Merge branch 'cernbox'

src/core/commoniface.py

@@ -0,0 +1,26 @@
+'''
+commoniface.py
+
+common entities used by all storage interfaces for the IOP WOPI server
+
+Author: Giuseppe.LoPresti@cern.ch, CERN/IT-ST
+'''
+
+import time
+import json
+
+# standard file missing message
+ENOENT_MSG = 'No such file or directory'
+
+# standard error thrown when attempting to overwrite a file/xattr in O_EXCL mode
+EXCL_ERROR = 'File exists and islock flag requested'
+
+# standard error thrown when attempting an operation without the required access rights
+ACCESS_ERROR = 'Operation not permitted'
+
+# name of the xattr storing the Reva lock
+LOCKKEY = 'user.iop.lock'
+
+def genrevalock(appname, value):
+    '''Return a JSON-formatted lock compatible with the Reva implementation of the CS3 Lock API'''
+    return json.dumps({'h': appname if appname else 'wopi', 't': int(time.time()), 'md': value})

src/core/cs3iface.py

@@ -21,7 +21,7 @@
 import cs3.rpc.v1beta1.code_pb2 as cs3code
 import cs3.types.v1beta1.types_pb2 as types
 
-ENOENT_MSG = 'No such file or directory'
+import core.commoniface as common
 
 # module-wide state
 ctx = {}            # "map" to store some module context: cf. init()
@@ -94,7 +94,7 @@ def stat(endpoint, fileid, userid, versioninv=1):
             'mtime': statInfo.info.mtime.seconds
         }
     ctx['log'].info('msg="Failed stat" inode="%s" reason="%s"' % (fileid, statInfo.status.message.replace('"', "'")))
-    raise IOError(ENOENT_MSG if statInfo.status.code == cs3code.CODE_NOT_FOUND else statInfo.status.message)
+    raise IOError(common.ENOENT_MSG if statInfo.status.code == cs3code.CODE_NOT_FOUND else statInfo.status.message)
 
 
 def statx(endpoint, fileid, userid, versioninv=0):
@@ -148,6 +148,26 @@ def rmxattr(_endpoint, filepath, userid, key):
     ctx['log'].debug('msg="Invoked rmxattr" result="%s"' % res)
 
 
+def setlock(endpoint, filepath, userid, appname, value):
+    '''Set a lock to filepath with the given value metadata and appname as holder'''
+    raise NotImplementedError
+
+
+def getlock(endpoint, filepath, userid, appname):
+    '''Get the lock metadata for the given filepath'''
+    raise NotImplementedError
+
+
+def refreshlock(endpoint, filepath, userid, appname, value):
+    '''Refresh the lock metadata for the given filepath'''
+    raise NotImplementedError
+
+
+def unlock(endpoint, filepath, userid, appname):
+    '''Remove the lock for the given filepath'''
+    raise NotImplementedError
+
+
 def readfile(_endpoint, filepath, userid):
     '''Read a file using the given userid as access token. Note that the function is a generator, managed by Flask.'''
     tstart = time.time()
@@ -156,7 +176,7 @@ def readfile(_endpoint, filepath, userid):
     initfiledownloadres = ctx['cs3stub'].InitiateFileDownload(request=req, metadata=[('x-access-token', userid)])
     if initfiledownloadres.status.code == cs3code.CODE_NOT_FOUND:
         ctx['log'].info('msg="File not found on read" filepath="%s"' % filepath)
-        yield IOError(ENOENT_MSG)
+        yield IOError(common.ENOENT_MSG)
     elif initfiledownloadres.status.code != cs3code.CODE_OK:
         ctx['log'].error('msg="Failed to initiateFileDownload on read" filepath="%s" reason="%s"' %
                          (filepath, initfiledownloadres.status.message.replace('"', "'")))
@@ -239,14 +259,14 @@ def renamefile(_endpoint, filepath, newfilepath, userid):
     ctx['log'].debug('msg="Invoked renamefile" result="%s"' % res)
 
 
-def removefile(_endpoint, filepath, userid, _force=0):
+def removefile(_endpoint, filepath, userid, force=False):
     '''Remove a file using the given userid as access token.
        The force argument is ignored for now for CS3 storage.'''
     reference = cs3spr.Reference(path=filepath)
     req = cs3sp.DeleteRequest(ref=reference)
     res = ctx['cs3stub'].Delete(request=req, metadata=[('x-access-token', userid)])
     if res.status.code != cs3code.CODE_OK:
-        if str(res) == ENOENT_MSG:
+        if str(res) == common.ENOENT_MSG:
             ctx['log'].info('msg="Invoked removefile on non-existing file" filepath="%s"' % filepath)
         else:
             ctx['log'].error('msg="Failed to remove file" filepath="%s" reason="%s"' % (filepath, res.status.message.replace('"', "'")))

src/core/ioplocks.py

@@ -7,6 +7,7 @@
 import time
 import http
 import core.wopiutils as utils
+import core.commoniface as common
 
 # convenience references to global entities
 st = None
@@ -133,7 +134,7 @@ def createLock(filestat, filename, userid, endpoint):
                  (filename, filestat['inode'], lockid))
         return str(lockid), http.client.OK
     except IOError as e:
-        if 'File exists and islock flag requested' not in str(e):
+        if common.EXCL_ERROR not in str(e):
             # writing failed
             log.error('msg="cboxLock: unable to store LibreOffice-compatible lock file" filename="%s" reason="%s"' %
                       (filename, e))

src/core/localiface.py

@@ -10,6 +10,8 @@
 import os
 import warnings
 from stat import S_ISDIR
+import json
+import core.commoniface as common
 
 # module-wide state
 config = None
@@ -101,6 +103,38 @@ def rmxattr(_endpoint, filepath, _userid, key):
         raise IOError(e)
 
 
+def setlock(endpoint, filepath, _userid, appname, value):
+    '''Set the lock as an xattr on behalf of the given userid'''
+    if not getxattr(endpoint, filepath, '0:0', common.LOCKKEY):
+        # we do not protect from race conditions here
+        setxattr(endpoint, filepath, '0:0', common.LOCKKEY, common.genrevalock(appname, value))
+    else:
+        raise IOError(common.EXCL_ERROR)
+
+
+def getlock(endpoint, filepath, _userid):
+    '''Get the lock metadata as an xattr on behalf of the given userid'''
+    l = getxattr(endpoint, filepath, '0:0', common.LOCKKEY)
+    if l:
+        return json.loads(l)
+    return None
+
+def refreshlock(endpoint, filepath, _userid, appname, value):
+    '''Refresh the lock value as an xattr on behalf of the given userid'''
+    l = getlock(endpoint, filepath, _userid)
+    if not l:
+        raise IOError('File was not locked')
+    if l['h'] != appname and l['h'] != 'wopi':
+        raise IOError('File is locked by %s' % l['h'])
+    # this is non-atomic, but the lock was already held
+    setxattr(endpoint, filepath, '0:0', common.LOCKKEY, common.genrevalock(appname, value))
+
+
+def unlock(endpoint, filepath, _userid, _appname):
+    '''Remove the lock as an xattr on behalf of the given userid'''
+    rmxattr(endpoint, filepath, '0:0', common.LOCKKEY)
+
+
 def readfile(_endpoint, filepath, _userid):
     '''Read a file on behalf of the given userid. Note that the function is a generator, managed by Flask.'''
     log.debug('msg="Invoking readFile" filepath="%s"' % filepath)
@@ -148,7 +182,7 @@ def writefile(_endpoint, filepath, _userid, content, islock=False):
             # as f goes out of scope here, we'd get a false ResourceWarning, which is ignored by the above filter
         except FileExistsError:
             log.info('msg="File exists on write but islock flag requested" filepath="%s"' % filepath)
-            raise IOError('File exists and islock flag requested')
+            raise IOError(common.EXCL_ERROR)
         except OSError as e:
             log.warning('msg="Error writing file in O_EXCL mode" filepath="%s" error="%s"' % (filepath, e))
             raise IOError(e)
@@ -174,7 +208,7 @@ def renamefile(_endpoint, origfilepath, newfilepath, _userid):
         raise IOError(e)
 
 
-def removefile(_endpoint, filepath, _userid, _force=0):
+def removefile(_endpoint, filepath, _userid, force=False):
     '''Remove a file on behalf of the given userid.
          The force argument is irrelevant and ignored for local storage.'''
     try: