Re: [Patch] BaseTool: Add cache for the result of SkipAutogen.

["Feng, Bob C" <bob.c.feng@intel.com>]

Hi Liming,

Based on my testing, a module will enter the CanSkip() multiple times even after CanSkip() return True. 
In this patch, I cache the module after CanSkip() return True to save the cost of later CanSkip() evaluation.
I think the CanSkip() will always return True after it return True at first time in one build process.

Thanks,
Bob

-----Original Message-----
From: Gao, Liming 
Sent: Monday, July 02, 2018 10:53 AM
To: Feng, Bob C <bob.c.feng@intel.com>; edk2-devel@lists.01.org
Subject: RE: [Patch] BaseTool: Add cache for the result of SkipAutogen.

Bob:
  When will this cache take effective? 

Thanks
Liming
>-----Original Message-----
>From: Feng, Bob C
>Sent: Monday, July 02, 2018 9:16 AM
>To: edk2-devel@lists.01.org
>Cc: Feng, Bob C <bob.c.feng@intel.com>; Gao, Liming 
><liming.gao@intel.com>
>Subject: [Patch] BaseTool: Add cache for the result of SkipAutogen.
>
>Add a cache for the value of skip ModuleAutoGen process flag. This 
>cache can improve build performance.
>
>Contributed-under: TianoCore Contribution Agreement 1.1
>Signed-off-by: Bob Feng <bob.c.feng@intel.com>
>Cc: Liming Gao <liming.gao@intel.com>
>---
> BaseTools/Source/Python/AutoGen/AutoGen.py   | 4 ++++
> BaseTools/Source/Python/Common/GlobalData.py | 1 +
> 2 files changed, 5 insertions(+)
>
>diff --git a/BaseTools/Source/Python/AutoGen/AutoGen.py
>b/BaseTools/Source/Python/AutoGen/AutoGen.py
>index 381dbc0a71..fc242992b7 100644
>--- a/BaseTools/Source/Python/AutoGen/AutoGen.py
>+++ b/BaseTools/Source/Python/AutoGen/AutoGen.py
>@@ -4305,15 +4305,18 @@ class ModuleAutoGen(AutoGen):
>
>     ## Decide whether we can skip the ModuleAutoGen process
>     def CanSkipbyHash(self):
>         if GlobalData.gUseHashCache:
>             return not self.GenModuleHash()
>+        return False
>
>     ## Decide whether we can skip the ModuleAutoGen process
>     #  If any source file is newer than the module than we cannot skip
>     #
>     def CanSkip(self):
>+        if self.MetaFile in GlobalData.gSikpAutoGenCache:
>+            return True
>         if not os.path.exists(self.GetTimeStampPath()):
>             return False
>         #last creation time of the module
>         DstTimeStamp = os.stat(self.GetTimeStampPath())[8]
>
>@@ -4328,10 +4331,11 @@ class ModuleAutoGen(AutoGen):
>                     return False
>                 if source not in ModuleAutoGen.TimeDict :
>                     ModuleAutoGen.TimeDict[source] = os.stat(source)[8]
>                 if ModuleAutoGen.TimeDict[source] > DstTimeStamp:
>                     return False
>+        GlobalData.gSikpAutoGenCache.add(self.MetaFile)
>         return True
>
>     def GetTimeStampPath(self):
>         if self._TimeStampPath is None:
>             self._TimeStampPath = os.path.join(self.MakeFileDir,
>'AutoGenTimeStamp')
>diff --git a/BaseTools/Source/Python/Common/GlobalData.py
>b/BaseTools/Source/Python/Common/GlobalData.py
>index afb3d8f020..fac7cde708 100644
>--- a/BaseTools/Source/Python/Common/GlobalData.py
>+++ b/BaseTools/Source/Python/Common/GlobalData.py
>@@ -111,5 +111,6 @@ gBinCacheDest = None  gBinCacheSource = None  
>gPlatformHash = None  gPackageHash = {}  gModuleHash = {}  
>gEnableGenfdsMultiThread = False
>+gSikpAutoGenCache = set()
>--
>2.16.2.windows.1