*: Fixup ownership of compositional backends v0.1.88

11 files changed, 24 insertions, 80 deletions

diff --git a/objectstore/chain/bytes.go b/objectstore/chain/bytes.go
index 007c7522..64771608 100644
--- a/objectstore/chain/bytes.go
+++ b/objectstore/chain/bytes.go
@@ -12,10 +12,6 @@ import (
 // ReadBytesFull reads a full serialized object from the first backend that has it.
 func (chain *Chain) ReadBytesFull(id objectid.ObjectID) ([]byte, error) {
 	for i, backend := range chain.backends {
-		if backend == nil {
-			continue
-		}
-
 		full, err := backend.ReadBytesFull(id)
 		if err == nil {
 			return full, nil
@@ -34,10 +30,6 @@ func (chain *Chain) ReadBytesFull(id objectid.ObjectID) ([]byte, error) {
 // ReadBytesContent reads an object's type and content bytes from the first backend that has it.
 func (chain *Chain) ReadBytesContent(id objectid.ObjectID) (objecttype.Type, []byte, error) {
 	for i, backend := range chain.backends {
-		if backend == nil {
-			continue
-		}
-
 		ty, content, err := backend.ReadBytesContent(id)
 		if err == nil {
 			return ty, content, nil
diff --git a/objectstore/chain/chain.go b/objectstore/chain/chain.go
index 2b17369d..00e98b91 100644
--- a/objectstore/chain/chain.go
+++ b/objectstore/chain/chain.go
@@ -1,4 +1,5 @@
-// Package chain provides a wrapper object storage backend to query a chain of backends.
+// Package chain provides a wrapper object storage backend to query a chain of
+// backends.
 package chain
 
 import (
@@ -6,6 +7,8 @@ import (
 )
 
 // Chain queries multiple object databases in order.
+//
+// Chain borrows its backend stores.
 type Chain struct {
 	backends []objectstore.Store
 }
diff --git a/objectstore/chain/close.go b/objectstore/chain/close.go
index 440afb10..6bd74565 100644
--- a/objectstore/chain/close.go
+++ b/objectstore/chain/close.go
@@ -1,21 +1,8 @@
 package chain
 
-import "errors"
-
-// Close closes all backends and joins close errors.
-func (chain *Chain) Close() error {
-	var errs []error
-
-	for _, backend := range chain.backends {
-		if backend == nil {
-			continue
-		}
-
-		err := backend.Close()
-		if err != nil {
-			errs = append(errs, err)
-		}
-	}
-
-	return errors.Join(errs...)
-}
+// Close releases wrapper-local resources.
+//
+// Chain borrows its backends, so Close does not close them.
+//
+// Repeated calls to Close are undefined behavior.
+func (chain *Chain) Close() error { return nil }
diff --git a/objectstore/chain/header.go b/objectstore/chain/header.go
index c1d4692c..59f6bba6 100644
--- a/objectstore/chain/header.go
+++ b/objectstore/chain/header.go
@@ -12,10 +12,6 @@ import (
 // ReadHeader reads object header data from the first backend that has it.
 func (chain *Chain) ReadHeader(id objectid.ObjectID) (objecttype.Type, int64, error) {
 	for i, backend := range chain.backends {
-		if backend == nil {
-			continue
-		}
-
 		ty, size, err := backend.ReadHeader(id)
 		if err == nil {
 			return ty, size, nil
diff --git a/objectstore/chain/new.go b/objectstore/chain/new.go
index ca00e9be..887904e3 100644
--- a/objectstore/chain/new.go
+++ b/objectstore/chain/new.go
@@ -3,6 +3,9 @@ package chain
 import "codeberg.org/lindenii/furgit/objectstore"
 
 // New creates an ordered object database chain.
+//
+// The provided backends must be non-nil and distinct.
+// Chain borrows the provided backends and does not close them in Close.
 func New(backends ...objectstore.Store) *Chain {
 	return &Chain{
 		backends: append([]objectstore.Store(nil), backends...),
diff --git a/objectstore/chain/reader.go b/objectstore/chain/reader.go
index e005d929..41060a5b 100644
--- a/objectstore/chain/reader.go
+++ b/objectstore/chain/reader.go
@@ -13,10 +13,6 @@ import (
 // ReadReaderFull reads a full serialized object stream from the first backend that has it.
 func (chain *Chain) ReadReaderFull(id objectid.ObjectID) (io.ReadCloser, error) {
 	for i, backend := range chain.backends {
-		if backend == nil {
-			continue
-		}
-
 		reader, err := backend.ReadReaderFull(id)
 		if err == nil {
 			return reader, nil
@@ -35,10 +31,6 @@ func (chain *Chain) ReadReaderFull(id objectid.ObjectID) (io.ReadCloser, error)
 // ReadReaderContent reads an object's type, declared content length, and content stream from the first backend that has it.
 func (chain *Chain) ReadReaderContent(id objectid.ObjectID) (objecttype.Type, int64, io.ReadCloser, error) {
 	for i, backend := range chain.backends {
-		if backend == nil {
-			continue
-		}
-
 		ty, size, reader, err := backend.ReadReaderContent(id)
 		if err == nil {
 			return ty, size, reader, nil
diff --git a/objectstore/chain/refresh.go b/objectstore/chain/refresh.go
index 66c6f0a0..c47352dc 100644
--- a/objectstore/chain/refresh.go
+++ b/objectstore/chain/refresh.go
@@ -7,10 +7,6 @@ func (chain *Chain) Refresh() error {
 	var errs []error
 
 	for _, backend := range chain.backends {
-		if backend == nil {
-			continue
-		}
-
 		err := backend.Refresh()
 		if err != nil {
 			errs = append(errs, err)
diff --git a/objectstore/chain/size.go b/objectstore/chain/size.go
index 38aa7abc..9815317f 100644
--- a/objectstore/chain/size.go
+++ b/objectstore/chain/size.go
@@ -11,10 +11,6 @@ import (
 // ReadSize reads object content length from the first backend that has it.
 func (chain *Chain) ReadSize(id objectid.ObjectID) (int64, error) {
 	for i, backend := range chain.backends {
-		if backend == nil {
-			continue
-		}
-
 		size, err := backend.ReadSize(id)
 		if err == nil {
 			return size, nil
diff --git a/objectstore/mix/close.go b/objectstore/mix/close.go
index b30116dc..53f6cd30 100644
--- a/objectstore/mix/close.go
+++ b/objectstore/mix/close.go
@@ -1,30 +1,8 @@
 package mix
 
-import (
-	"errors"
-
-	"codeberg.org/lindenii/furgit/objectstore"
-)
-
-// Close closes all backends and joins close errors.
-func (mix *Mix) Close() error {
-	mix.mu.RLock()
-
-	backends := make([]objectstore.Store, 0, len(mix.backendNodeByStore))
-	for node := mix.backendHead; node != nil; node = node.next {
-		backends = append(backends, node.backend)
-	}
-
-	mix.mu.RUnlock()
-
-	var errs []error
-
-	for _, backend := range backends {
-		err := backend.Close()
-		if err != nil {
-			errs = append(errs, err)
-		}
-	}
-
-	return errors.Join(errs...)
-}
+// Close releases wrapper-local resources.
+//
+// Mix borrows its backends, so Close does not close them.
+//
+// Repeated calls to Close are undefined behavior.
+func (mix *Mix) Close() error { return nil }
diff --git a/objectstore/mix/mix.go b/objectstore/mix/mix.go
index e2757705..ef381b95 100644
--- a/objectstore/mix/mix.go
+++ b/objectstore/mix/mix.go
@@ -9,6 +9,8 @@ import (
 )
 
 // Mix queries multiple object databases with an MRU backend preference.
+//
+// Mix borrows its backend stores.
 type Mix struct {
 	mu sync.RWMutex
 
diff --git a/objectstore/mix/new.go b/objectstore/mix/new.go
index c6fdeeee..16c6c9eb 100644
--- a/objectstore/mix/new.go
+++ b/objectstore/mix/new.go
@@ -3,6 +3,9 @@ package mix
 import "codeberg.org/lindenii/furgit/objectstore"
 
 // New creates a Mix from backends.
+//
+// The provided backends must be non-nil and distinct.
+// Mix borrows the provided backends and does not close them in Close.
 func New(backends ...objectstore.Store) *Mix {
 	nodeByStore := make(map[objectstore.Store]*backendNode, len(backends))
 
@@ -12,10 +15,6 @@ func New(backends ...objectstore.Store) *Mix {
 	)
 
 	for _, backend := range backends {
-		if backend == nil {
-			continue
-		}
-
 		node := &backendNode{
 			backend: backend,
 			prev:    tail,