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Performance improvements (#746)

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* Misc minor performance improvements

* Use more concise loop syntax

* Use more concise Collection sort syntax

* Use StringUtils pad methods

* Optimize some loops and double-map-lookups

* Optimize array instantiation

There are two styles to convert a collection to an array: either
using a pre-sized array (like c.toArray(new String[c.size()])) or
using an empty array (like c.toArray(new String[0]).

In older Java versions using pre-sized array was recommended,
as the reflection call which is necessary to create an array
of proper size was quite slow. However since late updates of
OpenJDK 6 this call was intrinsified, making the performance
of the empty array version the same and sometimes even better,
compared to the pre-sized version. Also passing pre-sized array
is dangerous for a concurrent or synchronized collection as
a data race is possible between the size and toArray call
which may result in extra nulls at the end of the array,
if the collection was concurrently shrunk during the operation.

* Cleanup string concatenation

* Use EnumMap where possible

* Use FastMath instead of Math

* Initialize complex things only once

* Reduce method size to aloow more JIT inlining

* remove map of short->float

* Move field to local variable

* Cleanup Map lookup

Co-authored-by: Rob Ekl <xwq876@zebra.com>
This commit is contained in:
robekl
2020-04-25 07:57:56 -04:00
committed by GitHub
parent 649258bd2b
commit 39f6d6c831
186 changed files with 2840 additions and 3464 deletions
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3
src/main/java/io/github/dsheirer/dsp/fsk/SampleBuffer.java
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@@ -15,6 +15,7 @@
******************************************************************************/
package io.github.dsheirer.dsp.fsk;
import org.apache.commons.math3.util.FastMath;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
@@ -47,7 +48,7 @@ public class SampleBuffer
mIntegerSamplesPerSymbol = (int)(samplesPerSymbol + 0.5f);
mHalfIntegerSamplesPerSymbol = (int)(samplesPerSymbol / 2.0f + 0.5f);
mMidSymbolSamplingPoint = samplesPerSymbol + mHalfIntegerSamplesPerSymbol;
mTwiceSamplesPerSymbol = (int)Math.floor(2.0 * samplesPerSymbol);
mTwiceSamplesPerSymbol = (int) FastMath.floor(2.0 * samplesPerSymbol);
mDelayLine = new boolean[2 * mTwiceSamplesPerSymbol];
}

6
src/main/java/io/github/dsheirer/dsp/fsk/ZeroCrossingErrorDetector.java
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@@ -15,6 +15,8 @@
******************************************************************************/
package io.github.dsheirer.dsp.fsk;
import org.apache.commons.math3.util.FastMath;
/**
* Zero crossing error detector. Provides symbol timing error correction values by detecting zero-crossings within
* each symbol period. Ideally there should be only 0 or 1 zero crossings within each symbol period. However, when
@@ -45,7 +47,7 @@ public class ZeroCrossingErrorDetector
*/
public ZeroCrossingErrorDetector(float samplesPerSymbol)
{
mBuffer = new boolean[(int)Math.ceil(samplesPerSymbol)];
mBuffer = new boolean[(int)FastMath.ceil(samplesPerSymbol)];
// mZeroCrossingIdeal = mBuffer.length - 1.5f - (samplesPerSymbol / 2.0f); //Preserve this for LTR
mZeroCrossingIdeal = (samplesPerSymbol / 2.0f);
}
@@ -108,7 +110,7 @@ public class ZeroCrossingErrorDetector
float errorDistanceOne = mZeroCrossingIdeal - mZeroCrossingOne;
float errorDistanceTwo = mZeroCrossingCount - mZeroCrossingTwo;
if(Math.abs(errorDistanceOne) < Math.abs(errorDistanceTwo))
if(FastMath.abs(errorDistanceOne) < FastMath.abs(errorDistanceTwo))
{
mDetectedZeroCrossing = mZeroCrossingOne;
}