ghc-datasize-0.2.2: Determine the size of data structures in GHC's memory

GHC.DataSize

Description

Synopsis

# Documentation

closureSize :: a -> IO Word Source #

Calculate size of GHC objects in Bytes. Note that an object may not be evaluated yet and only the size of the initial closure is returned.

recursiveSize :: a -> IO Word Source #

Calculate the recursive size of GHC objects in Bytes. Note that the actual size in memory is calculated, so shared values are only counted once.

Call with  recursiveSize $! 2  to force evaluation to WHNF before calculating the size. Call with  recursiveSize$!! "foobar"  (\$!! from Control.DeepSeq) to force full evaluation before calculating the size.

A garbage collection is performed before the size is calculated, because the garbage collector would make heap walks difficult.

This function works very quickly on small data structures, but can be slow on large and complex ones. If speed is an issue it's probably possible to get the exact size of a small portion of the data structure and then estimate the total size from that.

recursiveSizeNF :: NFData a => a -> IO Word Source #

Calculate the recursive size of GHC objects in Bytes after calling Control.DeepSeq.force on the data structure to force it into Normal Form. Using this function requires that the data structure has an NFData typeclass instance.