Notmuch

High-level interface to the notmuch mail indexer.

Example program to add/remove a tag on all messages matching a query:

main :: IO ()
main = getArgs >>= \args -> case args of
  [path, expr, '+':tag] -> go path expr tag messageAddTag
  [path, expr, '-':tag] -> go path expr tag messageRemoveTag
  _ -> die "usage: hs-notmuch-tag-set DB-DIR SEARCH-TERM +TAG|-TAG"
  where
    go path expr tag f =
      runExceptT (do
        db <- databaseOpen path
        query db (Bare expr) >>= messages >>= traverse_ (f (fromString tag))
      ) >>= either (die . (show :: Status -> String)) pure

File descriptor exhaustion

Some Message operations cause the message file to be opened (and remain open until the object gets garbage collected):

• messageHeader will open the file to read the headers, except for the From, Subject and Message-Id headers which are indexed.

If the RTS is using a multi-generation collector (the default), and if you are working with lots of messages, you may hit max open files limits. The best way to avoid this is to avoid the scenarios outlined above. Alternative approaches that could help include:

• Use a single-generation collector (build with -rtsopts and run with +RTS -G1). This incurs the cost of scanning the entire heap on every GC run.
• In an interactive program, build with -threaded to enable parallel GC. By default, major GC will be triggered when the program is idle for a certain time.
• Manually execute performMajorGC at relevant times to ensure that older generations get cleaned up.

Opening a database

databaseOpen :: (Mode a, AsNotmuchError e, MonadError e m, MonadIO m) => FilePath -> m (Database a)

Open a database. The database will be closed and associated resources freed upon garbage collection.

The mode is determined by usage. Because read-only functions also work on read-write databases, databaseOpenReadOnly is also provided for convenience.

databaseOpenReadOnly :: (AsNotmuchError e, MonadError e m, MonadIO m) => FilePath -> m (Database RO)

Convenience function for opening a database read-only

databaseVersion :: MonadIO m => Database a -> m Int

Database format version of the given database.

data Database (a :: DatabaseMode)

A database handle. The database will be closed and freed when it is garbage collected.

Use query to perform a search or findMessage to search for a particular message.

The Database type carries a phantom for the database mode, which is propgated to derived Query, Thread and Message objects. This is used to prevent write operations being performed against a read-only database.

Instances

HasTags (Database a)

Get all tags used in the database

Methods

tags :: MonadIO m => Database a -> m [Tag]

Database modes

class Mode a

This is an internal class whose instances are the promoted DatabaseMode constructors.

Minimal complete definition

getMode, upgrade

Instances

Mode DatabaseModeReadOnly

Methods

getMode :: Proxy DatabaseMode DatabaseModeReadOnly -> DatabaseMode

upgrade :: (AsNotmuchError e, MonadError e m, MonadIO m) => Database DatabaseModeReadOnly -> m (Database DatabaseModeReadOnly)

Mode DatabaseModeReadWrite

Methods

getMode :: Proxy DatabaseMode DatabaseModeReadWrite -> DatabaseMode

upgrade :: (AsNotmuchError e, MonadError e m, MonadIO m) => Database DatabaseModeReadWrite -> m (Database DatabaseModeReadWrite)

data DatabaseMode

Constructors

DatabaseModeReadOnly

DatabaseModeReadWrite

Instances

Enum DatabaseMode

Methods

succ :: DatabaseMode -> DatabaseMode

pred :: DatabaseMode -> DatabaseMode

toEnum :: Int -> DatabaseMode

fromEnum :: DatabaseMode -> Int

enumFrom :: DatabaseMode -> [DatabaseMode]

enumFromThen :: DatabaseMode -> DatabaseMode -> [DatabaseMode]

enumFromTo :: DatabaseMode -> DatabaseMode -> [DatabaseMode]

enumFromThenTo :: DatabaseMode -> DatabaseMode -> DatabaseMode -> [DatabaseMode]

type RO = DatabaseModeReadOnly

Convenience synonym for the promoted DatabaseModeReadOnly constructor.

type RW = DatabaseModeReadWrite

Convenience synonym for the promoted DatabaseModeReadWrite constructor.

Querying the database

data Query (a :: DatabaseMode)

Query object. Cleaned up when garbage collected.

Use messages or threads to get the results.

The Query type carries a phantom for the database mode, so that write operations on messages derived from it are restricted to read/write database sessions.

Instances

HasThreads Query

Retrieve the threads matching a Query

Methods

threads :: (AsNotmuchError e, MonadError e m, MonadIO m) => Query mode -> m [Thread mode]

HasMessages Query

Retrieve all messages matching a Query

Methods

messages :: (AsNotmuchError e, MonadError e m, MonadIO m) => Query mode -> m [Message 0 mode]

query :: MonadIO m => Database a -> SearchTerm -> m (Query a)

Query the database. To retrieve results from a Query, use threads or messages.

queryCountMessages :: (AsNotmuchError e, MonadError e m, MonadIO m) => Query a -> m Int

Count the number of messages matching a query.

Complexity: same as the underlying Xapian search…

queryCountThreads :: (AsNotmuchError e, MonadError e m, MonadIO m) => Query a -> m Int

Count the number of threads matching a query.

Θ(n) in the number of messages!

Search expressions

data SearchTerm

Search expression. Use Bare if you want to use a query string as-is (see also notmuch-search-terms(7)).

Use show to stringify a SearchTerm.

Constructors

FreeForm String

From String

To String

Subject String

Attachment String

Tag Tag

Id MessageId

Thread ThreadId

Folder String

Path String

Date String String

Asterisk

And SearchTerm SearchTerm

Or SearchTerm SearchTerm

Xor SearchTerm SearchTerm

Not SearchTerm

Bare String

Instances

Show SearchTerm

Stringify a query expression.

Methods

showsPrec :: Int -> SearchTerm -> ShowS

show :: SearchTerm -> String

showList :: [SearchTerm] -> ShowS

Generic SearchTerm

Associated Types

type Rep SearchTerm :: * -> *

Methods

from :: SearchTerm -> Rep SearchTerm x

to :: Rep SearchTerm x -> SearchTerm

NFData SearchTerm

Methods

rnf :: SearchTerm -> ()

type Rep SearchTerm

type Rep SearchTerm = D1 * (MetaData "SearchTerm" "Notmuch.Search" "notmuch-0.2.0.0-inplace" False) ((:+:) * ((:+:) * ((:+:) * ((:+:) * (C1 * (MetaCons "FreeForm" PrefixI False) (S1 * (MetaSel (Nothing Symbol) NoSourceUnpackedness NoSourceStrictness DecidedLazy) (Rec0 * String))) (C1 * (MetaCons "From" PrefixI False) (S1 * (MetaSel (Nothing Symbol) NoSourceUnpackedness NoSourceStrictness DecidedLazy) (Rec0 * String)))) ((:+:) * (C1 * (MetaCons "To" PrefixI False) (S1 * (MetaSel (Nothing Symbol) NoSourceUnpackedness NoSourceStrictness DecidedLazy) (Rec0 * String))) (C1 * (MetaCons "Subject" PrefixI False) (S1 * (MetaSel (Nothing Symbol) NoSourceUnpackedness NoSourceStrictness DecidedLazy) (Rec0 * String))))) ((:+:) * ((:+:) * (C1 * (MetaCons "Attachment" PrefixI False) (S1 * (MetaSel (Nothing Symbol) NoSourceUnpackedness NoSourceStrictness DecidedLazy) (Rec0 * String))) (C1 * (MetaCons "Tag" PrefixI False) (S1 * (MetaSel (Nothing Symbol) NoSourceUnpackedness NoSourceStrictness DecidedLazy) (Rec0 * Tag)))) ((:+:) * (C1 * (MetaCons "Id" PrefixI False) (S1 * (MetaSel (Nothing Symbol) NoSourceUnpackedness NoSourceStrictness DecidedLazy) (Rec0 * MessageId))) (C1 * (MetaCons "Thread" PrefixI False) (S1 * (MetaSel (Nothing Symbol) NoSourceUnpackedness NoSourceStrictness DecidedLazy) (Rec0 * ThreadId)))))) ((:+:) * ((:+:) * ((:+:) * (C1 * (MetaCons "Folder" PrefixI False) (S1 * (MetaSel (Nothing Symbol) NoSourceUnpackedness NoSourceStrictness DecidedLazy) (Rec0 * String))) (C1 * (MetaCons "Path" PrefixI False) (S1 * (MetaSel (Nothing Symbol) NoSourceUnpackedness NoSourceStrictness DecidedLazy) (Rec0 * String)))) ((:+:) * (C1 * (MetaCons "Date" PrefixI False) ((:*:) * (S1 * (MetaSel (Nothing Symbol) NoSourceUnpackedness NoSourceStrictness DecidedLazy) (Rec0 * String)) (S1 * (MetaSel (Nothing Symbol) NoSourceUnpackedness NoSourceStrictness DecidedLazy) (Rec0 * String)))) (C1 * (MetaCons "Asterisk" PrefixI False) (U1 *)))) ((:+:) * ((:+:) * (C1 * (MetaCons "And" PrefixI False) ((:*:) * (S1 * (MetaSel (Nothing Symbol) NoSourceUnpackedness NoSourceStrictness DecidedLazy) (Rec0 * SearchTerm)) (S1 * (MetaSel (Nothing Symbol) NoSourceUnpackedness NoSourceStrictness DecidedLazy) (Rec0 * SearchTerm)))) (C1 * (MetaCons "Or" PrefixI False) ((:*:) * (S1 * (MetaSel (Nothing Symbol) NoSourceUnpackedness NoSourceStrictness DecidedLazy) (Rec0 * SearchTerm)) (S1 * (MetaSel (Nothing Symbol) NoSourceUnpackedness NoSourceStrictness DecidedLazy) (Rec0 * SearchTerm))))) ((:+:) * (C1 * (MetaCons "Xor" PrefixI False) ((:*:) * (S1 * (MetaSel (Nothing Symbol) NoSourceUnpackedness NoSourceStrictness DecidedLazy) (Rec0 * SearchTerm)) (S1 * (MetaSel (Nothing Symbol) NoSourceUnpackedness NoSourceStrictness DecidedLazy) (Rec0 * SearchTerm)))) ((:+:) * (C1 * (MetaCons "Not" PrefixI False) (S1 * (MetaSel (Nothing Symbol) NoSourceUnpackedness NoSourceStrictness DecidedLazy) (Rec0 * SearchTerm))) (C1 * (MetaCons "Bare" PrefixI False) (S1 * (MetaSel (Nothing Symbol) NoSourceUnpackedness NoSourceStrictness DecidedLazy) (Rec0 * String))))))))

Working with threads

class HasThread a where

Objects with an associated ThreadId

Minimal complete definition

threadId

Methods

threadId :: MonadIO m => a -> m ThreadId

Instances

HasThread (Thread a)

Get the ThreadId of a Thread

Methods

threadId :: MonadIO m => Thread a -> m ThreadId

HasThread (Message n a)

Get the ThreadId of a Message

Methods

threadId :: MonadIO m => Message n a -> m ThreadId

data Thread (a :: DatabaseMode)

Thread object. Cleaned up when garbage collected.

Use messages to get the messages of a thread.

The Thread type carries a phantom for the database mode, so that write operations on messages derived from it are restricted to read/write database sessions.

Instances

HasMessages Thread

Retrieve the messages in a Thread

Methods

messages :: (AsNotmuchError e, MonadError e m, MonadIO m) => Thread mode -> m [Message 0 mode]

HasThread (Thread a)

Get the ThreadId of a Thread

Methods

threadId :: MonadIO m => Thread a -> m ThreadId

HasTags (Thread a)

Get all tags used in a thread

Methods

tags :: MonadIO m => Thread a -> m [Tag]

threadToplevelMessages :: (AsNotmuchError e, MonadError e m, MonadIO m) => Thread a -> m [Message 0 a]

Returns only messages in a thread which are not replies to other messages in the thread.

threadNewestDate :: MonadIO m => Thread a -> m UTCTime

O(1) Date of the newest message in a Thread.

threadSubject :: MonadIO m => Thread a -> m ByteString

Returns the subject of the first message in the query results that belongs to this thread.

threadAuthors :: MonadIO m => Thread a -> m ThreadAuthors

Return authors of a thread. These are split into:

• Authors of messages matching the query (accessible via matchedAuthors).
• Authors of non-matching messages (accessible via unmatchedAuthors).

threadTotalMessages :: MonadIO m => Thread a -> m Int

O(1) count of messages in the thread.

Thread ID

type ThreadId = ByteString

Thread identifier generated and used by libnotmuch.

class HasThreads a where

Objects with associated threads

Minimal complete definition

threads

Methods

threads :: (AsNotmuchError e, MonadError e m, MonadIO m) => a mode -> m [Thread mode]

Instances

HasThreads Query

Retrieve the threads matching a Query

Methods

threads :: (AsNotmuchError e, MonadError e m, MonadIO m) => Query mode -> m [Thread mode]

Thread authors

data ThreadAuthors

Authors belonging to messages in a query result of a thread ordered by date.

Instances

Show ThreadAuthors

Methods

showsPrec :: Int -> ThreadAuthors -> ShowS

show :: ThreadAuthors -> String

showList :: [ThreadAuthors] -> ShowS

Generic ThreadAuthors

Associated Types

type Rep ThreadAuthors :: * -> *

Methods

from :: ThreadAuthors -> Rep ThreadAuthors x

to :: Rep ThreadAuthors x -> ThreadAuthors

NFData ThreadAuthors

Methods

rnf :: ThreadAuthors -> ()

type Rep ThreadAuthors

type Rep ThreadAuthors = D1 * (MetaData "ThreadAuthors" "Notmuch" "notmuch-0.2.0.0-inplace" False) (C1 * (MetaCons "ThreadAuthors" PrefixI True) ((:*:) * (S1 * (MetaSel (Just Symbol "_matchedAuthors") NoSourceUnpackedness NoSourceStrictness DecidedLazy) (Rec0 * [Author])) (S1 * (MetaSel (Just Symbol "_unmatchedAuthors") NoSourceUnpackedness NoSourceStrictness DecidedLazy) (Rec0 * [Author]))))

type Author = Text

Author of a message.

matchedAuthors :: Lens' ThreadAuthors [Author]

Lens to matched authors. See also threadAuthors.

unmatchedAuthors :: Lens' ThreadAuthors [Author]

Lens to unmatched authors. See also threadAuthors.

Working with messages

findMessage :: (AsNotmuchError e, MonadError e m, MonadIO m) => Database a -> MessageId -> m (Maybe (Message 0 a))

Look for a particular message in the database.

class HasMessages a where

Objects with associated messages.

Minimal complete definition

messages

Methods

messages :: (AsNotmuchError e, MonadError e m, MonadIO m) => a mode -> m [Message 0 mode]

Instances

HasMessages Query

Retrieve all messages matching a Query

Methods

messages :: (AsNotmuchError e, MonadError e m, MonadIO m) => Query mode -> m [Message 0 mode]

HasMessages Thread

Retrieve the messages in a Thread

Methods

messages :: (AsNotmuchError e, MonadError e m, MonadIO m) => Thread mode -> m [Message 0 mode]

HasMessages (Message n)

Retrieve the replies to a Message

Methods

messages :: (AsNotmuchError e, MonadError e m, MonadIO m) => Message n mode -> m [Message 0 mode]

data Message (n :: Nat) (a :: DatabaseMode)

Message object. Cleaned up when garbage collected.

The Message type carries a phantom for the database mode, so that write operations are restricted to read/write database sessions.

There is also a phantom type parameter for the degree of frozenness of the message. Tag operations on a frozen message are atomic, only becoming visible to other threads/processes after the thaw. The freeze/thaw behaviour is available via withFrozenMessage.

Instances

HasMessages (Message n)

Retrieve the replies to a Message

Methods

messages :: (AsNotmuchError e, MonadError e m, MonadIO m) => Message n mode -> m [Message 0 mode]

HasThread (Message n a)

Get the ThreadId of a Message

Methods

threadId :: MonadIO m => Message n a -> m ThreadId

HasTags (Message n a)

Get the tags of a single message

Methods

tags :: MonadIO m => Message n a -> m [Tag]

type MessageId = ByteString

Message-Id header value.

messageId :: MonadIO m => Message n a -> m MessageId

Get the message ID.

messageDate :: MonadIO m => Message n a -> m UTCTime

Get the date the message was sent.

messageHeader :: MonadIO m => ByteString -> Message n a -> m (Maybe ByteString)

Get the named header as a UTF-8 encoded string. Empty string if header is missing or Nothing on error.

May open a file descriptor that will not be closed until the message gets garbage collected.

messageFilename :: MonadIO m => Message n a -> m FilePath

Get the filename of the message.

messageSetTags :: (MonadIO m, Foldable t) => t Tag -> Message 0 RW -> m ()

Set tags for the message. Atomic.

messageAddTag :: MonadIO m => Tag -> Message n RW -> m ()

Add the tag to a message. If adding/removing multiple tags, use messageSetTags to set the whole tag list atomically, or use withFrozenMessage to avoid inconsistent states when adding/removing tags.

messageRemoveTag :: MonadIO m => Tag -> Message n RW -> m ()

Remove the tag from a message. If adding/removing multiple tags, use messageSetTags to set the whole tag list atomically, or use withFrozenMessage to avoid inconsistent states when adding/removing tags.

withFrozenMessage :: (Message 1 RW -> IO a) -> Message 0 RW -> IO a

Freeze the message, run the given computation and return the result. The message is always thawed at the end. (Don't thaw the message as part of the computation!)

Have to start with Message 0 RW due to GHC type system limitation (type-level Nat is not inductive).

Tags

class HasTags a where

Objects with tags

Minimal complete definition

tags

Methods

tags :: MonadIO m => a -> m [Tag]

Instances

HasTags (Thread a)

Get all tags used in a thread

Methods

tags :: MonadIO m => Thread a -> m [Tag]

HasTags (Database a)

Get all tags used in the database

Methods

tags :: MonadIO m => Database a -> m [Tag]

HasTags (Message n a)

Get the tags of a single message

Methods

tags :: MonadIO m => Message n a -> m [Tag]

data Tag

Message tag. Use mkTag to construct a tag. Or use -XOverloadedStrings, but beware that the IsString instance is non-total.

This data type avoid copying when passing tags to libnotmuch. But copies do occur when reading tags from a database.

A previous experiment with interning showed no benefit. Tags are typically very short so the overhead erodes any advantage.

Instances

Eq Tag

Methods

(==) :: Tag -> Tag -> Bool

(/=) :: Tag -> Tag -> Bool

Ord Tag

Methods

compare :: Tag -> Tag -> Ordering

(<) :: Tag -> Tag -> Bool

(<=) :: Tag -> Tag -> Bool

(>) :: Tag -> Tag -> Bool

(>=) :: Tag -> Tag -> Bool

max :: Tag -> Tag -> Tag

min :: Tag -> Tag -> Tag

Show Tag

Methods

showsPrec :: Int -> Tag -> ShowS

show :: Tag -> String

showList :: [Tag] -> ShowS

IsString Tag

Throws exception if the tag is empty or too long.

Methods

fromString :: String -> Tag

NFData Tag

Methods

rnf :: Tag -> ()

mkTag :: ByteString -> Maybe Tag

O(n) Just a tag, or Nothing if the string is too long

Use UTF-8 encoding to include non-ASCII characters in a tag.

getTag :: Tag -> ByteString

O(1)

tagMaxLen :: Int

The maximum tag length. Defined as NOTMUCH_TAG_MAX in notmuch.h.

Errors

data Status

Constructors

StatusSuccess

StatusOutOfMemory

StatusReadOnlyDatabase

StatusXapianException

StatusFileError

StatusFileNotEmail

StatusDuplicateMessageId

StatusNullPointer

StatusTagTooLong

StatusUnbalancedFreezeThaw

StatusUnbalancedAtomic

StatusUnsupportedOperation

StatusUpgradeRequired

StatusPathError

StatusIgnored

StatusIllegalArgument

StatusMalformedCryptoProtocol

StatusFailedCryptoContextCreation

StatusUnknownCryptoProtocol

StatusLastStatus

Instances

Enum Status

Classy prism for injecting a libnotmuch status code.

Methods

succ :: Status -> Status

pred :: Status -> Status

toEnum :: Int -> Status

fromEnum :: Status -> Int

enumFrom :: Status -> [Status]

enumFromThen :: Status -> Status -> [Status]

enumFromTo :: Status -> Status -> [Status]

enumFromThenTo :: Status -> Status -> Status -> [Status]

Eq Status

Methods

(==) :: Status -> Status -> Bool

(/=) :: Status -> Status -> Bool

Show Status

Methods

showsPrec :: Int -> Status -> ShowS

show :: Status -> String

showList :: [Status] -> ShowS

AsNotmuchError Status

Methods

_NotmuchError :: Prism' Status Status

class AsNotmuchError s where

Minimal complete definition

_NotmuchError

Methods

_NotmuchError :: Prism' s Status

Instances

AsNotmuchError Status

Methods

_NotmuchError :: Prism' Status Status

Library information

libnotmuchVersion :: Version

The version of libnotmuch that hs-notmuch was built against. (The program could be running against a different version.)