Add tool to fix oversize files (the bug fixed by b98ff13)

extras/fix-oversize-files.py

@@ -0,0 +1,50 @@
+#!/usr/bin/python
+
+import os
+import sys
+import cPickle as pickle
+import argparse
+import fcntl
+import re
+from nilmdb.client.numpyclient import layout_to_dtype
+
+parser = argparse.ArgumentParser(
+    description = """
+Fix database corruption where binary writes caused too much data to be
+written to the file.  Truncates files to the correct length.  This was
+fixed by b98ff1331a515ad47fd3203615e835b529b039f9.
+""")
+parser.add_argument("path", action="store", help='Database root path')
+parser.add_argument("-y", "--yes", action="store_true", help='Fix them')
+args = parser.parse_args()
+
+lock = os.path.join(args.path, "data.lock")
+with open(lock, "w") as f:
+    fcntl.flock(f.fileno(), fcntl.LOCK_EX | fcntl.LOCK_NB)
+
+    fix = {}
+
+    for (path, dirs, files) in os.walk(args.path):
+        if "_format" in files:
+            with open(os.path.join(path, "_format")) as format:
+                fmt = pickle.load(format)
+                rowsize = layout_to_dtype(fmt["layout"]).itemsize
+                maxsize = rowsize * fmt["rows_per_file"]
+                fix[path] = maxsize
+                if maxsize < 128000000: # sanity check
+                    raise Exception("bad maxsize " + str(maxsize))
+
+    for fixpath in fix:
+        for (path, dirs, files) in os.walk(fixpath):
+            for fn in files:
+                if not re.match("^[0-9a-f]{4,}$", fn):
+                    continue
+                fn = os.path.join(path, fn)
+                size = os.path.getsize(fn)
+                maxsize = fix[fixpath]
+                if size > maxsize:
+                    diff = size - maxsize
+                    print diff, "too big:", fn
+                    if args.yes:
+                        with open(fn, "a+") as dbfile:
+                            dbfile.truncate(maxsize)