pm/remote/pull.go
2018-03-02 23:23:11 -08:00

64 lines
1.4 KiB
Go

package remote
import (
"encoding/json"
"net/http"
"os"
"path/filepath"
"github.com/pkg/errors"
"mcquay.me/pm"
)
const an = "var/lib/pm/available.json"
// Pull updates the available package database.
func Pull(root string) error {
db, err := load(root)
if err != nil {
return errors.Wrap(err, "loading db")
}
o := pm.Available{}
// Order here is important: the guarantee made is that any packages that
// exist in multiple remotes will be fetched by the first configured
// remote, which is why we traverse the database in reverse.
//
// TODO (sm): make this concurrent
for i := range db {
u := db[len(db)-i-1]
resp, err := http.Get(u.String() + "/available.json")
if err != nil {
return errors.Wrap(err, "http get")
}
a := pm.Available{}
if err := json.NewDecoder(resp.Body).Decode(&a); err != nil {
return errors.Wrap(err, "decode remote available")
}
a.SetRemote(u)
o.Update(a)
}
if err := saveAvailable(root, o); err != nil {
return errors.Wrap(err, "saving available db")
}
return nil
}
func saveAvailable(root string, db pm.Available) error {
f, err := os.Create(filepath.Join(root, an))
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
}