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Reduce allocations and copying when extracting PNGs created by Mac 

This logic is covered by the TestHSSFPictureData#testMacPicture() test.

git-svn-id: https://svn.apache.org/repos/asf/poi/trunk@1893779 13f79535-47bb-0310-9956-ffa450edef68
This commit is contained in:
Marius Volkhart 2021-10-01 12:07:10 +00:00
parent 9994a4286d
commit 1273415df3
1 changed files with 7 additions and 12 deletions
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19
poi/src/main/java/org/apache/poi/sl/image/ImageHeaderPNG.java
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@ -18,19 +18,15 @@
package org.apache.poi.sl.image;
import java.io.IOException;
import java.io.InputStream;
import org.apache.commons.io.input.UnsynchronizedByteArrayInputStream;
import org.apache.poi.poifs.filesystem.FileMagic;
import org.apache.poi.util.IOUtils;
import org.apache.poi.util.RecordFormatException;
import java.util.Arrays;
public final class ImageHeaderPNG {
private static final int MAGIC_OFFSET = 16;
private byte[] data;
private final byte[] data;
/**
* @param data The raw image data
@ -46,12 +42,11 @@ public final class ImageHeaderPNG {
public byte[] extractPNG() {
//
//Just cut it off!.
try (InputStream is = new UnsynchronizedByteArrayInputStream(data)) {
if (is.skip(MAGIC_OFFSET) == MAGIC_OFFSET && FileMagic.valueOf(is) == FileMagic.PNG) {
return IOUtils.toByteArray(is);
if (data.length >= MAGIC_OFFSET) {
byte[] newData = Arrays.copyOfRange(data, MAGIC_OFFSET, data.length);
if (FileMagic.valueOf(newData) == FileMagic.PNG) {
return newData;
}
} catch (IOException e) {
throw new RecordFormatException("Unable to parse PNG header", e);
}
return data;