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- /* ====================================================================
- Licensed to the Apache Software Foundation (ASF) under one or more
- contributor license agreements. See the NOTICE file distributed with
- this work for additional information regarding copyright ownership.
- The ASF licenses this file to You under the Apache License, Version 2.0
- (the "License"); you may not use this file except in compliance with
- the License. You may obtain a copy of the License at
-
- http://www.apache.org/licenses/LICENSE-2.0
-
- Unless required by applicable law or agreed to in writing, software
- distributed under the License is distributed on an "AS IS" BASIS,
- WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
- See the License for the specific language governing permissions and
- limitations under the License.
- ==================================================================== */
-
- package org.apache.poi.hdgf.chunks;
-
- import java.io.BufferedReader;
- import java.io.IOException;
- import java.io.InputStream;
- import java.io.InputStreamReader;
- import java.util.ArrayList;
- import java.util.HashMap;
- import java.util.Map;
- import java.util.StringTokenizer;
-
- import org.apache.poi.util.IOUtils;
- import org.apache.poi.util.LocaleUtil;
- import org.apache.poi.util.POILogFactory;
- import org.apache.poi.util.POILogger;
-
- /**
- * Factor class to create the appropriate chunks, which
- * needs the version of the file to process the chunk header
- * and trailer areas.
- * Makes use of chunks_parse_cmds.tbl from vsdump to be able
- * to process the chunk value area
- */
- public final class ChunkFactory {
-
- //arbitrarily selected; may need to increase
- private static final int MAX_RECORD_LENGTH = 1_000_000;
-
-
- /** The version of the currently open document */
- private int version;
- /**
- * Key is a Chunk's type, value is an array of its CommandDefinitions
- */
- private final Map<Integer, CommandDefinition[]> chunkCommandDefinitions =
- new HashMap<>();
- /**
- * What the name is of the chunk table definitions file?
- * This file comes from the scratchpad resources directory.
- */
- private static final String chunkTableName =
- "/org/apache/poi/hdgf/chunks_parse_cmds.tbl";
-
- /** For logging problems we spot with the file */
- private static final POILogger logger = POILogFactory.getLogger(ChunkFactory.class);
-
- public ChunkFactory(int version) throws IOException {
- this.version = version;
-
- processChunkParseCommands();
- }
-
- /**
- * Open chunks_parse_cmds.tbl and process it, to get the definitions
- * of all the different possible chunk commands.
- */
- private void processChunkParseCommands() throws IOException {
- String line;
- InputStream cpd = null;
- BufferedReader inp = null;
- try {
- cpd = ChunkFactory.class.getResourceAsStream(chunkTableName);
- if(cpd == null) {
- throw new IllegalStateException("Unable to find HDGF chunk definition on the classpath - " + chunkTableName);
- }
-
- inp = new BufferedReader(new InputStreamReader(cpd, LocaleUtil.CHARSET_1252));
-
- while( (line = inp.readLine()) != null ) {
- if (line.isEmpty() || "# \t".contains(line.substring(0,1))) {
- continue;
- }
-
- // Start xxx
- if(!line.matches("^start [0-9]+$")) {
- throw new IllegalStateException("Expecting start xxx, found " + line);
- }
- int chunkType = Integer.parseInt(line.substring(6));
- ArrayList<CommandDefinition> defsL = new ArrayList<>();
-
- // Data entries
- while( (line = inp.readLine()) != null ) {
- if (line.startsWith("end")) {
- break;
- }
- StringTokenizer st = new StringTokenizer(line, " ");
- int defType = Integer.parseInt(st.nextToken());
- int offset = Integer.parseInt(st.nextToken());
- String name = st.nextToken("\uffff").substring(1);
-
- CommandDefinition def = new CommandDefinition(defType,offset,name);
- defsL.add(def);
- }
-
- CommandDefinition[] defs = defsL.toArray(new CommandDefinition[0]);
-
- // Add to the map
- chunkCommandDefinitions.put(chunkType, defs);
- }
- } finally {
- if (inp != null) {
- inp.close();
- }
- if (cpd != null) {
- cpd.close();
- }
- }
- }
-
- public int getVersion() { return version; }
-
- /**
- * Creates the appropriate chunk at the given location.
- *
- * @param data the chunk bytes
- * @param offset the offset into the chunk bytes array to start reading from
- *
- * @return the new Chunk
- */
- public Chunk createChunk(byte[] data, int offset) {
- // Create the header
- ChunkHeader header =
- ChunkHeader.createChunkHeader(version, data, offset);
- // Sanity check
- if(header.getLength() < 0) {
- throw new IllegalArgumentException("Found a chunk with a negative length, which isn't allowed");
- }
-
- // How far up to look
- int endOfDataPos = offset + header.getLength() + header.getSizeInBytes();
-
- // Check we have enough data, and tweak the header size
- // as required
- if(endOfDataPos > data.length) {
- logger.log(POILogger.WARN,
- "Header called for " + header.getLength() +" bytes, but that would take us past the end of the data!");
-
- endOfDataPos = data.length;
- header.setLength(data.length - offset - header.getSizeInBytes());
-
- if(header.hasTrailer()) {
- header.setLength(header.getLength() - 8);
- endOfDataPos -= 8;
- }
- if(header.hasSeparator()) {
- header.setLength(header.getLength() - 4);
- endOfDataPos -= 4;
- }
- }
-
-
- // Create the trailer and separator, if required
- ChunkTrailer trailer = null;
- ChunkSeparator separator = null;
- if(header.hasTrailer()) {
- if(endOfDataPos <= data.length-8) {
- trailer = new ChunkTrailer(
- data, endOfDataPos);
- endOfDataPos += 8;
- } else {
- logger.log(POILogger.ERROR, "Header claims a length to " + endOfDataPos + " there's then no space for the trailer in the data (" + data.length + ")");
- }
- }
- if(header.hasSeparator()) {
- if(endOfDataPos <= data.length-4) {
- separator = new ChunkSeparator(
- data, endOfDataPos);
- } else {
- logger.log(POILogger.ERROR, "Header claims a length to " + endOfDataPos + " there's then no space for the separator in the data (" + data.length + ")");
- }
- }
-
- // Now, create the chunk
- byte[] contents = IOUtils.safelyAllocate(header.getLength(), MAX_RECORD_LENGTH);
- System.arraycopy(data, offset+header.getSizeInBytes(), contents, 0, contents.length);
- Chunk chunk = new Chunk(header, trailer, separator, contents);
-
- // Feed in the stuff from chunks_parse_cmds.tbl
- CommandDefinition[] defs = chunkCommandDefinitions.get(header.getType());
- if (defs == null) {
- defs = new CommandDefinition[0];
- }
- chunk.setCommandDefinitions(defs);
-
- // Now get the chunk to process its commands
- chunk.processCommands();
-
- // All done
- return chunk;
- }
-
- /**
- * The definition of a Command, which a chunk may hold.
- * The Command holds the value, this describes it.
- */
- public static class CommandDefinition {
- private int type;
- private int offset;
- private String name;
- public CommandDefinition(int type, int offset, String name) {
- this.type = type;
- this.offset = offset;
- this.name = name;
- }
-
- public String getName() {
- return name;
- }
- public int getOffset() {
- return offset;
- }
- public int getType() {
- return type;
- }
- }
- }
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