[Python-checkins] r52370 - sandbox/trunk/import_in_py/importer.py

[brett.cannon]

Author: brett.cannon
Date: Tue Oct 17 23:54:50 2006
New Revision: 52370

Modified:
   sandbox/trunk/import_in_py/importer.py
Log:
Remove notes on simple DB and zipimport rewrite.  It's a waste of time to use
PyPycBaseHandler and friends since they are geared towards the situation where
bytecode regeneration is a possibility.

For simple situations like zipimport or a DB that only has source or bytecode
it is easier to just either inline reading the source/bytecode and making the
code object or a simple handler that just takes in a string and just does the
compile/exec step immediately.


Modified: sandbox/trunk/import_in_py/importer.py
==============================================================================
--- sandbox/trunk/import_in_py/importer.py	(original)
+++ sandbox/trunk/import_in_py/importer.py	Tue Oct 17 23:54:50 2006
@@ -57,65 +57,43 @@
     + get_code_from_source()
         - Handle transforming source to pure Python source.
         - Return code object and timestamp.
-                
-zipimport use-case:
-* Importer
-    + Check if .py or .pyc file exists for module in zip file.
-* Loader
-    + Read .py or .pyc file into a StringIO instance.
-    + Set 'name' attribute to zip file plus file name.
-* Use PyPycFileHandler
-
-  
+ 
 sqlite3 importer use-case:
-* Simple way (only support just bytecode or source)
-    + DB
-        - For source just a column for module name and another containing the
-          source.
-        - For bytecode, a column for module name, another containing .pyc
-          output.
-    + Importer
-        - Query DB to see if module name is there.
-    + Loader
-        - Read entry in DB for module into a StringIO instance.
-        - Set 'name' attribute on StringIO instance to be DB path plus module name.
-    + Use the py/pyc file handler set for just source or bytecode.
-* Feature-rich way
-    + DB
-        - Module name.
-        - Source code.
-        - Marshalled code of the source.
-            * Set to NULL when source code is modified, which removes need of
-              storing the bytecode's timestamp.
-        - Magic number for bytecode.
-    + Importer
-        - Query DB to see if module is listed.
-        - Whether it is in bytecode or source form is irrelevant.
-    + Loader
-        - See if bytecode is in DB; if so then have that used, otherwise source.
-        - Pass in tuple of DB instance and requested module.
-    + Subclass PyPycBaseHandler
-        - Have both source and bytecode opaque objects be a tuple of the DB
-          instance and the module name that is being handled.
-        - get_bytecode()
-            * Reads DB and returns magic number, 0 for timestamp, and bytecode.
-            * Timestamp is unneeded as existence of bytecode implicitly means
-              that it is not outdated.
-        - find_source()
-            * Can return same tuple as passed into handle_code().
-        - verify_timestamp()
-            * ``return True``.
-        - get_code_from_source()
-            * Get source from DB.
-            * compile.
-            * return code object and 0 for timestamp.
-        - write_bytecode()
-            * Get marshalled string from code object.
-            * Write marshalled string to DB.
-            * Write current magic number to DB.
-        - get_location()
-            * Return the path to the DB and the module name.
-            * Could even return SQL statement to get module if one cared.
++ DB
+    - Module name.
+    - Source code.
+    - Marshalled code of the source.
+        * Set to NULL when source code is modified, which removes need of
+          storing the bytecode's timestamp.
+    - Magic number for bytecode.
++ Importer
+    - Query DB to see if module is listed.
+    - Whether it is in bytecode or source form is irrelevant.
++ Loader
+    - See if bytecode is in DB; if so then have that used, otherwise source.
+    - Pass in tuple of DB instance and requested module.
++ Subclass PyPycBaseHandler
+    - Have both source and bytecode opaque objects be a tuple of the DB
+      instance and the module name that is being handled.
+    - get_bytecode()
+        * Reads DB and returns magic number, 0 for timestamp, and bytecode.
+        * Timestamp is unneeded as existence of bytecode implicitly means
+          that it is not outdated.
+    - find_source()
+        * Can return same tuple as passed into handle_code().
+    - verify_timestamp()
+        * ``return True``.
+    - get_code_from_source()
+        * Get source from DB.
+        * compile.
+        * return code object and 0 for timestamp.
+    - write_bytecode()
+        * Get marshalled string from code object.
+        * Write marshalled string to DB.
+        * Write current magic number to DB.
+    - get_location()
+        * Return the path to the DB and the module name.
+        * Could even return SQL statement to get module if one cared.
 
 """
 from __future__ import with_statement
@@ -546,4 +524,4 @@
             with contextlib.closing(source_file):
                 source_location = self.get_location(source_file)
             bytecode_location = self.get_location(bytecode_file)
-        py_compile.compile(source_location, bytecode_location, doraise=True)
\ No newline at end of file
+        py_compile.compile(source_location, bytecode_location, doraise=True)