objectstore/mix: Rename from objectstore/chain

1 files changed, 0 insertions, 275 deletions

diff --git a/objectstore/chain/chain.go b/objectstore/chain/chain.go
deleted file mode 100644
index 8e10feb6..00000000
--- a/objectstore/chain/chain.go
+++ /dev/null
@@ -1,275 +0,0 @@
-// Package chain provides an adaptive wrapper over multiple object storage
-// backends.
-package chain
-
-import (
-	"errors"
-	"fmt"
-	"io"
-	"sync"
-
-	"codeberg.org/lindenii/furgit/objectid"
-	"codeberg.org/lindenii/furgit/objectstore"
-	"codeberg.org/lindenii/furgit/objecttype"
-)
-
-// Chain queries multiple object databases with an MRU backend preference.
-type Chain struct {
-	mu sync.RWMutex
-
-	backendHead        *backendNode
-	backendTail        *backendNode
-	backendNodeByStore map[objectstore.Store]*backendNode
-}
-
-// New creates a Chain from backends.
-func New(backends ...objectstore.Store) *Chain {
-	nodeByStore := make(map[objectstore.Store]*backendNode, len(backends))
-
-	var (
-		head *backendNode
-		tail *backendNode
-	)
-
-	for _, backend := range backends {
-		if backend == nil {
-			continue
-		}
-
-		node := &backendNode{
-			backend: backend,
-			prev:    tail,
-		}
-		if tail != nil {
-			tail.next = node
-		}
-
-		if head == nil {
-			head = node
-		}
-
-		tail = node
-		nodeByStore[backend] = node
-	}
-
-	return &Chain{
-		backendHead:        head,
-		backendTail:        tail,
-		backendNodeByStore: nodeByStore,
-	}
-}
-
-// ReadBytesFull reads a full serialized object from one backend that has it.
-func (chain *Chain) ReadBytesFull(id objectid.ObjectID) ([]byte, error) {
-	for i, backend := 0, chain.firstBackend(); backend != nil; i, backend = i+1, chain.nextBackend(backend) {
-		full, err := backend.ReadBytesFull(id)
-		if err == nil {
-			chain.touchBackend(backend)
-
-			return full, nil
-		}
-
-		if errors.Is(err, objectstore.ErrObjectNotFound) {
-			continue
-		}
-
-		return nil, fmt.Errorf("objectstore: backend %d read bytes full: %w", i, err)
-	}
-
-	return nil, objectstore.ErrObjectNotFound
-}
-
-// ReadBytesContent reads an object's type and content bytes from one backend
-// that has it.
-func (chain *Chain) ReadBytesContent(id objectid.ObjectID) (objecttype.Type, []byte, error) {
-	for i, backend := 0, chain.firstBackend(); backend != nil; i, backend = i+1, chain.nextBackend(backend) {
-		ty, content, err := backend.ReadBytesContent(id)
-		if err == nil {
-			chain.touchBackend(backend)
-
-			return ty, content, nil
-		}
-
-		if errors.Is(err, objectstore.ErrObjectNotFound) {
-			continue
-		}
-
-		return objecttype.TypeInvalid, nil, fmt.Errorf("objectstore: backend %d read bytes content: %w", i, err)
-	}
-
-	return objecttype.TypeInvalid, nil, objectstore.ErrObjectNotFound
-}
-
-// ReadReaderFull reads a full serialized object stream from one backend that
-// has it.
-func (chain *Chain) ReadReaderFull(id objectid.ObjectID) (io.ReadCloser, error) {
-	for i, backend := 0, chain.firstBackend(); backend != nil; i, backend = i+1, chain.nextBackend(backend) {
-		reader, err := backend.ReadReaderFull(id)
-		if err == nil {
-			chain.touchBackend(backend)
-
-			return reader, nil
-		}
-
-		if errors.Is(err, objectstore.ErrObjectNotFound) {
-			continue
-		}
-
-		return nil, fmt.Errorf("objectstore: backend %d read reader full: %w", i, err)
-	}
-
-	return nil, objectstore.ErrObjectNotFound
-}
-
-// ReadReaderContent reads an object's type, declared content length, and
-// content stream from one backend that has it.
-func (chain *Chain) ReadReaderContent(id objectid.ObjectID) (objecttype.Type, int64, io.ReadCloser, error) {
-	for i, backend := 0, chain.firstBackend(); backend != nil; i, backend = i+1, chain.nextBackend(backend) {
-		ty, size, reader, err := backend.ReadReaderContent(id)
-		if err == nil {
-			chain.touchBackend(backend)
-
-			return ty, size, reader, nil
-		}
-
-		if errors.Is(err, objectstore.ErrObjectNotFound) {
-			continue
-		}
-
-		return objecttype.TypeInvalid, 0, nil, fmt.Errorf("objectstore: backend %d read reader content: %w", i, err)
-	}
-
-	return objecttype.TypeInvalid, 0, nil, objectstore.ErrObjectNotFound
-}
-
-// ReadSize reads object content length from one backend that has it.
-func (chain *Chain) ReadSize(id objectid.ObjectID) (int64, error) {
-	for i, backend := 0, chain.firstBackend(); backend != nil; i, backend = i+1, chain.nextBackend(backend) {
-		size, err := backend.ReadSize(id)
-		if err == nil {
-			chain.touchBackend(backend)
-
-			return size, nil
-		}
-
-		if errors.Is(err, objectstore.ErrObjectNotFound) {
-			continue
-		}
-
-		return 0, fmt.Errorf("objectstore: backend %d read size: %w", i, err)
-	}
-
-	return 0, objectstore.ErrObjectNotFound
-}
-
-// ReadHeader reads object header data from one backend that has it.
-func (chain *Chain) ReadHeader(id objectid.ObjectID) (objecttype.Type, int64, error) {
-	for i, backend := 0, chain.firstBackend(); backend != nil; i, backend = i+1, chain.nextBackend(backend) {
-		ty, size, err := backend.ReadHeader(id)
-		if err == nil {
-			chain.touchBackend(backend)
-
-			return ty, size, nil
-		}
-
-		if errors.Is(err, objectstore.ErrObjectNotFound) {
-			continue
-		}
-
-		return objecttype.TypeInvalid, 0, fmt.Errorf("objectstore: backend %d read header: %w", i, err)
-	}
-
-	return objecttype.TypeInvalid, 0, objectstore.ErrObjectNotFound
-}
-
-// Close closes all backends and joins close errors.
-func (chain *Chain) Close() error {
-	chain.mu.RLock()
-
-	backends := make([]objectstore.Store, 0, len(chain.backendNodeByStore))
-	for node := chain.backendHead; node != nil; node = node.next {
-		backends = append(backends, node.backend)
-	}
-
-	chain.mu.RUnlock()
-
-	var errs []error
-
-	for _, backend := range backends {
-		err := backend.Close()
-		if err != nil {
-			errs = append(errs, err)
-		}
-	}
-
-	return errors.Join(errs...)
-}
-
-type backendNode struct {
-	backend objectstore.Store
-	prev    *backendNode
-	next    *backendNode
-}
-
-func (chain *Chain) firstBackend() objectstore.Store {
-	chain.mu.RLock()
-	defer chain.mu.RUnlock()
-
-	if chain.backendHead == nil {
-		return nil
-	}
-
-	return chain.backendHead.backend
-}
-
-func (chain *Chain) nextBackend(current objectstore.Store) objectstore.Store {
-	chain.mu.RLock()
-	defer chain.mu.RUnlock()
-
-	node := chain.backendNodeByStore[current]
-	if node == nil || node.next == nil {
-		return nil
-	}
-
-	return node.next.backend
-}
-
-func (chain *Chain) touchBackend(backend objectstore.Store) {
-	if backend == nil {
-		return
-	}
-
-	if !chain.mu.TryLock() {
-		return
-	}
-	defer chain.mu.Unlock()
-
-	node := chain.backendNodeByStore[backend]
-	if node == nil || node == chain.backendHead {
-		return
-	}
-
-	if node.prev != nil {
-		node.prev.next = node.next
-	}
-
-	if node.next != nil {
-		node.next.prev = node.prev
-	}
-
-	if chain.backendTail == node {
-		chain.backendTail = node.prev
-	}
-
-	node.prev = nil
-
-	node.next = chain.backendHead
-	if chain.backendHead != nil {
-		chain.backendHead.prev = node
-	}
-
-	chain.backendHead = node
-	if chain.backendTail == nil {
-		chain.backendTail = node
-	}
-}