Cache PdfReader.getPdfAConformanceLevel result for non pdfA docs

DEVSIX-7188

Author: Vitali Prudnikovich

kernel/src/main/java/com/itextpdf/kernel/pdf/PdfReader.java

@@ -61,6 +61,9 @@ This file is part of the iText (R) project.
 import com.itextpdf.kernel.exceptions.XrefCycledReferencesException;
 import com.itextpdf.kernel.pdf.filters.FilterHandlers;
 import com.itextpdf.kernel.pdf.filters.IFilterHandler;
+import com.itextpdf.kernel.xmp.XMPException;
+import com.itextpdf.kernel.xmp.XMPMeta;
+import com.itextpdf.kernel.xmp.XMPMetaFactory;
 
 import java.io.ByteArrayInputStream;
 import java.io.Closeable;
@@ -70,10 +73,6 @@ This file is part of the iText (R) project.
 import java.util.HashSet;
 import java.nio.charset.StandardCharsets;
 import java.util.Map;
-
-import com.itextpdf.kernel.xmp.XMPException;
-import com.itextpdf.kernel.xmp.XMPMetaFactory;
-
 import java.util.Set;
 import org.slf4j.Logger;
 import org.slf4j.LoggerFactory;
@@ -106,6 +105,8 @@ public class PdfReader implements Closeable {
     //indicate nearest first Indirect reference object which includes current reading the object, using for PdfString decrypt
     private PdfIndirectReference currentIndirectReference;
 
+    private XMPMeta xmpMeta;
+
     protected PdfTokenizer tokens;
     protected PdfEncryption decrypt;
 
@@ -641,14 +642,18 @@ public PdfAConformanceLevel getPdfAConformanceLevel() {
             if (pdfDocument == null || !pdfDocument.getXref().isReadingCompleted()) {
                 throw new PdfException(KernelExceptionMessageConstant.DOCUMENT_HAS_NOT_BEEN_READ_YET);
             }
-            if (pdfDocument.getXmpMetadata() != null) {
-                try {
-                    pdfAConformanceLevel = PdfAConformanceLevel.getConformanceLevel(
-                            XMPMetaFactory.parseFromBuffer(pdfDocument.getXmpMetadata()));
-                } catch (XMPException ignored) {
+
+            try {
+                if (xmpMeta == null && pdfDocument.getXmpMetadata() != null) {
+                    xmpMeta = XMPMetaFactory.parseFromBuffer(pdfDocument.getXmpMetadata());
+                }
+                if (xmpMeta != null) {
+                    pdfAConformanceLevel = PdfAConformanceLevel.getConformanceLevel(xmpMeta);
                 }
+            } catch (XMPException ignored) {
             }
         }
+
         return pdfAConformanceLevel;
     }
 

kernel/src/test/java/com/itextpdf/kernel/pdf/PdfReaderTest.java

@@ -60,7 +60,11 @@ This file is part of the iText (R) project.
 import com.itextpdf.kernel.exceptions.XrefCycledReferencesException;
 import com.itextpdf.kernel.pdf.PdfReader.StrictnessLevel;
 import com.itextpdf.kernel.utils.CompareTool;
+import com.itextpdf.kernel.xmp.XMPConst;
 import com.itextpdf.kernel.xmp.XMPException;
+import com.itextpdf.kernel.xmp.XMPMeta;
+import com.itextpdf.kernel.xmp.XMPMetaFactory;
+import com.itextpdf.kernel.xmp.options.PropertyOptions;
 import com.itextpdf.test.AssertUtil;
 import com.itextpdf.test.ExtendedITextTest;
 import com.itextpdf.test.annotations.LogMessage;
@@ -2298,6 +2302,12 @@ public void getPdfAConformanceLevelPdfDocumentNotReadTest() throws IOException {
         Assert.assertEquals(KernelExceptionMessageConstant.DOCUMENT_HAS_NOT_BEEN_READ_YET, e.getMessage());
     }
 
+    @Test
+    public void getPdfAConformanceLevelNoMetadataTest() throws IOException {
+        PdfDocument pdfDoc = new PdfDocument(new PdfReader(new ByteArrayInputStream(createPdfDocumentForTest())));
+        Assert.assertNull(pdfDoc.getReader().getPdfAConformanceLevel());
+    }
+
     @Test
     public void xrefStreamPointsItselfTest() throws IOException {
         String fileName = SOURCE_FOLDER + "xrefStreamPointsItself.pdf";
@@ -2636,6 +2646,26 @@ public void tokensPositionIsNotUpdatedWhileReadingLengthTest() throws IOExceptio
         }
     }
 
+    @Test
+    public void conformanceLevelCacheTest() throws IOException, XMPException {
+        String filename = DESTINATION_FOLDER + "simpleDoc.pdf";
+
+        PdfDocument pdfDoc = new PdfDocument(new PdfWriter(filename));
+        XMPMeta xmp = XMPMetaFactory.create();
+        xmp.appendArrayItem(XMPConst.NS_DC, "subject",
+                new PropertyOptions(PropertyOptions.ARRAY), "Hello World", null);
+        pdfDoc.setXmpMetadata(xmp);
+
+        pdfDoc.addNewPage();
+        pdfDoc.close();
+
+        TestPdfDocumentCache pdfTestDoc = new TestPdfDocumentCache(new PdfReader(filename));
+        for(int i = 0; i < 1000; ++i) {
+            pdfTestDoc.getReader().getPdfAConformanceLevel();
+        }
+        Assert.assertEquals(2, pdfTestDoc.getCounter());
+    }
+
     private static PdfDictionary getTestPdfDictionary() {
         HashMap<PdfName, PdfObject> tmpMap = new HashMap<PdfName, PdfObject>();
         tmpMap.put(new PdfName("b"), new PdfName("c"));
@@ -2650,4 +2680,22 @@ private static byte[] createPdfDocumentForTest() throws IOException {
             return baos.toByteArray();
         }
     }
+
+    private class TestPdfDocumentCache extends PdfDocument {
+        private int getXmpMetadataCounter;
+
+        public TestPdfDocumentCache(PdfReader pdfReader) {
+            super(pdfReader);
+        }
+
+        @Override
+        public byte[] getXmpMetadata(boolean createNew) {
+            ++getXmpMetadataCounter;
+            return super.getXmpMetadata(createNew);
+        }
+
+        public int getCounter() {
+            return getXmpMetadataCounter;
+        }
+    }
 }