feat(cli) add Deno.systemMemoryInfo()

cli/dts/lib.deno.unstable.d.ts

@@ -130,6 +130,31 @@ declare namespace Deno {
    */
   export function osRelease(): string;
 
+  /** **Unstable** new API. yet to be vetted. 
+   *
+   * Returns the release version of the Operating System.
+   *
+   * ```ts
+   * console.log(Deno.memoryInfo());
+   * ```
+   *
+   * Requires `allow-env` permission.
+   *
+   */
+  export function memoryInfo(): MemoryInfo;
+
+  export interface MemoryInfo {
+    /** Total physical memory. */
+    total: number;
+    free: number;
+    available: number;
+    buffers: number;
+    cached: number;
+    /** Total swap memory. */
+    swapTotal: number;
+    swapFree: number;
+  }
+
   /** **UNSTABLE**: new API, yet to be vetted.
    *
    * Open and initialize a plugin.

cli/ops/os.rs

@@ -21,6 +21,7 @@ pub fn init(s: &Rc<State>) {
   s.register_op_json_sync("op_hostname", op_hostname);
   s.register_op_json_sync("op_loadavg", op_loadavg);
   s.register_op_json_sync("op_os_release", op_os_release);
+  s.register_op_json_sync("op_memory_info", op_memory_info);
 }
 
 fn op_exec_path(
@@ -147,3 +148,24 @@ fn op_os_release(
   let release = sys_info::os_release().unwrap_or_else(|_| "".to_string());
   Ok(json!(release))
 }
+
+fn op_memory_info(
+  state: &State,
+  _args: Value,
+  _zero_copy: &mut [ZeroCopyBuf],
+) -> Result<Value, ErrBox> {
+  state.check_unstable("Deno.memoryInfo");
+  state.check_env()?;
+  match sys_info::mem_info() {
+    Ok(info) => Ok(json!({
+      "total": info.total,
+      "free": info.free,
+      "available": info.avail,
+      "buffers": info.buffers,
+      "cached": info.cached,
+      "swapTotal": info.swap_total,
+      "swapFree": info.swap_free
+    })),
+    Err(_) => Ok(json!({})),
+  }
+}

cli/rt/30_os.js

@@ -15,6 +15,10 @@
     return sendSync("op_os_release");
   }
 
+  function memoryInfo() {
+    return sendSync("op_memory_info");
+  }
+
   function exit(code = 0) {
     sendSync("op_exit", { code });
     throw new Error("Code not reachable");
@@ -50,6 +54,7 @@
     execPath,
     exit,
     osRelease,
+    memoryInfo,
     hostname,
     loadavg,
   };

cli/rt/90_deno_ns.js

@@ -103,6 +103,7 @@ __bootstrap.denoNsUnstable = {
   loadavg: __bootstrap.os.loadavg,
   hostname: __bootstrap.os.hostname,
   osRelease: __bootstrap.os.osRelease,
+  memoryInfo: __bootstrap.os.memoryInfo,
   applySourceMap: __bootstrap.errorStack.opApplySourceMap,
   formatDiagnostics: __bootstrap.errorStack.opFormatDiagnostics,
   shutdown: __bootstrap.net.shutdown,

cli/tests/unit/os_test.ts

@@ -177,3 +177,9 @@ unitTest({ perms: { env: false } }, function releasePerm(): void {
     Deno.osRelease();
   }, Deno.errors.PermissionDenied);
 });
+
+unitTest({ perms: { env: true } }, function memoryInfo(): void {
+  /* const info = Deno.memoryInfo(); */
+  /* assert(info.total >= 0); */
+  assertNotEquals(Deno.memoryInfo(), {});
+});