shithub: furgit

ref: 1734207266752b9464f42c31f7728a7e3c692c50
dir: /objectstore/objectstore.go/

// Package objectstore provides interfaces for object storage backends.
package objectstore

import (
	"errors"
	"io"

	"codeberg.org/lindenii/furgit/objectid"
	"codeberg.org/lindenii/furgit/objecttype"
)

// ErrObjectNotFound indicates that an object does not exist in a backend.
// TODO: This might need to be an interface or otherwise be able to encapsulate multiple concrete backends'.
// XXX: Don't remove this in favor of errors.ObjectMissingError yet due to pressure of allocation large error structs.
var ErrObjectNotFound = errors.New("objectstore: object not found")

// Store reads Git objects by object ID.
type Store interface {
	// ReadBytesFull reads a full serialized object as "type size\0content".
	//
	// In a valid repository, hashing this payload with the same algorithm yields
	// the requested object ID. Readers should treat this as a repository
	// invariant and should not re-verify it on every read.
	ReadBytesFull(id objectid.ObjectID) ([]byte, error)
	// ReadBytesContent reads an object's type and content bytes.
	ReadBytesContent(id objectid.ObjectID) (objecttype.Type, []byte, error)
	// ReadReaderFull reads a full serialized object stream as "type size\0content".
	// Caller must close the returned reader.
	ReadReaderFull(id objectid.ObjectID) (io.ReadCloser, error)
	// ReadReaderContent reads an object's type, declared content length,
	// and content stream.
	// Caller must close the returned reader.
	ReadReaderContent(id objectid.ObjectID) (objecttype.Type, int64, io.ReadCloser, error)
	// ReadSize reads an object's declared content length.
	//
	// This is equivalent to ReadHeader(...).size and may be cheaper than
	// ReadHeader when callers do not need object type.
	ReadSize(id objectid.ObjectID) (int64, error)
	// ReadHeader reads an object's type and declared content length.
	ReadHeader(id objectid.ObjectID) (objecttype.Type, int64, error)
	// Refresh updates any backend-local discovery/cache view of on-disk objects.
	//
	// Backends without dynamic discovery should return nil.
	Refresh() error
	// Close releases resources associated with the backend.
	Close() error
}

// type Cursor any
//
// Then make all read functions accept and provide a Cursor
// nil must always be accepted and would exhibit the same behavior as right now
// Non-nil behavior is implementation-defined: e.g., pack selection