/iVham/4vfdArNI=
 github.com/pkg/errors v0.9.1 h1:FEBLx1zS214owpjy7qsBeixbURkuhQAwrK5UwLGTwt4=
 github.com/pkg/errors v0.9.1/go.mod h1:bwawxfHBFNV+L2hUp1rHADufV3IMtnDRdf1r5NINEl0=
-gopkg.in/check.v1 v0.0.0-20161208181325-20d25e280405 h1:yhCVgyC4o1eVCa2tZl7eS0r+SDo693bJlVdllGtEeKM=
 gopkg.in/check.v1 v0.0.0-20161208181325-20d25e280405/go.mod h1:Co6ibVJAznAaIkqp8huTwlJQCZ016jof/cbN4VW5Yz0=
+gopkg.in/check.v1 v1.0.0-20180628173108-788fd7840127 h1:qIbj1fsPNlZgppZ+VLlY7N33q108Sa+fhmuc+sWQYwY=
+gopkg.in/check.v1 v1.0.0-20180628173108-788fd7840127/go.mod h1:Co6ibVJAznAaIkqp8huTwlJQCZ016jof/cbN4VW5Yz0=
 gopkg.in/yaml.v3 v3.0.0-20210107192922-496545a6307b h1:h8qDotaEPuJATrMmW04NCwg7v22aHH28wwpauUhK9Oo=
 gopkg.in/yaml.v3 v3.0.0-20210107192922-496545a6307b/go.mod h1:K4uyk7z7BCEPqu6E+C64Yfv1cQ7kz7rIZviUmN+EgEM=
diff --git a/navitia_api_client/client.go b/navitia_api_client/client.go
index d08ca19..aef8d0e 100644
--- a/navitia_api_client/client.go
+++ b/navitia_api_client/client.go
@@ -3,12 +3,21 @@ package navitia_api_client
 import (
 	"fmt"
 	"net/http"
+	"sync"
 	"time"
 )
 
 type Client struct {
 	baseURL    string
 	httpClient *http.Client
+
+	mutex sync.Mutex
+	cache map[string]cachedResult
+}
+
+type cachedResult struct {
+	ts     time.Time
+	result interface{}
 }
 
 func NewClient(token string) *Client {
@@ -17,5 +26,6 @@ func NewClient(token string) *Client {
 		httpClient: &http.Client{
 			Timeout: time.Minute,
 		},
+		cache: make(map[string]cachedResult),
 	}
 }
diff --git a/navitia_api_client/client_test.go b/navitia_api_client/client_test.go
index ec51a06..332b222 100644
--- a/navitia_api_client/client_test.go
+++ b/navitia_api_client/client_test.go
@@ -13,6 +13,7 @@ func NewTestClient(ts *httptest.Server) *Client {
 	return &Client{
 		baseURL:    fmt.Sprintf(ts.URL),
 		httpClient: ts.Client(),
+		cache:      make(map[string]cachedResult),
 	}
 }
 
diff --git a/navitia_api_client/departures.go b/navitia_api_client/departures.go
index a6dcf53..7738940 100644
--- a/navitia_api_client/departures.go
+++ b/navitia_api_client/departures.go
@@ -4,6 +4,7 @@ import (
 	"encoding/json"
 	"fmt"
 	"net/http"
+	"time"
 )
 
 type DeparturesResponse struct {
@@ -43,7 +44,16 @@ type DeparturesResponse struct {
 }
 
 func (c *Client) GetDepartures() (departures *DeparturesResponse, err error) {
-	req, err := http.NewRequest("GET", fmt.Sprintf("%s/coverage/sncf/stop_areas/stop_area:SNCF:87723502/departures", c.baseURL), nil)
+	request := fmt.Sprintf("%s/coverage/sncf/stop_areas/stop_area:SNCF:87723502/departures", c.baseURL)
+	start := time.Now()
+	c.mutex.Lock()
+	defer c.mutex.Unlock()
+	if cachedResult, ok := c.cache[request]; ok {
+		if start.Sub(cachedResult.ts) < 60*1000*1000*1000 {
+			return cachedResult.result.(*DeparturesResponse), nil
+		}
+	}
+	req, err := http.NewRequest("GET", request, nil)
 	if err != nil {
 		return nil, err
 	}
@@ -55,5 +65,9 @@ func (c *Client) GetDepartures() (departures *DeparturesResponse, err error) {
 	if err = json.NewDecoder(resp.Body).Decode(&departures); err != nil {
 		return nil, err
 	}
+	c.cache[request] = cachedResult{
+		ts:     start,
+		result: departures,
+	}
 	return
 }
diff --git a/navitia_api_client/departures_test.go b/navitia_api_client/departures_test.go
index 2c87429..a1658d2 100644
--- a/navitia_api_client/departures_test.go
+++ b/navitia_api_client/departures_test.go
@@ -45,4 +45,13 @@ func TestGetDepartures(t *testing.T) {
 	if len(departures.Departures) != 10 {
 		t.Fatalf("did not decode normal-crepieux departures properly, got %d departures when expected 10", len(departures.Departures))
 	}
+	// test the cache (assuming the test takes less than 60 seconds (and it really should) it will be accurate)
+	ts.Close()
+	departures, err = client.GetDepartures()
+	if err != nil {
+		t.Fatalf("could not get normal-crepieux departures : %s", err)
+	}
+	if len(departures.Departures) != 10 {
+		t.Fatalf("did not decode normal-crepieux departures properly, got %d departures when expected 10", len(departures.Departures))
+	}
 }
-- 
cgit v1.2.3