Database.TokyoCabinet.FDB

Contents

Basic API (tokyocabinet.idl compliant)

Description

Interface to Fixed-length DBM. See also, http://tokyocabinet.sourceforge.net/spex-en.html#tcfdbapi for details

Synopsis

Documentation

Example

    import Control.Monad
    import Database.TokyoCabinet.FDB

  
    main = do fdb <- new
              -- open the database
              open fdb "casket.tcf" [OWRITER, OCREAT] >>= err fdb
              -- store records
              puts fdb [(1, "one"), (12, "twelve"), (144, "one forty four")] >>=
                        err fdb . (all id)
              -- retrieve records
              get fdb (1 :: Int) >>= maybe (error "something goes wrong") putStrLn
              -- close the database
              close fdb >>= err fdb
        where
          puts :: FDB -> [(Int, String)] -> IO [Bool]
          puts fdb = mapM (uncurry $ put fdb)

  
          err :: FDB -> Bool -> IO ()
          err fdb = flip unless $ ecode fdb >>= error . show

data FDB Source

Instances

TCDB FDB

data ECODE Source

Represents error

Constructors

ESUCCESS	success
ETHREAD	threading error
EINVALID	invalid operation
ENOFILE	file not found
ENOPERM	no permission
EMETA	invalid meta data
ERHEAD	invalid record header
EOPEN	open error
ECLOSE	close error
ETRUNC	trunc error
ESYNC	sync error
ESTAT	stat error
ESEEK	seek error
EREAD	read error
EWRITE	write error
EMMAP	mmap error
ELOCK	lock error
EUNLINK	unlink error
ERENAME	rename error
EMKDIR	mkdir error
ERMDIR	rmdir error
EKEEP	existing record
ENOREC	no record found
EMISC	miscellaneous error

Instances

Eq ECODE
Ord ECODE
Show ECODE

data OpenMode Source

Constructors

OREADER
OWRITER
OCREAT
OTRUNC
ONOLCK
OLCKNB

Instances

Eq OpenMode
Ord OpenMode
Show OpenMode

data ID Source

Constructors

IDMIN
IDPREV
IDMAX
IDNEXT
ID Int64

Instances

Eq ID
Ord ID
Show ID
Key ID

Basic API (tokyocabinet.idl compliant)

new :: IO FDB Source

Create a Fixed-length database object.

delete :: FDB -> IO ()Source

Free FDB resource forcibly. FDB is kept by ForeignPtr, so Haskell runtime GC cleans up memory for almost situation. Most always, you don't need to call this. After call this, you must not touch FDB object. Its behavior is undefined.

ecode :: FDB -> IO ECODE Source

Return the last happened error code.

errmsg :: ECODE -> String Source

Convert error code to message string.

tune Source

Arguments

:: FDB	FDB object.
-> Int32	the width of the value of each record.
-> Int64	the limit size of the database file.
-> IO Bool	if successful, the return value is True.

Set the tuning parameters.

open :: FDB -> String -> [OpenMode] -> IO Bool Source

Open FDB database file.

close :: FDB -> IO Bool Source

Close the database file.

put :: (Key k, Storable v) => FDB -> k -> v -> IO Bool Source

Stora a record (key-value pair) on FDB. Key type must be instance of Key class. Value type must be instance of Storable.

putkeep :: (Key k, Storable v) => FDB -> k -> v -> IO Bool Source

Store a new record. If a record with the same key exists in the database, this function has no effect.

putcat :: (Key k, Storable v) => FDB -> k -> v -> IO Bool Source

Concatenate a value at the end of the existing record.

out :: Key k => FDB -> k -> IO Bool Source

Delete a record.

get :: (Key k, Storable v) => FDB -> k -> IO (Maybe v)Source

Return the value of record.

vsiz :: Key k => FDB -> k -> IO (Maybe Int)Source

Return the byte size of value in a record.

iterinit :: FDB -> IO Bool Source

Initialize the iterator of a FDB object.

iternext :: Key k => FDB -> IO (Maybe k)Source

Return the next key of the iterator of a FDB object.

range Source

Arguments

:: (Key k1, Key k2)
=> FDB	FDB object
-> k1	the lower limit of the range.
-> k1	the upper limit of the range.
-> Int	the maximum number of keys to be fetched.
-> IO [k2]	keys in the specified range.