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authorsiddharth ravikumar <s@ricketyspace.net>2022-06-07 01:05:11 -0400
committersiddharth ravikumar <s@ricketyspace.net>2022-06-07 01:05:11 -0400
commit521c07cbb8aa350939b21b569aa88ecd58978911 (patch)
tree5c8a2ac98fe42107270619d1148f48bd1b6c9cc0 /nws
parenta02238b012f2f303f1566f8bf351229e7409d20f (diff)
nws: implement caching for all endpoints
Diffstat (limited to 'nws')
-rw-r--r--nws/nws.go95
1 files changed, 77 insertions, 18 deletions
diff --git a/nws/nws.go b/nws/nws.go
index 567d1a8..8fec6ed 100644
--- a/nws/nws.go
+++ b/nws/nws.go
@@ -10,6 +10,7 @@ import (
"io"
"time"
+ "ricketyspace.net/peach/cache"
"ricketyspace.net/peach/client"
)
@@ -65,6 +66,16 @@ type Error struct {
Detail string
}
+var pCache *cache.Cache
+var fCache *cache.Cache
+var fhCache *cache.Cache
+
+func init() {
+ pCache = cache.NewCache()
+ fCache = cache.NewCache()
+ fhCache = cache.NewCache()
+}
+
func (e Error) Error() string {
return fmt.Sprintf("%d: %s: %s", e.Status, e.Type, e.Detail)
}
@@ -73,10 +84,19 @@ func (e Error) Error() string {
//
// TODO: return Error instead of error
func Points(lat, lng float32) (*Point, error) {
- url := fmt.Sprintf("https://api.weather.gov/points/%.4f,%.4f", lat, lng)
- body, nwsErr := get(url)
- if nwsErr != nil {
- return nil, fmt.Errorf("points: %v", nwsErr)
+ var nwsErr *Error
+ var expires time.Time
+ var body []byte
+
+ ll := fmt.Sprintf("%.4f,%.4f", lat, lng)
+ if body = pCache.Get(ll); len(body) == 0 {
+ url := fmt.Sprintf("https://api.weather.gov/points/%s", ll)
+ body, expires, nwsErr = get(url)
+ if nwsErr != nil {
+ return nil, fmt.Errorf("points: %v", nwsErr)
+ }
+ // Cache it.
+ pCache.Set(ll, body, expires)
}
// Unmarshal.
@@ -98,6 +118,10 @@ func Points(lat, lng float32) (*Point, error) {
//
// TODO: return Error instead of error.
func GetForecast(point *Point) (*Forecast, error) {
+ var nwsErr *Error
+ var expires time.Time
+ var body []byte
+
if point == nil {
return nil, fmt.Errorf("forecast: point nil")
}
@@ -105,10 +129,14 @@ func GetForecast(point *Point) (*Forecast, error) {
return nil, fmt.Errorf("forecast: link empty")
}
- // Get the forecast
- body, nwsErr := get(point.Properties.Forecast)
- if nwsErr != nil {
- return nil, fmt.Errorf("forecast: %v", nwsErr)
+ if body = fCache.Get(point.Properties.Forecast); len(body) == 0 {
+ // Get the forecast
+ body, expires, nwsErr = get(point.Properties.Forecast)
+ if nwsErr != nil {
+ return nil, fmt.Errorf("forecast: %v", nwsErr)
+ }
+ // Cache it.
+ fCache.Set(point.Properties.Forecast, body, expires)
}
// Unmarshal.
@@ -127,6 +155,10 @@ func GetForecast(point *Point) (*Forecast, error) {
//
// TODO: return Error instead of error
func GetForecastHourly(point *Point) (*Forecast, error) {
+ var nwsErr *Error
+ var expires time.Time
+ body := []byte{}
+
if point == nil {
return nil, fmt.Errorf("forecast hourly: point nil")
}
@@ -134,10 +166,14 @@ func GetForecastHourly(point *Point) (*Forecast, error) {
return nil, fmt.Errorf("forecast hourly: link empty")
}
- // Get the hourly forecast.
- body, nwsErr := get(point.Properties.ForecastHourly)
- if nwsErr != nil {
- return nil, fmt.Errorf("forecast hourly: %v", nwsErr)
+ if body = fhCache.Get(point.Properties.ForecastHourly); len(body) == 0 {
+ // Get the hourly forecast.
+ body, expires, nwsErr = get(point.Properties.ForecastHourly)
+ if nwsErr != nil {
+ return nil, fmt.Errorf("forecast hourly: %v", nwsErr)
+ }
+ // Cache it.
+ fhCache.Set(point.Properties.ForecastHourly, body, expires)
}
// Unmarshal.
@@ -153,13 +189,16 @@ func GetForecastHourly(point *Point) (*Forecast, error) {
}
// HTTP GET a NWS endpoint.
-func get(url string) ([]byte, *Error) {
+func get(url string) ([]byte, time.Time, *Error) {
+ // Default response expiration time
+ expires := time.Now()
+
tries := 5
retryDelay := 100 * time.Millisecond
for {
resp, err := client.Get(url)
if err != nil {
- return nil, &Error{
+ return nil, expires, &Error{
Title: fmt.Sprintf("http get failed: %v", url),
Type: "http-get",
Status: 500,
@@ -179,7 +218,7 @@ func get(url string) ([]byte, *Error) {
// Parse response body.
body, err := io.ReadAll(resp.Body)
if err != nil {
- return nil, &Error{
+ return nil, expires, &Error{
Title: fmt.Sprintf("parsing body: %v", url),
Type: "response-body",
Status: 500,
@@ -192,16 +231,36 @@ func get(url string) ([]byte, *Error) {
nwsErr := Error{}
err := json.Unmarshal(body, &nwsErr)
if err != nil {
- return nil, &Error{
+ return nil, expires, &Error{
Title: fmt.Sprintf("json decode: %v", url),
Type: "json-decode",
Status: 500,
Detail: err.Error(),
}
}
- return nil, &nwsErr
+ return nil, expires, &nwsErr
+ }
+
+ // Parse expiration time of the response.
+ expiresHeader := resp.Header.Get("expires")
+ if len(expiresHeader) < 1 {
+ return nil, expires, &Error{
+ Title: "expiration header empty",
+ Type: "expiration-header",
+ Status: 500,
+ Detail: "response expiration header is empty",
+ }
+ }
+ expires, err := time.Parse(time.RFC1123, expiresHeader)
+ if err != nil {
+ return nil, expires, &Error{
+ Title: "expiration header could not be parsed",
+ Type: "expiration-header-parse-failed",
+ Status: 500,
+ Detail: err.Error(),
+ }
}
// Response OK.
- return body, nil
+ return body, expires, nil
}
}