object/store/packed: Add basic ingestion

1 files changed, 161 insertions, 54 deletions

diff --git a/object/store/packed/quarantine.go b/object/store/packed/quarantine.go
index fac64402..5e0b85cb 100644
--- a/object/store/packed/quarantine.go
+++ b/object/store/packed/quarantine.go
@@ -1,57 +1,164 @@
 package packed
 
-// import (
-// 	"os"
-//
-// 	"lindenii.org/go/furgit/object/store"
-// )
-//
-// var (
-// 	_ store.PackQuarantiner = (*Packed)(nil)
-// 	_ store.PackQuarantine  = (*packQuarantine)(nil)
-// )
-//
-// // packQuarantine is one quarantined packed store
-// // rooted privately beneath a destination pack root.
-// type packQuarantine struct {
-// 	*Packed
-//
-// 	parent   *Packed
-// 	tempName string
-// 	tempRoot *os.Root
-// }
-//
-// // BeginPackQuarantine creates one quarantined packed store
-// // rooted privately beneath the destination pack root.
-// //
-// // Labels: Deps-Borrowed, Life-Parent, Close-No.
-// func (packed *Packed) BeginPackQuarantine(opts store.PackQuarantineOptions) (store.PackQuarantine, error)
-//
-// // Discard removes the quarantine
-// // and invalidates the receiver.
-// func (quarantine *packQuarantine) Discard() error
-//
-// // Promote publishes all finalized pack artifacts in the quarantine
-// // into the parent packed store,
-// // and invalidates the receiver.
-// func (quarantine *packQuarantine) Promote() error
-//
-// // promoteAll links every pack artifact in the quarantine
-// // into the parent packed store,
-// // in pack/rev/idx dependency order.
-// func (quarantine *packQuarantine) promoteAll() error
-//
-// // promoteFile links one quarantined pack artifact
-// // into the parent packed store,
-// // treating an already-present destination as success.
-// func (quarantine *packQuarantine) promoteFile(name string) error
-//
-// // createPackQuarantineRoot creates a private quarantine directory
-// // beneath parent,
-// // and returns its name and an os.Root over it.
-// func createPackQuarantineRoot(parent *os.Root) (string, *os.Root, error)
+import (
+	"crypto/rand"
+	"errors"
+	"fmt"
+	"io/fs"
+	"os"
+	"slices"
+	"strings"
+
+	"lindenii.org/go/furgit/object/store"
+)
+
+var (
+	_ store.PackQuarantiner = (*Packed)(nil)
+	_ store.PackQuarantine  = (*packQuarantine)(nil)
+)
+
+var errQuarantineNamesExhausted = errors.New("object/store/packed: exhausted quarantine directory names")
+
+// packQuarantine is one quarantined packed store
+// rooted privately beneath a destination pack root.
+type packQuarantine struct {
+	*Packed
+
+	parent *Packed
+
+	tempName string
+	tempRoot *os.Root
+}
+
+// BeginPackQuarantine creates one quarantined packed store
+// rooted privately beneath the destination pack root.
 //
-// // packPromotionPriority orders pack artifacts
-// // so that data files are linked
-// // before the index that publishes them.
-// func packPromotionPriority(name string) int
+// Labels: Deps-Borrowed, Life-Parent.
+func (packed *Packed) BeginPackQuarantine(_ store.PackQuarantineOptions) (store.PackQuarantine, error) { //nolint:ireturn
+	tempName, tempRoot, err := createPackQuarantineRoot(packed.root)
+	if err != nil {
+		return nil, err
+	}
+
+	quarantineStore, err := New(tempRoot, packed.objectFormat)
+	if err != nil {
+		_ = tempRoot.Close()
+		_ = packed.root.RemoveAll(tempName)
+
+		return nil, err
+	}
+
+	return &packQuarantine{
+		Packed:   quarantineStore,
+		parent:   packed,
+		tempName: tempName,
+		tempRoot: tempRoot,
+	}, nil
+}
+
+// Promote publishes the quarantined pack artifacts into the parent store,
+// refreshes the parent so the objects become available,
+// and invalidates the receiver.
+func (quarantine *packQuarantine) Promote() error {
+	closeErr := quarantine.Close()
+	promoteErr := quarantine.promoteAll()
+
+	var refreshErr error
+	if promoteErr == nil {
+		refreshErr = quarantine.parent.Refresh()
+	}
+
+	tempRootErr := quarantine.tempRoot.Close()
+	removeErr := quarantine.parent.root.RemoveAll(quarantine.tempName)
+
+	return errors.Join(closeErr, promoteErr, refreshErr, tempRootErr, removeErr)
+}
+
+// Discard removes the quarantine and invalidates the receiver.
+func (quarantine *packQuarantine) Discard() error {
+	closeErr := quarantine.Close()
+	tempRootErr := quarantine.tempRoot.Close()
+	removeErr := quarantine.parent.root.RemoveAll(quarantine.tempName)
+
+	return errors.Join(closeErr, tempRootErr, removeErr)
+}
+
+// promoteAll links every pack artifact in the quarantine into the parent store,
+// in pack/rev/idx dependency order.
+func (quarantine *packQuarantine) promoteAll() error {
+	entries, err := fs.ReadDir(quarantine.tempRoot.FS(), ".")
+	if err != nil {
+		return fmt.Errorf("object/store/packed: %w", err)
+	}
+
+	slices.SortFunc(entries, func(left, right fs.DirEntry) int {
+		return packPromotionPriority(left.Name()) - packPromotionPriority(right.Name())
+	})
+
+	for _, entry := range entries {
+		err := quarantine.promoteFile(entry.Name())
+		if err != nil {
+			return err
+		}
+	}
+
+	return nil
+}
+
+// promoteFile links one quarantined artifact into the parent store,
+// treating an already-present destination as success.
+func (quarantine *packQuarantine) promoteFile(name string) error {
+	src := quarantine.tempName + "/" + name
+
+	err := quarantine.parent.root.Link(src, name)
+	if err != nil && !errors.Is(err, fs.ErrExist) {
+		return fmt.Errorf("object/store/packed: promoting %q: %w", name, err)
+	}
+
+	_ = quarantine.parent.root.Remove(src)
+
+	return nil
+}
+
+// createPackQuarantineRoot creates a private quarantine directory beneath parent
+// and returns its name and an os.Root over it.
+func createPackQuarantineRoot(parent *os.Root) (string, *os.Root, error) {
+	for range 32 {
+		name := "tmp_packq_" + rand.Text()
+
+		err := parent.Mkdir(name, 0o700)
+		if err != nil {
+			if errors.Is(err, fs.ErrExist) {
+				continue
+			}
+
+			return "", nil, fmt.Errorf("object/store/packed: %w", err)
+		}
+
+		root, err := parent.OpenRoot(name)
+		if err != nil {
+			_ = parent.RemoveAll(name)
+
+			return "", nil, fmt.Errorf("object/store/packed: %w", err)
+		}
+
+		return name, root, nil
+	}
+
+	return "", nil, errQuarantineNamesExhausted
+}
+
+// packPromotionPriority orders pack artifacts
+// so that data files are linked before the index that publishes them.
+func packPromotionPriority(name string) int {
+	switch {
+	case strings.HasPrefix(name, "pack-") && strings.HasSuffix(name, ".pack"):
+		return 1
+	case strings.HasPrefix(name, "pack-") && strings.HasSuffix(name, ".rev"):
+		return 2
+	case strings.HasPrefix(name, "pack-") && strings.HasSuffix(name, ".idx"):
+		return 3
+	default:
+		return 0
+	}
+}