Author: j16sdiz
Date: 2008-05-21 06:34:43 +0000 (Wed, 21 May 2008)
New Revision: 19998
Modified:
branches/saltedhashstore/freenet/src/freenet/store/SaltedHashFreenetStore.java
Log:
Optimization
- don't unlockEntry in probeEntry0() on found
- write first offset on collision
Modified:
branches/saltedhashstore/freenet/src/freenet/store/SaltedHashFreenetStore.java
===================================================================
---
branches/saltedhashstore/freenet/src/freenet/store/SaltedHashFreenetStore.java
2008-05-21 06:34:22 UTC (rev 19997)
+++
branches/saltedhashstore/freenet/src/freenet/store/SaltedHashFreenetStore.java
2008-05-21 06:34:43 UTC (rev 19998)
@@ -105,6 +105,8 @@
return null;
}
+ unlockEntry(entry.curOffset);
+
try {
StorableBlock block =
entry.getStorableBlock(routingKey, fullKey);
incHits();
@@ -116,6 +118,14 @@
}
}
+ /**
+ * Find and lock an entry with a specific routing key. <strong>You have
to unlock the entry
+ * explicitly yourself!</strong>
+ *
+ * @param routingKey
+ * @return <code>Entry</code> object
+ * @throws IOException
+ */
private Entry probeEntry(byte[] routingKey) throws IOException {
Entry entry = probeEntry0(routingKey, storeSize);
@@ -126,7 +136,7 @@
}
private Entry probeEntry0(byte[] routingKey, long probeStoreSize)
throws IOException {
- Entry entry;
+ Entry entry = null;
long[] offset = getOffsetFromPlainKey(routingKey,
probeStoreSize);
for (int i = 0; i < offset.length; i++) {
@@ -139,15 +149,16 @@
}
try {
entry = readEntry(offset[i], routingKey);
+ if (entry != null)
+ return entry;
} catch (EOFException e) {
// may occur on resize, silent it a bit
Logger.error(this, "EOFException on
probeEntry", e);
continue;
} finally {
- unlockEntry(offset[i]);
+ if (entry == null)
+ unlockEntry(offset[i]);
}
- if (entry != null)
- return entry;
}
return null;
}
@@ -159,9 +170,10 @@
// don't use fetch(), as fetch() would do a miss++/hit++
Entry oldEntry = probeEntry(routingKey);
-
if (oldEntry != null) {
+ long oldOffset = oldEntry.curOffset;
try {
+ try {
StorableBlock oldBlock =
oldEntry.getStorableBlock(routingKey, fullKey);
if (!collisionPossible)
return;
@@ -174,6 +186,14 @@
} catch (KeyVerifyException e) {
// ignore
}
+
+ // Overwrite old offset
+ Entry entry = new Entry(routingKey, header, data);
+ writeEntry(entry, oldOffset);
+ return;
+ } finally {
+ unlockEntry(oldOffset);
+ }
}
Entry entry = new Entry(routingKey, header, data);
@@ -185,7 +205,7 @@
return;
}
try {
- if (isFree(offset[i], entry)) {
+ if (isFree(offset[i])) {
if (logDEBUG)
Logger.debug(this, "probing,
write to i=" + i + ", offset=" + offset[i]);
writeEntry(entry, offset[i]);
@@ -197,19 +217,18 @@
}
}
- // no free blocks?
- int i = random.nextInt(offset.length);
- if (!lockEntry(offset[i])) {
- Logger.error(this, "can't lock entry: " + offset[i]);
+ // no free blocks, overwrite the first one
+ if (!lockEntry(offset[0])) {
+ Logger.error(this, "can't lock entry: " +
offset[0]);
return;
}
try {
if (logDEBUG)
- Logger.debug(this, "collision, write to i=" + i
+ ", offset=" + offset[i]);
- writeEntry(entry, offset[i]);
+ Logger.debug(this, "collision, write to i=0,
offset=" + offset[0]);
+ writeEntry(entry, offset[0]);
incWrites();
} finally {
- unlockEntry(offset[i]);
+ unlockEntry(offset[0]);
}
}
@@ -272,7 +291,7 @@
private byte[] data;
private boolean isEncrypted;
- public long curOffset;
+ public long curOffset = -1;
/**
* Create a new entry
@@ -573,6 +592,8 @@
if (status == -1)
throw new EOFException();
} while (bf.hasRemaining());
+
+ entry.curOffset = offset;
}
/**
@@ -594,18 +615,16 @@
}
/**
- * Check if a block is free or occupied by a specific routing key
+ * Check if a block is free
*
* @param offset
- * @param entry
- * entry, maybe <code>null</code>
* @throws IOException
*/
- private boolean isFree(long offset, Entry entry) throws IOException {
+ private boolean isFree(long offset) throws IOException {
int split = (int) (offset % FILE_SPLIT);
- long rawOffset = (offset / FILE_SPLIT) * entryTotalLength;
+ long rawOffset = (offset / FILE_SPLIT) * entryTotalLength +
0x30;
- ByteBuffer bf = ByteBuffer.allocate((int) 0x38);
+ ByteBuffer bf = ByteBuffer.allocate((int) 0x8);
do {
int status = storeFC[split].read(bf, rawOffset +
bf.position());
@@ -613,17 +632,7 @@
throw new EOFException();
} while (bf.hasRemaining());
- if ((bf.getLong(0x30) & ENTRY_FLAG_OCCUPIED) == 0) {
- // free
- return true;
- } else if (entry != null) {
- // check digested key
- byte[] digestedRoutingKey = new byte[0x20];
- bf.position(0);
- bf.get(digestedRoutingKey);
- return Arrays.equals(digestedRoutingKey,
entry.getDigestedRoutingKey());
- }
- return false;
+ return ((bf.getLong(0) & ENTRY_FLAG_OCCUPIED) == 0);
}
private void flushAndClose() {
@@ -1006,7 +1015,7 @@
if (!lockEntry(newOffset[i])) // lock
continue;
try {
- if (isFree(newOffset[i],
entry)) {
+ if (isFree(newOffset[i])) {
if (logDEBUG)
Logger
.debug(this, "Put back old item: "
@@ -1070,7 +1079,7 @@
long occupied = 0;
while (sampled < numSample) {
try {
- if (!isFree(samplePos, null)) {
+ if (!isFree(samplePos)) {
occupied++;
}
sampled++;
