mirror of
https://github.com/fluencelabs/assemblyscript
synced 2025-04-28 00:12:15 +00:00
37 lines
1.4 KiB
TypeScript
37 lines
1.4 KiB
TypeScript
import { AL_MASK, MAX_SIZE_32 } from "./allocator";
|
|
|
|
/**
|
|
* The common runtime object header prepended to all managed objects. Has a size of 16 bytes in
|
|
* WASM32 and contains a classId (e.g. for instanceof checks), the allocation size (e.g. for
|
|
* .byteLength and .length computation) and additional reserved fields to be used by GC. If no
|
|
* GC is present, the HEADER is cut into half excluding the reserved fields, as indicated by
|
|
* HEADER_SIZE.
|
|
*/
|
|
@unmanaged export class HEADER {
|
|
/** Unique id of the respective class or a magic value if not yet registered.*/
|
|
classId: u32;
|
|
/** Size of the allocated payload. */
|
|
payloadSize: u32;
|
|
/** Reserved field for use by GC. Only present if GC is. */
|
|
reserved1: usize; // itcm: tagged next
|
|
/** Reserved field for use by GC. Only present if GC is. */
|
|
reserved2: usize; // itcm: prev
|
|
}
|
|
|
|
/** Common runtime header size. */
|
|
// @ts-ignore: decorator
|
|
@lazy
|
|
export const HEADER_SIZE: usize = isDefined(__ref_collect)
|
|
? (offsetof<HEADER>( ) + AL_MASK) & ~AL_MASK // full header if GC is present
|
|
: (offsetof<HEADER>("reserved1") + AL_MASK) & ~AL_MASK; // half header if GC is absent
|
|
|
|
/** Common runtime header magic. Used to assert registered/unregistered status. */
|
|
// @ts-ignore: decorator
|
|
@lazy
|
|
export const HEADER_MAGIC: u32 = 0xA55E4B17;
|
|
|
|
/** Maximum byte length of any buffer-like object. */
|
|
// @ts-ignore
|
|
@lazy
|
|
export const MAX_BYTELENGTH: i32 = MAX_SIZE_32 - HEADER_SIZE;
|