feat: cache labels to speed up evaluating many MRs in one command

Author: jippi

cmd/cmd_evaluate.go

@@ -3,25 +3,37 @@ package cmd
 import (
 	"fmt"
 
+	"github.com/jippi/gitlab-labeller/pkg/config"
+	"github.com/jippi/gitlab-labeller/pkg/scm/gitlab"
 	"github.com/jippi/gitlab-labeller/pkg/state"
 	"github.com/urfave/cli/v2"
 )
 
 func Evaluate(cCtx *cli.Context) error {
 	ctx := state.ContextWithProjectID(cCtx.Context, cCtx.String(FlagSCMProject))
 
+	cfg, err := config.LoadFile(cCtx.String(FlagConfigFile))
+	if err != nil {
+		return err
+	}
+
+	client, err := gitlab.NewClient(cCtx.String(FlagAPIToken), cCtx.String(FlagSCMBaseURL))
+	if err != nil {
+		return err
+	}
+
 	switch {
 	// If the flag is set, use that for evaluation
 	case cCtx.String(FlagMergeRequestID) != "":
-		return ProcessMR(ctx, cCtx, cCtx.String(FlagMergeRequestID))
+		return ProcessMR(ctx, client, cfg, cCtx.String(FlagMergeRequestID))
 
 	// If no flag is set, we require arguments
 	case cCtx.Args().Len() == 0:
 		return fmt.Errorf("Missing required argument: %s", FlagMergeRequestID)
 
 	default:
 		for _, mr := range cCtx.Args().Slice() {
-			if err := ProcessMR(ctx, cCtx, mr); err != nil {
+			if err := ProcessMR(ctx, client, cfg, mr); err != nil {
 				return err
 			}
 		}

cmd/shared.go

@@ -7,27 +7,15 @@ import (
 
 	"github.com/jippi/gitlab-labeller/pkg/config"
 	"github.com/jippi/gitlab-labeller/pkg/scm"
-	"github.com/jippi/gitlab-labeller/pkg/scm/gitlab"
 	"github.com/jippi/gitlab-labeller/pkg/state"
-	"github.com/urfave/cli/v2"
 )
 
-func ProcessMR(ctx context.Context, cCtx *cli.Context, mr string) error {
+func ProcessMR(ctx context.Context, client scm.Client, cfg *config.Config, mr string) error {
 	ctx = state.ContextWithMergeRequestID(ctx, mr)
 
 	// for mr := 900; mr <= 1000; mr++ {
 	fmt.Println("Processing MR", mr)
 
-	cfg, err := config.LoadFile(cCtx.String(FlagConfigFile))
-	if err != nil {
-		return err
-	}
-
-	client, err := gitlab.NewClient(cCtx.String(FlagAPIToken), cCtx.String(FlagSCMBaseURL))
-	if err != nil {
-		return err
-	}
-
 	remoteLabels, err := client.Labels().List(ctx)
 	if err != nil {
 		return err

pkg/scm/gitlab/client_label.go

@@ -14,13 +14,20 @@ var _ scm.LabelClient = (*LabelClient)(nil)
 
 type LabelClient struct {
 	client *Client
+
+	cache []*scm.Label
 }
 
 func NewLabelClient(client *Client) *LabelClient {
 	return &LabelClient{client: client}
 }
 
 func (client *LabelClient) List(ctx context.Context) ([]*scm.Label, error) {
+	// Check cache
+	if len(client.cache) != 0 {
+		return client.cache, nil
+	}
+
 	var results []*scm.Label
 
 	// Load all existing labels
@@ -49,6 +56,9 @@ func (client *LabelClient) List(ctx context.Context) ([]*scm.Label, error) {
 		opts.ListOptions.Page = resp.NextPage
 	}
 
+	// Store cache
+	client.cache = results
+
 	return results, nil
 }
 
@@ -80,6 +90,9 @@ func (client *LabelClient) list(ctx context.Context, opt *scm.ListLabelsOptions)
 }
 
 func (client *LabelClient) Create(ctx context.Context, opt *scm.CreateLabelOptions) (*scm.Label, *scm.Response, error) {
+	// Invalidate cache
+	client.cache = nil
+
 	project, err := ParseID(state.ProjectIDFromContext(ctx))
 	if err != nil {
 		return nil, nil, err
@@ -107,6 +120,9 @@ func (client *LabelClient) Create(ctx context.Context, opt *scm.CreateLabelOptio
 }
 
 func (client *LabelClient) Update(ctx context.Context, opt *scm.UpdateLabelOptions) (*scm.Label, *scm.Response, error) {
+	// Invalidate cache
+	client.cache = nil
+
 	project, err := ParseID(state.ProjectIDFromContext(ctx))
 	if err != nil {
 		return nil, nil, err