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-rw-r--r--src/Storage.hs73
-rw-r--r--src/preference_arrays.adb114
-rw-r--r--src/preference_arrays.ads38
-rw-r--r--src/testmain.hs21
4 files changed, 246 insertions, 0 deletions
diff --git a/src/Storage.hs b/src/Storage.hs
new file mode 100644
index 0000000..2697c39
--- /dev/null
+++ b/src/Storage.hs
@@ -0,0 +1,73 @@
+{-# LANGUAGE ForeignFunctionInterface #-}
+
+module Storage(
+ PrefStorage,
+ createStorage,
+ pokePref,
+ peekPref
+ ) where
+
+
+
+
+import Foreign
+import Foreign.C
+
+
+
+
+foreign import ccall "create_pref_array"
+ c_createPrefArray :: CInt -> CInt -> IO (Ptr PrefArray)
+
+foreign import ccall "free_pref_array"
+ c_freePrefArray :: CInt -> CInt -> Ptr PrefArray -> IO ()
+
+foreign import ccall "wrapper"
+ wrap :: (Ptr PrefArray -> IO ()) -> IO (FunPtr (Ptr PrefArray -> IO ()))
+
+foreign import ccall "poke_pref_array"
+ c_pokePrefArray :: CInt -> CInt -> Ptr PrefArray -> CInt -> CInt -> CInt -> IO ()
+
+foreign import ccall "peek_pref_array"
+ c_peekPrefArray :: CInt -> CInt -> Ptr PrefArray -> CInt -> CInt -> CInt -> IO CInt
+
+
+
+
+newtype PrefArray = PrefArray (Ptr PrefArray)
+
+data PrefStorage = PrefStorage { pointer :: ForeignPtr PrefArray
+ , numBallots :: Int
+ , sizeOfBallot :: Int }
+
+
+
+
+createStorage :: Int -> Int -> IO PrefStorage
+createStorage n s = do
+ x <- c_createPrefArray (fromIntegral n) (fromIntegral s)
+ f <- wrap (c_freePrefArray (fromIntegral n) (fromIntegral s))
+ y <- newForeignPtr f x
+ return (PrefStorage y n s)
+
+
+
+
+pokePref :: PrefStorage -> Int -> Int -> Int -> IO ()
+pokePref p n s r = do
+ let numBal = fromIntegral (numBallots p)
+ sizeBal = fromIntegral (sizeOfBallot p)
+ func a = c_pokePrefArray numBal sizeBal a (fromIntegral n) (fromIntegral s) (fromIntegral r)
+ withForeignPtr (pointer p) func
+
+
+
+
+peekPref :: PrefStorage -> Int -> Int -> Int -> IO Bool
+peekPref p n s r = do
+ let numBal = fromIntegral (numBallots p)
+ sizeBal = fromIntegral (sizeOfBallot p)
+ func a = c_peekPrefArray numBal sizeBal a (fromIntegral n) (fromIntegral s) (fromIntegral r)
+ result <- withForeignPtr (pointer p) func
+ return (result /= 0)
+
diff --git a/src/preference_arrays.adb b/src/preference_arrays.adb
new file mode 100644
index 0000000..0b1218a
--- /dev/null
+++ b/src/preference_arrays.adb
@@ -0,0 +1,114 @@
+
+
+with Ada.Unchecked_Deallocation;
+with System.Address_To_Access_Conversions;
+
+
+package body Preference_Arrays is
+
+
+ type Ranking is range 1 .. 255;
+
+ type Preference_Array is array (Positive range <>, Positive range <>) of Ranking;
+ pragma Pack (Preference_Array);
+
+
+
+
+ -- these following functions would be a lot smaller and neater
+ -- if the FFI could make use of fat pointers
+
+
+
+
+ function Create_Preference_Array
+ (Number_Of_Ballots, Size_Of_Ballot : in Interfaces.C.int)
+ return System.Address
+ is
+ subtype Constrained is Preference_Array
+ (1 .. Positive (Number_Of_Ballots),
+ 1 .. Positive (Size_Of_Ballot));
+
+ package Convert is new System.Address_To_Access_Conversions
+ (Object => Constrained);
+
+ Pref_Array : Convert.Object_Pointer;
+ begin
+ Pref_Array := new Preference_Array
+ (1 .. Positive (Number_Of_Ballots),
+ 1 .. Positive (Size_Of_Ballot));
+ return Convert.To_Address (Pref_Array);
+ end Create_Preference_Array;
+
+
+
+
+ procedure Free_Preference_Array
+ (Number_Of_Ballots, Size_Of_Ballot : in Interfaces.C.int;
+ Pref_Array_Address : in System.Address)
+ is
+ subtype Constrained is Preference_Array
+ (1 .. Positive (Number_Of_Ballots),
+ 1 .. Positive (Size_Of_Ballot));
+
+ package Convert is new System.Address_To_Access_Conversions
+ (Object => Constrained);
+ procedure Free_Pref_Array is new Ada.Unchecked_Deallocation
+ (Object => Constrained, Name => Convert.Object_Pointer);
+
+ Pref_Array : Convert.Object_Pointer;
+ begin
+ Pref_Array := Convert.To_Pointer (Pref_Array_Address);
+ Free_Pref_Array (Pref_Array);
+ end Free_Preference_Array;
+
+
+
+
+ procedure Poke_Preference_Array
+ (Number_Of_Ballots, Size_Of_Ballot : in Interfaces.C.int;
+ Pref_Array_Address : in System.Address;
+ Ballot_Index, Box_Number, Rank : in Interfaces.C.int)
+ is
+ subtype Constrained is Preference_Array
+ (1 .. Positive (Number_Of_Ballots),
+ 1 .. Positive (Size_Of_Ballot));
+
+ package Convert is new System.Address_To_Access_Conversions
+ (Object => Constrained);
+
+ Pref_Array : Convert.Object_Pointer;
+ begin
+ Pref_Array := Convert.To_Pointer (Pref_Array_Address);
+ Pref_Array (Positive (Ballot_Index), Positive (Box_Number)) := Ranking (Rank);
+ end Poke_Preference_Array;
+
+
+
+
+ function Peek_Preference_Array
+ (Number_Of_Ballots, Size_Of_Ballot : in Interfaces.C.int;
+ Pref_Array_Address : in System.Address;
+ Ballot_Index, Box_Number, Rank : in Interfaces.C.int)
+ return Interfaces.C.int
+ is
+ subtype Constrained is Preference_Array
+ (1 .. Positive (Number_Of_Ballots),
+ 1 .. Positive (Size_Of_Ballot));
+
+ package Convert is new System.Address_To_Access_Conversions
+ (Object => Constrained);
+
+ Pref_Array : Convert.Object_Pointer;
+ begin
+ Pref_Array := Convert.To_Pointer (Pref_Array_Address);
+ if Pref_Array (Positive (Ballot_Index), Positive (Box_Number)) = Ranking (Rank) then
+ return 1;
+ else
+ return 0;
+ end if;
+ end Peek_Preference_Array;
+
+
+end Preference_Arrays;
+
diff --git a/src/preference_arrays.ads b/src/preference_arrays.ads
new file mode 100644
index 0000000..c8245e0
--- /dev/null
+++ b/src/preference_arrays.ads
@@ -0,0 +1,38 @@
+
+
+with Interfaces.C;
+with System;
+
+
+package Preference_Arrays is
+
+
+ function Create_Preference_Array
+ (Number_Of_Ballots, Size_Of_Ballot : in Interfaces.C.int)
+ return System.Address;
+ pragma Export (C, Create_Preference_Array, "create_pref_array");
+
+
+ procedure Free_Preference_Array
+ (Number_Of_Ballots, Size_Of_Ballot : in Interfaces.C.int;
+ Pref_Array_Address : in System.Address);
+ pragma Export (C, Free_Preference_Array, "free_pref_array");
+
+
+ procedure Poke_Preference_Array
+ (Number_Of_Ballots, Size_Of_Ballot : in Interfaces.C.int;
+ Pref_Array_Address : in System.Address;
+ Ballot_Index, Box_Number, Rank : in Interfaces.C.int);
+ pragma Export (C, Poke_Preference_Array, "poke_pref_array");
+
+
+ function Peek_Preference_Array
+ (Number_Of_Ballots, Size_Of_Ballot : in Interfaces.C.int;
+ Pref_Array_Address : in System.Address;
+ Ballot_Index, Box_Number, Rank : in Interfaces.C.int)
+ return Interfaces.C.int;
+ pragma Export (C, Peek_Preference_Array, "peek_pref_array");
+
+
+end Preference_Arrays;
+
diff --git a/src/testmain.hs b/src/testmain.hs
new file mode 100644
index 0000000..3f340c2
--- /dev/null
+++ b/src/testmain.hs
@@ -0,0 +1,21 @@
+{-# LANGUAGE ForeignFunctionInterface #-}
+
+
+
+import qualified Storage as Store
+
+
+
+foreign import ccall adainit :: IO Int
+foreign import ccall adafinal :: IO Int
+
+
+
+main = do
+ adainit
+ s <- Store.createStorage 10 5
+ Store.pokePref s 1 2 3
+ r <- Store.peekPref s 1 2 3
+ putStrLn (show r)
+ adafinal
+
generated by cgit (git 2.30.0) at 2024-12-22 23:12:45 +0000