Data.DiskHash

Documentation

data DiskHashRO a

data DiskHashRW a

htOpenRO :: forall a. Storable a => FilePath -> Int -> IO (DiskHashRO a)

open a hash table in read-only mode

htOpenRW :: forall a. Storable a => FilePath -> Int -> IO (DiskHashRW a)

open a hash table in read-write mode

withDiskHashRW :: Storable a => FilePath -> Int -> (DiskHashRW a -> IO b) -> IO b

Open a hash table in read-write mode and pass it to an action

Once the action is is complete, the hashtable is closed (and sync'ed to disk).

htLookupRO :: Storable a => ByteString -> DiskHashRO a -> Maybe a

Lookup by key

htLookupRW :: Storable a => ByteString -> DiskHashRW a -> IO (Maybe a)

Lookup by key

htSizeRW :: DiskHashRW a -> IO Int

Retrieve the size of the hash table

htSizeRO :: DiskHashRO a -> Int

Retrieve the size of the hash table

htInsert

Arguments

:: Storable a

=> ByteString

key

-> a

value

-> DiskHashRW a

hash table

-> IO Bool

True if inserted, False if not

insert an element into the hash table

Returns whether an insertion took place (if an object with that key already exists, no insertion is made).

htModify :: Storable a => ByteString -> (a -> a) -> DiskHashRW a -> IO Bool

Modify a value

htReserve :: Storable a => Int -> DiskHashRW a -> IO Int

Reserve space in the hash table

If the operation fails, an exception is raised