Simplify read/write file opening

internal/library/library.go

@@ -3,7 +3,6 @@ package library
 import (
 	"context"
 	"io/fs"
-	"os"
 	"strings"
 
 	"github.com/google/uuid"
@@ -18,10 +17,9 @@ type Library struct {
 	cs   storage.Storage
 }
 
-func (l Library) Open(ctx context.Context, id uuid.UUID, flag int) (storage.ReadWriteSeekCloser, error) {
-	writeMode := flag&(os.O_RDWR|os.O_WRONLY) != 0
+func (l Library) Open(ctx context.Context, id uuid.UUID, write bool) (storage.ReadWriteSeekCloser, error) {
 	var callback func(int, string) error
-	if writeMode {
+	if write {
 		callback = func(len int, etag string) error {
 			return l.db.Queries().UpdateResourceContents(ctx, sql.UpdateResourceContentsParams{
 				ID:   id,
@@ -30,7 +28,7 @@ func (l Library) Open(ctx context.Context, id uuid.UUID, flag int) (storage.Read
 			})
 		}
 	}
-	return l.cs.Open(id, flag, callback)
+	return l.cs.Open(id, write, callback)
 }
 
 func (l Library) ReadDir(ctx context.Context, id uuid.UUID, includeRoot bool, recursive bool) ([]sql.ReadDirRow, error) {

internal/storage/hasher.go

@@ -1,31 +1,33 @@
 package storage
 
 import (
+	"errors"
 	"hash"
+	"io"
 )
 
 type hasher struct {
-	rwc           ReadWriteSeekCloser
+	dest          io.WriteCloser
 	len           int
 	sum           hash.Hash
 	closeCallback func(int, hash.Hash, error) error
 }
 
 func (c *hasher) Read(p []byte) (n int, err error) {
-	return c.rwc.Read(p)
-}
-
-func (c *hasher) Seek(offset int64, whence int) (int64, error) {
-	return c.rwc.Seek(offset, whence)
+	return 0, errors.New("read not supported")
 }
 
 func (c *hasher) Write(p []byte) (n int, err error) {
-	n, err = c.rwc.Write(p)
+	n, err = c.dest.Write(p)
 	c.sum.Write(p)
 	c.len += n
 	return
 }
 
-func (c *hasher) Close() error {
-	return c.closeCallback(c.len, c.sum, c.rwc.Close())
+func (c *hasher) Seek(offset int64, whence int) (int64, error) {
+	return 0, errors.New("seek not supported")
+}
+
+func (c *hasher) Close() error {
+	return c.closeCallback(c.len, c.sum, c.dest.Close())
 }

internal/storage/local_storage.go

@@ -24,17 +24,21 @@ func newLocalStorage(root string) (Storage, error) {
 	return localStorage(root), nil
 }
 
-func (l localStorage) Open(id uuid.UUID, flag int, writeCallback func(int, string) error) (file ReadWriteSeekCloser, err error) {
-	file, err = os.OpenFile(l.path(id), flag, 0640)
-	if err != nil || writeCallback == nil {
-		return
+func (l localStorage) Open(id uuid.UUID, write bool, callback func(int, string) error) (ReadWriteSeekCloser, error) {
+	if !write {
+		return os.OpenFile(l.path(id), os.O_RDONLY, 0640)
 	}
-	return &hasher{rwc: file, sum: md5.New(), closeCallback: func(len int, sum hash.Hash, err error) error {
+
+	file, err := os.OpenFile(l.path(id), os.O_CREATE|os.O_WRONLY|os.O_TRUNC, 0640)
+	if err != nil || callback == nil {
+		return file, err
+	}
+	return &hasher{dest: file, sum: md5.New(), closeCallback: func(len int, sum hash.Hash, err error) error {
 		if err != nil {
 			return err
 		}
 		etag := hex.EncodeToString(sum.Sum(nil))
-		return writeCallback(len, etag)
+		return callback(len, etag)
 	}}, nil
 }
 

internal/storage/storage.go

@@ -5,7 +5,7 @@ import (
 )
 
 type Storage interface {
-	Open(id uuid.UUID, flag int, writeCallback func(int, string) error) (ReadWriteSeekCloser, error)
+	Open(id uuid.UUID, write bool, callback func(int, string) error) (ReadWriteSeekCloser, error)
 	Delete(id uuid.UUID) error
 	String() string
 }

internal/webdav/adapter.go

@@ -6,7 +6,6 @@ import (
 	"io"
 	"io/fs"
 	"net/http"
-	"os"
 	"strings"
 
 	webdav "github.com/emersion/go-webdav"
@@ -25,7 +24,7 @@ func (a adapter) Open(ctx context.Context, name string) (io.ReadCloser, error) {
 	if err != nil {
 		return nil, err
 	}
-	return a.lib.Open(ctx, resource.ID, os.O_RDONLY)
+	return a.lib.Open(ctx, resource.ID, false)
 }
 
 func (a adapter) Stat(ctx context.Context, name string) (*webdav.FileInfo, error) {
@@ -89,7 +88,7 @@ func (a adapter) Create(ctx context.Context, name string) (io.WriteCloser, error
 		}
 	}
 
-	return a.lib.Open(ctx, id, os.O_CREATE|os.O_RDWR|os.O_TRUNC)
+	return a.lib.Open(ctx, id, true)
 }
 
 func (a adapter) RemoveAll(ctx context.Context, name string) error {

internal/webdav_xnet/adapter.go

@@ -61,7 +61,7 @@ func (a adapter) OpenFile(ctx context.Context, name string, flag int, perm os.Fi
 	}
 	var src storage.ReadWriteSeekCloser
 	if !dir {
-		src, err = a.lib.Open(ctx, resourceId, flag)
+		src, err = a.lib.Open(ctx, resourceId, flag&(os.O_RDWR|os.O_WRONLY) != 0)
 		if err != nil {
 			return nil, err
 		}

internal/webdav_xnet/file.go

@@ -18,18 +18,21 @@ type file struct {
 func (f file) Seek(offset int64, whence int) (int64, error) {
 	return f.src.Seek(offset, whence)
 }
+
 func (f file) Read(p []byte) (n int, err error) {
 	return f.src.Read(p)
 }
+
+func (f file) Write(p []byte) (n int, err error) {
+	return f.src.Write(p)
+}
+
 func (f file) Close() error {
-	if f.src == nil {
+	if f.dir {
 		return nil
 	}
 	return f.src.Close()
 }
-func (f file) Write(p []byte) (n int, err error) {
-	return f.src.Write(p)
-}
 
 func (f file) Readdir(count int) ([]fs.FileInfo, error) {
 	if !f.dir {