link function

void link(ReactiveNode dep, ReactiveNode sub, int version)

Registers dep as a dependency of sub for version.

Existing links are reused when possible while the subscriber and dependency chains are rewired.

Implementation

@pragma("vm:prefer-inline")
@pragma("wasm:prefer-inline")
@pragma("dart2js:prefer-inline")
void link(ReactiveNode dep, ReactiveNode sub, int version) {
  var prevDep = sub.depsTail;
  if (prevDep != null && identical(prevDep.dep, dep)) {
    return;
  }
  var nextDep = prevDep != null ? prevDep.nextDep : sub.deps;
  if (nextDep != null && identical(nextDep.dep, dep)) {
    nextDep.version = version;
    sub.depsTail = nextDep;
    return;
  }
  var prevSub = dep.subsTail;
  if (prevSub != null &&
      prevSub.version == version &&
      identical(prevSub.sub, sub)) {
    return;
  }
  final newLink = sub.depsTail = dep.subsTail = Link(
    version: version,
    dep: dep,
    sub: sub,
    prevDep: prevDep,
    nextDep: nextDep,
    prevSub: prevSub,
    nextSub: null,
  );
  if (nextDep != null) {
    nextDep.prevDep = newLink;
  }
  if (prevDep != null) {
    prevDep.nextDep = newLink;
  } else {
    sub.deps = newLink;
  }
  if (prevSub != null) {
    prevSub.nextSub = newLink;
  } else {
    dep.subs = newLink;
  }
  assert(() {
    JoltDevTools.notifyLinkUpdate('link', dep, sub);
    return true;
  }());
}