grow：Wasm 文字指令

(module
  (import "console" "log" (func $log (param i32)))
  (memory 1 2) ;; start with one memory page, and max of 2 pages
  (func $main

    ;; grow memory by 1 page
    ;; grow returns in 1 for success and -1 for failure
    ;; will fail if you change to more more than 1 page
    (memory.grow (i32.const 1))
    call $log ;; log the result

  )
  (start $main)
)

const url = "{%wasm-url%}";
await WebAssembly.instantiateStreaming(fetch(url), { console });

;; Grow default memory by a number of pages indicated by the top value on the stack
i32.const 3  ;; Number of pages to grow the memory (3)
memory.grow  ;; Grow the memory (by 3 pages)
;; the top item on the stack will now either be the previous number of pages (success) or `-1` (failure)

;; grow default memory by two pages using an S-function
(memory.grow (i32.const 2))

;; Grow memory with index 1
i32.const 1 ;; Number of pages to grow specified memory (1)
memory.grow (memory 1) ;; Grow memory index 1

;; Grow memory with name $memory1
i32.const 1  ;; Number of pages to grow specified memory (1)
memory.grow (memory $memory1) ;; Grow $memory1 by 1 page

;; Grow memory with name $memory1 by three pages using an S-function
(memory.grow (memory $memory1) (i32.const 3))
;; Will return -1 as max value is 4!

(module
  (import "console" "log" (func $log (param i32)))
  (memory 1 2) ;; default memory with one page and max of 2 pages

  (func $main
    ;; grow default memory by 1 page
    i32.const 1
    memory.grow
    call $log ;; log the result (previous no. pages = 1)

    ;; grow default memory, using an S-function
    (memory.grow (i32.const 1))
    call $log ;; log the result (-1: max is 2 pages for default memory declared above!)
  )
  (start $main) ;; call immediately on loading
)

start();
async function start() {
  const importObject = {
    console: {
      log(arg) {
        console.log(arg);
      },
    },
  };
  const result = await WebAssembly.instantiateStreaming(
    fetch("grow.wasm"),
    importObject,
  );
}
start();

(module
  (import "console" "log" (func $log (param i32)))
  (memory 1 2)  ;; Default memory with one page and max of 2 pages
  (memory $memory1 1 4)  ;; Memory with index 1, initial 1 page, max 4 pages
  (func $main
    ;; grow memory with index 1 by 1 page
    i32.const 1
    memory.grow (memory 1)
    call $log ;; log the result (previous no. pages = 1)
  )
  (start $main)
)

i32.const 1
memory.grow (memory $memory1)  ;; referencing memory by name

;; Using S-functions
(memory.grow (memory 1) (i32.const 1))  ;; reference memory by index
(memory.grow (memory $memory1) (i32.const 1)) ;; reference memory by name

i32.const 1
memory.grow (memory 0)  ;; referencing memory by index

;; Using S-functions
(memory.grow (memory 0) (i32.const 1))  ;; reference default memory by index
;; We can't reference this particular default memory by name, because it doesn't have one!