predictors: db tool workaround to solve sqlite3 compatibility problem.

tools/resource_prefetch_predictor/prefetch_predictor_tool.py

Index: tools/resource_prefetch_predictor/prefetch_predictor_tool.py
diff --git a/tools/resource_prefetch_predictor/prefetch_predictor_tool.py b/tools/resource_prefetch_predictor/prefetch_predictor_tool.py
index 1160f5f3a108505cfa20615fbccb5e881286ee22..4371d6fb4133c73fe10ea9cc4112f9a2390e86c9 100755
--- a/tools/resource_prefetch_predictor/prefetch_predictor_tool.py
+++ b/tools/resource_prefetch_predictor/prefetch_predictor_tool.py
@@ -13,6 +13,7 @@ adb pull \
 
 import argparse
 import sqlite3
+import os
 
 from resource_prefetch_predictor_pb2 import (PrefetchData, ResourceData)
 
@@ -77,6 +78,15 @@ class Entry(object):
         continue
       self._PrettyPrintResource(resource)
 
+# The current version of python sqilte3 library doesn't support views but

[Benoit L, 2017/01/11 09:36:45]

Not sure about the "current" version, at least the version we happen to have in
Ubuntu 14.04 LTS.

Also, sqlite3 not sqilte3 :-)

[alexilin, 2017/01/11 12:39:07]

Done.

+# command line util does.
+# TODO(alexilin): get rid of this when python sqlite3 adds view support.
+def CreateCompatibleDatabaseCopy(filename):
+  import tempfile, shutil
+  _, tmpfile = tempfile.mkstemp()
+  shutil.copy2(filename, tmpfile)
+  os.system('sqlite3 %s "DROP VIEW MmapStatus"' % (tmpfile,))

[Benoit L, 2017/01/11 09:36:45]

nit: why not subprocess.call(['sqlite3', tmpfile, 'DROP VIEW MmapStatus'])

?

No shell is best shell.

[alexilin, 2017/01/11 12:39:07]

Done.

+  return tmpfile
 
 def DatabaseStats(filename, domain):
   connection = sqlite3.connect(filename)
@@ -94,7 +104,9 @@ def main():
                       help='Path to the database')
   parser.add_argument('-d', dest='domain', default=None, help='Domain')
   args = parser.parse_args()
-  DatabaseStats(args.database_filename, args.domain)
+  database_copy = CreateCompatibleDatabaseCopy(args.database_filename)

[Benoit L, 2017/01/11 09:36:45]

nit:

try:
  bla bla
finally:
  os.remove(database_copy)

To not leave files around.

[alexilin, 2017/01/11 12:39:07]

Done.

+  DatabaseStats(database_copy, args.domain)
+  os.remove(database_copy)
 
 
 if __name__ == '__main__':