Bug 195789

Summary: Web Inspector: CPU Usage Timeline - the right edge of each column should align with a CPU measurement
Product: WebKit Reporter: Devin Rousso <hi>
Component: Web InspectorAssignee: Devin Rousso <hi>
Status: RESOLVED FIXED    
Severity: Normal CC: commit-queue, hi, inspector-bugzilla-changes, joepeck, webkit-bug-importer
Priority: P2 Keywords: InRadar
Version: WebKit Nightly Build   
Hardware: All   
OS: All   
Attachments:
Description Flags
Patch
none
Patch none

Description Devin Rousso 2019-03-14 20:06:22 PDT
Right now, we are rendering each column such that the middle of the column is aligned with the CPU measurement.  This could potentially be misleading, as due to the width of the bar, it implies that there was a period of time after the actual CPU measurement that is attributed to that same CPU measurement.

   1      2      3   
       _______       
       [  *  ]       
       [  *  ]_______
       [  *  ][  *  ]
_______[  *  ][  *  ]
[  *  ][  *  ][  *  ]
[__*__][__*__][__*__]
 A   B  C   D  E   F

In this example, a developer might "attribute" any work done at time B to record 1, when in reality it should be "attributed" to record 2, since the CPU measurement had already been taken by the time B was captured, meaning that the work for B hadn't yet been don and could therefore not have affected the CPU measurement

We should be rendering the columns such that the CPU measurement aligns with the trailing edge of the column.

  1      2      3    
    _______       ___
    [    *]       [  
    [    *]_______[  
    [    *][    *][  
____[    *][    *][  
  *][    *][    *][  
__*][____*][____*][__
 A   B  C   D  E   F

NOT: the drawing isn't exactly accurate, as the * would overlap the ].


Legend:
[     ] = a column for a CPU measurement (500ms wide to account for the fact that CPU measurements are 500ms apart)
* = the time when the measurement actually takes place
Comment 1 Radar WebKit Bug Importer 2019-03-14 22:00:34 PDT
<rdar://problem/48915271>
Comment 2 Devin Rousso 2019-03-14 22:04:04 PDT
Created attachment 364769 [details]
Patch
Comment 3 Devin Rousso 2019-03-15 20:49:33 PDT
Created attachment 364907 [details]
Patch
Comment 4 Joseph Pecoraro 2019-03-19 12:03:01 PDT
Comment on attachment 364907 [details]
Patch

r=me
Comment 5 WebKit Commit Bot 2019-03-19 13:13:08 PDT
Comment on attachment 364907 [details]
Patch

Clearing flags on attachment: 364907

Committed r243166: <https://trac.webkit.org/changeset/243166>
Comment 6 WebKit Commit Bot 2019-03-19 13:13:10 PDT
All reviewed patches have been landed.  Closing bug.