cayley/internal/dump.go
2015-08-10 02:28:39 -04:00

49 lines
920 B
Go

package internal
import (
"fmt"
"os"
"github.com/google/cayley/graph"
"github.com/google/cayley/exporter"
)
// Dump the content of the database into a file based
// on a few different formats
func Dump(qs graph.QuadStore, outFile, typ string) error {
var f *os.File
if outFile == "-" {
f = os.Stdout
} else {
var err error
f, err = os.Create(outFile)
if err != nil {
return fmt.Errorf("could not open file %q: %v", outFile, err)
}
defer f.Close()
fmt.Printf("dumping db to file %q\n", outFile)
}
export := exporter.NewExporter(f, qs)
if export.Err() != nil {
return export.Err()
}
switch typ {
case "nquad":
export.ExportNquad()
case "json":
export.ExportJson()
default:
return fmt.Errorf("unknown format %q", typ)
}
if export.Err() != nil {
return export.Err()
}
if outFile != "-" {
fmt.Printf("%d entries were written\n", export.Count())
}
return nil
}