From 87da4b78ab08f3fb3eaeecf0a28c6a57a45acbab Mon Sep 17 00:00:00 2001
From: zzz <zzz@mail.i2p>
Date: Thu, 23 Feb 2012 19:06:21 +0000
Subject: [PATCH] add negative cache to BFNS
---
.../client/naming/BlockfileNamingService.java | 22 ++++++++++++++++++-
.../i2p/client/naming/DummyNamingService.java | 2 +-
2 files changed, 22 insertions(+), 2 deletions(-)
diff --git a/core/java/src/net/i2p/client/naming/BlockfileNamingService.java b/core/java/src/net/i2p/client/naming/BlockfileNamingService.java
index 6d0e1bb6f3..8172ee7fd2 100644
--- a/core/java/src/net/i2p/client/naming/BlockfileNamingService.java
+++ b/core/java/src/net/i2p/client/naming/BlockfileNamingService.java
@@ -92,6 +92,7 @@ public class BlockfileNamingService extends DummyNamingService {
private final RAIFile _raf;
private final List<String> _lists;
private final List<InvalidEntry> _invalid;
+ private final Map<String, String> _negativeCache;
private volatile boolean _isClosed;
private final boolean _readOnly;
private boolean _needsUpgrade;
@@ -118,6 +119,9 @@ public class BlockfileNamingService extends DummyNamingService {
private static final String PROP_ADDED = "a";
private static final String PROP_SOURCE = "s";
+ private static final String DUMMY = "";
+ private static final int NEGATIVE_CACHE_SIZE = 32;
+
/**
* Opens the database at hostsdb.blockfile or creates a new
* one and imports entries from hosts.txt, userhosts.txt, and privatehosts.txt.
@@ -132,6 +136,7 @@ public class BlockfileNamingService extends DummyNamingService {
super(context);
_lists = new ArrayList();
_invalid = new ArrayList();
+ _negativeCache = new LHM(NEGATIVE_CACHE_SIZE);
BlockFile bf = null;
RAIFile raf = null;
boolean readOnly = false;
@@ -628,6 +633,10 @@ public class BlockfileNamingService extends DummyNamingService {
}
String key = hostname.toLowerCase(Locale.US);
+ synchronized(_negativeCache) {
+ if (_negativeCache.get(key) != null)
+ return null;
+ }
synchronized(_bf) {
if (_isClosed)
return null;
@@ -650,8 +659,13 @@ public class BlockfileNamingService extends DummyNamingService {
}
deleteInvalid();
}
- if (d != null)
+ if (d != null) {
putCache(hostname, d);
+ } else {
+ synchronized(_negativeCache) {
+ _negativeCache.put(key, DUMMY);
+ }
+ }
return d;
}
@@ -683,6 +697,9 @@ public class BlockfileNamingService extends DummyNamingService {
return false;
}
String key = hostname.toLowerCase(Locale.US);
+ synchronized(_negativeCache) {
+ _negativeCache.remove(key);
+ }
String listname = FALLBACK_LIST;
Properties props = new Properties();
props.setProperty(PROP_ADDED, Long.toString(_context.clock().now()));
@@ -1031,6 +1048,9 @@ public class BlockfileNamingService extends DummyNamingService {
}
_isClosed = true;
}
+ synchronized(_negativeCache) {
+ _negativeCache.clear();
+ }
clearCache();
}
diff --git a/core/java/src/net/i2p/client/naming/DummyNamingService.java b/core/java/src/net/i2p/client/naming/DummyNamingService.java
index 21f8a7c7cc..63c6cf2648 100644
--- a/core/java/src/net/i2p/client/naming/DummyNamingService.java
+++ b/core/java/src/net/i2p/client/naming/DummyNamingService.java
@@ -116,7 +116,7 @@ class DummyNamingService extends NamingService {
}
}
- private static class LHM<K, V> extends LinkedHashMap<K, V> {
+ protected static class LHM<K, V> extends LinkedHashMap<K, V> {
private final int _max;
public LHM(int max) {
--
GitLab