Complete rewrite of the library.

execute_query.go

@@ -0,0 +1,100 @@
+package gql
+
+import (
+	"bytes"
+	"fmt"
+	"io"
+	"net/http"
+	"time"
+
+	"github.com/avast/retry-go/v4"
+)
+
+func (qe *QueryExecutor) executeQuery() ([]byte, error) {
+	httpRequest, err := http.NewRequest("POST", qe.endpoint, bytes.NewBuffer(qe.Query))
+	if err != nil {
+		qe.Logger.Error("Can't create HTTP request;", map[string]interface{}{"error": err})
+		return nil, err
+	}
+
+	for key, value := range qe.Headers {
+		httpRequest.Header.Set(key, value.(string))
+	}
+
+	var retries_max int
+
+	if qe.Retries {
+		qe.Logger.Debug("Retries enabled - setting max retries", map[string]interface{}{"retries": qe.retries_number})
+		retries_max = qe.retries_number
+	} else {
+		qe.Logger.Debug("Retries disabled - setting max retries", map[string]interface{}{"retries": 1})
+		retries_max = 1
+	}
+
+	var httpResponse *http.Response
+	var queryResult queryResults
+
+	err = retry.Do(
+		func() error {
+			httpResponse, err = qe.client.Do(httpRequest)
+			if err != nil {
+				qe.Logger.Debug("Error while executing http request", map[string]interface{}{"error": err.Error()})
+				return err
+			}
+			defer io.Copy(io.Discard, httpResponse.Body)
+			defer httpResponse.Body.Close()
+
+			if httpResponse.StatusCode < 200 || httpResponse.StatusCode >= 204 {
+				return fmt.Errorf("HTTP error - unacceptable status code: \"%s\" for \"%s\"", httpResponse.Status, httpRequest.URL)
+			}
+
+			body, err := io.ReadAll(httpResponse.Body)
+			if err != nil {
+				qe.Logger.Debug("Error while reading http response;", map[string]interface{}{"error": err.Error()})
+				return fmt.Errorf("Error while reading http response: %s", err.Error())
+			}
+
+			err = json.Unmarshal(body, &queryResult)
+			if err != nil {
+				qe.Logger.Debug("Error while unmarshalling http response;", map[string]interface{}{"error": err.Error()})
+				return fmt.Errorf("Error while unmarshalling http response: %s", err.Error())
+			}
+
+			return nil
+		},
+		retry.OnRetry(func(n uint, err error) {
+			qe.Logger.Warning("Retrying query", map[string]interface{}{"error": err.Error(), "attempt": n})
+		}),
+		retry.Attempts(uint(retries_max)),
+		retry.DelayType(retry.BackOffDelay),
+		retry.Delay(time.Duration(qe.retries_delay)),
+		retry.LastErrorOnly(true),
+	)
+
+	if err != nil {
+		qe.Logger.Debug("Error while executing http request - target server", map[string]interface{}{"error": err.Error()})
+		return nil, err
+	}
+
+	if len(queryResult.Errors) > 0 {
+		qe.Logger.Debug("Error while executing query;", map[string]interface{}{"error": queryResult.Errors})
+		return nil, fmt.Errorf("Error while executing query: %s", queryResult.Errors)
+	}
+
+	if queryResult.Data == nil {
+		qe.Logger.Debug("Error while executing query", map[string]interface{}{"error": "no data"})
+		return nil, fmt.Errorf("Error while executing query: no data")
+	}
+
+	json_data, err := json.Marshal(queryResult.Data)
+	if err != nil {
+		qe.Logger.Debug("Error while marshalling query result;", map[string]interface{}{"error": err.Error(), "data": queryResult.Data})
+		return nil, fmt.Errorf("Error while marshalling query result: %s. Data: %s", err.Error(), queryResult.Data)
+	}
+
+	if qe.CacheKey != "no-cache" {
+		qe.cache.Set(qe.CacheKey, json_data, qe.CacheTTL)
+	}
+
+	return json_data, nil
+}