The cached file-system was implemented to speed up ngcc
processing, but in reality most files are not accessed many times
and there is no noticeable degradation in speed by removing it.
Benchmarking `ngcc -l debug` for AIO on a local machine
gave a range of 196-236 seconds with the cache and 197-224
seconds without the cache.
Moreover, when running in parallel mode, ngcc has a separate
file cache for each process. This results in excess memory usage.
Notably the master process, which only does analysis of entry-points
holds on to up to 500Mb for AIO when using the cache compared to
only around 30Mb when not using the cache.
Finally, the file-system cache being incorrectly primed with file
contents before being processed has been the cause of a number
of bugs. For example https://github.com/angular/angular-cli/issues/16860#issuecomment-614694269.
PR Close#36687
The change in e041ac6f0d8c519d104601b2b49c008721c074b7
to support sending unlocker process output to the main ngcc
console output prevents messages require that the main process
relinquishes the event-loop to allow the `stdout.on()` handler to
run. This results in none of the messages being written when ngcc
is run in `--no-async` mode, and some messages failing to be
written if the main process is killed (e.g. ctrl-C).
It appears that the problem with Windows and detached processes
is known - see https://github.com/nodejs/node/issues/3596#issuecomment-250890218.
But in the meantime, this commit is a workaround, where non-Windows
`inherit` the main process `stdout` while on Windows it reverts
to the async handler approach, which is better than nothing.
PR Close#36637
On Windows, the output of a detached process (such as the unlocker
process used by `LockFileWithChildProcess`) is not shown in the parent
process' stdout.
This commit addresses this by piping the spawned process' stdin/stdout
and manually writing to the parent process' stdout.
PR Close#36569
The current ngcc lock-file strategy spawns a new process in order to
capture a potential `SIGINT` and remove the lock-file. For more
information see #35861.
Previously, this unlocker process was spawned as soon as the `LockFile`
was instantiated in order to have it available as soon as possible
(given that spawning a process is an asynchronous operation). Since the
`LockFile` was instantiated and passed to the `Executor`, this meant
that an unlocker process was spawned for each cluster worker, when
running ngcc in parallel mode. These processes were not needed, since
the `LockFile` was not used in cluster workers, but we still had to pay
the overhead of each process' own memory and V8 instance.
(NOTE: This overhead was small compared to the memory consumed by ngcc's
normal operations, but still unnecessary.)
This commit avoids the extra processes by only spawning an unlocker
process when running on the cluster master process and not on worker
processes.
PR Close#36569
This version of `LockFile` creates an "unlocker" child-process that monitors
the main ngcc process and deletes the lock file if it exits unexpectedly.
This resolves the issue where the main process could not be killed by pressing
Ctrl-C at the terminal.
Fixes#35761
PR Close#35861
