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Internal Details
Deno and Linux analogy Jump to heading
| Linux | Deno |
|---|---|
| Processes | Web Workers |
| Syscalls | Ops |
| File descriptors (fd) | Resource ids (rid) |
| Scheduler | Tokio |
| Userland: libc++ / glib / boost | https://jsr.io/@std |
| /proc/$$/stat | Deno.metrics() |
| man pages | deno types / https://docs.deno.com |
Resources Jump to heading
Resources (AKA rid) are Deno's version of file descriptors. They are integer
values used to refer to open files, sockets, and other concepts. For testing it
would be good to be able to query the system for how many open resources there
are.
console.log(Deno.resources());
// { 0: "stdin", 1: "stdout", 2: "stderr" }
Deno.close(0);
console.log(Deno.resources());
// { 1: "stdout", 2: "stderr" }
Metrics Jump to heading
Metrics is Deno's internal counter for various statistics.
> console.table(Deno.metrics())
┌─────────────────────────┬───────────┐
│ (idx) │ Values │
├─────────────────────────┼───────────┤
│ opsDispatched │ 9 │
│ opsDispatchedSync │ 0 │
│ opsDispatchedAsync │ 0 │
│ opsDispatchedAsyncUnref │ 0 │
│ opsCompleted │ 9 │
│ opsCompletedSync │ 0 │
│ opsCompletedAsync │ 0 │
│ opsCompletedAsyncUnref │ 0 │
│ bytesSentControl │ 504 │
│ bytesSentData │ 0 │
│ bytesReceived │ 856 │
└─────────────────────────┴───────────┘
Conference Jump to heading
- Ryan Dahl. (May 27, 2020). An interesting case with Deno. Deno Israel.
- Bartek Iwańczuk. (Oct 6, 2020). Deno internals - how modern JS/TS runtime is built. Paris Deno.