Optimize work with absolute paths.

Optimize work with absolute paths.

This significantly improves MDL project analysis time.

Cold VM: 24600 ms -> 21586 ms, about 14% faster.
Hot  VM: 13100 ms -> 10080 ms, about 30% faster.


R=brianwilkerson@google.com, paulberry@google.com
BUG=

Committed: https://github.com/dart-lang/sdk/commit/b45f941d1e401b17b81f0db92bc63c9db73dc3df

[Brian Wilkerson, 2015-11-14 17:30:25]

LGTM

https://codereview.chromium.org/1443173004/diff/1/pkg/analyzer/lib/src/util/a...
File pkg/analyzer/lib/src/util/absolute_path.dart (right):

https://codereview.chromium.org/1443173004/diff/1/pkg/analyzer/lib/src/util/a...
pkg/analyzer/lib/src/util/absolute_path.dart:5: library
engine.utilities.absolute_path;
The library name should be "analyzer.src.util.absolute_path". (Although I'd like
it better if the directory name were "utilities". :-)

https://codereview.chromium.org/1443173004/diff/1/pkg/analyzer/lib/src/util/a...
pkg/analyzer/lib/src/util/absolute_path.dart:13: /// Append the given [suffix]
the given absolute [parent].
"[suffix]" --> "relative [suffix] to"

https://codereview.chromium.org/1443173004/diff/1/pkg/analyzer/lib/src/util/a...
pkg/analyzer/lib/src/util/absolute_path.dart:15: ///    
context.append('/path/to', 'foo'); // -> 'path/to/foo'
Missing leading '/' in result.

https://codereview.chromium.org/1443173004/diff/1/pkg/analyzer/lib/src/util/a...
pkg/analyzer/lib/src/util/absolute_path.dart:22: /// Gets the part of [path]
after the last separator on the context's
"Gets" --> "Return"
"[path]" --> "the absolute [path]"

https://codereview.chromium.org/1443173004/diff/1/pkg/analyzer/lib/src/util/a...
pkg/analyzer/lib/src/util/absolute_path.dart:32: /// Gets the part of [path]
before the last separator.
"Gets" --> "Return"
"[path]" --> "the absolute [path]"

https://codereview.chromium.org/1443173004/diff/1/pkg/analyzer/lib/src/util/a...
pkg/analyzer/lib/src/util/absolute_path.dart:42: /// otherwise.
"`parent`" --> "[parent]"
"." --> ". Both the [child] and [parent] paths must be absolute paths."

https://codereview.chromium.org/1443173004/diff/1/pkg/analyzer/lib/src/util/a...
pkg/analyzer/lib/src/util/absolute_path.dart:52: /// relative path from [parent]
to [child]. Otherwise returns `null`.
"`." --> "`. Both the [child] and [parent] paths must be absolute paths."

https://codereview.chromium.org/1443173004/diff/1/pkg/analyzer/test/src/util/...
File pkg/analyzer/test/src/util/absolute_path_test.dart (right):

https://codereview.chromium.org/1443173004/diff/1/pkg/analyzer/test/src/util/...
pkg/analyzer/test/src/util/absolute_path_test.dart:34:
expect(context.dirname(r'/path/to'), r'/path');
expect(context.dirname(r'/path'), r'/');
expect(context.dirname(r'/'), r'/');

https://codereview.chromium.org/1443173004/diff/1/pkg/analyzer/test/src/util/...
pkg/analyzer/test/src/util/absolute_path_test.dart:70:
expect(context.dirname(r'C:\path\to'), r'C:\path');
expect(context.dirname(r'C:\path'), r'C:\');
expect(context.dirname(r'C:\'), r'C:\');

[scheglov, 2015-11-14 22:40:13]

Thanks!

https://codereview.chromium.org/1443173004/diff/1/pkg/analyzer/lib/src/util/a...
File pkg/analyzer/lib/src/util/absolute_path.dart (right):

https://codereview.chromium.org/1443173004/diff/1/pkg/analyzer/lib/src/util/a...
pkg/analyzer/lib/src/util/absolute_path.dart:5: library
engine.utilities.absolute_path;
On 2015/11/14 17:30:25, Brian Wilkerson wrote:
> The library name should be "analyzer.src.util.absolute_path". (Although I'd
like
> it better if the directory name were "utilities". :-)

Done.

https://codereview.chromium.org/1443173004/diff/1/pkg/analyzer/lib/src/util/a...
pkg/analyzer/lib/src/util/absolute_path.dart:13: /// Append the given [suffix]
the given absolute [parent].
On 2015/11/14 17:30:25, Brian Wilkerson wrote:
> "[suffix]" --> "relative [suffix] to"

Done.

https://codereview.chromium.org/1443173004/diff/1/pkg/analyzer/lib/src/util/a...
pkg/analyzer/lib/src/util/absolute_path.dart:15: ///    
context.append('/path/to', 'foo'); // -> 'path/to/foo'
On 2015/11/14 17:30:24, Brian Wilkerson wrote:
> Missing leading '/' in result.

Done.

https://codereview.chromium.org/1443173004/diff/1/pkg/analyzer/lib/src/util/a...
pkg/analyzer/lib/src/util/absolute_path.dart:22: /// Gets the part of [path]
after the last separator on the context's
On 2015/11/14 17:30:25, Brian Wilkerson wrote:
> "Gets" --> "Return"
> "[path]" --> "the absolute [path]"

Done.

https://codereview.chromium.org/1443173004/diff/1/pkg/analyzer/lib/src/util/a...
pkg/analyzer/lib/src/util/absolute_path.dart:32: /// Gets the part of [path]
before the last separator.
On 2015/11/14 17:30:25, Brian Wilkerson wrote:
> "Gets" --> "Return"
> "[path]" --> "the absolute [path]"

Done.

https://codereview.chromium.org/1443173004/diff/1/pkg/analyzer/lib/src/util/a...
pkg/analyzer/lib/src/util/absolute_path.dart:42: /// otherwise.
On 2015/11/14 17:30:25, Brian Wilkerson wrote:
> "`parent`" --> "[parent]"
> "." --> ". Both the [child] and [parent] paths must be absolute paths."

Done.

https://codereview.chromium.org/1443173004/diff/1/pkg/analyzer/lib/src/util/a...
pkg/analyzer/lib/src/util/absolute_path.dart:52: /// relative path from [parent]
to [child]. Otherwise returns `null`.
On 2015/11/14 17:30:24, Brian Wilkerson wrote:
> "`." --> "`. Both the [child] and [parent] paths must be absolute paths."

Done.

https://codereview.chromium.org/1443173004/diff/1/pkg/analyzer/test/src/util/...
File pkg/analyzer/test/src/util/absolute_path_test.dart (right):

https://codereview.chromium.org/1443173004/diff/1/pkg/analyzer/test/src/util/...
pkg/analyzer/test/src/util/absolute_path_test.dart:34:
expect(context.dirname(r'/path/to'), r'/path');
On 2015/11/14 17:30:25, Brian Wilkerson wrote:
> expect(context.dirname(r'/path'), r'/');
> expect(context.dirname(r'/'), r'/');

Done.

https://codereview.chromium.org/1443173004/diff/1/pkg/analyzer/test/src/util/...
pkg/analyzer/test/src/util/absolute_path_test.dart:70:
expect(context.dirname(r'C:\path\to'), r'C:\path');
On 2015/11/14 17:30:25, Brian Wilkerson wrote:
> expect(context.dirname(r'C:\path'), r'C:\');
> expect(context.dirname(r'C:\'), r'C:\');

Done.

[scheglov, 2015-11-14 22:40:53]

Committed patchset #2 (id:20001) manually as
b45f941d1e401b17b81f0db92bc63c9db73dc3df (presubmit successful).