fix: add concurrency cli opt + propagate timeout opt

Author: ihadeed

cmd/autonats/main.go

@@ -27,6 +27,7 @@ func main() {
 				baseDir := ctx.String("dir")
 				timeout := ctx.Int("timeout")
 				outFile := ctx.String("out")
+				conc := ctx.Int("concurrency")
 
 				if outFile == "" {
 					outFile = "nats_client.go"
@@ -38,17 +39,27 @@ func main() {
 					timeout = 5
 				}
 
+				if conc <= 0 {
+					conc = 5
+				}
+
 				fmt.Printf("parsing '%s' and will export to '%s'\n", baseDir, outFile)
 
-				parser := autonats.NewParser()
+				parser := autonats.NewParser(&autonats.ParserConfig{
+					BaseDir:            baseDir,
+					DefaultTimeout:     timeout,
+					OutputFileName:     outFile,
+					DefaultConcurrency: conc,
+					Tracing:            ctx.Bool("tracing"),
+				})
 
 				if err := parser.ParseDir(baseDir); err != nil {
 					return fmt.Errorf("failed to parse the provided directory: %s", err.Error())
 				}
 
 				parser.Run()
 
-				return parser.Render(baseDir, outFile, timeout, true)
+				return parser.Render()
 			},
 			Flags: []cli.Flag{
 				cli.StringFlag{
@@ -71,9 +82,15 @@ func main() {
 				},
 				cli.BoolFlag{
 					Name:   "tracing",
-					Usage:  "Enable tracing",
+					Usage:  "Generate tracing code using OpenTracing library",
 					EnvVar: "AUTONATS_TRACING",
 				},
+				cli.IntFlag{
+					Name:   "concurrency, c",
+					Usage:  "Default handler concurrency",
+					EnvVar: "AUTONATS_CONCURRENCY",
+					Value:  5,
+				},
 			},
 		},
 	}

method.go

@@ -4,12 +4,14 @@ import (
 	"go/ast"
 )
 
+// Describes a service method that's exposed to the service mesh
 type Method struct {
 	Name               string
 	Params             []*Param
 	Results            []*Param
 	imports            map[string]bool
-	HandlerConcurrency int
+	HandlerConcurrency int // Method handler concurrency
+	Timeout            int // Method timeout
 }
 
 func MethodFromField(field *ast.Field) *Method {
@@ -23,7 +25,8 @@ func MethodFromField(field *ast.Field) *Method {
 		Results:            make([]*Param, nResults, nResults),
 		imports:            make(map[string]bool),
 		Name:               field.Names[0].Name,
-		HandlerConcurrency: 5,
+		HandlerConcurrency: 0, // TODO: add custom tag/comment to define concurrency for each method
+		Timeout:            0, // TODO: add custom  tag/comment to define timeout for each method
 	}
 
 	for ii, p := range fx.Params.List {

parser.go

@@ -9,13 +9,16 @@ import (
 
 // Parser config
 type ParserConfig struct {
-	BaseDir        string // Directory containing interfaces to scan
-	DefaultTimeout int    // Timeout for NATS requests
-	OutputFileName string // Output file name
+	BaseDir            string // Directory containing interfaces to scan
+	DefaultTimeout     int    // Timeout for NATS requests
+	OutputFileName     string // Output file name
+	DefaultConcurrency int    // Default handler concurrency
+	Tracing            bool   // Generate tracing code
 }
 
 // Parser object
 type Parser struct {
+	config      *ParserConfig
 	services    []*Service
 	rawPackages map[string]*ast.Package
 	packages    map[string]*Package
@@ -36,11 +39,12 @@ func ParseDir(path string) (map[string]*ast.Package, error) {
 }
 
 // Creates a new parser with the provided config
-func NewParser() *Parser {
+func NewParser(config *ParserConfig) *Parser {
 	return &Parser{
+		config:      config,
 		services:    make([]*Service, 0),
-		packages:    make(map[string]*Package),
 		rawPackages: make(map[string]*ast.Package),
+		packages:    make(map[string]*Package),
 	}
 }
 
@@ -79,14 +83,24 @@ func (par *Parser) Run() {
 			packages[service.FileName] = pkg
 		}
 
+		for _, m := range service.Methods {
+			if m.Timeout <= 0 {
+				m.Timeout = par.config.DefaultTimeout
+			}
+
+			if m.HandlerConcurrency <= 0 {
+				m.HandlerConcurrency = par.config.DefaultConcurrency
+			}
+		}
+
 		pkg.AddService(service)
 	}
 
 	par.services = services
 	par.packages = packages
 }
 
-func (par *Parser) Render(baseDir, outfile string, timeout int, tracing bool) error {
+func (par *Parser) Render() error {
 	imports := make([]string, 0)
 
 	for pk := range par.packages {
@@ -96,13 +110,13 @@ func (par *Parser) Render(baseDir, outfile string, timeout int, tracing bool) er
 	}
 
 	data := RenderData{
-		FileName: outfile,
-		Path:     baseDir,
+		FileName: par.config.OutputFileName,
+		Path:     par.config.BaseDir,
 		Services: par.services,
 		Imports:  imports,
-		Timeout:  timeout,
+		Timeout:  par.config.DefaultTimeout,
 		JsonLib:  "jsoniter",
-		Tracing:  tracing,
+		Tracing:  par.config.Tracing,
 	}
 
 	return Render(&data)

template.go

@@ -86,8 +86,6 @@ import (
 {{ end -}}
 )
 
-const timeout = time.Second * {{ .Timeout }}
-
 {{ range $srv := .Services }}
     {{ template "server_interface" $srv }}
 
@@ -119,7 +117,7 @@ const timeout = time.Second * {{ .Timeout }}
 				ext.Component.Set(replySpan, "autonats")
 
 				defer replySpan.Finish()
-				innerCtx, _ := context.WithTimeout(ctx, timeout)
+				innerCtx, _ := context.WithTimeout(ctx, time.Second * {{ $method.Timeout }})
 				innerCtxT := opentracing.ContextWithSpan(innerCtx, replySpan)
 
 				{{ $hasResult := gt (len $method.Results) 1 }}
@@ -269,7 +267,7 @@ const timeout = time.Second * {{ .Timeout }}
 			}
 		{{ end }}	
 
-		reqCtx, cancelFn := context.WithTimeout(reqCtx, timeout)
+		reqCtx, cancelFn := context.WithTimeout(reqCtx, time.Second * {{ $method.Timeout }})
 		defer cancelFn()
 		var replyMsg *nats.Msg
 		if replyMsg, err = client.NatsConn.RequestWithContext(ctx, "{{ $subject }}", t.Bytes()); err != nil {