[Checkins] SVN: Products.GenericSetup/trunk/Products/GenericSetup/ Add 'IChunkedImportContext' interface, allowing RAM-efficient chunked reads

[Tres Seaver]

Log message for revision 89988:
  Add 'IChunkedImportContext' interface, allowing RAM-efficient chunked reads
  of large files, and implement for 'DirectoryImportContext'.
  (https://bugs.launchpad.net/zope-cmf/+bug/259233)
  

Changed:
  U   Products.GenericSetup/trunk/Products/GenericSetup/CHANGES.txt
  U   Products.GenericSetup/trunk/Products/GenericSetup/context.py
  U   Products.GenericSetup/trunk/Products/GenericSetup/interfaces.py
  U   Products.GenericSetup/trunk/Products/GenericSetup/tests/conformance.py
  U   Products.GenericSetup/trunk/Products/GenericSetup/tests/test_context.py

-=-
Modified: Products.GenericSetup/trunk/Products/GenericSetup/CHANGES.txt
===================================================================
--- Products.GenericSetup/trunk/Products/GenericSetup/CHANGES.txt	2008-08-18 22:53:42 UTC (rev 89987)
+++ Products.GenericSetup/trunk/Products/GenericSetup/CHANGES.txt	2008-08-18 23:20:33 UTC (rev 89988)
@@ -4,6 +4,10 @@
 GenericSetup 1.5.0 (unreleased)
 -------------------------------
 
+- Add 'IChunkedImportContext' interface, allowing RAM-efficient chunked
+  reads of large files, and implement for 'DirectoryImportContext'.
+  (https://bugs.launchpad.net/zope-cmf/+bug/259233)
+
 - Add <genericsetup:upgradeDepends> ZCML tag; defines a specialized upgrade
   step that re-applies one or more import steps from the GS profile during
   an upgrade process

Modified: Products.GenericSetup/trunk/Products/GenericSetup/context.py
===================================================================
--- Products.GenericSetup/trunk/Products/GenericSetup/context.py	2008-08-18 22:53:42 UTC (rev 89987)
+++ Products.GenericSetup/trunk/Products/GenericSetup/context.py	2008-08-18 23:20:33 UTC (rev 89988)
@@ -40,6 +40,7 @@
 from zope.interface import implements
 
 from interfaces import IChunkableExportContext
+from interfaces import IChunkableImportContext
 from interfaces import IExportContext
 from interfaces import IImportContext
 from interfaces import ISetupEnviron
@@ -179,7 +180,7 @@
 
 class DirectoryImportContext( BaseContext ):
 
-    implements(IImportContext)
+    implements(IChunkableImportContext)
 
     security = ClassSecurityInfo()
 
@@ -194,8 +195,8 @@
         self._profile_path = profile_path
         self._should_purge = bool( should_purge )
 
-    security.declareProtected( ManagePortal, 'readDataFile' )
-    def readDataFile( self, filename, subdir=None ):
+    security.declareProtected( ManagePortal, 'openDataFile' )
+    def openDataFile( self, filename, subdir=None ):
 
         """ See IImportContext.
         """
@@ -207,10 +208,18 @@
         if not os.path.exists( full_path ):
             return None
 
-        file = open( full_path, 'rb' )
-        result = file.read()
-        file.close()
+        return open( full_path, 'rb' )
 
+    security.declareProtected( ManagePortal, 'readDataFile' )
+    def readDataFile( self, filename, subdir=None ):
+
+        """ See IImportContext.
+        """
+        result = None
+        file = self.openDataFile( filename, subdir )
+        if file is not None:
+            result = file.read()
+            file.close()
         return result
 
     security.declareProtected( ManagePortal, 'getLastModified' )

Modified: Products.GenericSetup/trunk/Products/GenericSetup/interfaces.py
===================================================================
--- Products.GenericSetup/trunk/Products/GenericSetup/interfaces.py	2008-08-18 22:53:42 UTC (rev 89987)
+++ Products.GenericSetup/trunk/Products/GenericSetup/interfaces.py	2008-08-18 23:20:33 UTC (rev 89988)
@@ -133,7 +133,22 @@
         o If 'path' does not point to a directory / folder, return None.
         """
 
+class IChunkableImportContext( IImportContext ):
 
+    def openDataFile( filename, subdir=None ):
+
+        """ Open a datafile for reading from the specified location.
+
+        o 'filename' is the unqualified name of the file.
+
+        o 'subdir', if passed, is a path to a subdirectory / folder in
+          which to find the file;  if not passed, write the file to the
+          "root" of the target.
+
+        o Return a readable file-like object;  the caller is responsible
+          for calling 'close' on it.
+        """
+
 class IImportPlugin( IPseudoInterface ):
 
     """ Signature for callables used to import portions of site configuration.

Modified: Products.GenericSetup/trunk/Products/GenericSetup/tests/conformance.py
===================================================================
--- Products.GenericSetup/trunk/Products/GenericSetup/tests/conformance.py	2008-08-18 22:53:42 UTC (rev 89987)
+++ Products.GenericSetup/trunk/Products/GenericSetup/tests/conformance.py	2008-08-18 23:20:33 UTC (rev 89988)
@@ -54,6 +54,15 @@
 
         verifyClass( IChunkableExportContext, self._getTargetClass() )
 
+class ConformsToIChunkableImportContext:
+
+    def test_IChunkableImportContext_conformance( self ):
+
+        from Products.GenericSetup.interfaces import IChunkableImportContext
+        from zope.interface.verify import verifyClass
+
+        verifyClass( IChunkableImportContext, self._getTargetClass() )
+
 class ConformsToIStepRegistry:
 
     def test_IStepRegistry_conformance( self ):

Modified: Products.GenericSetup/trunk/Products/GenericSetup/tests/test_context.py
===================================================================
--- Products.GenericSetup/trunk/Products/GenericSetup/tests/test_context.py	2008-08-18 22:53:42 UTC (rev 89987)
+++ Products.GenericSetup/trunk/Products/GenericSetup/tests/test_context.py	2008-08-18 23:20:33 UTC (rev 89988)
@@ -35,6 +35,7 @@
 from conformance import ConformsToIImportContext
 from conformance import ConformsToIExportContext
 from conformance import ConformsToIChunkableExportContext
+from conformance import ConformsToIChunkableImportContext
 
 
 class DummySite( Folder ):
@@ -49,6 +50,7 @@
 class DirectoryImportContextTests( FilesystemTestBase
                                  , ConformsToISetupContext
                                  , ConformsToIImportContext
+                                 , ConformsToIChunkableImportContext
                                  ):
 
     _PROFILE_PATH = '/tmp/ICTTexts'