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Posted to commits@poi.apache.org by ma...@apache.org on 2021/02/28 18:49:42 UTC
svn commit: r1887008 -
/poi/trunk/src/scratchpad/src/org/apache/poi/hwpf/model/EscherRecordHolder.java
Author: mariusvolkhart
Date: Sun Feb 28 18:49:42 2021
New Revision: 1887008
URL: http://svn.apache.org/viewvc?rev=1887008&view=rev
Log:
Rework EscherRecordHolder parsing
Modify the parsing done by EscherRecordHolder to be more deterministic. The format of the OfficeArtContent structure, which the EscherRecordHolder represents, is well defined in the MS-DOC spec. A clear class structure makes it easier to reason about the availability of data.
Modified:
poi/trunk/src/scratchpad/src/org/apache/poi/hwpf/model/EscherRecordHolder.java
Modified: poi/trunk/src/scratchpad/src/org/apache/poi/hwpf/model/EscherRecordHolder.java
URL: http://svn.apache.org/viewvc/poi/trunk/src/scratchpad/src/org/apache/poi/hwpf/model/EscherRecordHolder.java?rev=1887008&r1=1887007&r2=1887008&view=diff
==============================================================================
--- poi/trunk/src/scratchpad/src/org/apache/poi/hwpf/model/EscherRecordHolder.java (original)
+++ poi/trunk/src/scratchpad/src/org/apache/poi/hwpf/model/EscherRecordHolder.java Sun Feb 28 18:49:42 2021
@@ -18,15 +18,18 @@
package org.apache.poi.hwpf.model;
import java.util.ArrayList;
-import java.util.Iterator;
import java.util.List;
+import org.apache.logging.log4j.LogManager;
import org.apache.poi.ddf.DefaultEscherRecordFactory;
import org.apache.poi.ddf.EscherContainerRecord;
import org.apache.poi.ddf.EscherRecord;
import org.apache.poi.ddf.EscherRecordFactory;
+import org.apache.poi.ddf.EscherRecordTypes;
import org.apache.poi.util.Internal;
+import static org.apache.logging.log4j.util.Unbox.box;
+
/**
* Based on AbstractEscherRecordHolder from HSSF.
*
@@ -34,7 +37,27 @@ import org.apache.poi.util.Internal;
*/
@Internal
public final class EscherRecordHolder {
- private final ArrayList<EscherRecord> escherRecords = new ArrayList<>();
+
+ /**
+ * {@link EscherRecordTypes#DGG_CONTAINER} containing drawing group information for the document.
+ */
+ private final EscherContainerRecord drawingGroupData = new EscherContainerRecord();
+
+ /**
+ * {@link EscherRecordTypes#DG_CONTAINER} for drawings in the Main Document.
+ * <p>
+ * {@code null} to indicate that the document does not have a {@link EscherRecordTypes#DG_CONTAINER} for the Main
+ * Document.
+ */
+ private EscherContainerRecord mainDocumentDgContainer;
+
+ /**
+ * {@link EscherRecordTypes#DG_CONTAINER} for drawings in the Header Document.
+ * <p>
+ * {@code null} to indicate that the document does not have a {@link EscherRecordTypes#DG_CONTAINER} for the Header
+ * Document.
+ */
+ private EscherContainerRecord headerDocumentDgContainer;
public EscherRecordHolder(byte[] data, int offset, int size) {
fillEscherRecords(data, offset, size);
@@ -47,129 +70,77 @@ public final class EscherRecordHolder {
*
* @see FileInformationBlock#getLcbDggInfo()
*/
- private void fillEscherRecords(byte[] data, int offset, int size)
- {
+ private void fillEscherRecords(byte[] data, int offset, int size) {
if (size == 0) return;
EscherRecordFactory recordFactory = new DefaultEscherRecordFactory();
int pos = offset;
- while ( pos < offset + size)
- {
- EscherRecord r = recordFactory.createRecord(data, pos);
- escherRecords.add(r);
- int bytesRead = r.fillFields(data, pos, recordFactory);
- pos += bytesRead + 1; // There is an empty byte between each top-level record in a Word doc
- }
- }
-
- public List<EscherRecord> getEscherRecords() {
- return escherRecords;
- }
+ pos += drawingGroupData.fillFields(data, pos, recordFactory);
+ assert drawingGroupData.getRecordId() == EscherRecordTypes.DGG_CONTAINER.typeID;
- @Override
- public String toString() {
- StringBuilder buffer = new StringBuilder();
-
- if (escherRecords.size() == 0) {
- buffer.append("No Escher Records Decoded").append("\n");
- }
- Iterator<EscherRecord> iterator = escherRecords.iterator();
- while (iterator.hasNext()) {
- EscherRecord r = iterator.next();
- buffer.append(r);
- }
- return buffer.toString();
- }
-
- /**
- * If we have a EscherContainerRecord as one of our
- * children (and most top level escher holders do),
- * then return that.
- */
- public EscherContainerRecord getEscherContainer() {
- for(Iterator<EscherRecord> it = escherRecords.iterator(); it.hasNext();) {
- Object er = it.next();
- if(er instanceof EscherContainerRecord) {
- return (EscherContainerRecord)er;
+ /*
+ * After the drawingGroupData there is an array (2 slots max) that has data about drawings. According to the
+ * spec, the first slot is for the Main Document, the second for the Header Document. Additionally, the
+ * OfficeArtWordDrawing structure has a byte (dgglbl) that indicates whether the structure is for the Main or
+ * Header Document. In practice we've seen documents such as 61911.doc where the order of array entries does not
+ * match the dgglbl byte. As the byte is more likely to be reliable, we base the parsing off of that rather than
+ * array order.
+ */
+
+ // This should loop at most twice
+ while (pos < offset + size) {
+
+ // Named this way to match section 2.9.172 of [MS-DOC] - v20191119.
+ byte dgglbl = data[pos];
+ assert dgglbl == 0x00 || dgglbl == 0x01;
+ pos++;
+
+ EscherContainerRecord dgContainer = new EscherContainerRecord();
+ pos+= dgContainer.fillFields(data, pos, recordFactory);
+ assert dgContainer.getRecordId() == EscherRecordTypes.DG_CONTAINER.typeID;
+
+ switch (dgglbl) {
+ case 0x00:
+ mainDocumentDgContainer = dgContainer;
+ break;
+ case 0x01:
+ headerDocumentDgContainer = dgContainer;
+ break;
+ default:
+ LogManager.getLogger(EscherRecordHolder.class).atWarn()
+ .log("dgglbl {} for OfficeArtWordDrawing is out of bounds [0, 1]", box(dgglbl));
}
}
- return null;
- }
- /**
- * Descends into all our children, returning the
- * first EscherRecord with the given id, or null
- * if none found
- */
- public EscherRecord findFirstWithId(short id) {
- return findFirstWithId(id, getEscherRecords());
+ assert pos == offset + size;
}
- private static EscherRecord findFirstWithId(short id, List<EscherRecord> records) {
- // Check at our level
- for(Iterator<EscherRecord> it = records.iterator(); it.hasNext();) {
- EscherRecord r = it.next();
- if(r.getRecordId() == id) {
- return r;
- }
- }
- // Then check our children in turn
- for(Iterator<EscherRecord> it = records.iterator(); it.hasNext();) {
- EscherRecord r = it.next();
- if(r.isContainerRecord()) {
- EscherRecord found = findFirstWithId(id, r.getChildRecords());
- if(found != null) {
- return found;
- }
- }
- }
-
- // Not found in this lot
- return null;
+ public List<EscherRecord> getEscherRecords() {
+ return drawingGroupData.getChildRecords();
}
- public List<? extends EscherContainerRecord> getDgContainers()
- {
- List<EscherContainerRecord> dgContainers = new ArrayList<>(
- 1);
- for ( EscherRecord escherRecord : getEscherRecords() )
- {
- if ( escherRecord.getRecordId() == (short) 0xF002 )
- {
- dgContainers.add( (EscherContainerRecord) escherRecord );
- }
+ public List<? extends EscherContainerRecord> getDgContainers() {
+ List<EscherContainerRecord> dgContainers = new ArrayList<>(2);
+ if (mainDocumentDgContainer != null) {
+ dgContainers.add(mainDocumentDgContainer);
}
- return dgContainers;
- }
-
- public List<? extends EscherContainerRecord> getDggContainers()
- {
- List<EscherContainerRecord> dggContainers = new ArrayList<>(
- 1);
- for ( EscherRecord escherRecord : getEscherRecords() )
- {
- if ( escherRecord.getRecordId() == (short) 0xF000 )
- {
- dggContainers.add( (EscherContainerRecord) escherRecord );
- }
+ if (headerDocumentDgContainer != null) {
+ dgContainers.add(headerDocumentDgContainer);
}
- return dggContainers;
+ return dgContainers;
}
public List<? extends EscherContainerRecord> getBStoreContainers()
{
List<EscherContainerRecord> bStoreContainers = new ArrayList<>(
1);
- for ( EscherContainerRecord dggContainer : getDggContainers() )
- {
- for ( EscherRecord escherRecord : dggContainer.getChildRecords() )
- {
- if ( escherRecord.getRecordId() == (short) 0xF001 )
- {
- bStoreContainers.add( (EscherContainerRecord) escherRecord );
- }
- }
- }
+ for ( EscherRecord escherRecord : drawingGroupData.getChildRecords() )
+ {
+ if ( escherRecord.getRecordId() == (short) 0xF001 )
+ {
+ bStoreContainers.add( (EscherContainerRecord) escherRecord );
+ }
+ }
return bStoreContainers;
}
@@ -206,4 +177,13 @@ public final class EscherRecordHolder {
}
return spContainers;
}
+
+ @Override
+ public String toString() {
+ return "EscherRecordHolder{" +
+ "drawingGroupData=" + drawingGroupData +
+ ", mainDocumentDgContainer=" + mainDocumentDgContainer +
+ ", headerDocumentDgContainer=" + headerDocumentDgContainer +
+ '}';
+ }
}
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