From b6a01735d238733ef78f941a8b7c4bad59db2734 Mon Sep 17 00:00:00 2001 From: Justus Winter <4winter@informatik.uni-hamburg.de> Date: Mon, 26 Sep 2011 03:05:35 +0200 Subject: [PATCH] python: provide more exception classes To make the exception handling more effective in code using the python bindings it is necessary to differentiate between the different kind of failures. Add an exception class for each status code and add a decode classmethod to the NotmuchError class that acts as a factory. Import the new classes in __init__.py so they can be easily imported by anyone. Patch modifed by Sebastian Spaeth. Signed-off-by: Sebastian Spaeth Signed-off-by: Justus Winter <4winter@informatik.uni-hamburg.de> --- bindings/python/notmuch/__init__.py | 19 ++++++++-- bindings/python/notmuch/database.py | 37 ++++++++++---------- bindings/python/notmuch/globals.py | 54 +++++++++++++++++++++++++++-- 3 files changed, 86 insertions(+), 24 deletions(-) diff --git a/bindings/python/notmuch/__init__.py b/bindings/python/notmuch/__init__.py index a7b558fa..36e5fc7a 100644 --- a/bindings/python/notmuch/__init__.py +++ b/bindings/python/notmuch/__init__.py @@ -50,13 +50,28 @@ for more details. You should have received a copy of the GNU General Public License along with notmuch. If not, see . -Copyright 2010 Sebastian Spaeth ' +Copyright 2010-2011 Sebastian Spaeth """ from notmuch.database import Database, Query from notmuch.message import Messages, Message from notmuch.thread import Threads, Thread from notmuch.tag import Tags -from notmuch.globals import nmlib, STATUS, NotmuchError +from notmuch.globals import ( + nmlib, + STATUS, + NotmuchError, + OutOfMemoryError, + ReadOnlyDatabaseError, + XapianError, + FileError, + FileNotEmailError, + DuplicateMessageIdError, + NullPointerError, + TagTooLongError, + UnbalancedFreezeThawError, + UnbalancedAtomicError, + NotInitializedError +) from notmuch.version import __VERSION__ __LICENSE__ = "GPL v3+" __AUTHOR__ = 'Sebastian Spaeth ' diff --git a/bindings/python/notmuch/database.py b/bindings/python/notmuch/database.py index 1e6d3375..644e2e5f 100644 --- a/bindings/python/notmuch/database.py +++ b/bindings/python/notmuch/database.py @@ -112,7 +112,7 @@ class Database(object): def _assert_db_is_initialized(self): """Raises a NotmuchError in case self._db is still None""" if self._db is None: - raise NotmuchError(STATUS.NOT_INITIALIZED) + raise NotmuchError.get_subclass_exc(STATUS.NOT_INITIALIZED) def create(self, path): """Creates a new notmuch database @@ -157,8 +157,7 @@ class Database(object): res = Database._open(_str(path), mode) if res is None: - raise NotmuchError( - message="Could not open the specified database") + raise NotmuchError(message="Could not open the specified database") self._db = res def get_path(self): @@ -232,7 +231,7 @@ class Database(object): self._assert_db_is_initialized() status = nmlib.notmuch_database_begin_atomic(self._db) if status != STATUS.SUCCESS: - raise NotmuchError(status) + raise NotmuchError.get_subclass_exc(status) return status def end_atomic(self): @@ -254,7 +253,7 @@ class Database(object): self._assert_db_is_initialized() status = nmlib.notmuch_database_end_atomic(self._db) if status != STATUS.SUCCESS: - raise NotmuchError(status) + raise NotmuchError.get_subclass_exc(status) return status def get_directory(self, path): @@ -285,7 +284,7 @@ class Database(object): # we got an absolute path if not path.startswith(self.get_path()): # but its initial components are not equal to the db path - raise NotmuchError(STATUS.FILE_ERROR, + raise NotmuchError.get_subclass_exc(STATUS.FILE_ERROR, message="Database().get_directory() called " "with a wrong absolute path.") abs_dirpath = path @@ -356,7 +355,7 @@ class Database(object): byref(msg_p)) if not status in [STATUS.SUCCESS, STATUS.DUPLICATE_MESSAGE_ID]: - raise NotmuchError(status) + raise NotmuchError.get_subclass_exc(status) #construct Message() and return msg = Message(msg_p, self) @@ -450,7 +449,7 @@ class Database(object): self._assert_db_is_initialized() tags_p = Database._get_all_tags(self._db) if tags_p == None: - raise NotmuchError(STATUS.NULL_POINTER) + raise NotmuchError.get_subclass_exc(STATUS.NULL_POINTER) return Tags(tags_p, self) def create_query(self, querystring): @@ -574,13 +573,13 @@ class Query(object): (too little memory) """ if db.db_p is None: - raise NotmuchError(STATUS.NOT_INITIALIZED) + raise NotmuchError.get_subclass_exc(STATUS.NOT_INITIALIZED) # create reference to parent db to keep it alive self._db = db # create query, return None if too little mem available query_p = Query._create(db.db_p, _str(querystr)) if query_p is None: - raise NotmuchError(STATUS.NULL_POINTER) + raise NotmuchError.get_subclass_exc(STATUS.NULL_POINTER) self._query = query_p def set_sort(self, sort): @@ -594,7 +593,7 @@ class Query(object): been initialized. """ if self._query is None: - raise NotmuchError(STATUS.NOT_INITIALIZED) + raise NotmuchError.get_subclass_exc(STATUS.NOT_INITIALIZED) self.sort = sort nmlib.notmuch_query_set_sort(self._query, sort) @@ -620,7 +619,7 @@ class Query(object): * :attr:`STATUS`.NULL_POINTER if search_threads failed """ if self._query is None: - raise NotmuchError(STATUS.NOT_INITIALIZED) + raise NotmuchError.get_subclass_exc(STATUS.NOT_INITIALIZED) threads_p = Query._search_threads(self._query) @@ -643,12 +642,12 @@ class Query(object): * :attr:`STATUS`.NULL_POINTER if search_messages failed """ if self._query is None: - raise NotmuchError(STATUS.NOT_INITIALIZED) + raise NotmuchError.get_subclass_exc(STATUS.NOT_INITIALIZED) msgs_p = Query._search_messages(self._query) if msgs_p is None: - raise NotmuchError(STATUS.NULL_POINTER) + raise NotmuchError.get_subclass_exc(STATUS.NULL_POINTER) return Messages(msgs_p, self) @@ -668,7 +667,7 @@ class Query(object): * :attr:`STATUS`.NOT_INITIALIZED if query is not inited """ if self._query is None: - raise NotmuchError(STATUS.NOT_INITIALIZED) + raise NotmuchError.get_subclass_exc(STATUS.NOT_INITIALIZED) return Query._count_messages(self._query) @@ -711,7 +710,7 @@ class Directory(object): def _assert_dir_is_initialized(self): """Raises a NotmuchError(:attr:`STATUS`.NOT_INITIALIZED) if dir_p is None""" if self._dir_p is None: - raise NotmuchError(STATUS.NOT_INITIALIZED) + raise NotmuchError.get_subclass_exc(STATUS.NOT_INITIALIZED) def __init__(self, path, dir_p, parent): """ @@ -771,7 +770,7 @@ class Directory(object): if status == STATUS.SUCCESS: return #fail with Exception otherwise - raise NotmuchError(status) + raise NotmuchError.get_subclass_exc(status) def get_mtime(self): """Gets the mtime value of this directory in the database @@ -857,7 +856,7 @@ class Filenames(object): def next(self): if self._files_p is None: - raise NotmuchError(STATUS.NOT_INITIALIZED) + raise NotmuchError.get_subclass_exc(STATUS.NOT_INITIALIZED) if not nmlib.notmuch_filenames_valid(self._files_p): self._files_p = None @@ -880,7 +879,7 @@ class Filenames(object): for file in files: print file """ if self._files_p is None: - raise NotmuchError(STATUS.NOT_INITIALIZED) + raise NotmuchError.get_subclass_exc(STATUS.NOT_INITIALIZED) i = 0 while nmlib.notmuch_filenames_valid(self._files_p): diff --git a/bindings/python/notmuch/globals.py b/bindings/python/notmuch/globals.py index 097ab968..5fca3d9b 100644 --- a/bindings/python/notmuch/globals.py +++ b/bindings/python/notmuch/globals.py @@ -89,10 +89,32 @@ Invoke the class method `notmuch.STATUS.status2str` with a status value as argument to receive a human readable string""" STATUS.__name__ = 'STATUS' - class NotmuchError(Exception): - def __init__(self, status=None, message=None): - """Is initiated with a (notmuch.STATUS[,message=None])""" + """Is initiated with a (notmuch.STATUS[, message=None]). It will not + return an instance of the class NotmuchError, but a derived instance + of a more specific Error Message, e.g. OutOfMemoryError. Each status + but SUCCESS has a corresponding subclassed Exception.""" + + @classmethod + def get_subclass_exc(cls, status, message=None): + """Returns a fine grained Exception() type,detailing the error status""" + subclasses = { + STATUS.OUT_OF_MEMORY: OutOfMemoryError, + STATUS.READ_ONLY_DATABASE: ReadOnlyDatabaseError, + STATUS.XAPIAN_EXCEPTION: XapianError, + STATUS.FILE_ERROR: FileError, + STATUS.FILE_NOT_EMAIL: FileNotEmailError, + STATUS.DUPLICATE_MESSAGE_ID: DuplicateMessageIdError, + STATUS.NULL_POINTER: NullPointerError, + STATUS.TAG_TOO_LONG: TagTooLongError, + STATUS.UNBALANCED_FREEZE_THAW: UnbalancedFreezeThawError, + STATUS.UNBALANCED_ATOMIC: UnbalancedAtomicError, + STATUS.NOT_INITIALIZED: NotInitializedError + } + assert 0 < status <= len(subclasses) + return subclasses[status](status, message) + + def __init__(self, status, message=None): self.status = status self.message = message @@ -104,6 +126,32 @@ class NotmuchError(Exception): else: return 'Unknown error' +# List of Subclassed exceptions that correspond to STATUS values and are +# subclasses of NotmuchError: +class OutOfMemoryError(NotmuchError): + pass +class ReadOnlyDatabaseError(NotmuchError): + pass +class XapianError(NotmuchError): + pass +class FileError(NotmuchError): + pass +class FileNotEmailError(NotmuchError): + pass +class DuplicateMessageIdError(NotmuchError): + pass +class NullPointerError(NotmuchError): + pass +class TagTooLongError(NotmuchError): + pass +class UnbalancedFreezeThawError(NotmuchError): + pass +class UnbalancedAtomicError(NotmuchError): + pass +class NotInitializedError(NotmuchError): + pass + + def _str(value): """Ensure a nicely utf-8 encoded string to pass to libnotmuch -- 2.43.0