Work around Firefox-3.5 locking problems with a copy

Firefox-3.5 seems to always hold cookies.sqlite locked while the
browser is open. Work around this by, when we hit a lock error,
making a copy and reading from that. Not 100% reliable, but should
work much of the time.

1 files changed, 40 insertions, 10 deletions

diff --git a/git-bz b/git-bz
index 81918a5..5f8bce3 100755
--- a/git-bz
+++ b/git-bz
@@ -207,6 +207,7 @@ from pysqlite2 import dbapi2 as sqlite
 import re
 from StringIO import StringIO
 from subprocess import Popen, CalledProcessError, PIPE
+import shutil
 import sys
 import tempfile
 import time
@@ -477,19 +478,48 @@ def resolve_bug_reference(bug_reference):
 class CookieError(Exception):
     pass
 
-def get_cookies_from_sqlite(host, cookies_sqlite, browser):
+def do_get_cookies_from_sqlite(host, cookies_sqlite, browser):
     result = {}
+    # We use a timeout of 0 since we expect to hit the browser holding
+    # the lock often and we need to fall back to making a copy without a delay
+    connection = sqlite.connect(cookies_sqlite, timeout=0)
 
-    connection = sqlite.connect(cookies_sqlite)
-    cursor = connection.cursor()
-    cursor.execute("select name,value,path,expiry from moz_cookies where host = :host", { 'host': host })
+    try:
+        cursor = connection.cursor()
+        cursor.execute("select name,value,path,expiry from moz_cookies where host = :host", { 'host': host })
+
+        now = time.time()
+        for name,value,path,expiry in cursor.fetchall():
+            # Excessive caution: toss out values that need to be quoted in a cookie header
+            if float(expiry) > now and not re.search(r'[()<>@,;:\\"/\[\]?={} \t]', value):
+                result[name] = value
+
+        return result
+    finally:
+        connection.close()
+
+# Firefox 3.5 keeps the cookies database permamently locked; as a workaround
+# hack, we make a copy, read from that, then delete the copy. Of course,
+# we may hit an inconsistent state of the database
+def get_cookies_from_sqlite_with_copy(host, cookies_sqlite, browser):
+    db_copy = cookies_sqlite + ".git-bz-temp"
+    shutil.copyfile(cookies_sqlite, db_copy)
+    try:
+        return do_get_cookies_from_sqlite(host, db_copy, browser)
+    except sqlite.OperationalError, e:
+        raise CookieError("Cookie database was locked; temporary copy didn't work")
+    finally:
+        os.remove(db_copy)
 
-    now = time.time()
-    for name,value,path,expiry in cursor.fetchall():
-        # Excessive caution: toss out values that need to be quoted in a cookie header
-        if float(expiry) > now and not re.search(r'[()<>@,;:\\"/\[\]?={} \t]', value):
-            result[name] = value
-    connection.close()
+def get_cookies_from_sqlite(host, cookies_sqlite, browser):
+    try:
+        result = do_get_cookies_from_sqlite(host, cookies_sqlite, browser)
+    except sqlite.OperationalError, e:
+        if "database is locked" in str(e):
+            # Try making a temporary copy
+            result = get_cookies_from_sqlite_with_copy(host, cookies_sqlite, browser)
+        else:
+            raise
 
     if not ('Bugzilla_login' in result and 'Bugzilla_logincookie' in result):
         raise CookieError("You don't appear to be signed into %s; please log in with %s")