| Copyright | (c) 2011-2012 Leon P Smith |
|---|---|
| License | BSD3 |
| Maintainer | leon@melding-monads.com |
| Safe Haskell | None |
| Language | Haskell2010 |
Database.PostgreSQL.Simple.LargeObjects
Description
Support for PostgreSQL's Large Objects; see https://www.postgresql.org/docs/9.5/static/largeobjects.html for more information.
Note that Large Object File Descriptors are only valid within a single
database transaction, so if you are interested in using anything beyond
loCreat, loCreate, and loUnlink, you will need to run the entire
sequence of functions in a transaction. As loImport and loExport
are simply C functions that call loCreat, loOpen, loRead, and
loWrite, and do not perform any transaction handling themselves,
they also need to be wrapped in an explicit transaction.
Synopsis
- loCreat :: Connection -> IO Oid
- loCreate :: Connection -> Oid -> IO Oid
- loImport :: Connection -> FilePath -> IO Oid
- loImportWithOid :: Connection -> FilePath -> Oid -> IO Oid
- loExport :: Connection -> Oid -> FilePath -> IO ()
- loOpen :: Connection -> Oid -> IOMode -> IO LoFd
- loWrite :: Connection -> LoFd -> ByteString -> IO Int
- loRead :: Connection -> LoFd -> Int -> IO ByteString
- loSeek :: Connection -> LoFd -> SeekMode -> Int -> IO Int
- loTell :: Connection -> LoFd -> IO Int
- loTruncate :: Connection -> LoFd -> Int -> IO ()
- loClose :: Connection -> LoFd -> IO ()
- loUnlink :: Connection -> Oid -> IO ()
- newtype Oid = Oid CUInt
- data LoFd
- data IOMode
- data SeekMode
Documentation
loImportWithOid :: Connection -> FilePath -> Oid -> IO Oid Source #
loWrite :: Connection -> LoFd -> ByteString -> IO Int Source #
loRead :: Connection -> LoFd -> Int -> IO ByteString Source #
loTruncate :: Connection -> LoFd -> Int -> IO () Source #
LoFd is a Large Object (pseudo) File Descriptor. It is understood by libpq but not by operating system calls.
See openFile
Constructors
| ReadMode | |
| WriteMode | |
| AppendMode | |
| ReadWriteMode |
A mode that determines the effect of hSeek hdl mode i.
Constructors
| AbsoluteSeek | the position of |
| RelativeSeek | the position of |
| SeekFromEnd | the position of |
Instances
| Enum SeekMode | Since: base-4.2.0.0 |
| Eq SeekMode | Since: base-4.2.0.0 |
| Ord SeekMode | Since: base-4.2.0.0 |
Defined in GHC.IO.Device | |
| Read SeekMode | Since: base-4.2.0.0 |
| Show SeekMode | Since: base-4.2.0.0 |
| Ix SeekMode | Since: base-4.2.0.0 |
Defined in GHC.IO.Device | |