[Checkins] SVN: zc.recipe.cmmi/trunk/ fixed #695977: don't cause buildout to delete shared builds, rebuild ones deleted by a third party

[Thomas Lotze]

Log message for revision 119630:
  fixed #695977: don't cause buildout to delete shared builds, rebuild ones deleted by a third party

Changed:
  U   zc.recipe.cmmi/trunk/CHANGES.txt
  U   zc.recipe.cmmi/trunk/src/zc/recipe/cmmi/__init__.py
  U   zc.recipe.cmmi/trunk/src/zc/recipe/cmmi/misc.txt
  U   zc.recipe.cmmi/trunk/src/zc/recipe/cmmi/shared.txt

-=-
Modified: zc.recipe.cmmi/trunk/CHANGES.txt
===================================================================
--- zc.recipe.cmmi/trunk/CHANGES.txt	2011-01-18 06:45:40 UTC (rev 119629)
+++ zc.recipe.cmmi/trunk/CHANGES.txt	2011-01-18 07:43:15 UTC (rev 119630)
@@ -4,6 +4,9 @@
 1.4 (unreleased)
 ================
 
+- Fixed a bug in location book-keeping that caused shared builds to be deleted
+  from disk when a part didn't need them anymore. (#695977)
+
 - Made tests pass with both zc.buildout 1.4 and 1.5, lifted the upper version
   bound on zc.buildout. (#695732)
 

Modified: zc.recipe.cmmi/trunk/src/zc/recipe/cmmi/__init__.py
===================================================================
--- zc.recipe.cmmi/trunk/src/zc/recipe/cmmi/__init__.py	2011-01-18 06:45:40 UTC (rev 119629)
+++ zc.recipe.cmmi/trunk/src/zc/recipe/cmmi/__init__.py	2011-01-18 07:43:15 UTC (rev 119630)
@@ -96,6 +96,17 @@
         return sha1(''.join(state)).hexdigest()
 
     def install(self):
+        self.build()
+        if self.shared:
+            return ''
+        else:
+            return self.options['location']
+
+    def update(self):
+        if not os.path.isdir(self.options['location']):
+            self.build()
+
+    def build(self):
         logger = logging.getLogger(self.name)
         download = zc.buildout.download.Download(
             self.buildout['buildout'], namespace='cmmi', hash_name=True,
@@ -178,11 +189,6 @@
                 logger.error("cmmi failed: %s", tmp)
             raise
 
-        return dest
-
-    def update(self):
-        pass
-
     def cmmi(self, dest):
         """Do the 'configure; make; make install' command sequence.
 

Modified: zc.recipe.cmmi/trunk/src/zc/recipe/cmmi/misc.txt
===================================================================
--- zc.recipe.cmmi/trunk/src/zc/recipe/cmmi/misc.txt	2011-01-18 06:45:40 UTC (rev 119629)
+++ zc.recipe.cmmi/trunk/src/zc/recipe/cmmi/misc.txt	2011-01-18 07:43:15 UTC (rev 119630)
@@ -36,3 +36,39 @@
     >>> import os.path
     >>> os.path.isdir(join(sample_buildout, "parts", "foo"))
     True
+
+Removing the parts folder
+-------------------------
+
+As a result of featuring shared builds, the handling of zc.recipe.cmmi's
+associated file-system paths is not entirely trivial. Let's make sure that
+when not sharing the build, the recipe gets the book-keeping of its part
+directory right.
+
+The part's directory is created when the part is installed:
+
+    >>> remove('.installed.cfg')
+    >>> rmdir('parts', 'foo')
+
+    >>> print system('bin/buildout')
+    Installing...
+    ...
+    installing foo
+
+    >>> os.path.isdir(join(sample_buildout, "parts", "foo"))
+    True
+
+The part's directory is removed when it is no longer needed (e.g. because the
+part now uses a shared build or because the part is gone altogether):
+
+    >>> write('buildout.cfg',
+    ... """
+    ... [buildout]
+    ... parts = 
+    ... """)
+
+    >>> print system('bin/buildout')
+    Uninstalling foo.
+
+    >>> os.path.isdir(join(sample_buildout, "parts", "foo"))
+    False

Modified: zc.recipe.cmmi/trunk/src/zc/recipe/cmmi/shared.txt
===================================================================
--- zc.recipe.cmmi/trunk/src/zc/recipe/cmmi/shared.txt	2011-01-18 06:45:40 UTC (rev 119629)
+++ zc.recipe.cmmi/trunk/src/zc/recipe/cmmi/shared.txt	2011-01-18 07:43:15 UTC (rev 119630)
@@ -224,23 +224,112 @@
     <BLANKLINE>
 
 
+Interaction with other users of shared builds
+=============================================
+
+While shared builds are a way to cache a build between installation runs of a
+given buildout part, they are, more importantly, shared between multiple parts
+and most probably, multiple buildouts. This implies two general rules of
+behaviour: We should never delete shared builds, and we need to be prepared
+for shared builds to be deleted by other system at any time.
+
+In other words: Every install or update run of the recipe that uses a shared
+build needs to check whether the build still exists on disk and rebuild it if
+it does not. On the other hand, a part using the shared build must not declare
+the shared build its own property lest buildout remove it when the shared
+build is no longer needed, either because the part no longer uses it or
+because the part itself is no longer used.
+
+The last thing we did above was to install a shared build:
+
+    >>> ls(cache, 'cmmi', 'build')
+    d  <BUILDID>
+
+If someone deletes this shared build, updating the buildout part that needs it
+will cause it to be rebuilt:
+
+    >>> rmdir(cache, 'cmmi', 'build')
+    >>> print system('bin/buildout')
+    Updating foo.
+    foo: Unpacking and configuring
+    configuring foo /cache/cmmi/build/<BUILDID>
+    echo building foo
+    building foo
+    echo installing foo
+    installing foo
+
+    >>> ls(cache, 'cmmi', 'build')
+    d  <BUILDID>
+
+If we stop using the shared build, it stays in the build cache:
+
+    >>> write('buildout.cfg',
+    ... """
+    ... [buildout]
+    ... parts = foo
+    ... download-cache = %s
+    ...
+    ... [foo]
+    ... recipe = zc.recipe.cmmi
+    ... url = file://%s/foo.tgz
+    ... """ % (cache, distros))
+
+    >>> print system('bin/buildout')
+    Uninstalling foo.
+    Installing foo.
+    foo: Unpacking and configuring
+    configuring foo /sample-buildout/parts/foo
+    echo building foo
+    building foo
+    echo installing foo
+    installing foo
+
+    >>> ls(cache, 'cmmi', 'build')
+    d  <BUILDID>
+
+
 Regression: Keeping track of a reused shared build
 ==================================================
 
-zc.recipe.cmmi 1.2 had a bug that manifested when reusing a shared build by a
-second buildout: The part wouldn't keep track of the shared build and thus
-wasn't able to restore it if it got deleted from the cache. Let's simulate the
-second buildout by removing .installed.cfg, then this is how it should work:
+Let's first remove and rebuild everything to get some measure of isolation
+from the story so far:
 
     >>> remove('.installed.cfg')
+    >>> rmdir(cache, 'cmmi', 'build')
+
+    >>> write('buildout.cfg',
+    ... """
+    ... [buildout]
+    ... parts = foo
+    ... download-cache = %s
+    ...
+    ... [foo]
+    ... recipe = zc.recipe.cmmi
+    ... url = file://%s/foo.tgz
+    ... shared = True
+    ... """ % (cache, distros))
+
     >>> print system('bin/buildout')
     Installing foo.
+    foo: Unpacking and configuring
+    configuring foo /cache/cmmi/build/<BUILDID>
+    echo building foo
+    building foo
+    echo installing foo
+    installing foo
+
+zc.recipe.cmmi 1.2 had a bug that manifested after reusing a shared build: The
+part wouldn't keep track of the shared build and thus wasn't able to restore
+it if it got deleted from the cache. This is how it should work:
+
+    >>> remove('.installed.cfg')
+    >>> print system('bin/buildout')
+    Installing foo.
     foo: using existing shared build
 
     >>> rmdir(cache, 'cmmi', 'build')
     >>> print system('bin/buildout')
-    Uninstalling foo.
-    Installing foo.
+    Updating foo.
     foo: Unpacking and configuring
     configuring foo /cache/cmmi/build/<BUILDID>
     echo building foo