We are looking into caching loaded script in memory. To do so we need something
to cache.
At the moment, the `ScriptLoadRequest` structure hold all the fields which are
loaded, and used before executing JavaScript code. Then, the `ScriptLoadRequest`
is not guaranteed to out-live the first execution.
Therefore, we have to move fields out of the `ScriptLoadRequest` such that they
can later be used by any caching mechanism. The `LoadedScript` is the closest
existing structure which exists which fit the description.
This patch moves fields out of the ScriptLoadRequest into the `LoadedScript`,
which already has a `LoadedScript` field.
The `LoadedScript` field is initialized sooner, when the `ScriptLoadRequest` is
created, to be subsituted later by a real cache implementation. At the moment
the function `ScriptLoadRequest::NoCacheEntryFound` is used as a placeholder to
change the state of the `ScriptLoadRequest` from `CheckingCache` to `Fetching`.
Existing initializations are replaced by assertions to fail in debug build if
the current patch does not reproduce the expected state properly.
The `LoadedScript` get fields such as the source text, the text length, the
bytecode buffer (which also contains SRI), and the offset at which the bytecode
starts within the bytecode buffer. As these fields are no longer reachable by
name, multiple accessors are added to work-around the issue. Using this as an
opportunity to add extra assertions as part of these accessors.
A new class named `LoadedScriptDelegate` is added to re-add, by inheritance, all
the accessors which used to be part of `ScriptLoadRequest` as methods which are
delegating to the field which is holding the `LoadedScript`. This class is using
templates to avoid virtual inheritance which might hinder inlining, especially
since `ScriptLoadRequest` cannot be made final, as `ModuleLoadRequest` extends
it.
The `ScriptFetchOptions` structure is moved to its own file to solve C++ include
issues.
Differential Revision: https://phabricator.services.mozilla.com/D163615
We are looking into caching loaded script in memory. To do so we need something
to cache.
At the moment, the `ScriptLoadRequest` structure hold all the fields which are
loaded, and used before executing JavaScript code. Then, the `ScriptLoadRequest`
is not guaranteed to out-live the first execution.
Therefore, we have to move fields out of the `ScriptLoadRequest` such that they
can later be used by any caching mechanism. The `LoadedScript` is the closest
existing structure which exists which fit the description.
This patch moves fields out of the ScriptLoadRequest into the `LoadedScript`,
which already has a `LoadedScript` field.
The `LoadedScript` field is initialized sooner, when the `ScriptLoadRequest` is
created, to be subsituted later by a real cache implementation. At the moment
the function `ScriptLoadRequest::NoCacheEntryFound` is used as a placeholder to
change the state of the `ScriptLoadRequest` from `CheckingCache` to `Fetching`.
Existing initializations are replaced by assertions to fail in debug build if
the current patch does not reproduce the expected state properly.
The `LoadedScript` get fields such as the source text, the text length, the
bytecode buffer (which also contains SRI), and the offset at which the bytecode
starts within the bytecode buffer. As these fields are no longer reachable by
name, multiple accessors are added to work-around the issue. Using this as an
opportunity to add extra assertions as part of these accessors.
A new class named `LoadedScriptDelegate` is added to re-add, by inheritance, all
the accessors which used to be part of `ScriptLoadRequest` as methods which are
delegating to the field which is holding the `LoadedScript`. This class is using
templates to avoid virtual inheritance which might hinder inlining, especially
since `ScriptLoadRequest` cannot be made final, as `ModuleLoadRequest` extends
it.
The `ScriptFetchOptions` structure is moved to its own file to solve C++ include
issues.
Differential Revision: https://phabricator.services.mozilla.com/D163615
In Gecko we use a LoadedScript pointer as the referencing private for dynamic
imports. This is passed through the JS engine as a private value, which doesn't
care what it means. Currently we store this in the module loader as a JS::Value,
but we could just as well unpack it since we know what it is. That lets use a
RefPtr which also keeps it alive and will let use remove some manual reference
counting.
We also don't need to pass it to the CreateDynamicImport method twice.
This change makes it the responsibility of the module loader for keeping the
referencing private alive until FinishDynamicModuleImport is called.
Differential Revision: https://phabricator.services.mozilla.com/D196974
This reverts to the previous behaviour where inline module scripts with
dependencies would complete asynchronously. Previously this would have been
internal to the module loader base class.
Differential Revision: https://phabricator.services.mozilla.com/D192321
The request priority isn't propagated from `ScriptFetchOptions`, so
setting it has no effect for end-users. That will be implemented in a
following part.
Differential Revision: https://phabricator.services.mozilla.com/D183483
Based on the explanation on the bug, the solution would seem to be to call the
ModuleLoaderBase::OnModuleLoadComplete hook from a microtask. This causes a ton
of test failures.
Instead this patch changes the DOM script loader to implement this hook with a
runnable. This fixes the problem (verified manually) and all tests pass.
(Replacing the runnable with a microtask just in the DOM script loader also
does not work and results in many test failures. I'm still trying to understand
why.)
The changes to ContinueDynamicImport are removed because they are also on this
path and we don't need a microtask as well.
This takes us closer to the state before bug 1842798 landed when all the module
loader used MozPromise internally and completions like this happened via
runnables.
I was not able to immediately come up with a test for this.
Differential Revision: https://phabricator.services.mozilla.com/D185830
The request priority isn't propagated from `ScriptFetchOptions`, so
setting it has no effect for end-users. That will be implemented in a
following part.
Differential Revision: https://phabricator.services.mozilla.com/D183483
The request priority isn't propagated from `ScriptFetchOptions`, so
setting it has no effect for end-users. That will be implemented in a
following part.
Differential Revision: https://phabricator.services.mozilla.com/D183483
The aEarlyHintPreloaderId parameter for StartLoad/StartLoadInternal is changed
to be a member variable of ScriptLoadRequest instead so that an initiator type
of early hints can be set for module requests. Before, ModuleLoader would always
pass in a zero value for the id since ModuleLoaderBase has no concept of early
hints when it calls StartFetch.
As a prerequisite for early hints support, this commit also implements
modulepreload in link headers (Bug 1773056).
Differential Revision: https://phabricator.services.mozilla.com/D180020
Note that modules can't be specified in Link preloads with `rel=preload`,
only in `rel=modulepreload`. We currently only support `rel=preload` in
early hints. See Bug 1798319 for updates on module preloads.
Differential Revision: https://phabricator.services.mozilla.com/D161175
Note that modules can't be specified in Link preloads with `rel=preload`,
only in `rel=modulepreload`. We currently only support `rel=preload` in
early hints. See Bug 1798319 for updates on module preloads.
Differential Revision: https://phabricator.services.mozilla.com/D161175
It would be nice to assume this but CompileFetchedModule can potentially fail for reasons that
are not JS-related.
Also check for the exception being |undefined| which would cause
ModuleScript::HasParseError to return false. Such an exception should never be
thrown by parsing but check for it just in case.
Add a diagnostic assert to check module script state is as we expect to
hopefully catch related problems sooner.
Differential Revision: https://phabricator.services.mozilla.com/D160788
The problem is that synchronous XMLHttpRequest requests can spin the event loop
and cause us to process dynamic module loads (by calling
JS::FinishDynamicModuleImport) when we are already inside JS::ModuleEvaluate.
The module algorithms assume that they are not reentrant.
The patch changes dyammic module load processing to happen in the same way as
async script loads (of both classic scripts and modules), which are blocked
during sync XHR by Document::SuppressEventHandling calling
ScriptLoader::AddExecuteBlocker.
Differential Revision: https://phabricator.services.mozilla.com/D157218
Off-thread parse and decode all generate JS::Stencils so the various
specializations are not needed for methods that collect the results back to
main-thread.
Depends on D156335
Differential Revision: https://phabricator.services.mozilla.com/D156336
