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desruisseaux pushed a commit to branch geoapi-4.0
in repository https://gitbox.apache.org/repos/asf/sis.git
The following commit(s) were added to refs/heads/geoapi-4.0 by this push:
new 38626a67da Simplify the way to determine if a "band select" is an
identity operation.
38626a67da is described below
commit 38626a67dab39f7e97d6c5444d8f3614212c2e74
Author: Martin Desruisseaux <martin.desruisse...@geomatys.com>
AuthorDate: Wed Apr 12 19:26:42 2023 +0200
Simplify the way to determine if a "band select" is an identity operation.
---
.../org/apache/sis/image/BandAggregateImage.java | 5 +--
.../org/apache/sis/image/MultiSourceLayout.java | 4 +-
.../sis/internal/coverage/MultiSourceArgument.java | 50 ++++++++++------------
3 files changed, 25 insertions(+), 34 deletions(-)
diff --git
a/core/sis-feature/src/main/java/org/apache/sis/image/BandAggregateImage.java
b/core/sis-feature/src/main/java/org/apache/sis/image/BandAggregateImage.java
index 9583193eae..89b4532fa8 100644
---
a/core/sis-feature/src/main/java/org/apache/sis/image/BandAggregateImage.java
+++
b/core/sis-feature/src/main/java/org/apache/sis/image/BandAggregateImage.java
@@ -163,10 +163,7 @@ class BandAggregateImage extends MultiSourceImage {
* If we need to use `BandSelectImage` for reordering bands, the
`unwrap` argument
* MUST be false for avoiding `StackOverflowError` with never-ending
recusivity.
*/
- if (layout.bandSelect != null) {
- result = BandSelectImage.create(result, false, layout.bandSelect);
- }
- return result;
+ return BandSelectImage.create(result, false, layout.bandSelect);
}
/**
diff --git
a/core/sis-feature/src/main/java/org/apache/sis/image/MultiSourceLayout.java
b/core/sis-feature/src/main/java/org/apache/sis/image/MultiSourceLayout.java
index 42c005dcc1..a49f466d96 100644
--- a/core/sis-feature/src/main/java/org/apache/sis/image/MultiSourceLayout.java
+++ b/core/sis-feature/src/main/java/org/apache/sis/image/MultiSourceLayout.java
@@ -76,7 +76,7 @@ final class MultiSourceLayout extends ImageLayout {
private final int[][] bandsPerSource;
/**
- * Final band select operation to apply on the aggregated result, or
{@code null} if none.
+ * Final band select operation to apply on the aggregated result.
*/
final int[] bandSelect;
@@ -219,7 +219,7 @@ final class MultiSourceLayout extends ImageLayout {
*
* @param sources images to combine, in order.
* @param bandsPerSource bands to use for each source image, in
order. May contain {@code null} elements.
- * @param bandSelect final band select operation to apply on the
aggregated result, or {@code null}.
+ * @param bandSelect final band select operation to apply on the
aggregated result.
* @param domain bounds of the image to create.
* @param preferredTileSize the preferred tile size.
* @param commonDataType data type of the combined image.
diff --git
a/core/sis-feature/src/main/java/org/apache/sis/internal/coverage/MultiSourceArgument.java
b/core/sis-feature/src/main/java/org/apache/sis/internal/coverage/MultiSourceArgument.java
index 8c53d447a0..520ab3479a 100644
---
a/core/sis-feature/src/main/java/org/apache/sis/internal/coverage/MultiSourceArgument.java
+++
b/core/sis-feature/src/main/java/org/apache/sis/internal/coverage/MultiSourceArgument.java
@@ -17,7 +17,6 @@
package org.apache.sis.internal.coverage;
import java.util.List;
-import java.util.BitSet;
import java.util.Arrays;
import java.util.ArrayList;
import java.util.HashMap;
@@ -84,14 +83,8 @@ public final class MultiSourceArgument<S> {
private int[][] bandsPerSource;
/**
- * Number of bands per source. This array is built by {@code validate(…)}
methods.
- */
- private int[] numBandsPerSource;
-
- /**
- * Whether the bands selection for a given source is an identity operation.
- * For a source at index <var>i</var>, the bit <var>i</var> is set to 1 if
- * {@code bandsPerSource[i]} is a sequence selecting all bands in order.
+ * Number of bands for each source source. This information is necessary
+ * for determining whether a selection of bands is an identity operation.
*
* <p>This field is initially null and assigned on validation.
* Consequently this field can also be used for checking whether
@@ -100,7 +93,7 @@ public final class MultiSourceArgument<S> {
* @see #validate(Function)
* @see #validate(ToIntFunction)
*/
- private BitSet isIdentity;
+ private int[] numBandsPerSource;
/**
* Number of valid elements in {@link #sources} array after empty elements
have been removed.
@@ -164,7 +157,6 @@ public final class MultiSourceArgument<S> {
}
this.sources = sources.clone();
this.bandsPerSource = bandsPerSource;
- numBandsPerSource = new int[sources.length];
}
/**
@@ -174,7 +166,7 @@ public final class MultiSourceArgument<S> {
* {@code false} if the caller expects validation to not
be done yet.
*/
private void checkValidationState(final boolean expected) {
- if ((isIdentity == null) == expected) {
+ if ((numBandsPerSource == null) == expected) {
throw new IllegalStateException();
}
}
@@ -306,7 +298,7 @@ public final class MultiSourceArgument<S> {
*/
private void validate(final Function<S, List<SampleDimension>> getter,
final ToIntFunction<S> counter) {
final HashMap<Integer,int[]> identityPool = new HashMap<>();
- isIdentity = new BitSet();
+ numBandsPerSource = new int[sources.length];
next: for (int i=0; i<sources.length; i++) { // `sources.length`
may change during the loop.
S source;
int[] selected;
@@ -351,7 +343,6 @@ next: for (int i=0; i<sources.length; i++) { //
`sources.length` may
}
}
if (range.isIdentity()) {
- isIdentity.set(validatedSourceCount);
int[] previous = identityPool.putIfAbsent(numSourceBands,
selected);
if (previous != null) selected = previous;
}
@@ -376,13 +367,9 @@ next: for (int i=0; i<sources.length; i++) { //
`sources.length` may
* implementations rely on this optimization.
*
* @return the bands to specify in a "band select" operation for
reconstituting the user-specified band order.
- * If all band selections are identity operations, then this
method returns {@code null}.
*/
public int[] mergeDuplicatedSources() {
checkValidationState(true);
- if (isIdentity.cardinality() == validatedSourceCount) {
- return null;
- }
/*
* Merge together the bands of all sources that are repeated.
* The band indices are stored in 64 bits tuples as below:
@@ -411,7 +398,6 @@ next: for (int i=0; i<sources.length; i++) { //
`sources.length` may
final S source = sources[i];
final long[] tuples = mergedBands.remove(source);
if (tuples != null) {
- boolean noop = isIdentity.get(i);
int[] selected = bandsPerSource[i];
if (tuples.length > selected.length) {
/*
@@ -422,7 +408,6 @@ next: for (int i=0; i<sources.length; i++) { //
`sources.length` may
*/
Arrays.sort(tuples);
selected = new int[tuples.length];
- noop = (tuples.length == numBandsPerSource[i]) &&
ArraysExt.isRange(0, selected);
}
/*
* Rewrite the `selected` array with the potentially merged
bands.
@@ -436,15 +421,11 @@ next: for (int i=0; i<sources.length; i++) {
// `sources.length` may
selected[j] = sourceBand;
}
targetBand += tuples.length;
+ numBandsPerSource[validatedSourceCount] = numBandsPerSource[i];
bandsPerSource[validatedSourceCount] = selected;
- isIdentity.set(validatedSourceCount, noop);
sources[validatedSourceCount++] = source;
}
}
- final int n = isIdentity.length();
- if (n > validatedSourceCount) {
- isIdentity.clear(validatedSourceCount, n);
- }
return reordered;
}
@@ -455,7 +436,18 @@ next: for (int i=0; i<sources.length; i++) { //
`sources.length` may
*/
public boolean isIdentity() {
checkValidationState(true);
- return validatedSourceCount == 1 && isIdentity.cardinality() == 1;
+ return validatedSourceCount == 1 && isIdentity(0);
+ }
+
+ /**
+ * Returns {@code true} if the band selection at the specified index is an
identity operation.
+ *
+ * @param i index of a source.
+ * @return whether band selection for that source is an identity operation.
+ */
+ private boolean isIdentity(final int i) {
+ final int[] selected = bandsPerSource[i];
+ return selected.length == numBandsPerSource[i] && ArraysExt.isRange(0,
selected);
}
/**
@@ -481,8 +473,10 @@ next: for (int i=0; i<sources.length; i++) { //
`sources.length` may
checkValidationState(true);
bandsPerSource = ArraysExt.resize(bandsPerSource,
validatedSourceCount);
if (identityAsNull) {
- for (int i=0; (i = isIdentity.nextSetBit(i)) >= 0; i++) {
- bandsPerSource[i] = null;
+ for (int i=0; i<validatedSourceCount; i++) {
+ if (isIdentity(i)) {
+ bandsPerSource[i] = null;
+ }
}
}
return bandsPerSource;
