gen.rboot.go

// Copyright ©2018 The go-hep Authors. All rights reserved.
// Use of this source code is governed by a BSD-style
// license that can be found in the LICENSE file.

//go:build ignore

// gen.rboot generates rdict streamers from the C++/ROOT ones.
// gen.rboot generates ROOT class versions from the C++/ROOT streamers.
package main

import (
	"bytes"
	"encoding/json"
	"fmt"
	"io"
	"log"
	"os"
	"strings"
	"text/template"

	"go-hep.org/x/hep/groot/internal/genroot"
	"go-hep.org/x/hep/groot/internal/rtests"
	"go-hep.org/x/hep/groot/rbytes"
	"go-hep.org/x/hep/groot/rdict"
	"go-hep.org/x/hep/groot/riofs"
)

var (
	classes = []string{
		// rbase
		"TAttAxis", "TAttFill", "TAttLine", "TAttMarker",
		"TDatime",
		"TNamed",
		"TObject", "TObjString",
		"TProcessID", "TProcessUUID", "TRef", "TUUID",
		"TString",

		// rcont
		"TArray", "TArrayC", "TArrayS", "TArrayI", "TArrayL", "TArrayL64", "TArrayF", "TArrayD",
		"TBits",
		"TCollection",
		"TClonesArray",
		"TList",
		"THashList",
		"THashTable",
		"TMap",
		"TObjArray",
		"TRefArray",
		"TRefTable",
		"TSeqCollection",

		// rdict
		"TStreamerInfo",
		"TStreamerElement",
		"TStreamerBase",
		"TStreamerBasicType",
		"TStreamerBasicPointer",
		"TStreamerLoop",
		"TStreamerObject",
		"TStreamerObjectPointer",
		"TStreamerObjectAny",
		"TStreamerObjectAnyPointer",
		"TStreamerString",
		"TStreamerSTL",
		"TStreamerSTLstring",
		"TStreamerArtificial",

		// rhist
		"TAxis",
		"TConfidenceLevel",
		"TEfficiency",
		"TF1",
		"TF1AbsComposition", "TF1Convolution", "TF1NormSum", "TF1Parameters",
		"TFormula",
		"TGraph", "TGraphErrors", "TGraphAsymmErrors", "TGraphMultiErrors",
		"TH1", "TH1C", "TH1D", "TH1F", "TH1I", "TH1K", "TH1S",
		"TH2", "TH2C", "TH2D", "TH2F", "TH2I", "TH2Poly", "TH2PolyBin", "TH2S",
		"TLimit", "TLimitDataSource",
		"TMultiGraph",
		"TProfile", "TProfile2D",

		// riofs
		"TDirectory",
		"TDirectoryFile",
		"TFile",
		"TKey",

		// rntup
		// "ROOT::Experimental::RNTuple", // FIXME(sbinet): TODO

		// rphys
		"TFeldmanCousins",
		"TLorentzVector",
		"TVector2", "TVector3",

		// rtree
		"ROOT::TIOFeatures",
		"TBasket",
		"TBranch", "TBranchElement", "TBranchObject", "TBranchRef",
		"TChain",
		"TLeaf", "TLeafElement", "TLeafObject",
		"TLeafO",
		"TLeafB", "TLeafS", "TLeafI", "TLeafL",
		"TLeafF", "TLeafD",
		"TLeafF16", "TLeafD32",
		"TLeafC",
		"TNtuple", "TNtupleD",
		"TTree",
	}
)

func main() {
	genStreamers(classes)
}

func genStreamers(classes []string) {
	const (
		oname = "streamers.root"
	)
	defer os.Remove(oname)

	tmpl := template.Must(template.New("genstreamers").Parse(`
void genstreamers(const char* fname) {
	auto f = TFile::Open(fname, "RECREATE");

{{range .}}
	TClass::GetClass("{{.}}")->GetStreamerInfo()->Write("streamer-info-{{.}}");
{{end }}

	f->Write();
	f->Close();

	exit(0);
}
`))

	macro := new(strings.Builder)
	err := tmpl.Execute(macro, classes)
	if err != nil {
		log.Fatal(err)
	}

	out, err := rtests.RunCxxROOT("genstreamers", []byte(macro.String()), oname)
	if err != nil {
		log.Fatalf("could not run gen-streamers:\n%s\nerror: %+v", out, err)
	}

	root, err := riofs.Open(oname)
	if err != nil {
		log.Fatalf("could not open ROOT streamers file: %+v", err)
	}
	defer root.Close()

	var streamers []rbytes.StreamerInfo
	for _, k := range root.Keys() {
		if !strings.HasPrefix(k.Name(), "streamer-info-") {
			continue
		}
		obj, err := k.Object()
		if err != nil {
			log.Fatalf("could not load streamer %q: +v", k.Name(), err)
		}
		si, ok := obj.(rbytes.StreamerInfo)
		if !ok {
			log.Fatalf("object %q is not a streamer info: type=%T", k.Name(), obj)
		}
		streamers = append(streamers, si)
	}
	if got, want := len(streamers), len(classes); got != want {
		log.Fatalf("missing streamers: got=%d, want=%d", got, want)
	}

	var (
		fname = "rdict/cxx_root_streamers_gen.go"
		year  = genroot.ExtractYear(fname)
	)
	f, err := os.Create(fname)
	if err != nil {
		log.Fatal(err)
	}
	defer f.Close()

	_, err = f.Write([]byte(fmt.Sprintf(`// Copyright ©%d The go-hep Authors. All rights reserved.
// Use of this source code is governed by a BSD-style
// license that can be found in the LICENSE file.

// Automatically generated. DO NOT EDIT.

package rdict

import (
	"go-hep.org/x/hep/groot/rbase"
	"go-hep.org/x/hep/groot/rbytes"
	"go-hep.org/x/hep/groot/rmeta"
)

func init() {
`, year)))
	if err != nil {
		log.Fatalf("could not write groot streamers header: %+v", err)
	}
	for _, sinfo := range streamers {
		fmt.Fprintf(f, "StreamerInfos.Add(")
		err = writeStreamer(f, sinfo)
		if err != nil {
			log.Fatalf("could not generate groot streamer %v: %+v", sinfo, err)
		}
		f.WriteString(")\n")
	}
	fmt.Fprintf(f, "\n}\n")

	err = f.Close()
	if err != nil {
		log.Fatal(err)
	}
	genroot.GoFmt(f)

	genVersions(streamers)
}

func writeStreamer(w io.Writer, si rbytes.StreamerInfo) error {
	const verbose = true
	err := rdict.GenCxxStreamerInfo(w, si, verbose)
	if err != nil {
		return fmt.Errorf("could not write streamer info %q: %w", si.Name(), err)
	}
	return nil
}

type Type struct {
	Name    string `json:"name"`
	Version int    `json:"version"`
}

func (t Type) GoName() string {
	var (
		namespace = ""
		name      = t.Name
	)
	if strings.HasPrefix(name, "ROOT::Experimental") {
		namespace = "ROOT_Experimental"
		name = name[len("ROOT::Experimental"):]
	}

	if strings.HasPrefix(name, "ROOT::") {
		namespace = "ROOT_"
		name = name[len("ROOT::"):]
	}

	if strings.HasPrefix(name, "T") {
		name = name[1:]
	}
	return namespace + name
}

func genVersions(streamers []rbytes.StreamerInfo) {
	types, err := genROOTTypes(streamers)
	if err != nil {
		log.Fatalf("could not generate ROOT classes versions: %+v", err)
	}

	fname := "./rvers/versions_gen.go"
	year := genroot.ExtractYear(fname)
	f, err := os.Create(fname)
	if err != nil {
		log.Fatal(err)
	}
	defer f.Close()

	genroot.GenImports(year, "rvers", f)

	fmt.Fprintf(f, "\n\n// ROOT version\nconst ROOT = %d\n\n", types[len(types)-1].Version)

	tmpl := template.Must(template.New("types").Parse(tmpl))
	err = tmpl.Execute(f, types[:len(types)-1])
	if err != nil {
		log.Fatalf("error executing template: %+v\n", err)
	}

	err = f.Close()
	if err != nil {
		log.Fatalf("could not close generated Go file: %+v", err)
	}
	genroot.GoFmt(f)
}

func genROOTTypes(streamers []rbytes.StreamerInfo) ([]Type, error) {
	const (
		oname = "rversions.json"
	)
	defer os.Remove(oname)

	tmpl := template.Must(template.New("genrversions").Parse(`
#include <fstream>

void genrversions(const char* fname) {
	auto f = fopen(fname, "w");
	fprintf(f, "[\n");
{{range .}}
fprintf(f, "{\"name\": \"{{.Name}}\", \"version\": %d},\n", {{.ClassVersion}});
{{- end }}
	fprintf(f, "{\"name\": \"TROOT\", \"version\": %d}\n]\n", gROOT->GetVersionInt());

	fclose(f);

	exit(0);
}
`))

	macro := new(strings.Builder)
	err := tmpl.Execute(macro, streamers)
	if err != nil {
		log.Fatal(err)
	}

	out, err := rtests.RunCxxROOT("genrversions", []byte(macro.String()), oname)
	if err != nil {
		log.Fatalf("could not run gen-rversions:\n%s\nerror: %+v", out, err)
	}

	f, err := os.ReadFile(oname)
	if err != nil {
		log.Fatal(err)
	}

	var types []Type
	err = json.NewDecoder(bytes.NewReader(f)).Decode(&types)
	return types, err
}

const tmpl = `// ROOT classes versions
const (
{{range .}}
	{{.GoName}} = {{.Version}} // ROOT version for {{.Name}}
{{- end}}
)
`