Eliminate global variables

5 files changed, 99 insertions, 74 deletions

diff --git a/env.go b/env.go
new file mode 100644
index 0000000..ad8cf9a
--- /dev/null
+++ b/env.go
@@ -0,0 +1,74 @@
+package main
+
+import (
+	"code.laria.me/petrific/cache"
+	"code.laria.me/petrific/config"
+	"code.laria.me/petrific/storage"
+	"code.laria.me/petrific/storage/registry"
+	"fmt"
+)
+
+// Env provides commonly used objects for subcommands
+type Env struct {
+	Conf    config.Config
+	Store   storage.Storage
+	IdCache cache.Cache
+}
+
+func (e *Env) Close() {
+	if e.IdCache != nil {
+		e.IdCache.Close()
+	}
+
+	if e.Store != nil {
+		e.Store.Close()
+	}
+}
+
+func (env *Env) loadCache() error {
+	path := env.Conf.CachePath
+	if path == "" {
+		return nil
+	}
+
+	file_cache := cache.NewFileCache(config.ExpandTilde(path))
+	if err := file_cache.Load(); err != nil {
+		return fmt.Errorf("Loading cache %s: %s", path, err)
+	}
+
+	env.IdCache = file_cache
+	return nil
+}
+
+func NewEnv(confPath, storageName string) (*Env, error) {
+	env := new(Env)
+
+	var err error
+
+	// Load config
+
+	env.Conf, err = config.LoadConfig(confPath)
+	if err != nil {
+		return nil, err
+	}
+
+	// load storage
+
+	if storageName == "" {
+		storageName = env.Conf.DefaultStorage
+	}
+
+	env.Store, err = registry.LoadStorage(env.Conf, storageName)
+	if err != nil {
+		return nil, err
+	}
+
+	// Load cache
+
+	if err = env.loadCache(); err != nil {
+		env.Close()
+		return nil, err
+	}
+
+	return env, nil
+}
diff --git a/main.go b/main.go
index 5ea627f..b6b541b 100644
--- a/main.go
+++ b/main.go
@@ -1,16 +1,12 @@
 package main
 
 import (
-	"code.laria.me/petrific/cache"
-	"code.laria.me/petrific/config"
-	"code.laria.me/petrific/storage"
-	"code.laria.me/petrific/storage/registry"
 	"flag"
 	"fmt"
 	"os"
 )
 
-type subcmd func(args []string) int
+type subcmd func(env *Env, args []string) int
 
 var subcmds = map[string]subcmd{
 	"write-dir":        WriteDir,
@@ -43,10 +39,6 @@ var (
 	flagStorage  = flag.String("storage", "", "Operate on this storage instead of the default one")
 )
 
-var conf config.Config
-var objectstore storage.Storage
-var id_cache cache.Cache = cache.NopCache{}
-
 func main() {
 	os.Exit(Main())
 }
@@ -61,15 +53,13 @@ func Main() int {
 		flag.PrintDefaults()
 	}
 	flag.Parse()
-	if !loadConfig() {
-		return 1
-	}
-	defer objectstore.Close()
 
-	if !loadCache(conf) {
+	env, err := NewEnv(*flagConfPath, *flagStorage)
+	if err != nil {
+		fmt.Fprintln(os.Stderr, err)
 		return 1
 	}
-	defer id_cache.Close()
+	defer env.Close()
 
 	remaining := make([]string, 0)
 	for _, arg := range flag.Args() {
@@ -88,44 +78,5 @@ func Main() int {
 		return 1
 	}
 
-	return cmd(remaining[1:])
-}
-
-func loadCache(conf config.Config) bool {
-	if conf.CachePath == "" {
-		return true
-	}
-
-	file_cache := cache.NewFileCache(config.ExpandTilde(conf.CachePath))
-	if err := file_cache.Load(); err != nil {
-		fmt.Fprintf(os.Stderr, "Loading cache %s: %s", conf.CachePath, err)
-		return false
-	}
-
-	id_cache = file_cache
-
-	return true
-}
-
-func loadConfig() bool {
-	var err error
-	conf, err = config.LoadConfig(*flagConfPath)
-	if err != nil {
-		fmt.Fprintf(os.Stderr, "Failed reading config: %s\n", err)
-		return false
-	}
-
-	storageName := *flagStorage
-	if storageName == "" {
-		storageName = conf.DefaultStorage
-	}
-
-	s, err := registry.LoadStorage(conf, storageName)
-	if err != nil {
-		fmt.Fprintln(os.Stderr, err)
-		return false
-	}
-
-	objectstore = s
-	return true
+	return cmd(env, remaining[1:])
 }
diff --git a/restore_dir.go b/restore_dir.go
index 2961b70..4e45fae 100644
--- a/restore_dir.go
+++ b/restore_dir.go
@@ -7,7 +7,7 @@ import (
 	"fmt"
 )
 
-func RestoreDir(args []string) int {
+func RestoreDir(env *Env, args []string) int {
 	usage := subcmdUsage("restore-dir", "directory object-id", nil)
 	errout := subcmdErrout("restore-dir")
 
@@ -39,7 +39,7 @@ func RestoreDir(args []string) int {
 		return 1
 	}
 
-	if err := backup.RestoreDir(objectstore, id, d); err != nil {
+	if err := backup.RestoreDir(env.Store, id, d); err != nil {
 		errout(err)
 		return 1
 	}
diff --git a/snapshot.go b/snapshot.go
index db181ba..ff4c0be 100644
--- a/snapshot.go
+++ b/snapshot.go
@@ -14,7 +14,7 @@ import (
 	"time"
 )
 
-func createSnapshot(archive, comment string, tree_id objects.ObjectId, nosign bool) (objects.ObjectId, error) {
+func createSnapshot(env *Env, archive, comment string, tree_id objects.ObjectId, nosign bool) (objects.ObjectId, error) {
 	snapshot := objects.Snapshot{
 		Archive: archive,
 		Comment: comment,
@@ -28,7 +28,7 @@ func createSnapshot(archive, comment string, tree_id objects.ObjectId, nosign bo
 		payload = snapshot.Payload()
 	} else {
 		var err error
-		payload, err = snapshot.SignedPayload(conf.GPGSigner())
+		payload, err = snapshot.SignedPayload(env.Conf.GPGSigner())
 		if err != nil {
 			return objects.ObjectId{}, fmt.Errorf("could not sign: %s", err)
 		}
@@ -39,10 +39,10 @@ func createSnapshot(archive, comment string, tree_id objects.ObjectId, nosign bo
 		Payload: payload,
 	}
 
-	return storage.SetObject(objectstore, obj)
+	return storage.SetObject(env.Store, obj)
 }
 
-func CreateSnapshot(args []string) int {
+func CreateSnapshot(env *Env, args []string) int {
 	flags := flag.NewFlagSet(os.Args[0]+" create-snapshot", flag.ContinueOnError)
 	nosign := flags.Bool("nosign", false, "don't sign the snapshot (not recommended)")
 	comment := flags.String("comment", "", "comment for the snapshot")
@@ -68,7 +68,7 @@ func CreateSnapshot(args []string) int {
 		return 1
 	}
 
-	snapshot_id, err := createSnapshot(args[0], *comment, tree_id, *nosign)
+	snapshot_id, err := createSnapshot(env, args[0], *comment, tree_id, *nosign)
 	if err != nil {
 		errout(err)
 		return 1
@@ -78,7 +78,7 @@ func CreateSnapshot(args []string) int {
 	return 0
 }
 
-func TakeSnapshot(args []string) int {
+func TakeSnapshot(env *Env, args []string) int {
 	flags := flag.NewFlagSet(os.Args[0]+" take-snapshot", flag.ContinueOnError)
 	nosign := flags.Bool("nosign", false, "don't sign the snapshot (not recommended)")
 	comment := flags.String("comment", "", "comment for the snapshot")
@@ -114,13 +114,13 @@ func TakeSnapshot(args []string) int {
 		return 1
 	}
 
-	tree_id, err := backup.WriteDir(objectstore, dir_path, d, id_cache)
+	tree_id, err := backup.WriteDir(env.Store, dir_path, d, env.IdCache)
 	if err != nil {
 		errout(err)
 		return 1
 	}
 
-	snapshot_id, err := createSnapshot(args[0], *comment, tree_id, *nosign)
+	snapshot_id, err := createSnapshot(env, args[0], *comment, tree_id, *nosign)
 	if err != nil {
 		errout(err)
 		fmt.Fprintf(os.Stderr, "You can try again by running `%s create-snapshot -c '%s' '%s' '%s'\n`", os.Args[0], *comment, args[0], tree_id)
@@ -142,7 +142,7 @@ func (s sortableSnapshots) Len() int           { return len(s) }
 func (s sortableSnapshots) Less(i, j int) bool { return s[i].snapshot.Date.After(s[j].snapshot.Date) }
 func (s sortableSnapshots) Swap(i, j int)      { s[i], s[j] = s[j], s[i] }
 
-func ListSnapshots(args []string) int {
+func ListSnapshots(env *Env, args []string) int {
 	// usage := subcmdUsage("list-snapshots", "[archive]", nil)
 	errout := subcmdErrout("list-snapshots")
 
@@ -154,7 +154,7 @@ func ListSnapshots(args []string) int {
 		}
 	}
 
-	objids, err := objectstore.List(objects.OTSnapshot)
+	objids, err := env.Store.List(objects.OTSnapshot)
 	if err != nil {
 		errout(err)
 		return 1
@@ -164,7 +164,7 @@ func ListSnapshots(args []string) int {
 
 	failed := false
 	for _, objid := range objids {
-		_snapshot, err := storage.GetObjectOfType(objectstore, objid, objects.OTSnapshot)
+		_snapshot, err := storage.GetObjectOfType(env.Store, objid, objects.OTSnapshot)
 		if err != nil {
 			fmt.Fprintf(os.Stderr, "warning: list-snapshots: could not get snapshot %s: %s\n", objid, err)
 			failed = true
@@ -192,7 +192,7 @@ func ListSnapshots(args []string) int {
 	return 0
 }
 
-func RestoreSnapshot(args []string) int {
+func RestoreSnapshot(env *Env, args []string) int {
 	var snapshotId objects.ObjectId
 	flags := flag.NewFlagSet("restore-snapshot", flag.ContinueOnError)
 	flags.Var(&snapshotId, "id", "Object id of a snapshot")
@@ -247,13 +247,13 @@ func RestoreSnapshot(args []string) int {
 	var snapshot *objects.Snapshot
 
 	if *archive != "" {
-		snapshot, err = storage.FindLatestSnapshot(objectstore, *archive)
+		snapshot, err = storage.FindLatestSnapshot(env.Store, *archive)
 		if err != nil {
 			errout(err)
 			return 1
 		}
 	} else {
-		_snapshot, err := storage.GetObjectOfType(objectstore, snapshotId, objects.OTSnapshot)
+		_snapshot, err := storage.GetObjectOfType(env.Store, snapshotId, objects.OTSnapshot)
 		if err != nil {
 			errout(err)
 			return 1
@@ -266,7 +266,7 @@ func RestoreSnapshot(args []string) int {
 		return 1
 	}
 
-	if err := backup.RestoreDir(objectstore, snapshot.Tree, root); err != nil {
+	if err := backup.RestoreDir(env.Store, snapshot.Tree, root); err != nil {
 		errout(err)
 		return 1
 	}
diff --git a/write_dir.go b/write_dir.go
index 3ee5a97..d7c78e6 100644
--- a/write_dir.go
+++ b/write_dir.go
@@ -19,7 +19,7 @@ func abspath(p string) (string, error) {
 	return path.Clean(p), nil
 }
 
-func WriteDir(args []string) int {
+func WriteDir(env *Env, args []string) int {
 	usage := subcmdUsage("write-dir", "directory", nil)
 	errout := subcmdErrout("write-dir")
 
@@ -45,7 +45,7 @@ func WriteDir(args []string) int {
 		return 1
 	}
 
-	id, err := backup.WriteDir(objectstore, dir_path, d, id_cache)
+	id, err := backup.WriteDir(env.Store, dir_path, d, env.IdCache)
 	if err != nil {
 		errout(err)
 		return 1