ptg.java

来自「EXCEL read and write」· Java 代码 · 共 348 行

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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
   (the "License"); you may not use this file except in compliance with
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       http://www.apache.org/licenses/LICENSE-2.0

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   distributed under the License is distributed on an "AS IS" BASIS,
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   See the License for the specific language governing permissions and
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package org.apache.poi.hssf.record.formula;

import java.util.ArrayList;
import java.util.List;

import org.apache.poi.hssf.record.RecordInputStream;

/**
 * <tt>Ptg</tt> represents a syntactic token in a formula.  'PTG' is an acronym for 
 * '<b>p</b>arse <b>t</b>hin<b>g</b>'.  Originally, the name referred to the single 
 * byte identifier at the start of the token, but in POI, <tt>Ptg</tt> encapsulates
 * the whole formula token (initial byte + value data).
 * <p/>
 * 
 * <tt>Ptg</tt>s are logically arranged in a tree representing the structure of the
 * parsed formula.  However, in BIFF files <tt>Ptg</tt>s are written/read in 
 * <em>Reverse-Polish Notation</em> order. The RPN ordering also simplifies formula
 * evaluation logic, so POI mostly accesses <tt>Ptg</tt>s in the same way.
 *
 * @author  andy
 * @author avik
 * @author Jason Height (jheight at chariot dot net dot au)
 */
public abstract class Ptg implements Cloneable {
	public static final Ptg[] EMPTY_PTG_ARRAY = { }; 

	
	/**
	 * Reads <tt>size</tt> bytes of the input stream, to create an array of <tt>Ptg</tt>s.
	 * Extra data (beyond <tt>size</tt>) may be read if and <tt>ArrayPtg</tt>s are present.
	 */
	public static Ptg[] readTokens(int size, RecordInputStream in) {
		List temp = new ArrayList(4 + size / 2);
		int pos = 0;
		List arrayPtgs = null;
		while (pos < size) {
			Ptg ptg = Ptg.createPtg( in );
			if (ptg instanceof ArrayPtg) {
				if (arrayPtgs == null) {
					arrayPtgs = new ArrayList(5);
				}
				arrayPtgs.add(ptg);
				pos += ArrayPtg.PLAIN_TOKEN_SIZE;
			} else {
				pos += ptg.getSize();
			}
			temp.add( ptg );
		}
		if(pos != size) {
			throw new RuntimeException("Ptg array size mismatch");
		}
		if (arrayPtgs != null) {
			for (int i=0;i<arrayPtgs.size();i++) {
				ArrayPtg p = (ArrayPtg)arrayPtgs.get(i);
				p.readTokenValues(in);
			}
		}
		return toPtgArray(temp);
	}

	public static Ptg createPtg(RecordInputStream in) {
		byte id = in.readByte();
		
		if (id < 0x20) {
			return createBasePtg(id, in);
		}
		
		Ptg  retval = createClassifiedPtg(id, in);

		if (id >= 0x60) { 
			retval.setClass(CLASS_ARRAY);
		} else if (id >= 0x40) {
			retval.setClass(CLASS_VALUE);
		} else {
			retval.setClass(CLASS_REF);
		}

		return retval;
	}

	private static Ptg createClassifiedPtg(byte id, RecordInputStream in) {
		
		int baseId = id & 0x1F | 0x20;
		
		switch (baseId) {
			case ArrayPtg.sid:    return new ArrayPtg(in);    // 0x20, 0x40, 0x60
			case FuncPtg.sid:     return new FuncPtg(in);     // 0x21, 0x41, 0x61
			case FuncVarPtg.sid:  return new FuncVarPtg(in);  // 0x22, 0x42, 0x62
			case NamePtg.sid:     return new NamePtg(in);     // 0x23, 0x43, 0x63
			case RefPtg.sid:      return new RefPtg(in);      // 0x24, 0x44, 0x64
			case AreaPtg.sid:     return new AreaPtg(in);     // 0x25, 0x45, 0x65
			case MemAreaPtg.sid:  return new MemAreaPtg(in);  // 0x26, 0x46, 0x66
			case MemErrPtg.sid:   return new MemErrPtg(in);   // 0x27, 0x47, 0x67
			case MemFuncPtg.sid:  return new MemFuncPtg(in);  // 0x29, 0x49, 0x69
			case RefErrorPtg.sid: return new RefErrorPtg(in); // 0x2a, 0x4a, 0x6a
			case AreaErrPtg.sid:  return new AreaErrPtg(in);  // 0x2b, 0x4b, 0x6b
			case RefNPtg.sid:     return new RefNPtg(in);     // 0x2c, 0x4c, 0x6c
			case AreaNPtg.sid:    return new AreaNPtg(in);    // 0x2d, 0x4d, 0x6d

			case NameXPtg.sid:    return new NameXPtg(in);    // 0x39, 0x49, 0x79
			case Ref3DPtg.sid:    return new Ref3DPtg(in);    // 0x3a, 0x5a, 0x7a
			case Area3DPtg.sid:   return new Area3DPtg(in);   // 0x3b, 0x5b, 0x7b
			case DeletedRef3DPtg.sid:  return new DeletedRef3DPtg(in);   // 0x3c, 0x5c, 0x7c
			case DeletedArea3DPtg.sid: return  new DeletedArea3DPtg(in); // 0x3d, 0x5d, 0x7d
		}
		throw new UnsupportedOperationException(" Unknown Ptg in Formula: 0x"+
				   Integer.toHexString(id) + " (" + ( int ) id + ")");
	}

	private static Ptg createBasePtg(byte id, RecordInputStream in) {
		switch(id) {
			case 0x00:                return new UnknownPtg(); // TODO - not a real Ptg
			case ExpPtg.sid:          return new ExpPtg(in);          // 0x01
			case TblPtg.sid:          return new TblPtg(in);          // 0x02
			case AddPtg.sid:          return AddPtg.instance;         // 0x03
			case SubtractPtg.sid:     return SubtractPtg.instance;    // 0x04
			case MultiplyPtg.sid:     return MultiplyPtg.instance;    // 0x05
			case DividePtg.sid:       return DividePtg.instance;      // 0x06
			case PowerPtg.sid:        return PowerPtg.instance;       // 0x07
			case ConcatPtg.sid:       return ConcatPtg.instance;      // 0x08
			case LessThanPtg.sid:     return LessThanPtg.instance;    // 0x09
			case LessEqualPtg.sid:    return LessEqualPtg.instance;   // 0x0a
			case EqualPtg.sid:        return EqualPtg.instance;       // 0x0b
			case GreaterEqualPtg.sid: return GreaterEqualPtg.instance;// 0x0c
			case GreaterThanPtg.sid:  return GreaterThanPtg.instance; // 0x0d
			case NotEqualPtg.sid:     return NotEqualPtg.instance;    // 0x0e
			case IntersectionPtg.sid: return IntersectionPtg.instance;// 0x0f
			case UnionPtg.sid:        return UnionPtg.instance;       // 0x10
			case RangePtg.sid:        return RangePtg.instance;       // 0x11
			case UnaryPlusPtg.sid:    return UnaryPlusPtg.instance;   // 0x12
			case UnaryMinusPtg.sid:   return UnaryMinusPtg.instance;  // 0x13
			case PercentPtg.sid:      return PercentPtg.instance;     // 0x14
			case ParenthesisPtg.sid:  return ParenthesisPtg.instance; // 0x15
			case MissingArgPtg.sid:   return MissingArgPtg.instance;  // 0x16

			case StringPtg.sid:       return new StringPtg(in);       // 0x17
			case AttrPtg.sid:                
			case 0x1a:        return new AttrPtg(in); // 0x19
			case ErrPtg.sid:          return ErrPtg.read(in);         // 0x1c
			case BoolPtg.sid:         return new BoolPtg(in);         // 0x1d
			case IntPtg.sid:          return new IntPtg(in);          // 0x1e
			case NumberPtg.sid:       return new NumberPtg(in);       // 0x1f
		}
		throw new RuntimeException("Unexpected base token id (" + id + ")");
	}
	/**
	 * @return a distinct copy of this <tt>Ptg</tt> if the class is mutable, or the same instance
	 * if the class is immutable.
	 */
	public final Ptg copy() {
		// TODO - all base tokens are logically immutable, but AttrPtg needs some clean-up 
		if (this instanceof ValueOperatorPtg) {
			return this;
		}
		if (this instanceof ScalarConstantPtg) {
			return this;
		}
		return (Ptg) clone();
	}

	protected Object clone() {
		try {
			return super.clone();
		} catch (CloneNotSupportedException e) {
			throw new RuntimeException(e);
		}
	}
	private static Ptg[] toPtgArray(List l) {
		if (l.isEmpty()) {
			return EMPTY_PTG_ARRAY;
		}
		Ptg[] result = new Ptg[l.size()];
		l.toArray(result);
		return result;
	}
	/**
	 * This method will return the same result as {@link #getEncodedSizeWithoutArrayData(Ptg[])} 
	 * if there are no array tokens present.
	 * @return the full size taken to encode the specified <tt>Ptg</tt>s 
	 */
	public static int getEncodedSize(Ptg[] ptgs) {
		int result = 0;
		for (int i = 0; i < ptgs.length; i++) {
			result += ptgs[i].getSize();
		}
		return result;
	}
	/**
	 * Used to calculate value that should be encoded at the start of the encoded Ptg token array;
	 * @return the size of the encoded Ptg tokens not including any trailing array data.
	 */
	public static int getEncodedSizeWithoutArrayData(Ptg[] ptgs) {
		int result = 0;
		for (int i = 0; i < ptgs.length; i++) {
			Ptg ptg = ptgs[i];
			if (ptg instanceof ArrayPtg) {
				result += ArrayPtg.PLAIN_TOKEN_SIZE;
			} else {
				result += ptg.getSize();
			}
		}
		return result;
	}
	/**
	 * Writes the ptgs to the data buffer, starting at the specified offset.  
	 *
	 * <br/>
	 * The 2 byte encode length field is <b>not</b> written by this method.
	 * @return number of bytes written
	 */
	public static int serializePtgs(Ptg[] ptgs, byte[] array, int offset) {
		int pos = 0;
		int size = ptgs.length;

		List arrayPtgs = null;

		for (int k = 0; k < size; k++) {
			Ptg ptg = ptgs[k];

			ptg.writeBytes(array, pos + offset);
			if (ptg instanceof ArrayPtg) {
				if (arrayPtgs == null) {
					arrayPtgs = new ArrayList(5);
				}
				arrayPtgs.add(ptg);
				pos += ArrayPtg.PLAIN_TOKEN_SIZE;
			} else {
				pos += ptg.getSize();
			}
		}
		if (arrayPtgs != null) {
			for (int i=0;i<arrayPtgs.size();i++) {
				ArrayPtg p = (ArrayPtg)arrayPtgs.get(i);
				pos += p.writeTokenValueBytes(array, pos + offset);
			}
		}
		return pos;
	}

	/**
	 * @return the encoded length of this Ptg, including the initial Ptg type identifier byte. 
	 */
	public abstract int getSize();
	
	/**
	 * @return the encoded length of this Ptg, not including the initial Ptg type identifier byte. 
	 */
//    public abstract int getDataSize();

	public final byte [] getBytes()
	{
		int    size  = getSize();
		byte[] bytes = new byte[ size ];

		writeBytes(bytes, 0);
		return bytes;
	}
	/** write this Ptg to a byte array*/
	public abstract void writeBytes(byte [] array, int offset);

	/**
	 * return a string representation of this token alone
	 */
	public abstract String toFormulaString();
	/**
	 * dump a debug representation (hexdump) to a string
	 */
	public final String toDebugString() {
		byte[] ba = new byte[getSize()];
		String retval=null;
		writeBytes(ba,0);
		try {
			retval = org.apache.poi.util.HexDump.dump(ba,0,0);
		} catch (Exception e) {
			e.printStackTrace();
		}
		return retval;
	}

	/** Overridden toString method to ensure object hash is not printed.
	 * This helps get rid of gratuitous diffs when comparing two dumps
	 * Subclasses may output more relevant information by overriding this method
	 **/
	public String toString(){
		return this.getClass().toString();
	}

	public static final byte CLASS_REF = 0x00;
	public static final byte CLASS_VALUE = 0x20;
	public static final byte CLASS_ARRAY = 0x40;

	private byte ptgClass = CLASS_REF; //base ptg

	public final void setClass(byte thePtgClass) {
		if (isBaseToken()) {
			throw new RuntimeException("setClass should not be called on a base token");
		}
		ptgClass = thePtgClass;
	}

	/**
	 *  @return the 'operand class' (REF/VALUE/ARRAY) for this Ptg
	 */
	public final byte getPtgClass() {
		return ptgClass;
	}
	
	/**
	 * Debug / diagnostic method to get this token's 'operand class' type.
	 * @return 'R' for 'reference', 'V' for 'value', 'A' for 'array' and '.' for base tokens
	 */
	public final char getRVAType() {
		if (isBaseToken()) {
			return '.';
		}
		switch (ptgClass) {
			case Ptg.CLASS_REF:   return 'R';
			case Ptg.CLASS_VALUE: return 'V';
			case Ptg.CLASS_ARRAY: return 'A';
		}
		throw new RuntimeException("Unknown operand class (" + ptgClass + ")");
	}

	public abstract byte getDefaultOperandClass();

	/**
	 * @return <code>false</code> if this token is classified as 'reference', 'value', or 'array'
	 */
	public abstract boolean isBaseToken();
}