Previously the `ProgramBasedEntryPointFinder` was parsing all the
entry-points referenced by the program for dependencies even if all the
entry-points had been processed already.
Now this entry-point finder will re-use the `EntryPointManifest` to load
the entry-point dependencies when possible which avoids having to parse
them all again, on every invocation of ngcc.
Previously the `EntryPointManifest` was only used in the
`DirectoryWalkerEntryPointFinder`, which also contained the logic for
computing the contents of the manifest. This logic has been factored out
into an `EntryPointCollector` class. Both the `ProgramBasedEntryPointFinder`
and `DirectoryWalkerEntryPointFinder` now use the `EntryPointManifest` and
the `EntryPointCollector`.
The result of this change is that there is a small cost on the first run of
ngcc to compute and store the manifest - the processing takes 102% of the
processing time before this PR. But on subsequent runs there is a
significant benefit on subsequent runs - the processing takes around 50%
of the processing time before this PR.
PR Close#37665
9318e23e64