Modulestore-core-0.4.4.7Haskell2010

Data.Store.Core

8 types
24 values

Packagestore-core-0.4.4.7
Exports32
LanguageHaskell2010
LicenceMIT
SourceCore.hs

Core Types

13 declarations

newtypenewtype Poke a

Poke actions are useful for building sequential serializers.

They are actions which write values to bytes into memory specified by a Ptr base. The Applicative and Monad instances make it easy to write serializations, by keeping track of the Offset of the current byte. They allow you to chain Poke action such that subsequent Pokes write into subsequent portions of the output.

Constructors

Poke
- runPoke :: PokeState -> Offset -> IO (Offset, a)
  Run the Poke action, with the Ptr to the buffer where data is poked, and the current Offset. The result is the new offset, along with a return value.
  May throw a PokeException, though this should be avoided when possible. They usually indicate a programming error.

Instances5Monad, Functor, MonadFail, Applicative, MonadIO

Monad PokeDefined in store-core-0.4.4.7 · Data.Store.Core
Functor PokeDefined in store-core-0.4.4.7 · Data.Store.Core
MonadFail PokeDefined in store-core-0.4.4.7 · Data.Store.Core
Applicative PokeDefined in store-core-0.4.4.7 · Data.Store.Core
MonadIO PokeDefined in store-core-0.4.4.7 · Data.Store.Core

datadata PokeException

Exception thrown while running poke. Note that other types of exceptions could also be thrown. Invocations of fail in the Poke monad causes this exception to be thrown.

PokeExceptions are not expected to occur in ordinary circumstances, and usually indicate a programming error.

Constructors

PokeException
- pokeExByteIndex :: Offset
- pokeExMessage :: Text

Instances3Eq, Show, Exception

Eq PokeExceptionDefined in store-core-0.4.4.7 · Data.Store.Core
Show PokeExceptionDefined in store-core-0.4.4.7 · Data.Store.Core
Exception PokeExceptionDefined in store-core-0.4.4.7 · Data.Store.Core

valuepokeException :: Text -> Poke a

Throws a PokeException. These should be avoided when possible, they usually indicate a programming error.

newtypenewtype Peek a

Peek actions are useful for building sequential deserializers.

They are actions which read from memory and construct values from it. The Applicative and Monad instances make it easy to chain these together to get more complicated deserializers. This machinery keeps track of the current Ptr and end-of-buffer Ptr.

Constructors

Peek
- runPeek :: PeekState -> Ptr Word8 -> IO (PeekResult a)
  Run the Peek action, with a Ptr to the end of the buffer where data is poked, and a Ptr to the current position. The result is the Ptr, along with a return value.
  May throw a PeekException if the memory contains invalid values.

Instances7Monad, Functor, MonadFail, Applicative, MonadIO, PrimMonad, …

Monad PeekDefined in store-core-0.4.4.7 · Data.Store.Core
Functor PeekDefined in store-core-0.4.4.7 · Data.Store.Core
MonadFail PeekDefined in store-core-0.4.4.7 · Data.Store.Core
Applicative PeekDefined in store-core-0.4.4.7 · Data.Store.Core
MonadIO PeekDefined in store-core-0.4.4.7 · Data.Store.Core
PrimMonad PeekDefined in store-core-0.4.4.7 · Data.Store.Core
type PrimState Peek = RealWorldDefined in store-core-0.4.4.7 · Data.Store.Core

datadata PeekResult a

A result of a Peek action containing the current Ptr and a return value.

Constructors

PeekResult !(Ptr Word8) !a

Instances1Functor

Functor PeekResultDefined in store-core-0.4.4.7 · Data.Store.Core

datadata PeekException

Exception thrown while running peek. Note that other types of exceptions can also be thrown. Invocations of fail in the Poke monad causes this exception to be thrown.

PeekException is thrown when the data being decoded is invalid.

Constructors

PeekException
- peekExBytesFromEnd :: Offset
- peekExMessage :: Text

Instances3Eq, Show, Exception

Eq PeekExceptionDefined in store-core-0.4.4.7 · Data.Store.Core
Show PeekExceptionDefined in store-core-0.4.4.7 · Data.Store.Core
Exception PeekExceptionDefined in store-core-0.4.4.7 · Data.Store.Core

valuepeekException :: Text -> Peek a

Throws a PeekException.

valuetooManyBytes :: Int -> Int -> String -> IO void

Throws a PeekException about an attempt to read too many bytes.

newtypenewtype PokeState

Holds a pokeStatePtr, which is passed in to each Poke action. If the package is built with the 'force-alignment' flag, this also has a hidden Ptr field, which is used as scratch space during unaligned writes.

valuepokeStatePtr :: PokeState -> Ptr Word8

newtypenewtype PeekState

Holds a peekStatePtr, which is passed in to each Peek action. If the package is built with the 'force-alignment' flag, this also has a hidden Ptr field, which is used as scratch space during unaligned reads.

valuepeekStateEndPtr :: PeekState -> Ptr Word8

typetype Offset = Int

How far into the given Ptr to look

Encode ByteString

1 declaration

valueunsafeEncodeWith :: Poke () -> Int -> ByteString

Given a Poke and its length, uses it to fill a ByteString

This function is unsafe because the provided length must exactly match the number of bytes used by the Poke. It will throw PokeException errors when the buffer is under or overshot. However, in the case of overshooting the buffer, memory corruption and segfaults may occur.

Decode ByteString

7 declarations

valuedecodeWith :: Peek a -> ByteString -> Either PeekException a

Decodes a value from a ByteString, potentially throwing exceptions, and taking a Peek to run. It is an exception to not consume all input.

valuedecodeExWith :: Peek a -> ByteString -> a

Decodes a value from a ByteString, potentially throwing exceptions, and taking a Peek to run. It is an exception to not consume all input.

valuedecodeExPortionWith :: Peek a -> ByteString -> (Offset, a)

Similar to decodeExWith, but it allows there to be more of the buffer remaining. The Offset of the buffer contents immediately after the decoded value is returned.

valuedecodeIOWith :: Peek a -> ByteString -> IO a

Decodes a value from a ByteString, potentially throwing exceptions, and taking a Peek to run. It is an exception to not consume all input.

valuedecodeIOPortionWith :: Peek a -> ByteString -> IO (Offset, a)

Similar to decodeExPortionWith, but runs in the IO monad.

valuedecodeIOWithFromPtr :: Peek a -> Ptr Word8 -> Int -> IO a

Like decodeIOWith, but using Ptr and length instead of a ByteString.

valuedecodeIOPortionWithFromPtr :: Peek a -> Ptr Word8 -> Int -> IO (Offset, a)

Like decodeIOPortionWith, but using Ptr and length instead of a ByteString.

Storable

3 declarations

valuepokeStorable :: Storable a => a -> Poke ()

A poke implementation based on an instance of Storable.

valuepeekStorable :: (Storable a, Typeable a) => Peek a

A peek implementation based on an instance of Storable and Typeable.

valuepeekStorableTy :: Storable a => String -> Peek a

A peek implementation based on an instance of Storable. Use this if the type is not Typeable.

ForeignPtr

3 declarations

valuepokeFromForeignPtr :: ForeignPtr a -> Int -> Int -> Poke ()

Copy a section of memory, based on a ForeignPtr, to the output. Note that this operation is unsafe, the offset and length parameters are not checked.

valuepeekToPlainForeignPtr :: String -> Int -> Peek (ForeignPtr a)

Allocate a plain ForeignPtr (no finalizers), of the specified length and fill it with bytes from the input.

valuepokeFromPtr :: Ptr a -> Int -> Int -> Poke ()

Copy a section of memory, based on a Ptr, to the output. Note that this operation is unsafe, because the offset and length parameters are not checked.

ByteArray

2 declarations

valuepokeFromByteArray :: ByteArray# -> Int -> Int -> Poke ()

Copy a section of memory, based on a ByteArray#, to the output. Note that this operation is unsafe, because the offset and length parameters are not checked.

valuepeekToByteArray :: String -> Int -> Peek ByteArray

Allocate a ByteArray of the specified length and fill it with bytes from the input.

Creation of PokeState / PeekState

3 declarations

valueunsafeMakePokeState

:: Ptr Word8
pokeStatePtr
-> IO (Ptr Word8)
action to produce pokeStateAlignPtr
-> IO PokeState

Make a PokeState from a buffer pointer.

The first argument is a pointer to the memory to write to. The second argument is an IO action which is invoked if the store-core package was built with the force-alignment flag. The action should yield a pointer to scratch memory as large as maybeAlignmentBufferSize.

Since 0.4.2

valueunsafeMakePeekState

:: Ptr Word8
peekStateEndPtr
-> IO (Ptr Word8)
action to produce peekStateAlignPtr
-> IO PeekState

Make a PeekState from a buffer pointer.

Since 0.4.2

valuemaybeAlignmentBufferSize :: Maybe Int

If store-core is built with the force-alignment flag, then this will be a Just value indicating the amount of memory that is expected in the alignment buffer used by PeekState and PokeState. Currently this will either be Just 32 or Nothing.