[
https://issues.apache.org/jira/browse/BEAM-3612?focusedWorklogId=165044&page=com.atlassian.jira.plugin.system.issuetabpanels:worklog-tabpanel#worklog-165044
]
ASF GitHub Bot logged work on BEAM-3612:
----------------------------------------
Author: ASF GitHub Bot
Created on: 12/Nov/18 18:03
Start Date: 12/Nov/18 18:03
Worklog Time Spent: 10m
Work Description: aaltay closed pull request #7000: [BEAM-3612] Add a
shim generator tool
URL: https://github.com/apache/beam/pull/7000
This is a PR merged from a forked repository.
As GitHub hides the original diff on merge, it is displayed below for
the sake of provenance:
As this is a foreign pull request (from a fork), the diff is supplied
below (as it won't show otherwise due to GitHub magic):
diff --git a/sdks/go/cmd/starcgen/starcgen.go b/sdks/go/cmd/starcgen/starcgen.go
new file mode 100644
index 00000000000..87e80110b39
--- /dev/null
+++ b/sdks/go/cmd/starcgen/starcgen.go
@@ -0,0 +1,154 @@
+// Licensed to the Apache Software Foundation (ASF) under one or more
+// contributor license agreements. See the NOTICE file distributed with
+// this work for additional information regarding copyright ownership.
+// The ASF licenses this file to You under the Apache License, Version 2.0
+// (the "License"); you may not use this file except in compliance with
+// the License. You may obtain a copy of the License at
+//
+// http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+// starcgen is a tool to generate specialized type assertion shims to be
+// used in Apache Beam Go SDK pipelines instead of the default reflection shim.
+// This is done through static analysis of go sources for the package in
question.
+package main
+
+import (
+ "flag"
+ "fmt"
+ "go/ast"
+ "go/importer"
+ "go/parser"
+ "go/token"
+ "io"
+ "log"
+ "os"
+ "path/filepath"
+ "strings"
+
+ "github.com/apache/beam/sdks/go/pkg/beam/util/starcgenx"
+)
+
+var (
+ inputs = flag.String("inputs", "", "comma separated list of file with
types to create")
+ output = flag.String("output", "", "output file with types to create")
+ ids = flag.String("identifiers", "", "comma separated list of
package local identifiers for which to generate code")
+)
+
+// Generate takes the typechecked inputs, and generates the shim file for the
relevant
+// identifiers.
+func Generate(w io.Writer, filename, pkg string, ids []string, fset
*token.FileSet, files []*ast.File) error {
+ e := starcgenx.NewExtractor(pkg)
+ e.Ids = ids
+
+ // Importing from source should work in most cases.
+ imp := importer.For("source", nil)
+ if err := e.FromAsts(imp, fset, files); err != nil {
+ // Always print out the debugging info to the file.
+ if _, errw := w.Write(e.Bytes()); errw != nil {
+ return fmt.Errorf("error writing debug data to file
after err %v:%v", err, errw)
+ }
+ return fmt.Errorf("error extracting from asts: %v", err)
+ }
+
+ e.Print("*/\n")
+ data := e.Generate(filename)
+ if err := write(w, []byte(license)); err != nil {
+ return err
+ }
+ return write(w, data)
+}
+
+func write(w io.Writer, data []byte) error {
+ n, err := w.Write(data)
+ if err != nil && n < len(data) {
+ return fmt.Errorf("short write of data got %d, want %d", n,
len(data))
+ }
+ return err
+}
+
+func usage() {
+ fmt.Fprintf(os.Stderr, "Usage: %v [options] --inputs=<comma separated
of go files>\n", filepath.Base(os.Args[0]))
+ flag.PrintDefaults()
+}
+
+func main() {
+ flag.Usage = usage
+ flag.Parse()
+
+ log.SetFlags(log.Lshortfile)
+ log.SetPrefix("starcgen: ")
+
+ ipts := strings.Split(*inputs, ",")
+ fset := token.NewFileSet()
+ var fs []*ast.File
+ var pkg string
+
+ dir, err := filepath.Abs(filepath.Dir(os.Args[0]))
+ if err != nil {
+ log.Fatal(err)
+ }
+
+ for _, i := range ipts {
+ f, err := parser.ParseFile(fset, i, nil, 0)
+ if err != nil {
+ err1 := err
+ f, err = parser.ParseFile(fset, filepath.Join(dir, i),
nil, 0)
+ if err != nil {
+ log.Print(err1)
+ log.Fatal(err) // parse error
+ }
+ }
+
+ if pkg == "" {
+ pkg = f.Name.Name
+ } else if pkg != f.Name.Name {
+ log.Fatalf("Input file %v has mismatched package path,
got %q, want %q", i, f.Name.Name, pkg)
+ }
+ fs = append(fs, f)
+ }
+ if pkg == "" {
+ log.Fatalf("No package detected in input files: %v", inputs)
+ }
+
+ if *output == "" {
+ name := pkg
+ if len(ipts) == 1 {
+ name = filepath.Base(ipts[0])
+ if index := strings.Index(name, "."); index > 0 {
+ name = name[:index]
+ }
+ }
+ *output = filepath.Join(filepath.Dir(ipts[0]), name+".shims.go")
+ }
+
+ f, err := os.OpenFile(*output, os.O_WRONLY|os.O_CREATE|os.O_TRUNC, 0644)
+ if err != nil {
+ log.Fatal(err)
+ }
+ if err := Generate(f, *output, pkg, strings.Split(*ids, ","), fset,
fs); err != nil {
+ log.Fatal(err)
+ }
+}
+
+const license = `// Licensed to the Apache Software Foundation (ASF) under one
or more
+// contributor license agreements. See the NOTICE file distributed with
+// this work for additional information regarding copyright ownership.
+// The ASF licenses this file to You under the Apache License, Version 2.0
+// (the "License"); you may not use this file except in compliance with
+// the License. You may obtain a copy of the License at
+//
+// http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+`
diff --git a/sdks/go/cmd/starcgen/starcgen_test.go
b/sdks/go/cmd/starcgen/starcgen_test.go
new file mode 100644
index 00000000000..7282ada8a27
--- /dev/null
+++ b/sdks/go/cmd/starcgen/starcgen_test.go
@@ -0,0 +1,123 @@
+// Licensed to the Apache Software Foundation (ASF) under one or more
+// contributor license agreements. See the NOTICE file distributed with
+// this work for additional information regarding copyright ownership.
+// The ASF licenses this file to You under the Apache License, Version 2.0
+// (the "License"); you may not use this file except in compliance with
+// the License. You may obtain a copy of the License at
+//
+// http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package main
+
+import (
+ "bytes"
+ "go/ast"
+ "go/parser"
+ "go/token"
+ "strings"
+ "testing"
+)
+
+func TestGenerate(t *testing.T) {
+ tests := []struct {
+ name string
+ pkg string
+ files []string
+ ids []string
+ expected []string
+ excluded []string
+ }{
+ {name: "genAllSingleFile", files: []string{hello1}, pkg:
"hello", ids: []string{},
+ expected: []string{"runtime.RegisterFunction(MyTitle)",
"runtime.RegisterFunction(MyOtherDoFn)",
"runtime.RegisterType(reflect.TypeOf((*foo)(nil)).Elem())",
"funcMakerContext۰ContextStringГString", "funcMakerFooГString"},
+ },
+ {name: "genSpecificSingleFile", files: []string{hello1}, pkg:
"hello", ids: []string{"MyTitle"},
+ expected: []string{"runtime.RegisterFunction(MyTitle)",
"funcMakerContext۰ContextStringГString"},
+ excluded: []string{"MyOtherDoFn",
"runtime.RegisterType(reflect.TypeOf((*foo)(nil)).Elem())",
"funcMakerFooГString"},
+ },
+ {name: "genAllMultiFile", files: []string{hello1, hello2}, pkg:
"hello", ids: []string{},
+ expected: []string{"runtime.RegisterFunction(MyTitle)",
"runtime.RegisterFunction(MyOtherDoFn)", "runtime.RegisterFunction(anotherFn)",
"runtime.RegisterType(reflect.TypeOf((*foo)(nil)).Elem())",
"funcMakerContext۰ContextStringГString", "funcMakerFooГString",
"funcMakerShimx۰EmitterГString", "funcMakerShimx۰EmitterГFoo"},
+ },
+ {name: "genSpecificMultiFile1", files: []string{hello1,
hello2}, pkg: "hello", ids: []string{"MyTitle"},
+ expected: []string{"runtime.RegisterFunction(MyTitle)",
"funcMakerContext۰ContextStringГString"},
+ excluded: []string{"MyOtherDoFn", "anotherFn",
"runtime.RegisterType(reflect.TypeOf((*foo)(nil)).Elem())",
"funcMakerFooГString", "funcMakerShimx۰EmitterГString",
"funcMakerShimx۰EmitterГFoo"},
+ },
+ {name: "genSpecificMultiFile2", files: []string{hello1,
hello2}, pkg: "hello", ids: []string{"anotherFn"},
+ expected: []string{"funcMakerShimx۰EmitterГString",
"funcMakerShimx۰EmitterГString"},
+ excluded: []string{"MyOtherDoFn", "MyTitle",
"runtime.RegisterType(reflect.TypeOf((*foo)(nil)).Elem())",
"funcMakerFooГString"},
+ },
+ }
+ for _, test := range tests {
+ test := test
+ t.Run(test.name, func(t *testing.T) {
+ fset := token.NewFileSet()
+ var fs []*ast.File
+ for i, f := range test.files {
+ n, err := parser.ParseFile(fset, "", f, 0)
+ if err != nil {
+ t.Fatalf("couldn't parse
test.files[%d]: %v", i, err)
+ }
+ fs = append(fs, n)
+ }
+ var b bytes.Buffer
+ if err := Generate(&b, test.name+".go", test.pkg,
test.ids, fset, fs); err != nil {
+ t.Fatal(err)
+ }
+ s := string(b.Bytes())
+ for _, i := range test.expected {
+ if !strings.Contains(s, i) {
+ t.Errorf("expected %q in generated
file", i)
+ }
+ }
+ for _, i := range test.excluded {
+ if strings.Contains(s, i) {
+ t.Errorf("found %q in generated file",
i)
+ }
+ }
+ t.Log(s)
+ })
+ }
+}
+
+const hello1 = `
+package hello
+
+import (
+ "context"
+ "strings"
+)
+
+func MyTitle(ctx context.Context, v string) string {
+ return strings.Title(v)
+}
+
+type foo struct{}
+
+func MyOtherDoFn(v foo) string {
+ return "constant"
+}
+`
+
+const hello2 = `
+package hello
+
+import (
+ "context"
+ "strings"
+
+ "github.com/apache/beam/sdks/go/pkg/beam/util/shimx"
+)
+
+func anotherFn(v shimx.Emitter) string {
+ return v.Name
+}
+
+func fooFn(v shimx.Emitter) foo {
+ return foo{}
+}
+`
diff --git a/sdks/go/pkg/beam/util/shimx/generate.go
b/sdks/go/pkg/beam/util/shimx/generate.go
new file mode 100644
index 00000000000..6c0eb4a231e
--- /dev/null
+++ b/sdks/go/pkg/beam/util/shimx/generate.go
@@ -0,0 +1,413 @@
+// Licensed to the Apache Software Foundation (ASF) under one or more
+// contributor license agreements. See the NOTICE file distributed with
+// this work for additional information regarding copyright ownership.
+// The ASF licenses this file to You under the Apache License, Version 2.0
+// (the "License"); you may not use this file except in compliance with
+// the License. You may obtain a copy of the License at
+//
+// http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+// Package shimx specifies the templates for generating type assertion shims
for
+// Apache Beam Go SDK pipelines.
+//
+// In particular, the shims are used by the Beam Go SDK to avoid reflection at
runtime,
+// which is the default mode of operation. The shims are specialized for the
code
+// in question, using type assertion to convert arguments as required, and
invoke the
+// user code.
+//
+// Similar shims are required for emitters, and iterators in order to
propagate values
+// out of, and in to user functions respectively without reflection overhead.
+//
+// Registering user types is required to support user types as PCollection
+// types, while registering functions is required to avoid possibly expensive
function
+// resolution at worker start up, which defaults to using DWARF Symbol tables.
+//
+// The generator largely relies on basic types and strings to ensure that it's
usable
+// by dynamic processes via reflection, or by any static analysis approach
that is
+// used in the future.
+package shimx
+
+import (
+ "fmt"
+ "io"
+ "sort"
+ "strings"
+ "text/template"
+)
+
+// Beam imports that the generated code requires.
+var (
+ ExecImport =
"github.com/apache/beam/sdks/go/pkg/beam/core/runtime/exec"
+ TypexImport = "github.com/apache/beam/sdks/go/pkg/beam/core/typex"
+ ReflectxImport =
"github.com/apache/beam/sdks/go/pkg/beam/core/util/reflectx"
+ RuntimeImport = "github.com/apache/beam/sdks/go/pkg/beam/core/runtime"
+)
+
+func validateBeamImports() {
+ checkImportSuffix(ExecImport, "exec")
+ checkImportSuffix(TypexImport, "typex")
+ checkImportSuffix(ReflectxImport, "reflectx")
+ checkImportSuffix(RuntimeImport, "runtime")
+}
+
+func checkImportSuffix(path, suffix string) {
+ if !strings.HasSuffix(path, suffix) {
+ panic(fmt.Sprintf("expected %v to end with %v. can't generate
valid code", path, suffix))
+ }
+}
+
+// Top is the top level inputs into the template file for generating shims.
+type Top struct {
+ FileName, ToolName, Package string
+
+ Imports []string // the full import paths
+ Functions []string // the plain names of the functions to be registered.
+ Types []string // the plain names of the types to be registered.
+ Emitters []Emitter
+ Inputs []Input
+ Shims []Func
+}
+
+// sort orders the shims consistently to minimize diffs in the generated code.
+func (t *Top) sort() {
+ sort.Strings(t.Imports)
+ sort.Strings(t.Functions)
+ sort.Strings(t.Types)
+ sort.SliceStable(t.Emitters, func(i, j int) bool {
+ return t.Emitters[i].Name < t.Emitters[j].Name
+ })
+ sort.SliceStable(t.Inputs, func(i, j int) bool {
+ return t.Inputs[i].Name < t.Inputs[j].Name
+ })
+ sort.SliceStable(t.Shims, func(i, j int) bool {
+ return t.Shims[i].Name < t.Shims[j].Name
+ })
+}
+
+// processImports removes imports that are otherwise handled by the template
+// This method is on the value to shallow copy the Field references to avoid
+// mutating the user provided instance.
+func (t Top) processImports() *Top {
+ pred := map[string]bool{"reflect": true}
+ var filtered []string
+ if len(t.Emitters) > 0 {
+ pred["context"] = true
+ }
+ if len(t.Inputs) > 0 {
+ pred["fmt"] = true
+ pred["io"] = true
+ }
+ if len(t.Types) > 0 || len(t.Functions) > 0 {
+ filtered = append(filtered, RuntimeImport)
+ pred[RuntimeImport] = true
+ }
+ if len(t.Shims) > 0 {
+ filtered = append(filtered, ReflectxImport)
+ pred[ReflectxImport] = true
+ }
+ if len(t.Emitters) > 0 || len(t.Inputs) > 0 {
+ filtered = append(filtered, ExecImport)
+ pred[ExecImport] = true
+ }
+ needTypexImport := len(t.Emitters) > 0
+ for _, i := range t.Inputs {
+ if i.Time {
+ needTypexImport = true
+ break
+ }
+ }
+ if needTypexImport {
+ filtered = append(filtered, TypexImport)
+ pred[TypexImport] = true
+ }
+ for _, imp := range t.Imports {
+ if !pred[imp] {
+ filtered = append(filtered, imp)
+ }
+ }
+ t.Imports = filtered
+ return &t
+}
+
+// Emitter represents an emitter shim to be generated.
+type Emitter struct {
+ Name, Type string // The user name of the function, the type of the
emit.
+ Time bool // if this uses event time.
+ Key, Val string // The type of the emits.
+}
+
+// Input represents an iterator shim to be generated.
+type Input struct {
+ Name, Type string // The user name of the function, the type of the
iterator (including the bool).
+ Time bool // if this uses event time.
+ Key, Val string // The type of the inputs, pointers removed.
+}
+
+// Func represents a type assertion shim for function invocation to be
generated.
+type Func struct {
+ Name, Type string
+ In, Out []string
+}
+
+// Name creates a capitalized identifier from a type string. The identifier
+// follows the rules of go identifiers and should be compileable.
+// See https://golang.org/ref/spec#Identifiers for details.
+func Name(t string) string {
+ if strings.HasPrefix(t, "[]") {
+ return Name(t[2:] + "Slice")
+ }
+
+ t = strings.Replace(t, "beam.", "typex.", -1)
+ t = strings.Replace(t, ".", "۰", -1) // For packages
+ t = strings.Replace(t, "*", "Ꮨ", -1) // For pointers
+ t = strings.Replace(t, "[", "_", -1) // For maps
+ t = strings.Replace(t, "]", "_", -1)
+ return strings.Title(t)
+}
+
+// FuncName returns a compilable Go identifier for a function, given valid
+// type names as generated by Name.
+// See https://golang.org/ref/spec#Identifiers for details.
+func FuncName(inNames, outNames []string) string {
+ return fmt.Sprintf("%sГ%s", strings.Join(inNames, ""),
strings.Join(outNames, ""))
+}
+
+// File writes go code to the given writer.
+func File(w io.Writer, top *Top) {
+ validateBeamImports()
+ top = top.processImports()
+ top.sort()
+ vampireTemplate.Funcs(funcMap).Execute(w, top)
+}
+
+var vampireTemplate =
template.Must(template.New("vampire").Funcs(funcMap).Parse(`// Code generated
by {{.ToolName}}. DO NOT EDIT.
+// File: {{.FileName}}
+
+package {{.Package}}
+
+import (
+
+{{- if .Emitters}}
+ "context"
+{{- end}}
+{{- if .Inputs}}
+ "fmt"
+ "io"
+{{- end}}
+ "reflect"
+{{- if .Imports}}
+
+ // Library imports
+{{- end}}
+{{- range $import := .Imports}}
+ "{{$import}}"
+{{- end}}
+)
+
+func init() {
+{{- range $x := .Functions}}
+ runtime.RegisterFunction({{$x}})
+{{- end}}
+{{- range $x := .Types}}
+ runtime.RegisterType(reflect.TypeOf((*{{$x}})(nil)).Elem())
+{{- end}}
+{{- range $x := .Shims}}
+ reflectx.RegisterFunc(reflect.TypeOf((*{{$x.Type}})(nil)).Elem(),
funcMaker{{$x.Name}})
+{{- end}}
+{{- range $x := .Emitters}}
+ exec.RegisterEmitter(reflect.TypeOf((*{{$x.Type}})(nil)).Elem(),
emitMaker{{$x.Name}})
+{{- end}}
+{{- range $x := .Inputs}}
+ exec.RegisterInput(reflect.TypeOf((*{{$x.Type}})(nil)).Elem(),
iterMaker{{$x.Name}})
+{{- end}}
+}
+
+{{range $x := .Shims -}}
+type caller{{$x.Name}} struct {
+ fn {{$x.Type}}
+}
+
+func funcMaker{{$x.Name}}(fn interface{}) reflectx.Func {
+ f := fn.({{$x.Type}})
+ return &caller{{$x.Name}}{fn: f}
+}
+
+func (c *caller{{$x.Name}}) Name() string {
+ return reflectx.FunctionName(c.fn)
+}
+
+func (c *caller{{$x.Name}}) Type() reflect.Type {
+ return reflect.TypeOf(c.fn)
+}
+
+func (c *caller{{$x.Name}}) Call(args []interface{}) []interface{} {
+ {{mktuplef (len $x.Out) "out%d"}}{{- if len $x.Out}} := {{end
-}}c.fn({{mkparams "args[%d].(%v)" $x.In}})
+ return []interface{}{ {{- mktuplef (len $x.Out) "out%d" -}} }
+}
+
+func (c *caller{{$x.Name}}) Call{{len $x.In}}x{{len $x.Out}}({{mkargs (len
$x.In) "arg%v" "interface{}"}}) ({{- mktuple (len $x.Out) "interface{}"}}) {
+ {{if len $x.Out}}return {{end}}c.fn({{mkparams "arg%d.(%v)" $x.In}})
+}
+
+{{end}}
+{{if .Emitters -}}
+type emitNative struct {
+ n exec.ElementProcessor
+ fn interface{}
+
+ ctx context.Context
+ ws []typex.Window
+ et typex.EventTime
+}
+
+func (e *emitNative) Init(ctx context.Context, ws []typex.Window, et
typex.EventTime) error {
+ e.ctx = ctx
+ e.ws = ws
+ e.et = et
+ return nil
+}
+
+func (e *emitNative) Value() interface{} {
+ return e.fn
+}
+
+{{end -}}
+{{range $x := .Emitters -}}
+func emitMaker{{$x.Name}}(n exec.ElementProcessor) exec.ReusableEmitter {
+ ret := &emitNative{n: n}
+ ret.fn = ret.invoke{{.Name}}
+ return ret
+}
+
+func (e *emitNative) invoke{{$x.Name}}({{if $x.Time -}} t typex.EventTime,
{{end}}{{if $x.Key}}key {{$x.Key}}, {{end}}val {{$x.Val}}) {
+ value := exec.FullValue{Windows: e.ws, Timestamp: {{- if $x.Time}}
t{{else}} e.et{{end}}, {{- if $x.Key}} Elm: key, Elm2: val {{else}} Elm:
val{{end -}} }
+ if err := e.n.ProcessElement(e.ctx, value); err != nil {
+ panic(err)
+ }
+}
+
+{{end}}
+{{- if .Inputs -}}
+type iterNative struct {
+ s exec.ReStream
+ fn interface{}
+
+ // cur is the "current" stream, if any.
+ cur exec.Stream
+}
+
+func (v *iterNative) Init() error {
+ cur, err := v.s.Open()
+ if err != nil {
+ return err
+ }
+ v.cur = cur
+ return nil
+}
+
+func (v *iterNative) Value() interface{} {
+ return v.fn
+}
+
+func convToString(v interface{}) string {
+ switch v.(type) {
+ case []byte:
+ return string(v.([]byte))
+ default:
+ return v.(string)
+ }
+}
+
+func (v *iterNative) Reset() error {
+ if err := v.cur.Close(); err != nil {
+ return err
+ }
+ v.cur = nil
+ return nil
+}
+{{- end}}
+{{- range $x := .Inputs}}
+func iterMaker{{$x.Name}}(s exec.ReStream) exec.ReusableInput {
+ ret := &iterNative{s: s}
+ ret.fn = ret.read{{$x.Name}}
+ return ret
+}
+
+func (v *iterNative) read{{$x.Name}}({{if $x.Time -}} et *typex.EventTime,
{{end}}{{if $x.Key}}key *{{$x.Key}}, {{end}}value *{{$x.Val}}) bool {
+ elm, err := v.cur.Read()
+ if err != nil {
+ if err == io.EOF {
+ return false
+ }
+ panic(fmt.Sprintf("broken stream: %v", err))
+ }
+
+{{- if $x.Time}}
+ *et = elm.Timestamp
+{{- end}}
+{{- if eq $x.Key "string"}}
+ *key = convToString(elm.Elm)
+{{- else if $x.Key}}
+ *key = elm.Elm.({{$x.Key}})
+{{- end}}
+{{- if eq $x.Val "string"}}
+ *value = convToString(elm.Elm{{- if $x.Key -}} 2 {{- end -}})
+{{- else}}
+ *value = elm.Elm{{- if $x.Key -}} 2 {{- end -}}.({{$x.Val}})
+{{- end}}
+ return true
+}
+{{- end}}
+
+// DO NOT MODIFY: GENERATED CODE
+`))
+
+// funcMap contains useful functions for use in the template.
+var funcMap template.FuncMap = map[string]interface{}{
+ "mkargs": mkargs,
+ "mkparams": mkparams,
+ "mktuple": mktuple,
+ "mktuplef": mktuplef,
+}
+
+// mkargs(n, type) returns "<fmt.Sprintf(format, 0)>, .., <fmt.Sprintf(format,
n-1)> type".
+// If n is 0, it returns the empty string.
+func mkargs(n int, format, typ string) string {
+ if n == 0 {
+ return ""
+ }
+ return fmt.Sprintf("%v %v", mktuplef(n, format), typ)
+}
+
+// mkparams(format, []type) returns "<fmt.Sprintf(format, 0, type[0])>, ..,
<fmt.Sprintf(format, n-1, type[0])>".
+func mkparams(format string, types []string) string {
+ var ret []string
+ for i, t := range types {
+ ret = append(ret, fmt.Sprintf(format, i, t))
+ }
+ return strings.Join(ret, ", ")
+}
+
+// mktuple(n, v) returns "v, v, ..., v".
+func mktuple(n int, v string) string {
+ var ret []string
+ for i := 0; i < n; i++ {
+ ret = append(ret, v)
+ }
+ return strings.Join(ret, ", ")
+}
+
+// mktuplef(n, format) returns "<fmt.Sprintf(format, 0)>, ..,
<fmt.Sprintf(format, n-1)>"
+func mktuplef(n int, format string) string {
+ var ret []string
+ for i := 0; i < n; i++ {
+ ret = append(ret, fmt.Sprintf(format, i))
+ }
+ return strings.Join(ret, ", ")
+}
diff --git a/sdks/go/pkg/beam/util/shimx/generate_test.go
b/sdks/go/pkg/beam/util/shimx/generate_test.go
new file mode 100644
index 00000000000..3696bbab7f3
--- /dev/null
+++ b/sdks/go/pkg/beam/util/shimx/generate_test.go
@@ -0,0 +1,217 @@
+// Licensed to the Apache Software Foundation (ASF) under one or more
+// contributor license agreements. See the NOTICE file distributed with
+// this work for additional information regarding copyright ownership.
+// The ASF licenses this file to You under the Apache License, Version 2.0
+// (the "License"); you may not use this file except in compliance with
+// the License. You may obtain a copy of the License at
+//
+// http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package shimx
+
+import (
+ "bytes"
+ "sort"
+ "testing"
+)
+
+func TestTop_Sort(t *testing.T) {
+ top := Top{
+ Imports: []string{"z", "a", "r"},
+ Functions: []string{"z", "a", "r"},
+ Types: []string{"z", "a", "r"},
+ Emitters: []Emitter{{Name: "z"}, {Name: "a"}, {Name: "r"}},
+ Inputs: []Input{{Name: "z"}, {Name: "a"}, {Name: "r"}},
+ Shims: []Func{{Name: "z"}, {Name: "a"}, {Name: "r"}},
+ }
+
+ top.sort()
+ if !sort.SliceIsSorted(top.Imports, func(i, j int) bool { return
top.Imports[i] < top.Imports[j] }) {
+ t.Errorf("top.Imports not sorted: got %v, want it sorted",
top.Imports)
+ }
+ if !sort.SliceIsSorted(top.Functions, func(i, j int) bool { return
top.Functions[i] < top.Functions[j] }) {
+ t.Errorf("top.Types not sorted: got %v, want it sorted",
top.Functions)
+ }
+ if !sort.SliceIsSorted(top.Types, func(i, j int) bool { return
top.Types[i] < top.Types[j] }) {
+ t.Errorf("top.Types not sorted: got %v, want it sorted",
top.Types)
+ }
+ if !sort.SliceIsSorted(top.Emitters, func(i, j int) bool { return
top.Emitters[i].Name < top.Emitters[j].Name }) {
+ t.Errorf("top.Emitters not sorted by name: got %v, want it
sorted", top.Emitters)
+ }
+ if !sort.SliceIsSorted(top.Inputs, func(i, j int) bool { return
top.Inputs[i].Name < top.Inputs[j].Name }) {
+ t.Errorf("top.Inputs not sorted by name: got %v, want it
sorted", top.Inputs)
+ }
+ if !sort.SliceIsSorted(top.Shims, func(i, j int) bool { return
top.Shims[i].Name < top.Shims[j].Name }) {
+ t.Errorf("top.Shims not sorted: got %v, want it sorted",
top.Shims)
+ }
+}
+
+func TestTop_ProcessImports(t *testing.T) {
+ needsFiltering := []string{"context", "keepit", "fmt", "io", "reflect",
"unrelated"}
+
+ tests := []struct {
+ name string
+ got *Top
+ want []string
+ }{
+ {name: "default", got: &Top{}, want: []string{"context",
"keepit", "fmt", "io", "unrelated"}},
+ {name: "emit", got: &Top{Emitters: []Emitter{{Name: "emit"}}},
want: []string{ExecImport, TypexImport, "keepit", "fmt", "io", "unrelated"}},
+ {name: "iter", got: &Top{Inputs: []Input{{Name: "iter"}}},
want: []string{ExecImport, "context", "keepit", "unrelated"}},
+ {name: "iterWTime", got: &Top{Inputs: []Input{{Name:
"iterWTime", Time: true}}}, want: []string{ExecImport, TypexImport, "context",
"keepit", "unrelated"}},
+ {name: "shim", got: &Top{Shims: []Func{{Name: "emit"}}}, want:
[]string{ReflectxImport, "context", "keepit", "fmt", "io", "unrelated"}},
+ {name: "iter&emit", got: &Top{Emitters: []Emitter{{Name:
"emit"}}, Inputs: []Input{{Name: "iter"}}}, want: []string{ExecImport,
TypexImport, "keepit", "unrelated"}},
+ {name: "functions", got: &Top{Functions: []string{"func1"}},
want: []string{RuntimeImport, "context", "keepit", "fmt", "io", "unrelated"}},
+ {name: "types", got: &Top{Types: []string{"func1"}}, want:
[]string{RuntimeImport, "context", "keepit", "fmt", "io", "unrelated"}},
+ }
+ for _, test := range tests {
+ t.Run(test.name, func(t *testing.T) {
+ top := test.got
+ top.Imports = needsFiltering
+ top = top.processImports()
+ for i := range top.Imports {
+ if top.Imports[i] != test.want[i] {
+ t.Fatalf("want %v, got %v", test.want,
top.Imports)
+ }
+ }
+ })
+ }
+}
+
+func TestName(t *testing.T) {
+ tests := []struct {
+ have, want string
+ }{
+ {"int", "Int"},
+ {"foo.MyInt", "Foo۰MyInt"},
+ {"[]beam.X", "Typex۰XSlice"},
+ {"map[int]beam.X", "Map_int_typex۰X"},
+ {"map[string]*beam.X", "Map_string_Ꮨtypex۰X"},
+ }
+ for _, test := range tests {
+ if got := Name(test.have); got != test.want {
+ t.Errorf("Name(%v) = %v, want %v", test.have, got,
test.want)
+ }
+ }
+}
+
+func TestFuncName(t *testing.T) {
+ tests := []struct {
+ in, out []string
+ want string
+ }{
+ {in: []string{"Int"}, out: []string{"Int"}, want: "IntГInt"},
+ {in: []string{"Int"}, out: []string{}, want: "IntГ"},
+ {in: []string{}, out: []string{"Bool"}, want: "ГBool"},
+ {in: []string{"Bool", "String"}, out: []string{"Int", "Bool"},
want: "BoolStringГIntBool"},
+ {in: []string{"String", "Map_int_typex۰X"}, out:
[]string{"Int", "Typex۰XSlice"}, want: "StringMap_int_typex۰XГIntTypex۰XSlice"},
+ }
+ for _, test := range tests {
+ if got := FuncName(test.in, test.out); got != test.want {
+ t.Errorf("FuncName(%v,%v) = %v, want %v", test.in,
test.out, got, test.want)
+ }
+ }
+}
+
+func TestFile(t *testing.T) {
+ top := Top{
+ Package: "gentest",
+ Imports: []string{"z", "a", "r"},
+ Functions: []string{"z", "a", "r"},
+ Types: []string{"z", "a", "r"},
+ Emitters: []Emitter{
+ {Name: "z", Type: "func(int)", Val: "Int"},
+ {Name: "a", Type: "func(bool, int) bool", Key: "bool",
Val: "int"},
+ {Name: "r", Type: "func(typex.EventTime, string) bool",
Time: true, Val: "string"},
+ },
+ Inputs: []Input{
+ {Name: "z", Type: "func(*int) bool"},
+ {Name: "a", Type: "func(*bool, *int) bool", Key:
"bool", Val: "int"},
+ {Name: "r", Type: "func(*typex.EventTime, *string)
bool", Time: true, Val: "string"},
+ },
+ Shims: []Func{
+ {Name: "z", Type: "func(string, func(int))", In:
[]string{"string", "func(int)"}},
+ {Name: "a", Type: "func(float64) (int, int)", In:
[]string{"float64"}, Out: []string{"int", "int"}},
+ {Name: "r", Type: "func(string, func(int))", In:
[]string{"string", "func(int)"}},
+ },
+ }
+ top.sort()
+
+ var b bytes.Buffer
+ if err := vampireTemplate.Funcs(funcMap).Execute(&b, top); err != nil {
+ t.Errorf("error generating template: %v", err)
+ }
+}
+
+func TestMkargs(t *testing.T) {
+ tests := []struct {
+ n int
+ format, typ string
+ want string
+ }{
+ {n: 0, format: "Foo", typ: "Bar", want: ""},
+ {n: 1, format: "arg%d", typ: "Bar", want: "arg0 Bar"},
+ {n: 4, format: "a%d", typ: "Baz", want: "a0, a1, a2, a3 Baz"},
+ }
+ for _, test := range tests {
+ if got := mkargs(test.n, test.format, test.typ); got !=
test.want {
+ t.Errorf("mkargs(%v,%v,%v) = %v, want %v", test.n,
test.format, test.typ, got, test.want)
+ }
+ }
+}
+
+func TestMkparams(t *testing.T) {
+ tests := []struct {
+ format string
+ types []string
+ want string
+ }{
+ {format: "Foo", types: []string{}, want: ""},
+ {format: "arg%d %v", types: []string{"Bar"}, want: "arg0 Bar"},
+ {format: "a%d %v", types: []string{"Foo", "Baz",
"interface{}"}, want: "a0 Foo, a1 Baz, a2 interface{}"},
+ }
+ for _, test := range tests {
+ if got := mkparams(test.format, test.types); got != test.want {
+ t.Errorf("mkparams(%v,%v) = %v, want %v", test.format,
test.types, got, test.want)
+ }
+ }
+}
+
+func TestMktuple(t *testing.T) {
+ tests := []struct {
+ n int
+ v string
+ want string
+ }{
+ {n: 0, v: "Foo", want: ""},
+ {n: 1, v: "Bar", want: "Bar"},
+ {n: 4, v: "Baz", want: "Baz, Baz, Baz, Baz"},
+ }
+ for _, test := range tests {
+ if got := mktuple(test.n, test.v); got != test.want {
+ t.Errorf("mktuple(%v,%v) = %v, want %v", test.n,
test.v, got, test.want)
+ }
+ }
+}
+
+func TestMktuplef(t *testing.T) {
+ tests := []struct {
+ n int
+ format, typ string
+ want string
+ }{
+ {n: 0, format: "Foo%d", want: ""},
+ {n: 1, format: "arg%d", want: "arg0"},
+ {n: 4, format: "a%d", want: "a0, a1, a2, a3"},
+ }
+ for _, test := range tests {
+ if got := mktuplef(test.n, test.format); got != test.want {
+ t.Errorf("mktuplef(%v,%v) = %v, want %v", test.n,
test.format, got, test.want)
+ }
+ }
+}
diff --git a/sdks/go/pkg/beam/util/starcgenx/starcgenx.go
b/sdks/go/pkg/beam/util/starcgenx/starcgenx.go
new file mode 100644
index 00000000000..003a3c91df7
--- /dev/null
+++ b/sdks/go/pkg/beam/util/starcgenx/starcgenx.go
@@ -0,0 +1,562 @@
+// Licensed to the Apache Software Foundation (ASF) under one or more
+// contributor license agreements. See the NOTICE file distributed with
+// this work for additional information regarding copyright ownership.
+// The ASF licenses this file to You under the Apache License, Version 2.0
+// (the "License"); you may not use this file except in compliance with
+// the License. You may obtain a copy of the License at
+//
+// http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+// Package starcgenx is a Static Analysis Type Assertion shim and Registration
Code Generator
+// which provides an extractor to extract types from a package, in order to
generate
+// approprate shimsr a package so code can be generated for it.
+//
+// It's written for use by the starcgen tool, but separate to permit
+// alternative "go/importer" Importers for accessing types from imported
packages.
+package starcgenx
+
+import (
+ "bytes"
+ "fmt"
+ "go/ast"
+ "go/token"
+ "go/types"
+ "strings"
+
+ "github.com/apache/beam/sdks/go/pkg/beam/util/shimx"
+)
+
+// NewExtractor returns an extractor for the given package.
+func NewExtractor(pkg string) *Extractor {
+ return &Extractor{
+ Package: pkg,
+ functions: make(map[string]struct{}),
+ types: make(map[string]struct{}),
+ funcs: make(map[string]*types.Signature),
+ emits: make(map[string]shimx.Emitter),
+ iters: make(map[string]shimx.Input),
+ imports: make(map[string]struct{}),
+ allExported: true,
+ }
+}
+
+// Extractor contains and uniquifies the cache of types and things that need
to be generated.
+type Extractor struct {
+ w bytes.Buffer
+ Package string
+ debug bool
+
+ // Ids is an optional slice of package local identifiers
+ Ids []string
+
+ // Register and uniquify the needed shims for each kind.
+ // Functions to Register
+ functions map[string]struct{}
+ // Types to Register (structs, essentially)
+ types map[string]struct{}
+ // FuncShims needed
+ funcs map[string]*types.Signature
+ // Emitter Shims needed
+ emits map[string]shimx.Emitter
+ // Iterator Shims needed
+ iters map[string]shimx.Input
+
+ // list of packages we need to import.
+ imports map[string]struct{}
+
+ allExported bool // Marks if all ptransforms are exported and available
in main.
+}
+
+// Summary prints out a summary of the shims and registrations to
+// be generated to the buffer.
+func (e *Extractor) Summary() {
+ e.Print("\n")
+ e.Print("Summary\n")
+ e.Printf("All exported?: %v\n", e.allExported)
+ e.Printf("%d\t Functions\n", len(e.functions))
+ e.Printf("%d\t Types\n", len(e.types))
+ e.Printf("%d\t Shims\n", len(e.funcs))
+ e.Printf("%d\t Emits\n", len(e.emits))
+ e.Printf("%d\t Inputs\n", len(e.iters))
+}
+
+// lifecycleMethodName returns if the passed in string is one of the lifecycle
method names used
+// by the Go SDK as DoFn or CombineFn lifecycle methods. These are the only
methods that need
+// shims generated for them, as per beam/core/graph/fn.go
+// TODO(lostluck): Move this to beam/core/graph/fn.go, so it can stay up to
date.
+func lifecycleMethodName(n string) bool {
+ switch n {
+ case "ProcessElement", "StartBundle", "FinishBundle", "Setup",
"Teardown", "CreateAccumulator", "AddInput", "MergeAccumulators",
"ExtractOutput", "Compact":
+ return true
+ default:
+ return false
+ }
+}
+
+// Bytes forwards to fmt.Fprint to the extractor buffer.
+func (e *Extractor) Bytes() []byte {
+ return e.w.Bytes()
+}
+
+// Print forwards to fmt.Fprint to the extractor buffer.
+func (e *Extractor) Print(s string) {
+ if e.debug {
+ fmt.Fprint(&e.w, s)
+ }
+}
+
+// Printf forwards to fmt.Printf to the extractor buffer.
+func (e *Extractor) Printf(f string, args ...interface{}) {
+ if e.debug {
+ fmt.Fprintf(&e.w, f, args...)
+ }
+}
+
+// FromAsts analyses the contents of a package
+func (e *Extractor) FromAsts(imp types.Importer, fset *token.FileSet, files
[]*ast.File) error {
+ conf := types.Config{
+ Importer: imp,
+ IgnoreFuncBodies: true,
+ DisableUnusedImportCheck: true,
+ }
+ info := &types.Info{
+ Defs: make(map[*ast.Ident]types.Object),
+ }
+ if len(e.Ids) != 0 {
+ // TODO(lostluck): This becomes unnnecessary iff we can figure
out
+ // which ParDos are being passed to beam.ParDo or beam.Combine.
+ // If there are ids, we need to also look at function bodies,
and uses.
+ var checkFuncBodies bool
+ for _, v := range e.Ids {
+ if strings.Contains(v, ".") {
+ checkFuncBodies = true
+ break
+ }
+ }
+ conf.IgnoreFuncBodies = !checkFuncBodies
+ info.Uses = make(map[*ast.Ident]types.Object)
+ }
+
+ if _, err := conf.Check(e.Package, fset, files, info); err != nil {
+ return fmt.Errorf("failed to type check package %s : %v",
e.Package, err)
+ }
+
+ e.Print("/*\n")
+ var idsRequired, idsFound map[string]bool
+ if len(e.Ids) > 0 {
+ e.Printf("Filtering by %d identifiers: %q\n", len(e.Ids),
strings.Join(e.Ids, ", "))
+ idsRequired = make(map[string]bool)
+ idsFound = make(map[string]bool)
+ for _, id := range e.Ids {
+ idsRequired[id] = true
+ }
+ }
+ e.Print("CHECKING DEFS\n")
+ for id, obj := range info.Defs {
+ e.fromObj(fset, id, obj, idsRequired, idsFound)
+ }
+ e.Print("CHECKING USES\n")
+ for id, obj := range info.Uses {
+ e.fromObj(fset, id, obj, idsRequired, idsFound)
+ }
+ var notFound []string
+ for _, k := range e.Ids {
+ if !idsFound[k] {
+ notFound = append(notFound, k)
+ }
+ }
+ if len(notFound) > 0 {
+ return fmt.Errorf("couldn't find the following identifiers;
please check for typos, or remove them: %v", strings.Join(notFound, ", "))
+ }
+ e.Print("*/\n")
+
+ return nil
+}
+
+func (e *Extractor) isRequired(ident string, obj types.Object, idsRequired,
idsFound map[string]bool) bool {
+ if idsRequired == nil {
+ return true
+ }
+ if idsFound == nil {
+ panic("broken invariant: idsFound map is nil, but idsRequired
map exists")
+ }
+ // If we're filtering IDs, then it needs to be in the filtered
identifiers,
+ // or it's receiver type identifier needs to be in the filtered
identifiers.
+ if idsRequired[ident] {
+ idsFound[ident] = true
+ return true
+ }
+ // Check if this is a function.
+ sig, ok := obj.Type().(*types.Signature)
+ if !ok {
+ return false
+ }
+ // If this is a function, and it has a receiver, it's a method.
+ if recv := sig.Recv(); recv != nil && lifecycleMethodName(ident) {
+ // We don't want to care about pointers, so dereference to
value type.
+ t := recv.Type()
+ p, ok := t.(*types.Pointer)
+ for ok {
+ t = p.Elem()
+ p, ok = t.(*types.Pointer)
+ }
+ ts := types.TypeString(t, e.qualifier)
+ e.Printf("RRR has %v, ts: %s %s--- ", sig, ts, ident)
+ if !idsRequired[ts] {
+ e.Print("IGNORE\n")
+ return false
+ }
+ e.Print("KEEP\n")
+ idsFound[ts] = true
+ return true
+ }
+ return false
+}
+
+func (e *Extractor) fromObj(fset *token.FileSet, id *ast.Ident, obj
types.Object, idsRequired, idsFound map[string]bool) {
+ if obj == nil { // Omit the package declaration.
+ e.Printf("%s: %q has no object, probably a package\n",
+ fset.Position(id.Pos()), id.Name)
+ return
+ }
+
+ pkg := obj.Pkg()
+ if pkg == nil {
+ e.Printf("%s: %q has no package \n",
+ fset.Position(id.Pos()), id.Name)
+ // No meaningful identifier.
+ return
+ }
+ ident := fmt.Sprintf("%s.%s", pkg.Name(), obj.Name())
+ if pkg.Name() == e.Package {
+ ident = obj.Name()
+ }
+ if !e.isRequired(ident, obj, idsRequired, idsFound) {
+ return
+ }
+
+ switch ot := obj.(type) {
+ case *types.Var:
+ // Vars are tricky since they could be anything, and anywhere
(package scope, parameters, etc)
+ // eg. Flags, or Field Tags, among others.
+ // I'm increasingly convinced that we should simply igonore
vars.
+ // Do nothing for vars.
+ case *types.Func:
+ sig := obj.Type().(*types.Signature)
+ if recv := sig.Recv(); recv != nil {
+ // Methods don't need registering, but they do need
shim generation.
+ e.Printf("%s: %q is a method of %v -> %v--- %T %v %v
%v\n",
+ fset.Position(id.Pos()), id.Name, recv.Type(),
obj, obj, id, obj.Pkg(), obj.Type())
+ if !lifecycleMethodName(id.Name) {
+ // If this is not a lifecycle method, we should
ignore it.
+ return
+ }
+ } else if id.Name != "init" {
+ // init functions are special and should be ignored.
+ // Functions need registering, as well as shim
generation.
+ e.Printf("%s: %q is a top level func %v --- %T %v %v
%v\n",
+ fset.Position(id.Pos()), ident, obj, obj, id,
obj.Pkg(), obj.Type())
+ e.functions[ident] = struct{}{}
+ }
+ // For functions from other packages.
+ if pkg.Name() != e.Package {
+ e.imports[pkg.Path()] = struct{}{}
+ }
+
+ e.funcs[e.sigKey(sig)] = sig
+ e.extractParameters(sig)
+ e.Printf("\t%v\n", sig)
+ case *types.TypeName:
+ e.Printf("%s: %q is a type %v --- %T %v %v %v %v\n",
+ fset.Position(id.Pos()), id.Name, obj, obj, id,
obj.Pkg(), obj.Type(), obj.Name())
+ // Probably need to sanity check that this type actually is/has
a ProcessElement
+ // or MergeAccumulators defined for this type so unnecessary
registrations don't happen,
+ // an can explicitly produce an error if an explicitly named
type *isn't* a DoFn or CombineFn.
+ e.extractType(ot)
+ default:
+ e.Printf("%s: %q defines %v --- %T %v %v %v\n",
+ fset.Position(id.Pos()), types.ObjectString(obj,
e.qualifier), obj, obj, id, obj.Pkg(), obj.Type())
+ }
+}
+
+func (e *Extractor) extractType(ot *types.TypeName) {
+ name := types.TypeString(ot.Type(), e.qualifier)
+ // Unwrap an alias by one level.
+ // Attempting to deference a full chain of aliases runs the risk of
crossing
+ // a visibility boundary such as internal packages.
+ // A single level is safe since the code we're analysing imports it,
+ // so we can assume the generated code can access it too.
+ if ot.IsAlias() {
+ if t, ok := ot.Type().(*types.Named); ok {
+ ot = t.Obj()
+ name = types.TypeString(t, e.qualifier)
+
+ if pkg := t.Obj().Pkg(); pkg != nil {
+ e.imports[pkg.Path()] = struct{}{}
+ }
+ }
+ }
+ e.types[name] = struct{}{}
+}
+
+// Examines the signature and extracts types of parameters for generating
+// necessary imports and emitter and iterator code.
+func (e *Extractor) extractParameters(sig *types.Signature) {
+ in := sig.Params() // *types.Tuple
+ for i := 0; i < in.Len(); i++ {
+ s := in.At(i) // *types.Var
+
+ // Pointer types need to be iteratively unwrapped until we're
at the base type,
+ // so we can get the import if necessary.
+ t := s.Type()
+ p, ok := t.(*types.Pointer)
+ for ok {
+ t = p.Elem()
+ p, ok = t.(*types.Pointer)
+ }
+ // Here's were we ensure we register new imports.
+ if t, ok := t.(*types.Named); ok {
+ if pkg := t.Obj().Pkg(); pkg != nil {
+ e.imports[pkg.Path()] = struct{}{}
+ }
+ e.extractType(t.Obj())
+ }
+
+ if a, ok := s.Type().(*types.Signature); ok {
+ // Check if the type is an emitter or iterator for the
specialized
+ // shim generation for those types.
+ if emt, ok := e.makeEmitter(a); ok {
+ e.emits[emt.Name] = emt
+ }
+ if ipt, ok := e.makeInput(a); ok {
+ e.iters[ipt.Name] = ipt
+ }
+ // Tail recurse on functional parameters.
+ e.extractParameters(a)
+ }
+ }
+}
+
+func (e *Extractor) qualifier(pkg *types.Package) string {
+ n := tail(pkg.Name())
+ if n == e.Package {
+ return ""
+ }
+ return n
+}
+
+func tail(path string) string {
+ if i := strings.LastIndex("/", path); i >= 0 {
+ path = path[i:]
+ }
+ return path
+}
+
+func (e *Extractor) tupleStrings(t *types.Tuple) []string {
+ var vs []string
+ for i := 0; i < t.Len(); i++ {
+ v := t.At(i)
+ vs = append(vs, types.TypeString(v.Type(), e.qualifier))
+ }
+ return vs
+}
+
+// sigKey produces a variable name agnostic key for the function signature.
+func (e *Extractor) sigKey(sig *types.Signature) string {
+ ps, rs := e.tupleStrings(sig.Params()), e.tupleStrings(sig.Results())
+ return fmt.Sprintf("func(%v) (%v)", strings.Join(ps, ","),
strings.Join(rs, ","))
+}
+
+// Generate produces an additional file for the Go package that was extracted,
+// to be included in a subsequent compilation.
+func (e *Extractor) Generate(filename string) []byte {
+ var functions []string
+ for fn := range e.functions {
+ // No extra processing necessary, since these should all be
package local.
+ functions = append(functions, fn)
+ }
+ var typs []string
+ for t := range e.types {
+ typs = append(typs, t)
+ }
+ var shims []shimx.Func
+ for sig, t := range e.funcs {
+ shim := shimx.Func{Type: sig}
+ var inNames []string
+ in := t.Params() // *types.Tuple
+ for i := 0; i < in.Len(); i++ {
+ s := in.At(i) // *types.Var
+ shim.In = append(shim.In, types.TypeString(s.Type(),
e.qualifier))
+ inNames = append(inNames, e.NameType(s.Type()))
+ }
+ var outNames []string
+ out := t.Results() // *types.Tuple
+ for i := 0; i < out.Len(); i++ {
+ s := out.At(i)
+ shim.Out = append(shim.Out, types.TypeString(s.Type(),
e.qualifier))
+ outNames = append(outNames, e.NameType(s.Type()))
+ }
+ shim.Name = shimx.FuncName(inNames, outNames)
+ shims = append(shims, shim)
+ }
+ var emits []shimx.Emitter
+ for _, t := range e.emits {
+ emits = append(emits, t)
+ }
+ var inputs []shimx.Input
+ for _, t := range e.iters {
+ inputs = append(inputs, t)
+ }
+
+ var imports []string
+ for k := range e.imports {
+ if k == "" || k == e.Package {
+ continue
+ }
+ imports = append(imports, k)
+ }
+
+ top := shimx.Top{
+ FileName: filename,
+ ToolName: "starcgen",
+ Package: e.Package,
+ Imports: imports,
+ Functions: functions,
+ Types: typs,
+ Shims: shims,
+ Emitters: emits,
+ Inputs: inputs,
+ }
+ e.Print("\n")
+ shimx.File(&e.w, &top)
+ return e.w.Bytes()
+}
+
+func (e *Extractor) makeEmitter(sig *types.Signature) (shimx.Emitter, bool) {
+ // Emitters must have no return values.
+ if sig.Results().Len() != 0 {
+ return shimx.Emitter{}, false
+ }
+ p := sig.Params()
+ emt := shimx.Emitter{Type: e.sigKey(sig)}
+ switch p.Len() {
+ case 1:
+ emt.Time = false
+ emt.Val = e.varString(p.At(0))
+ case 2:
+ // TODO(rebo): Fix this when imports are resolved.
+ // This is the tricky one... Need to verify what happens with
aliases.
+ // And get a candle to compare this against somehwere.
isEventTime(p.At(0)) maybe.
+ // if p.At(0) == typex.EventTimeType {
+ // emt.Time = true
+ // } else {
+ emt.Key = e.varString(p.At(0))
+ //}
+ emt.Val = e.varString(p.At(1))
+ case 3:
+ // If there's 3, the first one must be typex.EventTime.
+ emt.Time = true
+ emt.Key = e.varString(p.At(1))
+ emt.Val = e.varString(p.At(2))
+ default:
+ return shimx.Emitter{}, false
+ }
+ if emt.Time {
+ emt.Name = fmt.Sprintf("ET%s%s", shimx.Name(emt.Key),
shimx.Name(emt.Val))
+ } else {
+ emt.Name = fmt.Sprintf("%s%s", shimx.Name(emt.Key),
shimx.Name(emt.Val))
+ }
+ return emt, true
+}
+
+// makeInput checks if the given signature is an iterator or not, and if so,
+// returns a shimx.Input struct for the signature for use by the code
+// generator. The canonical check for an iterater signature is in the
+// funcx.UnfoldIter function which uses the reflect library,
+// and this logic is replicated here.
+func (e *Extractor) makeInput(sig *types.Signature) (shimx.Input, bool) {
+ r := sig.Results()
+ if r.Len() != 1 {
+ return shimx.Input{}, false
+ }
+ // Iterators must return a bool.
+ if b, ok := r.At(0).Type().(*types.Basic); !ok || b.Kind() !=
types.Bool {
+ return shimx.Input{}, false
+ }
+ p := sig.Params()
+ for i := 0; i < p.Len(); i++ {
+ // All params for iterators must be pointers.
+ if _, ok := p.At(i).Type().(*types.Pointer); !ok {
+ return shimx.Input{}, false
+ }
+ }
+ itr := shimx.Input{Type: e.sigKey(sig)}
+ switch p.Len() {
+ case 1:
+ itr.Time = false
+ itr.Val = e.deref(p.At(0))
+ case 2:
+ // TODO(rebo): Fix this when imports are resolved.
+ // This is the tricky one... Need to verify what happens with
aliases.
+ // And get a candle to compare this against somehwere.
isEventTime(p.At(0)) maybe.
+ // if p.At(0) == typex.EventTimeType {
+ // itr.Time = true
+ // } else {
+ itr.Key = e.deref(p.At(0))
+ //}
+ itr.Val = e.deref(p.At(1))
+ case 3:
+ // If there's 3, the first one must be typex.EventTime.
+ itr.Time = true
+ itr.Key = e.deref(p.At(1))
+ itr.Val = e.deref(p.At(2))
+ default:
+ return shimx.Input{}, false
+ }
+ if itr.Time {
+ itr.Name = fmt.Sprintf("ET%s%s", shimx.Name(itr.Key),
shimx.Name(itr.Val))
+ } else {
+ itr.Name = fmt.Sprintf("%s%s", shimx.Name(itr.Key),
shimx.Name(itr.Val))
+ }
+ return itr, true
+}
+
+// deref returns the string identifier for the element type of a pointer var.
+// deref panics if the var type is not a pointer.
+func (e *Extractor) deref(v *types.Var) string {
+ p := v.Type().(*types.Pointer)
+ return types.TypeString(p.Elem(), e.qualifier)
+}
+
+// varString provides the correct type for a variable within the
+// package for which we're generated code.
+func (e *Extractor) varString(v *types.Var) string {
+ return types.TypeString(v.Type(), e.qualifier)
+}
+
+// NameType turns a reflect.Type into a strying based on it's name.
+// It prefixes Emit or Iter if the function satisfies the constrains of those
types.
+func (e *Extractor) NameType(t types.Type) string {
+ switch a := t.(type) {
+ case *types.Signature:
+ if emt, ok := e.makeEmitter(a); ok {
+ return "Emit" + emt.Name
+ }
+ if ipt, ok := e.makeInput(a); ok {
+ return "Iter" + ipt.Name
+ }
+ return shimx.Name(e.sigKey(a))
+ case *types.Pointer:
+ return e.NameType(a.Elem())
+ case *types.Slice:
+ return "Sliceof" + e.NameType(a.Elem())
+ default:
+ return shimx.Name(types.TypeString(t, e.qualifier))
+ }
+}
diff --git a/sdks/go/pkg/beam/util/starcgenx/starcgenx_test.go
b/sdks/go/pkg/beam/util/starcgenx/starcgenx_test.go
new file mode 100644
index 00000000000..9141acb114e
--- /dev/null
+++ b/sdks/go/pkg/beam/util/starcgenx/starcgenx_test.go
@@ -0,0 +1,145 @@
+// Licensed to the Apache Software Foundation (ASF) under one or more
+// contributor license agreements. See the NOTICE file distributed with
+// this work for additional information regarding copyright ownership.
+// The ASF licenses this file to You under the Apache License, Version 2.0
+// (the "License"); you may not use this file except in compliance with
+// the License. You may obtain a copy of the License at
+//
+// http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package starcgenx
+
+import (
+ "go/ast"
+ "go/importer"
+ "go/parser"
+ "go/token"
+ "strings"
+ "testing"
+)
+
+func TestExtractor(t *testing.T) {
+ tests := []struct {
+ name string
+ pkg string
+ files []string
+ ids []string
+ expected []string
+ excluded []string
+ }{
+ {name: "pardo1", files: []string{pardo}, pkg: "pardo",
+ expected: []string{"runtime.RegisterFunction(MyIdent)",
"runtime.RegisterFunction(MyDropVal)", "runtime.RegisterFunction(MyOtherDoFn)",
"runtime.RegisterType(reflect.TypeOf((*foo)(nil)).Elem())",
"funcMakerStringГString", "funcMakerIntStringГInt", "funcMakerFooГStringFoo"},
+ },
+ {name: "emits1", files: []string{emits}, pkg: "emits",
+ expected:
[]string{"runtime.RegisterFunction(anotherFn)",
"runtime.RegisterFunction(emitFn)",
"runtime.RegisterType(reflect.TypeOf((*reInt)(nil)).Elem())",
"funcMakerEmitIntIntГ", "emitMakerIntInt", "funcMakerIntIntEmitIntIntГError"},
+ },
+ {name: "iters1", files: []string{iters}, pkg: "iters",
+ expected: []string{"runtime.RegisterFunction(iterFn)",
"funcMakerStringIterIntГ", "iterMakerInt"},
+ },
+ {name: "structs1", files: []string{structs}, pkg: "structs",
ids: []string{"myDoFn"},
+ expected:
[]string{"runtime.RegisterType(reflect.TypeOf((*myDoFn)(nil)).Elem())",
"funcMakerEmitIntГ", "emitMakerInt", "funcMakerValTypeValTypeEmitIntГ",
"runtime.RegisterType(reflect.TypeOf((*valType)(nil)).Elem())"},
+ excluded: []string{"funcMakerStringГ",
"emitMakerString", "nonPipelineType"},
+ },
+ }
+ for _, test := range tests {
+ test := test
+ t.Run(test.name, func(t *testing.T) {
+ fset := token.NewFileSet()
+ var fs []*ast.File
+ for i, f := range test.files {
+ n, err := parser.ParseFile(fset, "", f, 0)
+ if err != nil {
+ t.Fatalf("couldn't parse
test.files[%d]: %v", i, err)
+ }
+ fs = append(fs, n)
+ }
+ e := NewExtractor(test.pkg)
+ e.Ids = test.ids
+ if err := e.FromAsts(importer.Default(), fset, fs); err
!= nil {
+ t.Fatal(err)
+ }
+ data := e.Generate("test_shims.go")
+ s := string(data)
+ for _, i := range test.expected {
+ if !strings.Contains(s, i) {
+ t.Errorf("expected %q in generated
file", i)
+ }
+ }
+ for _, i := range test.excluded {
+ if strings.Contains(s, i) {
+ t.Errorf("found %q in generated file",
i)
+ }
+ }
+ t.Log(s)
+ })
+ }
+}
+
+const pardo = `
+package pardo
+
+func MyIdent(v string) string {
+ return v
+}
+
+func MyDropVal(k int,v string) int {
+ return k
+}
+
+// A user defined type
+type foo struct{}
+
+func MyOtherDoFn(v foo) (string,foo) {
+ return "constant"
+}
+`
+
+const emits = `
+package emits
+
+type reInt int
+
+func anotherFn(emit func(int,int)) {
+ emit(0, 0)
+}
+
+func emitFn(k,v int, emit func(int,int)) error {
+ for i := 0; i < v; i++ { emit(k, i) }
+ return nil
+}
+`
+const iters = `
+package iters
+
+func iterFn(k string, iters func(*int) bool) {}
+`
+
+const structs = `
+package structs
+
+type myDoFn struct{}
+
+// valType should be picked up via processElement
+type valType int
+
+func (f *myDoFn) ProcessElement(k, v valType, emit func(int)) {}
+
+func (f *myDoFn) Setup(emit func(int)) {}
+func (f *myDoFn) StartBundle(emit func(int)) {}
+func (f *myDoFn) FinishBundle(emit func(int)) error {}
+func (f *myDoFn) Teardown(emit func(int)) {}
+
+type nonPipelineType int
+
+// UnrelatedMethods shouldn't have shims or tangents generated for them
+func (f *myDoFn) UnrelatedMethod1(v string) {}
+func (f *myDoFn) UnrelatedMethod2(notEmit func(string)) {}
+
+func (f *myDoFn) UnrelatedMethod3(notEmit func(nonPipelineType)) {}
+`
----------------------------------------------------------------
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Issue Time Tracking
-------------------
Worklog Id: (was: 165044)
Time Spent: 6h 20m (was: 6h 10m)
> Make it easy to generate type-specialized Go SDK reflectx.Funcs
> ---------------------------------------------------------------
>
> Key: BEAM-3612
> URL: https://issues.apache.org/jira/browse/BEAM-3612
> Project: Beam
> Issue Type: Improvement
> Components: sdk-go
> Reporter: Henning Rohde
> Assignee: Robert Burke
> Priority: Major
> Time Spent: 6h 20m
> Remaining Estimate: 0h
>
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