From b3b75207973bc46604a0bc08fba13ce57d0efb76 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Paul=20O=E2=80=99Shannessy?= <paul@oshannessy.com>
Date: Tue, 3 Aug 2010 19:01:42 -0700
Subject: [PATCH] Bug 545752 - DB Statements aren't finalized in HistoryStore
 [r=mconnor] (CLOSED TREE)

Also nullifies the cached service so we don't leak.
---
 services/sync/modules/engines/history.js | 47 ++++++++++++++----------
 1 file changed, 28 insertions(+), 19 deletions(-)

diff --git a/services/sync/modules/engines/history.js b/services/sync/modules/engines/history.js
index b367dc3706e..526fa3122fb 100644
--- a/services/sync/modules/engines/history.js
+++ b/services/sync/modules/engines/history.js
@@ -86,27 +86,44 @@ HistoryEngine.prototype = {
 
 function HistoryStore(name) {
   Store.call(this, name);
+
+  // Explicitly nullify our references to our cached services so we don't leak
+  Observers.add("places-shutdown", function() {
+    for each([query, stmt] in Iterator(this._stmts))
+      stmt.finalize();
+    this.__hsvc = null;
+    this._stmts = [];
+  }, this);
 }
 HistoryStore.prototype = {
   __proto__: Store.prototype,
 
+  __hsvc: null,
   get _hsvc() {
-    let hsvc = Cc["@mozilla.org/browser/nav-history-service;1"].
-      getService(Ci.nsINavHistoryService);
-    hsvc.QueryInterface(Ci.nsIGlobalHistory2);
-    hsvc.QueryInterface(Ci.nsIBrowserHistory);
-    hsvc.QueryInterface(Ci.nsPIPlacesDatabase);
-    this.__defineGetter__("_hsvc", function() hsvc);
-    return hsvc;
+    if (!this.__hsvc)
+      this.__hsvc = Cc["@mozilla.org/browser/nav-history-service;1"].
+                    getService(Ci.nsINavHistoryService).
+                    QueryInterface(Ci.nsIGlobalHistory2).
+                    QueryInterface(Ci.nsIBrowserHistory).
+                    QueryInterface(Ci.nsPIPlacesDatabase);
+    return this.__hsvc;
   },
 
   get _db() {
     return this._hsvc.DBConnection;
   },
 
+  _stmts: [],
+  _getStmt: function(query) {
+    if (query in this._stmts)
+      return this._stmts[query];
+
+    this._log.trace("Creating SQL statement: " + query);
+    return this._stmts[query] = this._db.createStatement(query);
+  },
+
   get _visitStm() {
-    this._log.trace("Creating SQL statement: _visitStm");
-    let stm = this._db.createStatement(
+    return this._getStmt(
       "SELECT visit_type type, visit_date date " +
       "FROM moz_historyvisits_view " +
       "WHERE place_id = (" +
@@ -114,13 +131,10 @@ HistoryStore.prototype = {
         "FROM moz_places_view " +
         "WHERE url = :url) " +
       "ORDER BY date DESC LIMIT 10");
-    this.__defineGetter__("_visitStm", function() stm);
-    return stm;
   },
 
   get _urlStm() {
-    this._log.trace("Creating SQL statement: _urlStm");
-    let stm = this._db.createStatement(
+    return this._getStmt(
       "SELECT url, title, frecency " +
       "FROM moz_places_view " +
       "WHERE id = (" +
@@ -130,20 +144,15 @@ HistoryStore.prototype = {
           "SELECT id " +
           "FROM moz_anno_attributes " +
           "WHERE name = '" + GUID_ANNO + "'))");
-    this.__defineGetter__("_urlStm", function() stm);
-    return stm;
   },
 
   get _allUrlStm() {
-    this._log.trace("Creating SQL statement: _allUrlStm");
-    let stm = this._db.createStatement(
+    return this._getStmt(
       "SELECT url " +
       "FROM moz_places_view " +
       "WHERE last_visit_date > :cutoff_date " +
       "ORDER BY frecency DESC " +
       "LIMIT :max_results");
-    this.__defineGetter__("_allUrlStm", function() stm);
-    return stm;
   },
 
   // See bug 320831 for why we use SQL here