Service isolate requests Observatory assets from embedder

Service isolate requests Observatory assets from embedder

- Provide a new callback to Dart_Initialize that will be called when the service isolate needs the Observatory assets
- Move asset management code out of embedder and into common dart:_vmservice
- Use the tar format as the archive format
- Add build script to generate .cc file containing the archive
- Add a simple tar parser to service isolate

This makes it possible for embedders to not bake Observatory into their executable but instead load it off disk or over the network. The standalone embedder still links Observatory into the executable.

R=rmacnak@google.com

Committed: https://github.com/dart-lang/sdk/commit/2844eb86cac7358ccc6e638c3de41e293824098d

[Cutch, 2015-10-23 00:10:30]

johnmccutchan@google.com changed reviewers:
+ rmacnak@google.com

[Cutch, 2015-10-23 00:13:00]

Description was changed from

==========
Service isolate requests Observatory assets from embedder
==========

to

==========
Service isolate requests Observatory assets from embedder

- Provide a new callback to Dart_Initialize that will be called when the service
isolate needs the Observatory assets
- Move asset management code out of embedder and into common dart:_vmservice
- Use the tar format as the archive format
- Add build script to generate .cc file containing the archive
- Add a simple tar parser to service isolate

This makes it possible for embedders to not bake in Observatory to their
executable but instead load it off disk or over the network. The standalone
embedder still links in the executable.
==========

[Cutch, 2015-10-23 00:14:22]

Description was changed from

==========
Service isolate requests Observatory assets from embedder

- Provide a new callback to Dart_Initialize that will be called when the service
isolate needs the Observatory assets
- Move asset management code out of embedder and into common dart:_vmservice
- Use the tar format as the archive format
- Add build script to generate .cc file containing the archive
- Add a simple tar parser to service isolate

This makes it possible for embedders to not bake in Observatory to their
executable but instead load it off disk or over the network. The standalone
embedder still links in the executable.
==========

to

==========
Service isolate requests Observatory assets from embedder

- Provide a new callback to Dart_Initialize that will be called when the service
isolate needs the Observatory assets
- Move asset management code out of embedder and into common dart:_vmservice
- Use the tar format as the archive format
- Add build script to generate .cc file containing the archive
- Add a simple tar parser to service isolate

This makes it possible for embedders to not bake Observatory into their
executable but instead load it off disk or over the network. The standalone
embedder still links Observatory into the executable.
==========

[rmacnak, 2015-10-23 20:54:48]

https://chromiumcodereview.appspot.com/1411853003/diff/20001/runtime/bin/dart...
File runtime/bin/dartutils.cc (right):

https://chromiumcodereview.appspot.com/1411853003/diff/20001/runtime/bin/dart...
runtime/bin/dartutils.cc:287: Dart_Handle DartUtils::ReadBytesFromFile(const
char* filename) {
Dead

https://chromiumcodereview.appspot.com/1411853003/diff/20001/runtime/bin/dart...
runtime/bin/dartutils.cc:300: Dart_Handle DartUtils::MakeUint8Array(const
uint8_t* buffer, intptr_t len) {
Might as well be an external array for the standalone embedder

https://chromiumcodereview.appspot.com/1411853003/diff/20001/runtime/bin/obse...
File runtime/bin/observatory_assets_empty.cc (right):

https://chromiumcodereview.appspot.com/1411853003/diff/20001/runtime/bin/obse...
runtime/bin/observatory_assets_empty.cc:5: // This file is linked into the dart
executable when it does not have a
not have a Observatory -> not have Observatory

https://chromiumcodereview.appspot.com/1411853003/diff/20001/runtime/bin/obse...
runtime/bin/observatory_assets_empty.cc:22: void observatory_assets_unused() {
Compiler shouldn't complain about variables with global linkage not being used
in this compilation unit.

https://chromiumcodereview.appspot.com/1411853003/diff/20001/runtime/vm/servi...
File runtime/vm/service.cc (right):

https://chromiumcodereview.appspot.com/1411853003/diff/20001/runtime/vm/servi...
runtime/vm/service.cc:173: if (Dart_IsError(handle)) {
Throw

https://chromiumcodereview.appspot.com/1411853003/diff/20001/runtime/vm/servi...
runtime/vm/service.cc:180: if (!object.IsTypedData()) {
Throw

https://chromiumcodereview.appspot.com/1411853003/diff/20001/runtime/vm/servi...
runtime/vm/service.cc:185: return Object::null();
Throw

https://chromiumcodereview.appspot.com/1411853003/diff/20001/sdk/lib/vmservic...
File sdk/lib/vmservice/asset.dart (right):

https://chromiumcodereview.appspot.com/1411853003/diff/20001/sdk/lib/vmservic...
sdk/lib/vmservice/asset.dart:43: try {
Let exceptions propagate to caller

https://chromiumcodereview.appspot.com/1411853003/diff/20001/sdk/lib/vmservic...
sdk/lib/vmservice/asset.dart:113: static const List<int> tarMagic = const [
0x75, 0x73, 0x74, 0x61, 0x72, 0 ];
dead

https://chromiumcodereview.appspot.com/1411853003/diff/20001/sdk/lib/vmservic...
sdk/lib/vmservice/asset.dart:114: static const List<int> tarVersion = const [
0x30, 0x30 ];
dead

https://chromiumcodereview.appspot.com/1411853003/diff/20001/sdk/lib/vmservic...
sdk/lib/vmservice/asset.dart:190: static int count = 0;
Dead

[Cutch, 2015-10-23 21:47:30]

https://chromiumcodereview.appspot.com/1411853003/diff/20001/runtime/bin/dart...
File runtime/bin/dartutils.cc (right):

https://chromiumcodereview.appspot.com/1411853003/diff/20001/runtime/bin/dart...
runtime/bin/dartutils.cc:287: Dart_Handle DartUtils::ReadBytesFromFile(const
char* filename) {
On 2015/10/23 20:54:47, rmacnak wrote:
> Dead

Done.

https://chromiumcodereview.appspot.com/1411853003/diff/20001/runtime/bin/dart...
runtime/bin/dartutils.cc:300: Dart_Handle DartUtils::MakeUint8Array(const
uint8_t* buffer, intptr_t len) {
On 2015/10/23 20:54:47, rmacnak wrote:
> Might as well be an external array for the standalone embedder

This can't be done safely because the data is read only but an external typed
array is mutable.

https://chromiumcodereview.appspot.com/1411853003/diff/20001/runtime/bin/obse...
File runtime/bin/observatory_assets_empty.cc (right):

https://chromiumcodereview.appspot.com/1411853003/diff/20001/runtime/bin/obse...
runtime/bin/observatory_assets_empty.cc:5: // This file is linked into the dart
executable when it does not have a
On 2015/10/23 20:54:48, rmacnak wrote:
> not have a Observatory -> not have Observatory

Done.

https://chromiumcodereview.appspot.com/1411853003/diff/20001/runtime/bin/obse...
runtime/bin/observatory_assets_empty.cc:22: void observatory_assets_unused() {
On 2015/10/23 20:54:47, rmacnak wrote:
> Compiler shouldn't complain about variables with global linkage not being used
> in this compilation unit.

I expected the same but kept being complained at on Mac. I've removed this
function and am hoping for the best.

https://chromiumcodereview.appspot.com/1411853003/diff/20001/runtime/vm/servi...
File runtime/vm/service.cc (right):

https://chromiumcodereview.appspot.com/1411853003/diff/20001/runtime/vm/servi...
runtime/vm/service.cc:173: if (Dart_IsError(handle)) {
On 2015/10/23 20:54:48, rmacnak wrote:
> Throw

Done.

https://chromiumcodereview.appspot.com/1411853003/diff/20001/runtime/vm/servi...
runtime/vm/service.cc:180: if (!object.IsTypedData()) {
On 2015/10/23 20:54:48, rmacnak wrote:
> Throw

Done.

https://chromiumcodereview.appspot.com/1411853003/diff/20001/runtime/vm/servi...
runtime/vm/service.cc:185: return Object::null();
On 2015/10/23 20:54:48, rmacnak wrote:
> Throw

Done.

https://chromiumcodereview.appspot.com/1411853003/diff/20001/sdk/lib/vmservic...
File sdk/lib/vmservice/asset.dart (right):

https://chromiumcodereview.appspot.com/1411853003/diff/20001/sdk/lib/vmservic...
sdk/lib/vmservice/asset.dart:43: try {
On 2015/10/23 20:54:48, rmacnak wrote:
> Let exceptions propagate to caller

Done.

https://chromiumcodereview.appspot.com/1411853003/diff/20001/sdk/lib/vmservic...
sdk/lib/vmservice/asset.dart:113: static const List<int> tarMagic = const [
0x75, 0x73, 0x74, 0x61, 0x72, 0 ];
On 2015/10/23 20:54:48, rmacnak wrote:
> dead

Acknowledged.

https://chromiumcodereview.appspot.com/1411853003/diff/20001/sdk/lib/vmservic...
sdk/lib/vmservice/asset.dart:114: static const List<int> tarVersion = const [
0x30, 0x30 ];
On 2015/10/23 20:54:48, rmacnak wrote:
> dead

Acknowledged.

https://chromiumcodereview.appspot.com/1411853003/diff/20001/sdk/lib/vmservic...
sdk/lib/vmservice/asset.dart:190: static int count = 0;
On 2015/10/23 20:54:48, rmacnak wrote:
> Dead

Done.

[rmacnak, 2015-10-23 22:00:14]

lgtm

[Cutch, 2015-10-26 14:21:28]

Committed patchset #4 (id:60001) manually as
2844eb86cac7358ccc6e638c3de41e293824098d.