ipld-eth-server/pkg/autogen/generator.go

139 lines
3.6 KiB
Go

// VulcanizeDB
// Copyright © 2018 Vulcanize
// This program is free software: you can redistribute it and/or modify
// it under the terms of the GNU Affero General Public License as published by
// the Free Software Foundation, either version 3 of the License, or
// (at your option) any later version.
// This program is distributed in the hope that it will be useful,
// but WITHOUT ANY WARRANTY; without even the implied warranty of
// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
// GNU Affero General Public License for more details.
// You should have received a copy of the GNU Affero General Public License
// along with this program. If not, see <http://www.gnu.org/licenses/>.
package autogen
import (
"errors"
"os"
"os/exec"
"path/filepath"
"strings"
. "github.com/dave/jennifer/jen"
"github.com/mitchellh/go-homedir"
)
type Generator interface {
GenerateTransformerPlugin() error
}
type generator struct {
*Config
}
func NewGenerator(config Config) *generator {
return &generator{
Config: &config,
}
}
func (g *generator) GenerateTransformerPlugin() error {
if g.Config == nil {
return errors.New("generator needs a config file")
}
if g.Config.FilePath == "" {
return errors.New("generator is missing file path")
}
if len(g.Config.Imports) < 1 {
return errors.New("generator needs to be configured with imports")
}
// Create file path
goFile, soFile, err := GetPaths(*g.Config)
if err != nil {
return err
}
// Clear previous .go and .so files if they exist
err = ClearFiles(goFile, soFile)
if err != nil {
return err
}
// Begin code generation
f := NewFile("main")
f.HeaderComment("This exporter is generated to export the configured transformer initializers")
// Import TransformerInitializers
f.ImportAlias("github.com/vulcanize/vulcanizedb/libraries/shared/transformer", "interface")
for alias, imp := range g.Config.Imports {
f.ImportAlias(imp, alias)
}
// Collect TransformerInitializer names
importedInitializers := make([]Code, 0, len(g.Config.Imports))
for _, path := range g.Config.Imports {
importedInitializers = append(importedInitializers, Qual(path, "TransformerInitializer"))
}
// Create Exporter variable with method to export a set of the configured TransformerInitializers
f.Type().Id("exporter").String()
f.Var().Id("Exporter").Id("exporter")
f.Func().Params(
Id("e").Id("exporter"),
).Id("Export").Params().Index().Qual(
"github.com/vulcanize/vulcanizedb/libraries/shared/transformer",
"TransformerInitializer").Block(
Return(Index().Qual(
"github.com/vulcanize/vulcanizedb/libraries/shared/transformer",
"TransformerInitializer").Values(importedInitializers...)))
// Write code to destination file
err = f.Save(goFile)
if err != nil {
return err
}
// Build the .go file into a .so plugin
return exec.Command("go", "build", "-buildmode=plugin", "-o", soFile, goFile).Run()
}
func GetPaths(config Config) (string, string, error) {
path, err := homedir.Expand(filepath.Clean(config.FilePath))
if err != nil {
return "", "", err
}
if strings.Contains(path, "$GOPATH") {
env := os.Getenv("GOPATH")
spl := strings.Split(path, "$GOPATH")[1]
path = filepath.Join(env, spl)
}
name := strings.Split(config.FileName, ".")[0]
goFile := filepath.Join(path, name+".go")
soFile := filepath.Join(path, name+".so")
return goFile, soFile, nil
}
func ClearFiles(files ...string) error {
for _, file := range files {
if _, err := os.Stat(file); err == nil {
err = os.Remove(file)
if err != nil {
return err
}
} else if os.IsNotExist(err) {
// fall through
} else {
return err
}
}
return nil
}