Vergara_Tech/mongodb
2
0
Fork 0
Code Issues Pull requests Projects Releases Packages Wiki Activity
mongodb/Database/MongoDB.hs
Scott R. Parish 442ed03027 module level documentation to point to tutorials
2010-03-13 22:09:47 -06:00

1040 lines
38 KiB
Haskell
Raw Blame History

{-
Copyright (C) 2010 Scott R Parish <srp@srparish.net>
Permission is hereby granted, free of charge, to any person obtaining
a copy of this software and associated documentation files (the
"Software"), to deal in the Software without restriction, including
without limitation the rights to use, copy, modify, merge, publish,
distribute, sublicense, and/or sell copies of the Software, and to
permit persons to whom the Software is furnished to do so, subject to
the following conditions:
The above copyright notice and this permission notice shall be
included in all copies or substantial portions of the Software.
THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE
LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION
OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION
WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
-}
-- | A driver for MongoDB
--
-- This module lets you connect to MongoDB, do inserts, queries,
-- updates, etc. Also has many convience functions inspired by HDBC
-- such as more easily converting between the BsonValue types and
-- native Haskell types.
--
-- * Tutorial for this driver:
-- <http://github.com/srp/mongoDB/blob/master/tutorial.md>
--
-- * Map/Reduce example for this driver:
-- <http://github.com/srp/mongoDB/blob/master/map-reduce-example.md>
--
-- * MongoDB:
-- <http://www.mongodb.org/>
--
module Database.MongoDB
(
-- * Connection
Connection, ConnectOpt(..),
connect, connectOnPort, conClose, disconnect, dropDatabase,
connectCluster, connectClusterOnPort,
serverInfo, serverShutdown,
databasesInfo, databaseNames,
-- * Database
Database, MongoDBCollectionInvalid, Password, Username,
ColCreateOpt(..),
collectionNames, createCollection, dropCollection,
renameCollection, runCommand, validateCollection,
auth, addUser, login, logout,
-- * Collection
Collection, FieldSelector, FullCollection,
NumToSkip, NumToReturn, Selector,
QueryOpt(..),
UpdateFlag(..),
count, countMatching, delete, insert, insertMany, query, remove, update,
save,
-- * Convenience collection operations
find, findOne, quickFind, quickFind',
-- * Query Helpers
whereClause,
-- * Cursor
Cursor,
allDocs, allDocs', finish, nextDoc,
-- * Index
Key, Unique,
Direction(..),
createIndex, dropIndex, dropIndexes, indexInformation,
-- * Map-Reduce
MapReduceOpt(..),
mapReduce, mapReduceWScopes,
runMapReduce, runMapReduceWScopes,
mapReduceResults,
)
where
import Control.Exception
import Control.Monad
import Data.Binary()
import Data.Binary.Get
import Data.Binary.Put
import Data.Bits
import Data.ByteString.Char8 (pack)
import Data.ByteString.Internal (c2w)
import qualified Data.ByteString.Lazy as L
import qualified Data.ByteString.Lazy.UTF8 as L8
import Data.Digest.OpenSSL.MD5
import Data.Int
import Data.IORef
import qualified Data.List as List
import Data.Maybe
import Data.Typeable
import Database.MongoDB.BSON as BSON
import Database.MongoDB.Util
import qualified Network
import Network.Socket hiding (connect, send, sendTo, recv, recvFrom)
import Prelude hiding (getContents)
import System.IO
import System.IO.Unsafe
import System.Random
-- | A list of handles to database connections
data Connection = Connection {
cHandle :: IORef Handle,
cRand :: IORef [Int],
cOidGen :: ObjectIdGen
}
data ConnectOpt
= SlaveOK -- ^ It's fine to connect to the slave
deriving (Show, Eq)
-- | Establish a connection to a MongoDB server
connect :: HostName -> [ConnectOpt] -> IO Connection
connect = flip connectOnPort (Network.PortNumber 27017)
-- | Establish connections to a list of MongoDB servers
connectCluster :: [HostName] -> [ConnectOpt] -> IO Connection
connectCluster xs =
connectClusterOnPort (fmap (flip (,) $ Network.PortNumber 27017) xs)
-- | Establish connections to a list of MongoDB servers specifying each port.
connectClusterOnPort :: [(HostName, Network.PortID)] -> [ConnectOpt]
-> IO Connection
connectClusterOnPort [] _ = throwOpFailure "No hostnames in list"
connectClusterOnPort servers opts = newConnection servers opts
-- | Establish a connection to a MongoDB server on a non-standard port
connectOnPort :: HostName -> Network.PortID -> [ConnectOpt] -> IO Connection
connectOnPort host port = newConnection [(host, port)]
newConnection :: [(HostName, Network.PortID)] -> [ConnectOpt] -> IO Connection
newConnection servers opts = do
r <- newStdGen
let ns = randomRs (fromIntegral (minBound :: Int32),
fromIntegral (maxBound :: Int32)) r
nsRef <- newIORef ns
hRef <- openHandle (head servers) >>= newIORef
oidGen <- mkObjectIdGen
let c = Connection hRef nsRef oidGen
res <- isMaster c
if fromBson (fromLookup $ List.lookup (s2L "ismaster") res) == (1::Int) ||
isJust (List.elemIndex SlaveOK opts)
then return c
else case List.lookup (s2L "remote") res of
Nothing -> throwConFailure "Couldn't find master to connect to"
Just server -> do
hRef' <- openHandle (splitHostPort $ fromBson server) >>= newIORef
return $ c {cHandle = hRef'}
openHandle :: (HostName, Network.PortID) -> IO Handle
openHandle (host, port) = do
h <- Network.connectTo host port
hSetBuffering h NoBuffering
return h
getHandle :: Connection -> IO Handle
getHandle c = readIORef $ cHandle c
cPut :: Connection -> L.ByteString -> IO ()
cPut c msg = getHandle c >>= flip L.hPut msg
-- | Close database connection
conClose :: Connection -> IO ()
conClose c = readIORef (cHandle c) >>= hClose
-- | Information about the databases on the server.
databasesInfo :: Connection -> IO BsonDoc
databasesInfo c =
runCommand c (s2L "admin") $ toBsonDoc [("listDatabases", BsonInt32 1)]
-- | Return a list of database names on the server.
databaseNames :: Connection -> IO [Database]
databaseNames c = do
info <- databasesInfo c
let (BsonArray dbs) = fromLookup $ List.lookup (s2L "databases") info
names = mapMaybe (List.lookup (s2L "name") . fromBson) dbs
return $ List.map fromBson (names::[BsonValue])
-- | Alias for 'conClose'
disconnect :: Connection -> IO ()
disconnect = conClose
-- | Drop a database.
dropDatabase :: Connection -> Database -> IO ()
dropDatabase c db = do
_ <- runCommand c db $ toBsonDoc [("dropDatabase", BsonInt32 1)]
return ()
isMaster :: Connection -> IO BsonDoc
isMaster c = runCommand c (s2L "admin") $ toBsonDoc [("ismaster", BsonInt32 1)]
-- | Get information about the MongoDB server we're connected to.
serverInfo :: Connection -> IO BsonDoc
serverInfo c =
runCommand c (s2L "admin") $ toBsonDoc [("buildinfo", BsonInt32 1)]
-- | Shut down the MongoDB server.
--
-- Force a clean exit, flushing and closing all data files.
-- Note that it will wait until all ongoing operations are complete.
serverShutdown :: Connection -> IO BsonDoc
serverShutdown c =
runCommand c (s2L "admin") $ toBsonDoc [("shutdown", BsonInt32 1)]
-- | Return a list of collections in /Database/.
collectionNames :: Connection -> Database -> IO [FullCollection]
collectionNames c db = do
docs <- quickFind' c (L.append db $ s2L ".system.namespaces") empty
let names = flip List.map docs $
fromBson . fromLookup . List.lookup (s2L "name")
return $ List.filter (L.notElem $ c2w '$') names
data ColCreateOpt = CCOSize Int64 -- ^ Desired initial size for the
-- collection (in bytes). must be
-- less than or equal to
-- 10000000000. For capped
-- collections this size is the max
-- size of the collection.
| CCOCapped Bool -- ^ If 'True', this is a capped collection.
| CCOMax Int64 -- ^ Maximum number of objects if capped.
deriving (Show, Eq)
colCreateOptToBson :: ColCreateOpt -> (String, BsonValue)
colCreateOptToBson (CCOSize sz) = ("size", toBson sz)
colCreateOptToBson (CCOCapped b) = ("capped", toBson b)
colCreateOptToBson (CCOMax m) = ("max", toBson m)
-- | Create a new collection in this database.
--
-- Normally collection creation is automatic. This function should
-- only be needed if you want to specify 'ColCreateOpt's on creation.
-- 'MongoDBCollectionInvalid' is thrown if the collection already
-- exists.
createCollection :: Connection -> FullCollection -> [ColCreateOpt] -> IO ()
createCollection c col opts = do
(db, col') <- validateCollectionName col
dbcols <- collectionNames c db
when (col `List.elem` dbcols) $
throwColInvalid $ "Collection already exists: " ++ show col
let cmd = ("create", toBson col') : List.map colCreateOptToBson opts
_ <- runCommand c db $ toBsonDoc cmd
return ()
-- | Drop a collection.
dropCollection :: Connection -> FullCollection -> IO ()
dropCollection c col = do
let (db, col') = splitFullCol col
_ <- runCommand c db $ toBsonDoc [("drop", toBson col')]
return ()
-- | Rename a collection--first /FullCollection/ argument is the
-- existing name, the second is the new name. At the moment this command
-- can also be used to move a collection between databases.
renameCollection :: Connection -> FullCollection -> FullCollection -> IO ()
renameCollection c col newName = do
_ <- validateCollectionName col
_ <- runCommand c (s2L "admin") $ toBsonDoc [("renameCollection", toBson col),
("to", toBson newName)]
return ()
-- | Return a string of validation info about the collection.
--
-- Example output (note this probably can/will change with different
-- versions of the server):
--
-- > validate
-- > details: 0x7fe5cc2c1da4 ofs:e7da4
-- > firstExtent:0:24100 ns:test.foo.bar
-- > lastExtent:0:24100 ns:test.foo.bar
-- > # extents:1
-- > datasize?:180 nrecords?:5 lastExtentSize:1024
-- > padding:1
-- > first extent:
-- > loc:0:24100 xnext:null xprev:null
-- > nsdiag:test.foo.bar
-- > size:1024 firstRecord:0:241e4 lastRecord:0:24280
-- > 5 objects found, nobj:5
-- > 260 bytes data w/headers
-- > 180 bytes data wout/headers
-- > deletedList: 0100100000000000000
-- > deleted: n: 4 size: 588
-- > nIndexes:1
-- > test.foo.bar.$_id_ keys:5
validateCollection :: Connection -> FullCollection -> IO String
validateCollection c col = do
let (db, col') = splitFullCol col
res <- runCommand c db $ toBsonDoc [("validate", toBson col')]
return $ fromBson $ fromLookup $ List.lookup (s2L "result") res
splitFullCol :: FullCollection -> (Database, Collection)
splitFullCol col = (L.takeWhile (c2w '.' /=) col,
L.tail $ L.dropWhile (c2w '.' /=) col)
splitHostPort :: String -> (HostName, Network.PortID)
splitHostPort hp = (host, port)
where host = List.takeWhile (':' /=) hp
port = case List.dropWhile (':' /=) hp of
"" -> Network.PortNumber 27017
pstr -> Network.Service $ List.tail pstr
-- | Run a database command. Usually this is unneeded as driver wraps
-- all of the commands for you (eg 'createCollection',
-- 'dropCollection', etc).
runCommand :: Connection -> Database -> BsonDoc -> IO BsonDoc
runCommand c db cmd = do
mres <- findOne c (L.append db $ s2L ".$cmd") cmd
let res = fromLookup mres
when (BsonDouble 1.0 /= fromLookup (List.lookup (s2L "ok") res)) $
throwOpFailure $ "command \"" ++ show cmd ++ "\" failed: " ++
fromBson (fromLookup $ List.lookup (s2L "errmsg") res)
return res
-- | An Iterator over the results of a query. Use 'nextDoc' to get each
-- successive result document, or 'allDocs' or 'allDocs'' to get lazy or
-- strict lists of results.
data Cursor = Cursor {
curCon :: Connection,
curID :: IORef Int64,
curNumToRet :: Int32,
curCol :: FullCollection,
curDocBytes :: IORef L.ByteString,
curClosed :: IORef Bool
}
data Opcode
= OPReply -- 1 Reply to a client request. responseTo is set
| OPMsg -- 1000 generic msg command followed by a string
| OPUpdate -- 2001 update document
| OPInsert -- 2002 insert new document
| OPGetByOid -- 2003 is this used?
| OPQuery -- 2004 query a collection
| OPGetMore -- 2005 Get more data from a query. See Cursors
| OPDelete -- 2006 Delete documents
| OPKillCursors -- 2007 Tell database client is done with a cursor
deriving (Show, Eq)
data MongoDBInternalError = MongoDBInternalError String
deriving (Eq, Show, Read)
mongoDBInternalError :: TyCon
mongoDBInternalError = mkTyCon "Database.MongoDB.MongoDBInternalError"
instance Typeable MongoDBInternalError where
typeOf _ = mkTyConApp mongoDBInternalError []
instance Exception MongoDBInternalError
data MongoDBCollectionInvalid = MongoDBCollectionInvalid String
deriving (Eq, Show, Read)
mongoDBCollectionInvalid :: TyCon
mongoDBCollectionInvalid = mkTyCon "Database.MongoDB.MongoDBcollectionInvalid"
instance Typeable MongoDBCollectionInvalid where
typeOf _ = mkTyConApp mongoDBCollectionInvalid []
instance Exception MongoDBCollectionInvalid
throwColInvalid :: String -> a
throwColInvalid = throw . MongoDBCollectionInvalid
data MongoDBOperationFailure = MongoDBOperationFailure String
deriving (Eq, Show, Read)
mongoDBOperationFailure :: TyCon
mongoDBOperationFailure = mkTyCon "Database.MongoDB.MongoDBoperationFailure"
instance Typeable MongoDBOperationFailure where
typeOf _ = mkTyConApp mongoDBOperationFailure []
instance Exception MongoDBOperationFailure
throwOpFailure :: String -> a
throwOpFailure = throw . MongoDBOperationFailure
data MongoDBConnectionFailure = MongoDBConnectionFailure String
deriving (Eq, Show, Read)
mongoDBConnectionFailure :: TyCon
mongoDBConnectionFailure = mkTyCon "Database.MongoDB.MongoDBconnectionFailure"
instance Typeable MongoDBConnectionFailure where
typeOf _ = mkTyConApp mongoDBConnectionFailure []
instance Exception MongoDBConnectionFailure
throwConFailure :: String -> a
throwConFailure = throw . MongoDBConnectionFailure
fromOpcode :: Opcode -> Int32
fromOpcode OPReply = 1
fromOpcode OPMsg = 1000
fromOpcode OPUpdate = 2001
fromOpcode OPInsert = 2002
fromOpcode OPGetByOid = 2003
fromOpcode OPQuery = 2004
fromOpcode OPGetMore = 2005
fromOpcode OPDelete = 2006
fromOpcode OPKillCursors = 2007
toOpcode :: Int32 -> Opcode
toOpcode 1 = OPReply
toOpcode 1000 = OPMsg
toOpcode 2001 = OPUpdate
toOpcode 2002 = OPInsert
toOpcode 2003 = OPGetByOid
toOpcode 2004 = OPQuery
toOpcode 2005 = OPGetMore
toOpcode 2006 = OPDelete
toOpcode 2007 = OPKillCursors
toOpcode n = throw $ MongoDBInternalError $ "Got unexpected Opcode: " ++ show n
-- | The name of a database.
type Database = L8.ByteString
-- | The full collection name. The full collection name is the
-- concatenation of the database name with the collection name, using
-- a @.@ for the concatenation. For example, for the database @foo@
-- and the collection @bar@, the full collection name is @foo.bar@.
type FullCollection = L8.ByteString
-- | The same as 'FullCollection' but without the 'Database' prefix.
type Collection = L8.ByteString
-- | A 'BsonDoc' representing restrictions for a query much like the
-- /where/ part of an SQL query.
type Selector = BsonDoc
-- | A list of field names that limits the fields in the returned
-- documents. The list can contains zero or more elements, each of
-- which is the name of a field that should be returned. An empty list
-- means that no limiting is done and all fields are returned.
type FieldSelector = [L8.ByteString]
type RequestID = Int32
-- | Sets the number of documents to omit - starting from the first
-- document in the resulting dataset - when returning the result of
-- the query.
type NumToSkip = Int32
-- | This controls how many documents are returned at a time. The
-- cursor works by requesting /NumToReturn/ documents, which are then
-- immediately all transfered over the network; these are held locally
-- until the those /NumToReturn/ are all consumed and then the network
-- will be hit again for the next /NumToReturn/ documents.
--
-- If the value @0@ is given, the database will choose the number of
-- documents to return.
--
-- Otherwise choosing a good value is very dependant on the document size
-- and the way the cursor is being used.
type NumToReturn = Int32
type Username = String
type Password = String
type JSCode = L8.ByteString
-- | Options that control the behavior of a 'query' operation.
data QueryOpt = QOTailableCursor
| QOSlaveOK
| QOOpLogReplay
| QONoCursorTimeout
deriving (Show)
fromQueryOpts :: [QueryOpt] -> Int32
fromQueryOpts opts = List.foldl (.|.) 0 $ fmap toVal opts
where toVal QOTailableCursor = 2
toVal QOSlaveOK = 4
toVal QOOpLogReplay = 8
toVal QONoCursorTimeout = 16
-- | Options that effect the behavior of a 'update' operation.
data UpdateFlag = UFUpsert
| UFMultiupdate
deriving (Show, Enum)
fromUpdateFlags :: [UpdateFlag] -> Int32
fromUpdateFlags flags = List.foldl (.|.) 0 $
flip fmap flags $ (1 `shiftL`) . fromEnum
-- | Return the number of documents in /FullCollection/.
count :: Connection -> FullCollection -> IO Integer
count c col = countMatching c col empty
-- | Return the number of documents in /FullCollection/ matching /Selector/
countMatching :: Connection -> FullCollection -> Selector -> IO Integer
countMatching c col sel = do
let (db, col') = splitFullCol col
res <- runCommand c db $ toBsonDoc [("count", toBson col'),
("query", toBson sel)]
let cnt = (fromBson $ fromLookup $ List.lookup (s2L "n") res :: Double)
return $ truncate cnt
-- | Delete documents matching /Selector/ from the given /FullCollection/.
delete :: Connection -> FullCollection -> Selector -> IO RequestID
delete c col sel = do
let body = runPut $ do
putI32 0
putCol col
putI32 0
putBsonDoc sel
(reqID, msg) <- packMsg c OPDelete body
cPut c msg
return reqID
-- | An alias for 'delete'.
remove :: Connection -> FullCollection -> Selector -> IO RequestID
remove = delete
moveOidToFrontOrGen :: Connection -> BsonDoc -> IO BsonDoc
moveOidToFrontOrGen c doc =
case List.lookup (s2L "_id") doc of
Nothing -> do
oid <- genObjectId $ cOidGen c
return $ (s2L "_id", oid) : doc
Just oid -> do
let keyEq = (\(k1, _) (k2, _) -> k1 == k2)
delByKey = \k -> List.deleteBy keyEq (k, undefined)
return $ (s2L "_id", oid) : delByKey (s2L "_id") doc
-- | Insert a single document into /FullCollection/ returning the /_id/ field.
insert :: Connection -> FullCollection -> BsonDoc -> IO BsonValue
insert c col doc = do
doc' <- moveOidToFrontOrGen c doc
let body = runPut $ do
putI32 0
putCol col
putBsonDoc doc'
(_reqID, msg) <- packMsg c OPInsert body
cPut c msg
return $ snd $ head doc'
-- | Insert a list of documents into /FullCollection/ returing the
-- /_id/ field for each one in the same order as they were given.
insertMany :: Connection -> FullCollection -> [BsonDoc] -> IO [BsonValue]
insertMany c col docs = do
docs' <- mapM (moveOidToFrontOrGen c) docs
let body = runPut $ do
putI32 0
putCol col
forM_ docs' putBsonDoc
(_, msg) <- packMsg c OPInsert body
cPut c msg
return $ List.map (snd . head) docs'
-- | Open a cursor to find documents. If you need full functionality,
-- see 'query'
find :: Connection -> FullCollection -> Selector -> IO Cursor
find c col sel = query c col [] 0 0 sel []
-- | Query, but only return the first result, if any.
findOne :: Connection -> FullCollection -> Selector -> IO (Maybe BsonDoc)
findOne c col sel = query c col [] 0 (-1) sel [] >>= nextDoc
-- | Perform a query and return the result as a lazy list. Be sure to
-- understand the comments about using the lazy list given for
-- 'allDocs'.
quickFind :: Connection -> FullCollection -> Selector -> IO [BsonDoc]
quickFind c col sel = find c col sel >>= allDocs
-- | Perform a query and return the result as a strict list.
quickFind' :: Connection -> FullCollection -> Selector -> IO [BsonDoc]
quickFind' c col sel = find c col sel >>= allDocs'
-- | Open a cursor to find documents in /FullCollection/ that match
-- /Selector/. See the documentation for each argument's type for
-- information about how it effects the query.
query :: Connection -> FullCollection -> [QueryOpt] ->
NumToSkip -> NumToReturn -> Selector -> FieldSelector -> IO Cursor
query c col opts nskip ret sel fsel = do
h <- getHandle c
let body = runPut $ do
putI32 $ fromQueryOpts opts
putCol col
putI32 nskip
putI32 ret
putBsonDoc sel
case fsel of
[] -> putNothing
_ -> putBsonDoc $ toBsonDoc $ List.zip fsel $
repeat $ BsonInt32 1
(reqID, msg) <- packMsg c OPQuery body
L.hPut h msg
hdr <- getHeader h
assert (OPReply == hOp hdr) $ return ()
assert (hRespTo hdr == reqID) $ return ()
reply <- getReply h
assert (rRespFlags reply == 0) $ return ()
docBytes <- L.hGet h (fromIntegral $ hMsgLen hdr - 16 - 20) >>= newIORef
closed <- newIORef False
cid <- newIORef $ rCursorID reply
return Cursor {
curCon = c,
curID = cid,
curNumToRet = ret,
curCol = col,
curDocBytes = docBytes,
curClosed = closed
}
-- | Update documents with /BsonDoc/ in /FullCollection/ that match /Selector/.
update :: Connection -> FullCollection ->
[UpdateFlag] -> Selector -> BsonDoc -> IO RequestID
update c col flags sel obj = do
let body = runPut $ do
putI32 0
putCol col
putI32 $ fromUpdateFlags flags
putBsonDoc sel
putBsonDoc obj
(reqID, msg) <- packMsg c OPUpdate body
cPut c msg
return reqID
-- | log into the mongodb /Database/ attached to the /Connection/
login :: Connection -> Database -> Username -> Password -> IO BsonDoc
login c db user pass = do
doc <- runCommand c db (toBsonDoc [("getnonce", toBson (1 :: Int))])
let nonce = fromBson $ fromLookup $ List.lookup (s2L "nonce") doc :: String
digest = md5sum $ pack $ nonce ++ user ++
md5sum (pack (user ++ ":mongo:" ++ pass))
request = toBsonDoc [("authenticate", toBson (1 :: Int)),
("user", toBson user),
("nonce", toBson nonce),
("key", toBson digest)]
in runCommand c db request
auth :: Connection -> Database -> Username -> Password -> IO BsonDoc
auth = login
logout :: Connection -> Database -> IO ()
logout c db =
runCommand c db (toBsonDoc [(s2L "logout", BsonInt32 1)]) >> return ()
-- | create a new user in the current /Database/
addUser :: Connection -> Database -> Username -> Password -> IO BsonDoc
addUser c db user pass = do
let userDoc = toBsonDoc [(s2L "user", toBson user)]
fdb = L.append db (s2L ".system.users")
doc <- findOne c fdb userDoc
let pwd = md5sum $ pack (user ++ ":mongo:" ++ pass)
doc' = (s2L "pwd", toBson pwd) :
List.deleteBy (\(k1,_) (k2,_) -> (k1 == k2))
(s2L user, undefined)
(fromMaybe userDoc doc)
_ <- save c fdb doc'
return doc'
data MapReduceOpt
= MROptQuery BsonDoc -- ^ query filter object
-- | MRSort ???? TODO <sort the query. useful for optimization>
| MROptLimit Int64 -- ^ number of objects to return from
-- collection
| MROptOut L8.ByteString -- ^ output-collection name
| MROptKeepTemp -- ^ If set the generated collection is
-- not treated as temporary, as it will
-- be by defualt. When /MROptOut/ is
-- specified, the collection is
-- automatically made permanent.
| MROptFinalize JSCode -- ^ function to apply to all the
-- results when finished
| MROptScope BsonDoc -- ^ can pass in variables that can be
-- access from map/reduce/finalize
| MROptVerbose -- ^ provide statistics on job execution
-- time
mrOptToTuple :: MapReduceOpt -> (String, BsonValue)
mrOptToTuple (MROptQuery q) = ("query", BsonDoc q)
mrOptToTuple (MROptLimit l) = ("limit", BsonInt64 l)
mrOptToTuple (MROptOut c) = ("out", BsonString c)
mrOptToTuple MROptKeepTemp = ("keeptemp", BsonBool True)
mrOptToTuple (MROptFinalize f) = ("finalize", BsonJSCode f)
mrOptToTuple (MROptScope s) = ("scope", BsonDoc s)
mrOptToTuple MROptVerbose = ("verbose", BsonBool True)
-- | Issue a map/reduce command and return the results metadata. If
-- all you care about is the actual map/reduce results you might want
-- to use the 'mapReduce' command instead.
--
-- The results meta-document will look something like this:
--
-- > {"result": "tmp.mr.mapreduce_1268095152_14",
-- > "timeMillis": 67,
-- > "counts": {"input": 4,
-- > "emit": 6,
-- > "output": 3},
-- > "ok": 1.0}
--
-- The /results/ field is the collection name within the same Database
-- that contain the results of the map/reduce.
runMapReduce :: Connection -> FullCollection
-> JSCode -- ^ mapping javascript function
-> JSCode -- ^ reducing javascript function
-> [MapReduceOpt]
-> IO BsonDoc
runMapReduce c fc m r opts = do
let (db, col) = splitFullCol fc
doc = [("mapreduce", toBson col),
("map", BsonJSCode m),
("reduce", BsonJSCode r)] ++ List.map mrOptToTuple opts
runCommand c db $ toBsonDoc doc
-- | Issue a map/reduce command with associated scopes and return the
-- results metadata. If all you care about is the actual map/reduce
-- results you might want to use the 'mapReduce' command instead.
--
-- See 'runMapReduce' for more information about the form of the
-- result metadata.
runMapReduceWScopes :: Connection -> FullCollection
-> JSCode -- ^ mapping javascript function
-> BsonDoc -- ^ Scope for mapping function
-> JSCode -- ^ reducing javascript function
-> BsonDoc -- ^ Scope for reducing function
-> [MapReduceOpt]
-> IO BsonDoc
runMapReduceWScopes c fc m ms r rs opts = do
let (db, col) = splitFullCol fc
doc = [("mapreduce", toBson col),
("map", BsonJSCodeWScope m ms),
("reduce", BsonJSCodeWScope r rs)] ++ List.map mrOptToTuple opts
runCommand c db $ toBsonDoc doc
-- | Given a result metadata from a 'mapReduce' command (or
-- 'mapReduceWScope'), issue the 'find' command that will produce the
-- actual map/reduce results.
mapReduceResults :: Connection -> Database -> BsonDoc -> IO Cursor
mapReduceResults c db r = do
let col = case List.lookup (s2L "result") r of
Just bCol -> fromBson bCol
Nothing -> throwOpFailure "No 'result' in mapReduce response"
fc = L.append (L.append db $ s2L ".") col
find c fc []
-- | Run map/reduce and produce a cursor on the results.
mapReduce :: Connection -> FullCollection
-> JSCode -- ^ mapping javascript function
-> JSCode -- ^ reducing javascript function
-> [MapReduceOpt]
-> IO Cursor
mapReduce c fc m r opts =
runMapReduce c fc m r opts >>= mapReduceResults c (fst $ splitFullCol fc)
-- | Run map/reduce with associated scopes and produce a cursor on the
-- results.
mapReduceWScopes :: Connection -> FullCollection
-> JSCode -- ^ mapping javascript function
-> BsonDoc -- ^ Scope for mapping function
-> JSCode -- ^ reducing javascript function
-> BsonDoc -- ^ Scope for mapping function
-> [MapReduceOpt]
-> IO Cursor
mapReduceWScopes c fc m ms r rs opts =
runMapReduceWScopes c fc m ms r rs opts >>=
mapReduceResults c (fst $ splitFullCol fc)
-- | Conveniently stores the /BsonDoc/ to the /FullCollection/
-- if there is an _id present in the /BsonDoc/ then it already has
-- a place in the DB, so we update it using the _id, otherwise
-- we insert it
save :: Connection -> FullCollection -> BsonDoc -> IO BsonValue
save c fc doc =
case List.lookup (s2L "_id") doc of
Nothing -> insert c fc doc
Just oid -> update c fc [UFUpsert] (toBsonDoc [("_id", oid)]) doc >>
return oid
-- | Use this in the place of the query portion of a select type query
-- This uses javascript and a scope supplied by a /BsonDoc/ to evaluate
-- documents in the database for retrieval.
--
-- Example:
--
-- > findOne conn mycoll $ whereClause "this.name == (name1 + name2)"
-- > Just (toBsonDoc [("name1", toBson "mar"), ("name2", toBson "tha")])
whereClause :: String -> Maybe BsonDoc -> BsonDoc
whereClause qry Nothing = toBsonDoc [("$where", BsonJSCode (s2L qry))]
whereClause qry (Just scope) =
toBsonDoc [("$where", BsonJSCodeWScope (s2L qry) scope)]
data Hdr = Hdr {
hMsgLen :: Int32,
-- hReqID :: Int32,
hRespTo :: Int32,
hOp :: Opcode
} deriving (Show)
data Reply = Reply {
rRespFlags :: Int32,
rCursorID :: Int64
-- rStartFrom :: Int32,
-- rNumReturned :: Int32
} deriving (Show)
getHeader :: Handle -> IO Hdr
getHeader h = do
hdrBytes <- L.hGet h 16
return $ flip runGet hdrBytes $ do
msgLen <- getI32
skip 4 -- reqID <- getI32
respTo <- getI32
op <- getI32
return $ Hdr msgLen respTo $ toOpcode op
getReply :: Handle -> IO Reply
getReply h = do
replyBytes <- L.hGet h 20
return $ flip runGet replyBytes $ do
respFlags <- getI32
cursorID <- getI64
skip 4 -- startFrom <- getI32
skip 4 -- numReturned <- getI32
return $ Reply respFlags cursorID
-- | Return one document or Nothing if there are no more.
-- Automatically closes the cursor when last document is read
nextDoc :: Cursor -> IO (Maybe BsonDoc)
nextDoc cur = do
closed <- readIORef $ curClosed cur
if closed
then return Nothing
else do
docBytes <- readIORef $ curDocBytes cur
cid <- readIORef $ curID cur
case L.length docBytes of
0 -> if cid == 0
then writeIORef (curClosed cur) True >> return Nothing
else getMore cur
_ -> do
let (doc, docBytes') = getFirstDoc docBytes
writeIORef (curDocBytes cur) docBytes'
return $ Just doc
-- | Return a lazy list of all (of the rest) of the documents in the
-- cursor. This works much like hGetContents--it will lazily read the
-- cursor data out of the database as the list is used. The cursor is
-- automatically closed when the list has been fully read.
--
-- If you manually finish the cursor before consuming off this list
-- you won't get all the original documents in the cursor.
--
-- If you don't consume to the end of the list, you must manually
-- close the cursor or you will leak the cursor, which may also leak
-- on the database side.
allDocs :: Cursor -> IO [BsonDoc]
allDocs cur = unsafeInterleaveIO $ do
doc <- nextDoc cur
case doc of
Nothing -> return []
Just d -> liftM (d :) (allDocs cur)
-- | Returns a strict list of all (of the rest) of the documents in
-- the cursor. This means that all of the documents will immediately
-- be read out of the database and loaded into memory.
allDocs' :: Cursor -> IO [BsonDoc]
allDocs' cur = do
doc <- nextDoc cur
case doc of
Nothing -> return []
Just d -> liftM (d :) (allDocs' cur)
getFirstDoc :: L.ByteString -> (BsonDoc, L.ByteString)
getFirstDoc docBytes = flip runGet docBytes $ do
doc <- getBsonDoc
docBytes' <- getRemainingLazyByteString
return (doc, docBytes')
getMore :: Cursor -> IO (Maybe BsonDoc)
getMore cur = do
h <- getHandle $ curCon cur
cid <- readIORef $ curID cur
let body = runPut $ do
putI32 0
putCol $ curCol cur
putI32 $ curNumToRet cur
putI64 cid
(reqID, msg) <- packMsg (curCon cur) OPGetMore body
L.hPut h msg
hdr <- getHeader h
assert (OPReply == hOp hdr) $ return ()
assert (hRespTo hdr == reqID) $ return ()
reply <- getReply h
assert (rRespFlags reply == 0) $ return ()
case rCursorID reply of
0 -> writeIORef (curID cur) 0
ncid -> assert (ncid == cid) $ return ()
docBytes <- (L.hGet h $ fromIntegral $ hMsgLen hdr - 16 - 20)
case L.length docBytes of
0 -> writeIORef (curClosed cur) True >> return Nothing
_ -> do
let (doc, docBytes') = getFirstDoc docBytes
writeIORef (curDocBytes cur) docBytes'
return $ Just doc
-- | Manually close a cursor -- usually not needed if you use
-- 'allDocs', 'allDocs'', or 'nextDoc'.
finish :: Cursor -> IO ()
finish cur = do
h <- getHandle $ curCon cur
cid <- readIORef $ curID cur
unless (cid == 0) $ do
let body = runPut $ do
putI32 0
putI32 1
putI64 cid
(_reqID, msg) <- packMsg (curCon cur) OPKillCursors body
L.hPut h msg
writeIORef (curClosed cur) True
return ()
-- | The field key to index on.
type Key = L8.ByteString
-- | Direction to index.
data Direction = Ascending
| Descending
deriving (Show, Eq)
fromDirection :: Direction -> Int
fromDirection Ascending = 1
fromDirection Descending = - 1
-- | Should this index guarantee uniqueness?
type Unique = Bool
-- | Create a new index on /FullCollection/ on the list of /Key/ /
-- /Direction/ pairs.
createIndex :: Connection -> FullCollection ->
[(Key, Direction)] -> Unique -> IO L8.ByteString
createIndex c col keys uniq = do
let (db, _col') = splitFullCol col
name = indexName keys
keysDoc = flip fmap keys $
\(k, d) -> (k, toBson $ fromDirection d :: BsonValue)
_ <- insert c (L.append db $ s2L ".system.indexes") $
toBsonDoc [("name", toBson name),
("ns", toBson col),
("key", toBson keysDoc),
("unique", toBson uniq)]
return name
-- | Drop the specified index on the given /FullCollection/.
dropIndex :: Connection -> FullCollection -> [(Key, Direction)] -> IO ()
dropIndex c col keys = do
let (db, col') = splitFullCol col
name = indexName keys
_ <- runCommand c db $ toBsonDoc [("deleteIndexes", toBson col'),
("index", toBson name)]
return ()
-- | Drop all indexes on /FullCollection/.
dropIndexes :: Connection -> FullCollection -> IO ()
dropIndexes c col = do
let (db, col') = splitFullCol col
_ <- runCommand c db $ toBsonDoc [("deleteIndexes", toBson col'),
("index", toBson "*")]
return ()
-- | Return a BsonDoc describing the existing indexes on /FullCollection/.
--
-- With the current server versions (1.2) this will return documents
-- such as:
--
-- > {"key": {"lastname": -1, "firstname": 1},
-- > "name": "lastname_-1_firstname_1",
-- > "ns": "mydb.people",
-- > "unique": true}
--
-- Which is a single key that indexes on @lastname@ (descending) and
-- then @firstname@ (ascending) on the collection @people@ of the
-- database @mydb@ with a uniqueness requirement.
indexInformation :: Connection -> FullCollection -> IO [BsonDoc]
indexInformation c col = do
let (db, _col') = splitFullCol col
quickFind' c (L.append db $ s2L ".system.indexes") $
toBsonDoc [("ns", toBson col)]
indexName :: [(Key, Direction)] -> L8.ByteString
indexName = L.intercalate (s2L "_") . List.map partName
where partName (k, Ascending) = L.append k $ s2L "_1"
partName (k, Descending) = L.append k $ s2L "_-1"
putCol :: Collection -> Put
putCol col = putLazyByteString col >> putNull
packMsg :: Connection -> Opcode -> L.ByteString -> IO (RequestID, L.ByteString)
packMsg c op body = do
reqID <- randNum c
let msg = runPut $ do
putI32 $ fromIntegral $ L.length body + 16
putI32 reqID
putI32 0
putI32 $ fromOpcode op
putLazyByteString body
return (reqID, msg)
randNum :: Connection -> IO Int32
randNum Connection { cRand = nsRef } = atomicModifyIORef nsRef $ \ns ->
(List.tail ns,
fromIntegral $ List.head ns)
s2L :: String -> L8.ByteString
s2L = L8.fromString
validateCollectionName :: FullCollection -> IO (Database, Collection)
validateCollectionName col = do
let (db, col') = splitFullCol col
when (s2L ".." `List.elem` L.group col) $
throwColInvalid $ "Collection can't contain \"..\": " ++ show col
when (c2w '$' `L.elem` col &&
not (s2L "oplog.$mail" `L.isPrefixOf` col' ||
s2L "$cmd" `L.isPrefixOf` col')) $
throwColInvalid $ "Collection can't contain '$': " ++ show col
when (L.head col == c2w '.' || L.last col == c2w '.') $
throwColInvalid $ "Collection can't start or end with '.': " ++ show col
return (db, col')
fromLookup :: Maybe a -> a
fromLookup (Just m) = m
fromLookup Nothing = throwColInvalid "cannot find key"
Reference in a new issue View git blame Copy permalink