| Portability | non-portable -- posix only |
|---|---|
| Stability | provisional |
| Maintainer | Don Stewart <dons@galois.com> |
| Safe Haskell | None |
System.IO.Posix.MMap
Contents
Description
mmap a file or device into memory as a strict ByteString.
- unsafeMMapFile :: FilePath -> IO ByteString
Memory mapped files
unsafeMMapFile :: FilePath -> IO ByteStringSource
The unsafeMMapFile function maps a file or device into memory,
returning a strict ByteString that accesses the mapped file.
If the mmap fails for some reason, an error is thrown.
Memory mapped files will behave as if they were read lazily -- pages from the file will be loaded into memory on demand.
The storage manager is used to free the mapped memory. When
the garbage collector notices there are no further references to the
mapped memory, a call to munmap is made. It is not necessary to do
this yourself. In tight memory situations, it may be profitable to
use performGC or finalizeForeignPtr to force an unmap.
Note: this operation may break referential transparency! If
any other process on the system changes the file when it is mapped
into Haskell, the contents of your ByteString will change.