package db import ( "encoding/json" "fmt" "io" "net/http" "os" "path/filepath" "github.com/pkg/errors" "mcquay.me/fs" "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.Wrapf(err, "decode remote available for %q", u.String()) } a.SetRemote(u) o.Update(a) } if err := saveAvailable(root, o); err != nil { return errors.Wrap(err, "saving available db") } return nil } // ListAvailable prints all installable packages func ListAvailable(root string, w io.Writer) error { db, err := loadAvailable(root) if err != nil { return errors.Wrap(err, "loading") } for m := range db.Traverse() { fmt.Fprintf(w, "%v\t%v\t%v\n", m.Name, m.Version, m.Remote.String()) } return nil } func loadAvailable(root string) (pm.Available, error) { r := pm.Available{} dbn := filepath.Join(root, rn) if !fs.Exists(dbn) { return r, nil } f, err := os.Open(filepath.Join(root, an)) 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 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 }