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Micro-optimize DeltaWindow maxMemory test to be != 0 

Instead of using a compare-with-0 use a does not equal 0.
javac bytecode has a special instruction for this, as it
is very common in software. We can assume the JIT knows
how to efficiently translate the opcode to machine code,
and processors can do != 0 very quickly.

Change-Id: Idb84c1d744d2874517fd4bfa1db390e2dbf64eac
This commit is contained in:
Shawn Pearce 2013-04-10 22:21:18 -07:00
parent 4db695c1c6
commit 6903fa4a34
1 changed files with 5 additions and 8 deletions
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13
org.eclipse.jgit/src/org/eclipse/jgit/internal/storage/pack/DeltaWindow.java
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@ -62,11 +62,8 @@ final class DeltaWindow {
private static final int NEXT_SRC = 1; private static final int NEXT_SRC = 1;
private final PackConfig config; private final PackConfig config;
private final DeltaCache deltaCache; private final DeltaCache deltaCache;
private final ObjectReader reader; private final ObjectReader reader;
private final ProgressMonitor monitor; private final ProgressMonitor monitor;
private final DeltaWindowEntry[] window; private final DeltaWindowEntry[] window;
@ -136,7 +133,7 @@ final class DeltaWindow {
for (int i = 0; i < window.length; i++) for (int i = 0; i < window.length; i++)
window[i] = new DeltaWindowEntry(); window[i] = new DeltaWindowEntry();
maxMemory = config.getDeltaSearchMemoryLimit(); maxMemory = Math.max(0, config.getDeltaSearchMemoryLimit());
maxDepth = config.getMaxDeltaDepth(); maxDepth = config.getMaxDeltaDepth();
} }
@ -172,7 +169,7 @@ void search() throws IOException {
next = toSearch[cur++]; next = toSearch[cur++];
} }
res = window[resSlot]; res = window[resSlot];
if (0 < maxMemory) { if (maxMemory != 0) {
clear(res); clear(res);
int tail = next(resSlot); int tail = next(resSlot);
final long need = estimateSize(next); final long need = estimateSize(next);
@ -480,7 +477,7 @@ private DeltaIndex index(DeltaWindowEntry ent)
e.setObjectId(ent.object); e.setObjectId(ent.object);
throw e; throw e;
} }
if (0 < maxMemory) if (maxMemory != 0)
loaded += idx.getIndexSize() - idx.getSourceSize(); loaded += idx.getIndexSize() - idx.getSourceSize();
ent.index = idx; ent.index = idx;
} }
@ -494,7 +491,7 @@ private byte[] buffer(DeltaWindowEntry ent) throws MissingObjectException,
checkLoadable(ent, ent.size()); checkLoadable(ent, ent.size());
buf = PackWriter.buffer(config, reader, ent.object); buf = PackWriter.buffer(config, reader, ent.object);
if (0 < maxMemory) if (maxMemory != 0)
loaded += buf.length; loaded += buf.length;
ent.buffer = buf; ent.buffer = buf;
} }
@ -502,7 +499,7 @@ private byte[] buffer(DeltaWindowEntry ent) throws MissingObjectException,
} }
private void checkLoadable(DeltaWindowEntry ent, long need) { private void checkLoadable(DeltaWindowEntry ent, long need) {
if (maxMemory <= 0) if (maxMemory == 0)
return; return;
int tail = next(resSlot); int tail = next(resSlot);