On Wednesday 21 May 2008 07:34, j16sdiz at freenetproject.org wrote:
> 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)
> @@ -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);
So readEntry() unlocks the entry?
> + 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]);
... And if it fails, we have to do that here?
> }
> - 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);
> + }
You should move this into the catch (KeyVerifyException) block. It would be
much clearer what's going on.
> }
>
> 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;
To reduce average seeks? You can't think of a good reason to use a random one?
> }
> 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]);
What's going on here?
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