History

Pete Bacon Darwin 7f2330a968 perf(ivy): ngcc - add a cache to the FileSystem (#30525 )

When profiling ngcc it is notable that a large amount of time
is spent dealing with an exception that is thrown (and handled
internally by fs) when checking the existence of a file.

We check file existence a lot in both finding entry-points
and when TS is compiling code. This commit adds a simple
cached `FileSystem`, which wraps a real `FileSystem` delegate.
This will reduce the number of calls through to `fs.exists()` and
`fs.readFile()` on the delegate.

Initial benchmarks indicate that the cache is miss to hit ratio
for `exists()` is about 2:1, which means that we save about 1/3
of the calls to `fs.existsSync()`.

Note that this implements a "non-expiring" cache, so it is not suitable
for a long lived `FileSystem`, where files may be modified externally.
The cache will be updated if a file is changed or moved via
calls to `FileSystem` methods but it will not be aware of changes
to the files system from outside the `FileSystem` service.

For ngcc we must create a new `FileSystem` service
for each run of `mainNgcc` and ensure that all file operations
(including TS compilation) use the `FileSystem` service.
This ensures that it is very unlikely that a file will change
externally during `mainNgcc` processing.

PR Close #30525

2019-07-09 09:40:46 -07:00

src

fix(ivy): ngcc - remove unwanted logging message (#30525 )

2019-07-09 09:40:46 -07:00

test

fix(ivy): handle namespaced imports correctly (#31367 )

2019-07-09 09:40:30 -07:00

BUILD.bazel

refactor(ivy): implement a virtual file-system layer in ngtsc + ngcc (#30921 )

2019-06-25 16:25:24 -07:00

index.ts

perf(ivy): ngcc - add a cache to the FileSystem (#30525 )

2019-07-09 09:40:46 -07:00

main-ngcc.ts

perf(ivy): ngcc - add a cache to the FileSystem (#30525 )

2019-07-09 09:40:46 -07:00

README.md

refactor(ivy): move ngcc into a higher level folder (#29092 )

2019-03-20 14:45:54 -04:00

README.md

Angular Compatibility Compiler (ngcc)

This compiler will convert node_modules compiled with ngc, into node_modules which appear to have been compiled with ngtsc.

This conversion will allow such "legacy" packages to be used by the Ivy rendering engine.

Building

The project is built using Bazel:

yarn bazel build //packages/compiler-cli/ngcc

Unit Testing

The unit tests are built and run using Bazel:

yarn bazel test //packages/compiler-cli/ngcc/test

Integration Testing

There are tests that check the behavior of the overall executable:

yarn bazel test //packages/compiler-cli/ngcc/test:integration