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(* SPDX-License-Identifier: AGPL-3.0-or-later *)
(* Copyright © 2021-2024 OCamlPro *)
(* Written by the Owi programmers *)
open Types
let page_size = 65_536
type t =
{ mutable limits : limits
; mutable data : bytes
}
let init limits : t =
let data = Bytes.make (page_size * limits.min) '\x00' in
{ limits; data }
let update_memory mem data =
let limits =
{ mem.limits with min = max mem.limits.min (Bytes.length data / page_size) }
in
mem.limits <- limits;
mem.data <- data
let grow mem delta =
let delta = Int32.to_int delta in
let old_size = Bytes.length mem.data in
let new_mem = Bytes.extend mem.data 0 delta in
Bytes.unsafe_fill new_mem old_size delta (Char.chr 0);
update_memory mem new_mem
let fill mem ~pos ~len c =
let pos = Int32.to_int pos in
let len = Int32.to_int len in
pos < 0 || len < 0
|| pos + len > Bytes.length mem.data
||
( Bytes.unsafe_fill mem.data pos len c;
false )
let blit mem ~src ~dst ~len =
let src = Int32.to_int src in
let dst = Int32.to_int dst in
let len = Int32.to_int len in
let data_len = Bytes.length mem.data in
src < 0 || dst < 0 || len < 0
|| src + len > data_len
|| dst + len > data_len
||
( Bytes.unsafe_blit mem.data src mem.data dst len;
false )
let blit_string mem str ~src ~dst ~len =
let str_len = String.length str in
let src = Int32.to_int src in
let dst = Int32.to_int dst in
let len = Int32.to_int len in
src < 0 || dst < 0 || len < 0
|| src + len > str_len
|| dst + len > Bytes.length mem.data
||
( Bytes.unsafe_blit_string str src mem.data dst len;
false )
let get_limit_max { limits; _ } = Option.map Int64.of_int limits.max
let get_limits { limits; _ } = limits
let store_8 mem ~addr n =
let addr = Int32.to_int addr in
let n = Int32.to_int n in
Bytes.set_int8 mem.data addr n
let store_16 mem ~addr n =
let addr = Int32.to_int addr in
let n = Int32.to_int n in
Bytes.set_int16_le mem.data addr n
let store_32 mem ~addr n =
let addr = Int32.to_int addr in
Bytes.set_int32_le mem.data addr n
let store_64 mem ~addr n =
let addr = Int32.to_int addr in
Bytes.set_int64_le mem.data addr n
let load_8_s mem addr =
let addr = Int32.to_int addr in
Int32.of_int @@ Bytes.get_int8 mem.data addr
let load_8_u mem addr =
let addr = Int32.to_int addr in
Int32.of_int @@ Bytes.get_uint8 mem.data addr
let load_16_s mem addr =
let addr = Int32.to_int addr in
Int32.of_int @@ Bytes.get_int16_le mem.data addr
let load_16_u mem addr =
let addr = Int32.to_int addr in
Int32.of_int @@ Bytes.get_uint16_le mem.data addr
let load_32 mem addr =
let addr = Int32.to_int addr in
Bytes.get_int32_le mem.data addr
let load_64 mem addr =
let addr = Int32.to_int addr in
Bytes.get_int64_le mem.data addr
let size_in_pages mem = Int32.of_int @@ (Bytes.length mem.data / page_size)
let size mem = Int32.of_int @@ Bytes.length mem.data