pm/db/installed.go
2018-03-06 00:10:46 -08:00

86 lines
1.7 KiB
Go

package db
import (
"encoding/json"
"fmt"
"io"
"os"
"path/filepath"
"github.com/pkg/errors"
"mcquay.me/fs"
"mcquay.me/pm"
)
const in = "var/lib/pm/installed.json"
// AddInstalled adds m to the installed package database.
func AddInstalled(root string, m pm.Meta) error {
db, err := loadi(root)
if err != nil {
return errors.Wrap(err, "loading installed db")
}
db[m.Name] = m
return savei(root, db)
}
// IsInstalled checks if m is in the installed package database.
func IsInstalled(root string, m pm.Meta) (bool, error) {
db, err := loadi(root)
if err != nil {
return false, errors.Wrap(err, "loading installed db")
}
_, r := db[m.Name]
return r, nil
}
// ListInstalled pretty prints the installed database to w.
func ListInstalled(root string, w io.Writer) error {
db, err := loadi(root)
if err != nil {
return errors.Wrap(err, "loading installed db")
}
for m := range db.Traverse() {
fmt.Fprintf(w, "%v\t%v\t%v\n", m.Name, m.Version, m.Remote.String())
}
return nil
}
func loadi(root string) (pm.Installed, error) {
r := pm.Installed{}
dbn := filepath.Join(root, in)
if !fs.Exists(dbn) {
return r, nil
}
f, err := os.Open(dbn)
if err != nil {
return r, errors.Wrap(err, "open")
}
if err := json.NewDecoder(f).Decode(&r); err != nil {
return r, errors.Wrap(err, "decoding db")
}
return r, nil
}
func savei(root string, db pm.Installed) error {
f, err := os.Create(filepath.Join(root, in))
if err != nil {
return errors.Wrap(err, "create")
}
enc := json.NewEncoder(f)
enc.SetIndent("", "\t")
if err := enc.Encode(&db); err != nil {
return errors.Wrap(err, "decoding db")
}
if err := f.Close(); err != nil {
return errors.Wrap(err, "close db")
}
return nil
}