4.3. Email Database¶
The python bindings to libnotmuch define notmuch.Thread
and
notmuch.Message
, which unfortunately are very fragile.
Alot defines the wrapper classes alot.db.Thread
and alot.db.Message
that
use an manager.DBManager
instance to transparently provide persistent objects.
alot.db.Message
moreover contains convenience methods
to extract information about the message like reformated header values, a summary,
decoded and interpreted body text and a list of Attachments
.
The central UI
instance carries around a DBManager
object that
is used for any lookups or modifications of the email base. DBManager
can
directly look up Thread
and Message
objects and is able to
postpone/cache/retry writing operations in case the Xapian index is locked by another
process.
4.3.1. Database Manager¶
-
class
alot.db.manager.
DBManager
(path=None, ro=False)¶ Keeps track of your index parameters, maintains a write-queue and lets you look up threads and messages directly to the persistent wrapper classes.
Parameters: - path (str) – absolute path to the notmuch index
- ro (bool) – open the index in read-only mode
-
add_message
(path, tags=None, afterwards=None)¶ Adds a file to the notmuch index.
Parameters: - path (str) – path to the file
- tags (list of str) – tagstrings to add
- afterwards (callable or None) – callback to trigger after adding
-
async
(cbl, fun)¶ return a pair (pipe, process) so that the process writes fun(a) to the pipe for each element a in the iterable returned by the callable cbl.
Parameters: - cbl (callable) – a function returning something iterable
- fun (callable) – an unary translation function
Return type: (
multiprocessing.Pipe
,multiprocessing.Process
)
-
count_messages
(querystring)¶ returns number of messages that match querystring
-
count_threads
(querystring)¶ returns number of threads that match querystring
-
flush
()¶ write out all queued write-commands in order, each one in a separate
atomic
transaction.If this fails the current action is rolled back, stays in the write queue and an exception is raised. You are responsible to retry flushing at a later time if you want to ensure that the cached changes are applied to the database.
Exception: DatabaseROError
if db is opened read-onlyException: DatabaseLockedError
if db is locked
returns all tagsstrings used in the database :rtype: list of str
-
get_threads
(querystring, sort='newest_first')¶ asynchronously look up thread ids matching querystring.
Parameters: - querystring (str.) – The query string to use for the lookup
- sort – Sort order. one of [‘oldest_first’, ‘newest_first’, ‘message_id’, ‘unsorted’]
Returns: a pipe together with the process that asynchronously writes to it.
Return type: (
multiprocessing.Pipe
,multiprocessing.Process
)
-
kill_search_processes
()¶ terminate all search processes that originate from this managers
get_threads()
.
-
query
(querystring)¶ creates
notmuch.Query
objects on demandParameters: querystring – The query string to use for the lookup Returns: notmuch.Query
– the query object.
-
remove_message
(message, afterwards=None)¶ Remove a message from the notmuch index
Parameters: - message (
Message
) – message to remove - afterwards (callable or None) – callback to trigger after removing
- message (
-
tag
(querystring, tags, afterwards=None, remove_rest=False)¶ add tags to messages matching querystring. This appends a tag operation to the write queue and raises
DatabaseROError
if in read only mode.Parameters: - querystring (str) – notmuch search string
- tags (list of str) – a list of tags to be added
- afterwards (callable) – callback that gets called after successful application of this tagging operation
- remove_rest (bool) – remove tags from matching messages before tagging
Exception: Note
This only adds the requested operation to the write queue. You need to call
DBManager.flush()
to actually write out.
-
untag
(querystring, tags, afterwards=None)¶ removes tags from messages that match querystring. This appends an untag operation to the write queue and raises
DatabaseROError
if in read only mode.Parameters: - querystring (str) – notmuch search string
- tags (list of str) – a list of tags to be added
- afterwards (callable) – callback that gets called after successful application of this tagging operation
Exception: Note
This only adds the requested operation to the write queue. You need to call
DBManager.flush()
to actually write out.
4.3.2. Errors¶
-
class
alot.db.errors.
DatabaseError
¶
-
class
alot.db.errors.
DatabaseROError
¶ cannot write to read-only database
-
class
alot.db.errors.
DatabaseLockedError
¶ cannot write to locked index
-
class
alot.db.errors.
NonexistantObjectError
¶ requested thread or message does not exist in the index
4.3.3. Wrapper¶
-
class
alot.db.
Thread
(dbman, thread)¶ A wrapper around a notmuch mailthread (
notmuch.database.Thread
) that ensures persistence of the thread: It can be safely read multiple times, its manipulation is done via aalot.db.DBManager
and it can directly provide contained messages asMessage
.Parameters: - dbman (
DBManager
) – db manager that is used for further lookups - thread (
notmuch.database.Thread
) – the wrapped thread
add tags to all messages in this thread
Note
This only adds the requested operation to this objects
DBManager's
write queue. You need to callDBManager.flush
to actually write out.Parameters: - tags (list of str) – a list of tags to be added
- afterwards (callable) – callback that gets called after successful application of this tagging operation
- remove_rest (bool) – remove all other tags
returns a list of authors (name, addr) of the messages. The authors are ordered by msg date and unique (by name/addr).
Return type: list of (str, str)
returns a string of comma-separated authors Depending on settings, it will substitute “me” for author name if address is user’s own.
Parameters: - own_addrs (list of str) – list of own email addresses to replace
- replace_own (bool) – whether or not to actually do replacement
Return type: str
-
get_messages
()¶ returns all messages in this thread as dict mapping all contained messages to their direct responses.
Return type: dict mapping Message
to a list ofMessage
.
-
get_newest_date
()¶ returns date header of newest message in this thread as
datetime
-
get_oldest_date
()¶ returns date header of oldest message in this thread as
datetime
-
get_replies_to
(msg)¶ returns all replies to the given message contained in this thread.
Parameters: msg ( Message
) – parent message to look upReturns: list of Message
or None
-
get_subject
()¶ returns subject string
returns tagsstrings attached to this thread
Parameters: intersection (bool) – return tags present in all contained messages instead of in at least one (union) Return type: set of str
-
get_thread_id
()¶ returns id of this thread
-
get_toplevel_messages
()¶ returns all toplevel messages contained in this thread. This are all the messages without a parent message (identified by ‘in-reply-to’ or ‘references’ header.
Return type: list of Message
-
get_total_messages
()¶ returns number of contained messages
-
matches
(query)¶ Check if this thread matches the given notmuch query.
Parameters: query (string) – The query to check against Returns: True if this thread matches the given query, False otherwise Return type: bool
-
refresh
(thread=None)¶ refresh thread metadata from the index
remove tags (list of str) from all messages in this thread
Note
This only adds the requested operation to this objects
DBManager's
write queue. You need to callDBManager.flush
to actually write out.Parameters: - tags (list of str) – a list of tags to be added
- afterwards (callable) – callback that gets called after successful application of this tagging operation
- dbman (
-
class
alot.db.
Message
(dbman, msg, thread=None)¶ a persistent notmuch message object. It it uses a
DBManager
for cached manipulation and lazy lookups.Parameters: - dbman (alot.db.DBManager) – db manager that is used for further lookups
- msg (notmuch.database.Message) – the wrapped message
- thread (
Thread
or None) – this messages thread (will be looked up later if None)
-
accumulate_body
()¶ returns bodystring extracted from this mail
adds tags to message
Note
This only adds the requested operation to this objects
DBManager's
write queue. You need to callflush()
to write out.Parameters: - tags (list of str) – a list of tags to be added
- afterwards (callable) – callback that gets called after successful application of this tagging operation
- remove_rest (bool) – remove all other tags
-
get_attachments
()¶ returns messages attachments
Derived from the leaves of the email mime tree that and are not part of RFC 2015 syntax for encrypted/signed mails and either have Content-Disposition attachment or have Content-Disposition inline but specify a filename (as parameter to Content-Disposition).
Return type: list of Attachment
returns realname and address of this messages author
Return type: (str,str)
-
get_date
()¶ returns Date header value as
datetime
-
get_datestring
()¶ returns reformated datestring for this message.
It uses
SettingsManager.represent_datetime()
to represent this messages Date headerReturn type: str
-
get_email
()¶ returns
email.Message
for this message
-
get_filename
()¶ returns absolute path of message files location
-
get_headers_string
(headers)¶ returns subset of this messages headers as human-readable format: all header values are decoded, the resulting string has one line “KEY: VALUE” for each requested header present in the mail.
Parameters: headers (list of str) – headers to extract
-
get_message_id
()¶ returns messages id (str)
-
get_message_parts
()¶ yield all body parts of this message
-
get_replies
()¶ returns replies to this message as list of
Message
returns tags attached to this message as list of strings
-
get_thread_id
()¶ returns id (str) of the thread this message belongs to
-
has_replies
()¶ returns true if this message has at least one reply
-
matches
(querystring)¶ tests if this messages is in the resultset for querystring
remove tags from message
Note
This only adds the requested operation to this objects
DBManager's
write queue. You need to callflush()
to actually out.Parameters: - tags (list of str) – a list of tags to be added
- afterwards (callable) – callback that gets called after successful application of this tagging operation
4.3.4. Other Structures¶
-
class
alot.db.attachment.
Attachment
(emailpart)¶ represents a mail attachment
Parameters: emailpart ( email.message.Message
) – a non-multipart email that is the attachment-
get_content_type
()¶ mime type of the attachment part
-
get_data
()¶ return data blob from wrapped file
-
get_filename
()¶ return name of attached file. If the content-disposition header contains no file name, this returns None
-
get_mime_representation
()¶ returns mime part that constitutes this attachment
-
get_size
()¶ returns attachments size in bytes
-
save
(path)¶ save the attachment to disk. Uses
get_filename()
in case path is a directory
-
write
(fhandle)¶ writes content to a given filehandle
-
-
class
alot.db.envelope.
Envelope
(template=None, bodytext=None, headers=None, attachments=None, sign=False, sign_key=None, encrypt=False, tags=None)¶ a message that is not yet sent and still editable. It holds references to unencoded! body text and mail headers among other things. Envelope implements the python container API for easy access of header values. So e[‘To’], e[‘To’] = ‘foo@bar.baz’ and ‘e.get_all(‘To’)’ would work for an envelope e..
Parameters: - template (str) – if not None, the envelope will be initialised by
parsing
this string before setting any other values given to this constructor. - bodytext (str) – text used as body part
- headers (dict (str -> [unicode])) – unencoded header values
- attachments (list of
Attachment
) – file attachments to include - tags (list of str) – tags to add after successful sendout and saving this msg
-
add
(key, value)¶ add header value
-
attach
(attachment, filename=None, ctype=None)¶ attach a file
Parameters: - attachment (
Attachment
or str) – File to attach, given asAttachment
object or path to a file. - filename – filename to use in content-disposition. Will be ignored if path matches multiple files
- ctype (str) – force content-type to be used for this attachment
- attachment (
-
construct_mail
()¶ compiles the information contained in this envelope into a
email.Message
.
-
get
(key, fallback=None)¶ secure getter for header values that allows specifying a fallback return string (defaults to None). This returns the first matching value and doesn’t raise KeyErrors
-
get_all
(key, fallback=None)¶ returns all header values for given key
-
parse_template
(tmp, reset=False, only_body=False)¶ parses a template or user edited string to fills this envelope.
Parameters: - tmp (str) – the string to parse.
- reset (bool) – remove previous envelope content
-
attachments
= None¶ list of
Attachments
-
body
= None¶ mail body as unicode string
-
headers
= None¶ dict containing the mail headers (a list of strings for each header key)
tags to add after successful sendout
-
tmpfile
= None¶ template text for initial content
- template (str) – if not None, the envelope will be initialised by
4.3.5. Utilities¶
-
alot.db.utils.
add_signature_headers
(mail, sigs, error_msg)¶ Add pseudo headers to the mail indicating whether the signature verification was successful.
Parameters: - mail –
email.message.Message
the message to entitle - sigs – list of
gpgme.Signature
- error_msg – str containing an error message, the empty string indicating no error
- mail –
-
alot.db.utils.
decode_header
(header, normalize=False)¶ decode a header value to a unicode string
values are usually a mixture of different substrings encoded in quoted printable using different encodings. This turns it into a single unicode string
Parameters: - header (str) – the header value
- normalize (bool) – replace trailing spaces after newlines
Return type: unicode
-
alot.db.utils.
encode_header
(key, value)¶ encodes a unicode string as a valid header value
Parameters: - key (str) – the header field this value will be stored in
- value (unicode) – the value to be encoded
-
alot.db.utils.
extract_body
(mail, types=None, field_key='copiousoutput')¶ returns a body text string for given mail. If types is None, text/* is used: The exact preferred type is specified by the prefer_plaintext config option which defaults to text/html.
Parameters: - mail (
email.Message
) – the mail to use - types (list of str) – mime content types to use for body string
- mail (
-
alot.db.utils.
extract_headers
(mail, headers=None)¶ returns subset of this messages headers as human-readable format: all header values are decoded, the resulting string has one line “KEY: VALUE” for each requested header present in the mail.
Parameters: - mail (
email.Message
) – the mail to use - headers (list of str) – headers to extract
- mail (
-
alot.db.utils.
get_params
(mail, failobj=None, header='content-type', unquote=True)¶ Get Content-Type parameters as dict.
RFC 2045 specifies that parameter names are case-insensitive, so we normalize them here.
Parameters: - mail –
email.message.Message
- failobj – object to return if no such header is found
- header – the header to search for parameters, default
- unquote – unquote the values
Returns: a dict containing the parameters
- mail –
-
alot.db.utils.
message_from_file
(handle)¶ Reads a mail from the given file-like object and returns an email object, very much like email.message_from_file. In addition to that OpenPGP encrypted data is detected and decrypted. If this succeeds, any mime messages found in the recovered plaintext message are added to the returned message object.
Parameters: handle – a file-like object Returns: email.message.Message
possibly augmented with decrypted data
-
alot.db.utils.
message_from_string
(s)¶ Reads a mail from the given string. This is the equivalent of
email.message_from_string()
which does nothing but to wrap the given string in a StringIO object and to callemail.message_from_file()
.Please refer to the documentation of
message_from_file()
for details.