github.com/cockroachdb/pebble@v0.0.0-20231214172447-ab4952c5f87b/objstorage/objstorageprovider/shared_writable.go (about)

     1  // Copyright 2023 The LevelDB-Go and Pebble Authors. All rights reserved. Use
     2  // of this source code is governed by a BSD-style license that can be found in
     3  // the LICENSE file.
     4  
     5  package objstorageprovider
     6  
     7  import (
     8  	"io"
     9  
    10  	"github.com/cockroachdb/pebble/objstorage"
    11  )
    12  
    13  // NewRemoteWritable creates an objstorage.Writable out of an io.WriteCloser.
    14  func NewRemoteWritable(obj io.WriteCloser) objstorage.Writable {
    15  	return &sharedWritable{storageWriter: obj}
    16  }
    17  
    18  // sharedWritable is a very simple implementation of Writable on top of the
    19  // WriteCloser returned by remote.Storage.CreateObject.
    20  type sharedWritable struct {
    21  	// Either both p and meta must be unset / zero values, or both must be set.
    22  	// The case where both are unset is true only in tests.
    23  	p             *provider
    24  	meta          objstorage.ObjectMetadata
    25  	storageWriter io.WriteCloser
    26  }
    27  
    28  var _ objstorage.Writable = (*sharedWritable)(nil)
    29  
    30  // Write is part of the Writable interface.
    31  func (w *sharedWritable) Write(p []byte) error {
    32  	_, err := w.storageWriter.Write(p)
    33  	return err
    34  }
    35  
    36  // Finish is part of the Writable interface.
    37  func (w *sharedWritable) Finish() error {
    38  	err := w.storageWriter.Close()
    39  	w.storageWriter = nil
    40  	if err != nil {
    41  		w.Abort()
    42  		return err
    43  	}
    44  
    45  	// Create the marker object.
    46  	if w.p != nil {
    47  		if err := w.p.sharedCreateRef(w.meta); err != nil {
    48  			w.Abort()
    49  			return err
    50  		}
    51  	}
    52  	return nil
    53  }
    54  
    55  // Abort is part of the Writable interface.
    56  func (w *sharedWritable) Abort() {
    57  	if w.storageWriter != nil {
    58  		_ = w.storageWriter.Close()
    59  		w.storageWriter = nil
    60  	}
    61  	if w.p != nil {
    62  		w.p.removeMetadata(w.meta.DiskFileNum)
    63  	}
    64  	// TODO(radu): delete the object if it was created.
    65  }