Inline source maps as part of each script.

Inline source maps as part of each script.

Unfortunately this is required as even with ideal caching, performing
XHRs to load all source maps increased load times by ~5 seconds for large
applications. Performance hit is now minimal.

BUG=

Committed: https://github.com/dart-lang/sdk/commit/bbaf2e5089a52b6628823eaa735722749acb574f

[Jacob, 2017-03-11 04:48:23]

jacobr@google.com changed reviewers:
+ vsm@google.com

[Jacob, 2017-03-11 04:48:23]

Inline source maps as part of each script.

Unfortunately this is required as even with ideal caching, performing
XHRs to load all source maps increased load times by ~5 seconds for large
applications.

[vsm, 2017-03-13 15:25:28]

https://codereview.chromium.org/2747513003/diff/1/pkg/dev_compiler/lib/src/co...
File pkg/dev_compiler/lib/src/compiler/compiler.dart (right):

https://codereview.chromium.org/2747513003/diff/1/pkg/dev_compiler/lib/src/co...
pkg/dev_compiler/lib/src/compiler/compiler.dart:446: /// Unique identifier used
to location where to insline the source map
insline -> inline

https://codereview.chromium.org/2747513003/diff/1/pkg/dev_compiler/lib/src/co...
pkg/dev_compiler/lib/src/compiler/compiler.dart:449: /// Due to execution order
constriants we have cannot generate the source map
constriants -> constraints

https://codereview.chromium.org/2747513003/diff/1/pkg/dev_compiler/lib/src/co...
pkg/dev_compiler/lib/src/compiler/compiler.dart:518: text =
text.replaceFirst(sourceMapHoleID, JSON.encode(rawSourceMap));
So, are we sending the source map twice now?  Once as a Dart arg and once
normally?

https://codereview.chromium.org/2747513003/diff/1/pkg/dev_compiler/lib/src/co...
pkg/dev_compiler/lib/src/compiler/compiler.dart:612: if
(url.contains('/js_lib/')) {
Perhaps everything under _internal?

https://codereview.chromium.org/2747513003/diff/1/pkg/dev_compiler/lib/src/co...
pkg/dev_compiler/lib/src/compiler/compiler.dart:615: // TODO(jacobr): use a
cleaner way to normalize dart: urls.
Yeah, should be able to plumb the analyzer normalized uris through here rather
than mapping back.

What are these paths relative to anyway?  Looks brittle.

[Jacob, 2017-03-13 15:50:09]

Description was changed from

==========
Inline source maps as part of each script.

Unfortunately this is required as even with ideal caching, performing
XHRs to load all source maps increased load times by ~5 seconds for large
applications. Performance hit is now minimal.

BUG=
==========

to

==========
Inline source maps as part of each script.

Unfortunately this is required as even with ideal caching, performing
XHRs to load all source maps increased load times by ~5 seconds for large
applications. Performance hit is now minimal.

BUG=

Committed:
https://github.com/dart-lang/sdk/commit/bbaf2e5089a52b6628823eaa735722749acb574f
==========

[Jacob, 2017-03-13 15:50:10]

Committed patchset #3 (id:20001) manually as
bbaf2e5089a52b6628823eaa735722749acb574f (presubmit successful).

[Jacob, 2017-03-13 15:51:13]

https://codereview.chromium.org/2747513003/diff/1/pkg/dev_compiler/lib/src/co...
File pkg/dev_compiler/lib/src/compiler/compiler.dart (right):

https://codereview.chromium.org/2747513003/diff/1/pkg/dev_compiler/lib/src/co...
pkg/dev_compiler/lib/src/compiler/compiler.dart:446: /// Unique identifier used
to location where to insline the source map
On 2017/03/13 15:25:28, vsm wrote:
> insline -> inline

Done.

https://codereview.chromium.org/2747513003/diff/1/pkg/dev_compiler/lib/src/co...
pkg/dev_compiler/lib/src/compiler/compiler.dart:449: /// Due to execution order
constriants we have cannot generate the source map
On 2017/03/13 15:25:27, vsm wrote:
> constriants -> constraints
cleaned up this comment.

https://codereview.chromium.org/2747513003/diff/1/pkg/dev_compiler/lib/src/co...
pkg/dev_compiler/lib/src/compiler/compiler.dart:518: text =
text.replaceFirst(sourceMapHoleID, JSON.encode(rawSourceMap));
On 2017/03/13 15:25:27, vsm wrote:
> So, are we sending the source map twice now?  Once as a Dart arg and once
> normally?
We are encoding the source map in the source file only once.
I've changed where the sourcemap is inlined with this CL. With the flag set, the
sourceMappingURL still points to the regular url instead of a Data url.
It is true the separate devtools process will request the sourcemaps from a
different url (e.g. yourfile.js.map) with this CL so by that measure the
sourcemap is sent twice.

https://codereview.chromium.org/2747513003/diff/1/pkg/dev_compiler/lib/src/co...
pkg/dev_compiler/lib/src/compiler/compiler.dart:612: if
(url.contains('/js_lib/')) {
On 2017/03/13 15:25:28, vsm wrote:
> Perhaps everything under _internal?

Done.

https://codereview.chromium.org/2747513003/diff/1/pkg/dev_compiler/lib/src/co...
pkg/dev_compiler/lib/src/compiler/compiler.dart:615: // TODO(jacobr): use a
cleaner way to normalize dart: urls.
On 2017/03/13 15:25:28, vsm wrote:
> Yeah, should be able to plumb the analyzer normalized uris through here rather
> than mapping back.
> 
> What are these paths relative to anyway?  Looks brittle.  

I think these relative urls are technically correct given where the dart_sdk.js
is generated. I've removed this line from the CL. The right place to do the
normalization to dart:html urls is probably really when we parse the Dart stack
traces. There is existing support for that although I wasn't able to get it
working Friday.

[vsm, 2017-03-13 17:21:25]

lgtm