Concurrent blocking imports #1091
Merged
Conversation
This file contains hidden or bidirectional Unicode text that may be interpreted or compiled differently than what appears below. To review, open the file in an editor that reveals hidden Unicode characters.
Learn more about bidirectional Unicode characters
Allows dynamic imports to be loading asynchronously. I know reddit isnt the best example, since it doesn't fully load, but this reduced the load time from ~7.2s to ~4.8s.
fix typos Co-authored-by: Pierre Tachoire <pierre@lightpanda.io>
This changes how non-async module loading works. In general, module loading is triggered by a v8 callback. We ask it to process a module (a <script type= module>) and then for every module that it depends on, we get a callback. This callback expects the nested v8.Module instance, so we need to load it then and there (as opposed to dynamic imports, where we only have to return a promise). Previously, we solved this by issuing a blocking HTTP get in each callback. The HTTP loop was able to continuing downloading already-queued resources, but if a module depended on 20 nested modules, we'd issue 20 blocking gets one after the other. Once a module is compiled, we can ask v8 for a list of its dependent module. We can them immediately start to download all of those modules. We then evaluate the original module, which will trigger our callback. At this point, we still need to block and wait for the response, but we've already started the download and it's much faster. Sure, for the first module, we might need to wait the same amount of time, but for the other 19, chances are by the time the callback executes, we already have it downloaded and ready.
karlseguin
force-pushed
the
concurrent_blocking_imports
branch
from
ed458ea to
418dc6f
Compare
Sign up for free
to subscribe to this conversation on GitHub.
Already have an account?
Sign in.
Add this suggestion to a batch that can be applied as a single commit.
This suggestion is invalid because no changes were made to the code.
Suggestions cannot be applied while the pull request is closed.
Suggestions cannot be applied while viewing a subset of changes.
Only one suggestion per line can be applied in a batch.
Add this suggestion to a batch that can be applied as a single commit.
Applying suggestions on deleted lines is not supported.
You must change the existing code in this line in order to create a valid suggestion.
Outdated suggestions cannot be applied.
This suggestion has been applied or marked resolved.
Suggestions cannot be applied from pending reviews.
Suggestions cannot be applied on multi-line comments.
Suggestions cannot be applied while the pull request is queued to merge.
Suggestion cannot be applied right now. Please check back later.
Builds on top of #1088
Where #1088 focuses on improve async module loading, this PR improve normal (aka blocking) module loading.