AfflictionNetworks/samskivert
1
0
Fork 0
Code Issues Pull Requests Actions Packages Projects Releases Wiki Activity

Fixed the column names; added proper synchronization to ensure that two

Browse Source 
threads don't initiate a site table reload simultaneously; made our
references volatile to ensure that when they are changed, other threads
can see the updates.

Arguably, if someone were to insert a site while another thread was
enumerating them, it would throw a ConcurrentModificationException, but
sites are only enumerated and inserted by management code, not in the
normal order of business, so we'll let that slide.


git-svn-id: https://samskivert.googlecode.com/svn/trunk@1302 6335cc39-0255-0410-8fd6-9bcaacd3b74c
This commit is contained in:
mdb
2003-11-13 17:28:58 +00:00
parent 57c1e5e57d
commit 246e26f6e1
1 changed files with 15 additions and 10 deletions
Download Patch File Download Diff File Expand all files Collapse all files
projects/samskivert/src/java/com/samskivert/servlet/JDBCTableSiteIdentifier.java
+15 -10
View File
@@ -1,5 +1,5 @@
// //
// $Id: JDBCTableSiteIdentifier.java,v 1.9 2003/11/13 17:05:09 mdb Exp $ // $Id: JDBCTableSiteIdentifier.java,v 1.10 2003/11/13 17:28:58 mdb Exp $
// //
// samskivert library - useful routines for java programs // samskivert library - useful routines for java programs
// Copyright (C) 2001 Michael Bayne // Copyright (C) 2001 Michael Bayne
@@ -158,8 +158,13 @@ public class JDBCTableSiteIdentifier implements SiteIdentifier
protected void checkReloadSites () protected void checkReloadSites ()
{ {
long now = System.currentTimeMillis(); long now = System.currentTimeMillis();
if (now - _lastReload > RELOAD_INTERVAL) { boolean reload = false;
_lastReload = now; synchronized (this) {
if (reload = (now - _lastReload > RELOAD_INTERVAL)) {
_lastReload = now;
}
}
if (reload) {
try { try {
_repo.refreshSiteData(); _repo.refreshSiteData();
} catch (PersistenceException pe) { } catch (PersistenceException pe) {
@@ -193,7 +198,7 @@ public class JDBCTableSiteIdentifier implements SiteIdentifier
Statement stmt = conn.createStatement(); Statement stmt = conn.createStatement();
try { try {
// first load up the list of sites // first load up the list of sites
String query = "select siteId, stringId from sites"; String query = "select siteId, siteString from sites";
ResultSet rs = stmt.executeQuery(query); ResultSet rs = stmt.executeQuery(query);
HashIntMap sites = new HashIntMap(); HashIntMap sites = new HashIntMap();
HashMap strings = new HashMap(); HashMap strings = new HashMap();
@@ -213,10 +218,10 @@ public class JDBCTableSiteIdentifier implements SiteIdentifier
mappings.add(new SiteMapping(rs.getInt(2), mappings.add(new SiteMapping(rs.getInt(2),
rs.getString(1))); rs.getString(1)));
} }
_mappings = mappings;
// sort the mappings in order of specificity // sort the mappings in order of specificity
Collections.sort(_mappings); Collections.sort(mappings);
_mappings = mappings;
// Log.info("Loaded site mappings " + // Log.info("Loaded site mappings " +
// StringUtil.toString(_mappings) + "."); // StringUtil.toString(_mappings) + ".");
@@ -241,7 +246,7 @@ public class JDBCTableSiteIdentifier implements SiteIdentifier
PreparedStatement stmt = null; PreparedStatement stmt = null;
try { try {
stmt = conn.prepareStatement( stmt = conn.prepareStatement(
"insert into sites (stringId) VALUES (?)"); "insert into sites (siteString) VALUES (?)");
stmt.setString(1, site.siteString); stmt.setString(1, site.siteString);
if (1 != stmt.executeUpdate()) { if (1 != stmt.executeUpdate()) {
throw new PersistenceException( throw new PersistenceException(
@@ -310,15 +315,15 @@ public class JDBCTableSiteIdentifier implements SiteIdentifier
/** The list of domain to site identifier mappings ordered from most /** The list of domain to site identifier mappings ordered from most
* specific domain to least specific. */ * specific domain to least specific. */
protected ArrayList _mappings = new ArrayList(); protected volatile ArrayList _mappings = new ArrayList();
/** The mapping from integer site identifiers to string site /** The mapping from integer site identifiers to string site
* identifiers. */ * identifiers. */
protected HashIntMap _sitesById = new HashIntMap(); protected volatile HashIntMap _sitesById = new HashIntMap();
/** The mapping from string site identifiers to integer site /** The mapping from string site identifiers to integer site
* identifiers. */ * identifiers. */
protected HashMap _sitesByString = new HashMap(); protected volatile HashMap _sitesByString = new HashMap();
/** Used to periodically reload our site data. */ /** Used to periodically reload our site data. */
protected long _lastReload; protected long _lastReload;