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Apparently the dummy transaction hasn't been necessary since 2007 or so

Browse Source 
https://bugzilla.mozilla.org/show_bug.cgi?id=380345
This commit is contained in:
Dan Stillman 2013-02-16 23:06:31 -05:00
parent e7d7d2a943
commit 50a0b2d36c
2 changed files with 2 additions and 76 deletions
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76
chrome/content/zotero/xpcom/db.js
View File

@ -23,7 +23,8 @@
***** END LICENSE BLOCK *****
*/
// Exclusive locking mode (default) prevents access to Zotero database while Firefox is open.
// Exclusive locking mode (default) prevents access to Zotero database while Zotero is open
// and speeds up DB access (http://www.sqlite.org/pragma.html#pragma_locking_mode).
// Normal mode is more convenient for development, but risks database corruption, particularly if
// the same database is accessed simultaneously by multiple Zotero instances.
const DB_LOCK_EXCLUSIVE = true;
@ -793,7 +794,6 @@ Zotero.DBConnection.prototype.checkException = function (e) {
Zotero.DBConnection.prototype.closeDatabase = function () {
if(this._connection) {
this.stopDummyStatement();
this._connection.close();
return true;
}
@ -875,14 +875,10 @@ Zotero.DBConnection.prototype.backupDatabase = function (suffix) {
// Turn off DB locking before backup and reenable after, since otherwise
// the lock is lost
var hadDummyStatement = !!this._dummyStatement;
try {
if (DB_LOCK_EXCLUSIVE) {
this.query("PRAGMA locking_mode=NORMAL");
}
if (hadDummyStatement) {
this.stopDummyStatement();
}
var store = Components.classes["@mozilla.org/storage/service;1"].
getService(Components.interfaces.mozIStorageService);
@ -897,9 +893,6 @@ Zotero.DBConnection.prototype.backupDatabase = function (suffix) {
if (DB_LOCK_EXCLUSIVE) {
this.query("PRAGMA locking_mode=EXCLUSIVE");
}
if (hadDummyStatement) {
this.startDummyStatement();
}
}
// Opened database files can't be moved on Windows, so we have to skip
@ -968,71 +961,6 @@ Zotero.DBConnection.prototype.backupDatabase = function (suffix) {
}
/*
* Keep the SQLite shared cache live between transactions with a dummy statement,
* which speeds up DB access dramatically (at least on Windows and Linux--OS X
* seems to be much faster already, perhaps due to its own disk cache)
*
* This is the same technique used by Mozilla code. The one downside is that it
* prevents schema changes, so this is called after schema updating. If the
* schema really needs to be updated at another point, use stopDummyStatement().
*
* See http://developer.mozilla.org/en/docs/Storage:Performance for more info.
*/
Zotero.DBConnection.prototype.startDummyStatement = function () {
try {
if (!this._dummyConnection) {
this._debug("Opening database '" + this._dbName + "' for dummy statement");
// Get the storage service
var store = Components.classes["@mozilla.org/storage/service;1"].
getService(Components.interfaces.mozIStorageService);
var file = Zotero.getZoteroDatabase(this._dbName);
this._dummyConnection = store.openDatabase(file);
}
if (this._dummyStatement) {
Zotero.debug("Dummy statement is already open");
return;
}
Zotero.debug("Initializing dummy statement for '" + this._dbName + "'");
var sql = "CREATE TABLE IF NOT EXISTS zoteroDummyTable (id INTEGER PRIMARY KEY)";
this._dummyConnection.executeSimpleSQL(sql);
sql = "INSERT OR IGNORE INTO zoteroDummyTable VALUES (1)";
this._dummyConnection.executeSimpleSQL(sql);
sql = "SELECT id FROM zoteroDummyTable LIMIT 1"
this._dummyStatement = this._dummyConnection.createStatement(sql)
this._dummyStatement.executeStep()
}
catch (e) {
Components.utils.reportError(e);
Zotero.debug(e);
}
}
/*
* Stop the dummy statement temporarily to allow for schema changess
*
* The statement needs to be started again or performance will suffer.
*/
Zotero.DBConnection.prototype.stopDummyStatement = function () {
if (!this._dummyStatement) {
return;
}
Zotero.debug("Stopping dummy statement for '" + this._dbName + "'");
this._dummyStatement.finalize();
this._dummyConnection.close();
delete this._dummyConnection;
delete this._dummyStatement;
}
/**
* Determine the necessary data type for SQLite parameter binding
*

2
chrome/content/zotero/xpcom/zotero.js
View File

@ -640,8 +640,6 @@ Components.utils.import("resource://gre/modules/Services.jsm");
}
}
Zotero.DB.startDummyStatement();
// Populate combined tables for custom types and fields -- this is likely temporary
if (!upgraded && !updated) {
Zotero.Schema.updateCustomTables();