poi/src/testcases/org/apache/poi/hssf/record/TestSSTRecordSizeCalculator.java

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   this work for additional information regarding copyright ownership.
   The ASF licenses this file to You under the Apache License, Version 2.0
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       http://www.apache.org/licenses/LICENSE-2.0

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package org.apache.poi.hssf.record;

import junit.framework.TestCase;

import org.apache.poi.hssf.record.common.UnicodeString;
import org.apache.poi.hssf.record.cont.ContinuableRecordOutput;
import org.apache.poi.util.IntMapper;

/**
 * Tests that records size calculates correctly.
 * 
 * @author Glen Stampoultzis (glens at apache.org)
 */
public final class TestSSTRecordSizeCalculator extends TestCase {
	private static final String SMALL_STRING = "Small string";
	private static final int COMPRESSED_PLAIN_STRING_OVERHEAD = 3;
	private static final int OPTION_FIELD_SIZE = 1;
	
	private final IntMapper<UnicodeString> strings = new IntMapper<UnicodeString>();

	private void confirmSize(int expectedSize) {
		ContinuableRecordOutput cro = ContinuableRecordOutput.createForCountingOnly();
		SSTSerializer ss = new SSTSerializer(strings, 0, 0);
		ss.serialize(cro);
		assertEquals(expectedSize, cro.getTotalSize());
	}

	public void testBasic() {
		strings.add(makeUnicodeString(SMALL_STRING));
		confirmSize(SSTRecord.SST_RECORD_OVERHEAD
				+ COMPRESSED_PLAIN_STRING_OVERHEAD
				+ SMALL_STRING.length());
	}

	public void testBigStringAcrossUnicode() {
		int bigString = SSTRecord.MAX_DATA_SPACE + 100;
		strings.add(makeUnicodeString(bigString));
		confirmSize(SSTRecord.SST_RECORD_OVERHEAD
				+ COMPRESSED_PLAIN_STRING_OVERHEAD
				+ SSTRecord.MAX_DATA_SPACE
				+ SSTRecord.STD_RECORD_OVERHEAD
				+ OPTION_FIELD_SIZE
				+ 100);
	}

	public void testPerfectFit() {
		int perfectFit = SSTRecord.MAX_DATA_SPACE - COMPRESSED_PLAIN_STRING_OVERHEAD;
		strings.add(makeUnicodeString(perfectFit));
		confirmSize(SSTRecord.SST_RECORD_OVERHEAD
				+ COMPRESSED_PLAIN_STRING_OVERHEAD
				+ perfectFit);
	}

	public void testJustOversized() {
		int tooBig = SSTRecord.MAX_DATA_SPACE - COMPRESSED_PLAIN_STRING_OVERHEAD + 1;
		strings.add(makeUnicodeString(tooBig));
		confirmSize(SSTRecord.SST_RECORD_OVERHEAD
				+ COMPRESSED_PLAIN_STRING_OVERHEAD
				+ tooBig - 1
				// continue record
				+ SSTRecord.STD_RECORD_OVERHEAD
				+ OPTION_FIELD_SIZE + 1);

	}

	public void testSecondStringStartsOnNewContinuation() {
		int perfectFit = SSTRecord.MAX_DATA_SPACE - COMPRESSED_PLAIN_STRING_OVERHEAD;
		strings.add(makeUnicodeString(perfectFit));
		strings.add(makeUnicodeString(SMALL_STRING));
		confirmSize(SSTRecord.SST_RECORD_OVERHEAD
				+ SSTRecord.MAX_DATA_SPACE
				// second string
				+ SSTRecord.STD_RECORD_OVERHEAD
				+ COMPRESSED_PLAIN_STRING_OVERHEAD
				+ SMALL_STRING.length());
	}

	public void testHeaderCrossesNormalContinuePoint() {
		int almostPerfectFit = SSTRecord.MAX_DATA_SPACE - COMPRESSED_PLAIN_STRING_OVERHEAD - 2;
		strings.add(makeUnicodeString(almostPerfectFit));
		String oneCharString = new String(new char[1]);
		strings.add(makeUnicodeString(oneCharString));
		confirmSize(SSTRecord.SST_RECORD_OVERHEAD
				+ COMPRESSED_PLAIN_STRING_OVERHEAD
				+ almostPerfectFit
				// second string
				+ SSTRecord.STD_RECORD_OVERHEAD
				+ COMPRESSED_PLAIN_STRING_OVERHEAD
				+ oneCharString.length());

	}
	private static UnicodeString makeUnicodeString(int size) {
		String s = new String(new char[size]);
		return makeUnicodeString(s);
	}

	private static UnicodeString makeUnicodeString(String s) {
		UnicodeString st = new UnicodeString(s);
		st.setOptionFlags((byte) 0);
		return st;
	}
}