GHC.Vacuum

vacuum is a library that allows you to look at the graph representation of an arbitrary value or expression.

Evaluation in Haskell proceeds by graph reduction, where values on the GHC heap are represented in a graph structure, and where nodes in the graph represent things like constructors or regular values. With this library, you can extract the graph representation of said heap values, and display them in meaningful ways to observe properties like sharing, or a birds eye view of how much memory you're using.

By itself, this module and package is not very useful to the end user - it is meant to be consumed by those who would want to visualise the abstract graph output in some meaningful way, using graphviz or ubigraph, for example.

If you are an end user who wants to visualize their data structures and nothing more, please look at the vacuum-graphviz package, which exports convenient APIs for rendering the output graphs into pretty PNG/SVG files.

Documentation

type HNodeId = Int

data HNode

Constructors

HNode

Fields

nodePtrs :: [HNodeId]

nodeLits :: [Word]

nodeInfo :: InfoTab

Instances

Eq HNode

Ord HNode

Read HNode

Show HNode

emptyHNode :: ClosureType -> HNode

summary :: HNode -> ([String], [HNodeId], [Word])

vacuum :: a -> IntMap HNode

Vacuums the entire reachable heap subgraph rooted at the a.

vacuumTo :: Int -> a -> IntMap HNode

Stop after a given depth.

vacuumLazy :: a -> IntMap HNode

Doesn't force anything.

vacuumStream :: a -> [(HNodeId, HNode)]

Returns nodes as it encounters them.

vacuumDebug :: a -> IntMap [(StableName HValue, HNodeId)]

dump :: a -> IO (IntMap HNode)

dumpTo :: Int -> a -> IO (IntMap HNode)

dumpLazy :: a -> IO (IntMap HNode)

toAdjList :: IntMap HNode -> [(Int, [Int])]

toAdjPair :: (HNodeId, HNode) -> (Int, [Int])

nameGraph :: IntMap HNode -> [(String, [String])]

data ShowHNode

Constructors

ShowHNode

Fields

showHNode :: Int -> HNode -> String

externHNode :: Int -> String

showHNodes :: ShowHNode -> IntMap HNode -> [(String, [String])]

data Draw e v m a

To assist in "rendering" the graph to some source.

Constructors

Draw

Fields

mkV :: Int -> a -> m v

mkE :: v -> v -> m e

succs :: a -> [Int]

newtype G e v

Constructors

G

Fields

unG :: IntMap (v, IntMap e)

Instances

(Eq e, Eq v) => Eq (G e v)

(Eq (G e v), Ord e, Ord v) => Ord (G e v)

(Read e, Read v) => Read (G e v)

(Show e, Show v) => Show (G e v)

draw :: Monad m => Draw e v m a -> IntMap a -> m (G e v)

printDraw :: Draw (Int, Int) Int IO HNode

An example Draw

split :: (a -> [Int]) -> IntMap a -> IntMap ([Int], [Int])

Build a map to (preds,succs)

data Closure

Constructors

Closure

Fields

closPtrs :: [HValue]

closLits :: [Word]

closITab :: InfoTab

Instances

Show Closure

data InfoTab

Constructors

ConInfo

Fields

itabPkg :: String

itabMod :: String

itabCon :: String

itabPtrs :: Word

itabLits :: Word

itabType :: ClosureType

itabSrtLen :: Word

itabCode :: [Word]

OtherInfo

Fields

itabPtrs :: Word

itabLits :: Word

itabType :: ClosureType

itabSrtLen :: Word

itabCode :: [Word]

Instances

Eq InfoTab

Ord InfoTab

Read InfoTab

Show InfoTab

getClosure :: a -> IO Closure

This is in part borrowed from RtClosureInspect.getClosureData.

closureType :: a -> IO ClosureType

getInfoTab :: a -> IO InfoTab

getInfoPtr :: a -> Ptr StgInfoTable

peekInfoTab :: Ptr StgInfoTable -> IO InfoTab

nodePkg :: HNode -> String

nodeMod :: HNode -> String

nodeName :: HNode -> String

itabName :: InfoTab -> (String, String, String)

type HValue = Any