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Diffstat (limited to 'tests')
-rw-r--r-- | tests/hashmap_on_disk/HashmapMain.Properties.fst | 300 |
1 files changed, 300 insertions, 0 deletions
diff --git a/tests/hashmap_on_disk/HashmapMain.Properties.fst b/tests/hashmap_on_disk/HashmapMain.Properties.fst new file mode 100644 index 00000000..8bf395ed --- /dev/null +++ b/tests/hashmap_on_disk/HashmapMain.Properties.fst @@ -0,0 +1,300 @@ +(** Properties about the hashmap written on disk *) +module HashmapMain.Properties +open Primitives +open HashmapMain.Funs + +#set-options "--z3rlimit 50 --fuel 0 --ifuel 1" + +/// Below, we focus on the functions to read from disk/write to disk to showcase +/// how such reasoning which mixes opaque functions together with a state-error +/// monad can be performed. + +(*** Hypotheses *) + +/// [state_v] gives us the hash map currently stored on disk +assume +val state_v : state -> hashmap_hash_map_t u64 + +/// [serialize] updates the hash map stored on disk +assume +val serialize_lem (hm : hashmap_hash_map_t u64) (st : state) : Lemma ( + match hashmap_utils_serialize_fwd hm st with + | Fail -> True + | Return (st', ()) -> state_v st' == hm) + [SMTPat (hashmap_utils_serialize_fwd hm st)] + +/// [deserialize] gives us the hash map stored on disk, without updating it +assume +val deserialize_lem (st : state) : Lemma ( + match hashmap_utils_deserialize_fwd st with + | Fail -> True + | Return (st', hm) -> hm == state_v st /\ st' == st) + [SMTPat (hashmap_utils_deserialize_fwd st)] + +(*** Lemmas - auxiliary *) + +/// The below proofs are trivial: we just prove that the hashmap insert function +/// doesn't update the state... As F* is made for *intrinsic* proofs, we have +/// to copy-paste the definitions, hence the huge verbosity... + +/// We will probably do some analysis in the future to use the proper monad when +/// generating the definitions (no monad if functions can't fail, error monad if +/// they can fail but don't need manipulate the state, etc. in addition to proper +/// lifting). + +#push-options "--fuel 1" +let rec hashmap_hash_map_insert_in_list_fwd_lem + (t : Type0) (key : usize) (value : t) (ls : hashmap_list_t t) (st : state) : + Lemma + (ensures ( + match hashmap_hash_map_insert_in_list_fwd t key value ls st with + | Fail -> True + | Return (st', _) -> st' == st)) + (decreases (hashmap_hash_map_insert_in_list_decreases t key value ls st)) + = + begin match ls with + | HashmapListCons ckey cvalue ls0 -> + if ckey = key + then () + else + hashmap_hash_map_insert_in_list_fwd_lem t key value ls0 st + | HashmapListNil -> () + end +#pop-options + +#push-options "--fuel 1" +let rec hashmap_hash_map_insert_in_list_back_lem + (t : Type0) (key : usize) (value : t) (ls : hashmap_list_t t) (st : state) : + Lemma + (ensures ( + match hashmap_hash_map_insert_in_list_back t key value ls st with + | Fail -> True + | Return (st', _) -> st' == st)) + (decreases (hashmap_hash_map_insert_in_list_decreases t key value ls st)) + = + begin match ls with + | HashmapListCons ckey cvalue ls0 -> + if ckey = key then () + else hashmap_hash_map_insert_in_list_back_lem t key value ls0 st + | HashmapListNil -> () + end +#pop-options + +let hashmap_hash_map_insert_no_resize_back_lem + (t : Type0) (self : hashmap_hash_map_t t) (key : usize) (value : t) + (st : state) : + Lemma + (ensures ( + match hashmap_hash_map_insert_no_resize_back t self key value st with + | Fail -> True + | Return (st', _) -> st' == st)) + = + begin match hashmap_hash_key_fwd key st with + | Fail -> () + | Return (st0, i) -> + let i0 = vec_len (hashmap_list_t t) self.hashmap_hash_map_slots in + begin match usize_rem i i0 with + | Fail -> () + | Return hash_mod -> + begin match + vec_index_mut_fwd (hashmap_list_t t) self.hashmap_hash_map_slots + hash_mod with + | Fail -> () + | Return l -> + hashmap_hash_map_insert_in_list_fwd_lem t key value l st0; + begin match hashmap_hash_map_insert_in_list_fwd t key value l st0 with + | Fail -> () + | Return (st1, b) -> + if b + then + begin match usize_add self.hashmap_hash_map_num_entries 1 with + | Fail -> () + | Return i1 -> hashmap_hash_map_insert_in_list_back_lem t key value l st1 + end + else hashmap_hash_map_insert_in_list_back_lem t key value l st1 + end + end + end + end + +#push-options "--fuel 1" +let rec hashmap_hash_map_allocate_slots_fwd_lem + (t : Type0) (slots : vec (hashmap_list_t t)) (n : usize) (st : state) : + Lemma (ensures ( + match hashmap_hash_map_allocate_slots_fwd t slots n st with + | Fail -> True + | Return (st', _) -> st' == st)) + (decreases (hashmap_hash_map_allocate_slots_decreases t slots n st)) + = + begin match n with + | 0 -> () + | _ -> + begin match vec_push_back (hashmap_list_t t) slots HashmapListNil with + | Fail -> () + | Return v -> + begin match usize_sub n 1 with + | Fail -> () + | Return i -> + hashmap_hash_map_allocate_slots_fwd_lem t v i st + end + end + end +#pop-options + +let hashmap_hash_map_new_with_capacity_fwd_lem + (t : Type0) (capacity : usize) (max_load_dividend : usize) + (max_load_divisor : usize) (st : state) : + Lemma (ensures ( + match hashmap_hash_map_new_with_capacity_fwd t capacity max_load_dividend max_load_divisor st with + | Fail -> True + | Return (st', _) -> st' == st)) + = + let v = vec_new (hashmap_list_t t) in + hashmap_hash_map_allocate_slots_fwd_lem t v capacity st + +#push-options "--fuel 1" +let rec hashmap_hash_map_move_elements_from_list_back_lem + (t : Type0) (ntable : hashmap_hash_map_t t) (ls : hashmap_list_t t) + (st : state) : + Lemma (ensures ( + match hashmap_hash_map_move_elements_from_list_back t ntable ls st with + | Fail -> True + | Return (st', _) -> st' == st)) + (decreases (hashmap_hash_map_move_elements_from_list_decreases t ntable ls st)) + = + begin match ls with + | HashmapListCons k v tl -> + hashmap_hash_map_insert_no_resize_back_lem t ntable k v st; + begin match hashmap_hash_map_insert_no_resize_back t ntable k v st with + | Fail -> () + | Return (st0, hm) -> + hashmap_hash_map_move_elements_from_list_back_lem t hm tl st0 + end + | HashmapListNil -> () + end +#pop-options + +#push-options "--fuel 1" +let rec hashmap_hash_map_move_elements_back_lem + (t : Type0) (ntable : hashmap_hash_map_t t) (slots : vec (hashmap_list_t t)) + (i : usize) (st : state) : + Lemma (ensures ( + match hashmap_hash_map_move_elements_back t ntable slots i st with + | Fail -> True + | Return (st', _) -> st' == st)) + (decreases (hashmap_hash_map_move_elements_decreases t ntable slots i st)) + = + let i0 = vec_len (hashmap_list_t t) slots in + if i < i0 + then + begin match vec_index_mut_fwd (hashmap_list_t t) slots i with + | Fail -> () + | Return l -> + let l0 = mem_replace_fwd (hashmap_list_t t) l HashmapListNil in + hashmap_hash_map_move_elements_from_list_back_lem t ntable l0 st; + begin match hashmap_hash_map_move_elements_from_list_back t ntable l0 st + with + | Fail -> () + | Return (st0, hm) -> + let l1 = mem_replace_back (hashmap_list_t t) l HashmapListNil in + begin match vec_index_mut_back (hashmap_list_t t) slots i l1 with + | Fail -> () + | Return v -> + begin match usize_add i 1 with + | Fail -> () + | Return i1 -> hashmap_hash_map_move_elements_back_lem t hm v i1 st0 + end + end + end + end + else () +#pop-options + +let hashmap_hash_map_try_resize_back_lem + (t : Type0) (self : hashmap_hash_map_t t) (st : state) : + Lemma (ensures ( + match hashmap_hash_map_try_resize_back t self st with + | Fail -> True + | Return (st', _) -> st' == st)) + = + let i = vec_len (hashmap_list_t t) self.hashmap_hash_map_slots in + begin match usize_div 4294967295 2 with + | Fail -> () + | Return n1 -> + let (i0, i1) = self.hashmap_hash_map_max_load_factor in + begin match usize_div n1 i0 with + | Fail -> () + | Return i2 -> + if i <= i2 + then + begin match usize_mul i 2 with + | Fail -> () + | Return i3 -> + hashmap_hash_map_new_with_capacity_fwd_lem t i3 i0 i1 st; + begin match hashmap_hash_map_new_with_capacity_fwd t i3 i0 i1 st with + | Fail -> () + | Return (st0, hm) -> + hashmap_hash_map_move_elements_back_lem t hm self.hashmap_hash_map_slots 0 st0 + end + end + else () + end + end + +let hashmap_hash_map_insert_back_lem + (t : Type0) (self : hashmap_hash_map_t t) (key : usize) (value : t) + (st : state) : + Lemma (ensures ( + match hashmap_hash_map_insert_back t self key value st with + | Fail -> True + | Return (st', _) -> st' == st)) + [SMTPat (hashmap_hash_map_insert_back t self key value st)] + = + hashmap_hash_map_insert_no_resize_back_lem t self key value st; + begin match hashmap_hash_map_insert_no_resize_back t self key value st with + | Fail -> () + | Return (st0, hm) -> + begin match hashmap_hash_map_len_fwd t hm st0 with + | Fail -> () + | Return (st1, i) -> + if i > hm.hashmap_hash_map_max_load + then + hashmap_hash_map_try_resize_back_lem t (Mkhashmap_hash_map_t + hm.hashmap_hash_map_num_entries hm.hashmap_hash_map_max_load_factor + hm.hashmap_hash_map_max_load hm.hashmap_hash_map_slots) st1 + else () + end + end + + +(*** Lemmas *) + + +/// The obvious lemma about [insert_on_disk]: the updated hash map stored on disk +/// is exactly the hash map produced from inserting the binding ([key], [value] +/// in the hash map previously stored on disk. +val insert_on_disk_fwd_lem (key : usize) (value : u64) (st : state) : Lemma ( + match insert_on_disk_fwd key value st with + | Fail -> True + | Return (st', ()) -> + let hm = state_v st in + match hashmap_hash_map_insert_back u64 hm key value st with + | Fail -> False + | Return (_, hm') -> hm' == state_v st') + +let insert_on_disk_fwd_lem key value st = + deserialize_lem st; + begin match hashmap_utils_deserialize_fwd st with + | Fail -> () + | Return (st0, hm) -> + hashmap_hash_map_insert_back_lem u64 hm key value st0; + begin match hashmap_hash_map_insert_back u64 hm key value st0 with + | Fail -> () + | Return (st1, hm0) -> + serialize_lem hm0 st1; + begin match hashmap_utils_serialize_fwd hm0 st1 with + | Fail -> () + | Return (st2, _) -> () + end + end + end |