github.com/cs3org/reva/v2@v2.27.7/pkg/storage/fs/ocis/blobstore/blobstore.go (about)

     1  // Copyright 2018-2021 CERN
     2  //
     3  // Licensed under the Apache License, Version 2.0 (the "License");
     4  // you may not use this file except in compliance with the License.
     5  // You may obtain a copy of the License at
     6  //
     7  //     http://www.apache.org/licenses/LICENSE-2.0
     8  //
     9  // Unless required by applicable law or agreed to in writing, software
    10  // distributed under the License is distributed on an "AS IS" BASIS,
    11  // WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
    12  // See the License for the specific language governing permissions and
    13  // limitations under the License.
    14  //
    15  // In applying this license, CERN does not waive the privileges and immunities
    16  // granted to it by virtue of its status as an Intergovernmental Organization
    17  // or submit itself to any jurisdiction.
    18  
    19  package blobstore
    20  
    21  import (
    22  	"bufio"
    23  	"fmt"
    24  	"io"
    25  	"os"
    26  	"path/filepath"
    27  	"strings"
    28  
    29  	"github.com/cs3org/reva/v2/pkg/storage/utils/decomposedfs/lookup"
    30  	"github.com/cs3org/reva/v2/pkg/storage/utils/decomposedfs/node"
    31  	"github.com/cs3org/reva/v2/pkg/utils"
    32  	"github.com/pkg/errors"
    33  )
    34  
    35  // ErrBlobIDEmpty is returned when the BlobID is empty
    36  var ErrBlobIDEmpty = fmt.Errorf("blobstore: BlobID is empty")
    37  
    38  // Blobstore provides an interface to an filesystem based blobstore
    39  type Blobstore struct {
    40  	root string
    41  }
    42  
    43  // New returns a new Blobstore
    44  func New(root string) (*Blobstore, error) {
    45  	err := os.MkdirAll(root, 0700)
    46  	if err != nil {
    47  		return nil, err
    48  	}
    49  
    50  	return &Blobstore{
    51  		root: root,
    52  	}, nil
    53  }
    54  
    55  // Upload stores some data in the blobstore under the given key
    56  func (bs *Blobstore) Upload(node *node.Node, source string) error {
    57  	if node.BlobID == "" {
    58  		return ErrBlobIDEmpty
    59  	}
    60  
    61  	dest := bs.Path(node)
    62  
    63  	// ensure parent path exists
    64  	if err := os.MkdirAll(filepath.Dir(dest), 0700); err != nil {
    65  		return errors.Wrap(err, "Decomposedfs: oCIS blobstore: error creating parent folders for blob")
    66  	}
    67  
    68  	if err := os.Rename(source, dest); err == nil {
    69  		return nil
    70  	}
    71  
    72  	// Rename failed, file needs to be copied.
    73  	file, err := os.Open(source)
    74  	if err != nil {
    75  		return errors.Wrap(err, "Decomposedfs: oCIS blobstore: Can not open source file to upload")
    76  	}
    77  	defer file.Close()
    78  
    79  	f, err := os.OpenFile(dest, os.O_CREATE|os.O_WRONLY, 0700)
    80  	if err != nil {
    81  		return errors.Wrapf(err, "could not open blob '%s' for writing", dest)
    82  	}
    83  
    84  	w := bufio.NewWriter(f)
    85  	_, err = w.ReadFrom(file)
    86  	if err != nil {
    87  		return errors.Wrapf(err, "could not write blob '%s'", dest)
    88  	}
    89  
    90  	return w.Flush()
    91  }
    92  
    93  // Download retrieves a blob from the blobstore for reading
    94  func (bs *Blobstore) Download(node *node.Node) (io.ReadCloser, error) {
    95  	if node.BlobID == "" {
    96  		return nil, ErrBlobIDEmpty
    97  	}
    98  
    99  	dest := bs.Path(node)
   100  	file, err := os.Open(dest)
   101  	if err != nil {
   102  		return nil, errors.Wrapf(err, "could not read blob '%s'", dest)
   103  	}
   104  	return file, nil
   105  }
   106  
   107  // Delete deletes a blob from the blobstore
   108  func (bs *Blobstore) Delete(node *node.Node) error {
   109  	if node.BlobID == "" {
   110  		return ErrBlobIDEmpty
   111  	}
   112  	dest := bs.Path(node)
   113  	if err := utils.RemoveItem(dest); err != nil {
   114  		return errors.Wrapf(err, "could not delete blob '%s'", dest)
   115  	}
   116  	return nil
   117  }
   118  
   119  // List lists all blobs in the Blobstore
   120  func (bs *Blobstore) List() ([]*node.Node, error) {
   121  	dirs, err := filepath.Glob(filepath.Join(bs.root, "spaces", "*", "*", "blobs", "*", "*", "*", "*", "*"))
   122  	if err != nil {
   123  		return nil, err
   124  	}
   125  	blobids := make([]*node.Node, 0, len(dirs))
   126  	for _, d := range dirs {
   127  		_, s, _ := strings.Cut(d, "spaces")
   128  		spaceraw, blobraw, _ := strings.Cut(s, "blobs")
   129  		blobids = append(blobids, &node.Node{
   130  			SpaceID: strings.ReplaceAll(spaceraw, "/", ""),
   131  			BlobID:  strings.ReplaceAll(blobraw, "/", ""),
   132  		})
   133  	}
   134  	return blobids, nil
   135  }
   136  
   137  func (bs *Blobstore) Path(node *node.Node) string {
   138  	return filepath.Join(
   139  		bs.root,
   140  		filepath.Clean(filepath.Join(
   141  			"/", "spaces", lookup.Pathify(node.SpaceID, 1, 2), "blobs", lookup.Pathify(node.BlobID, 4, 2)),
   142  		),
   143  	)
   144  }