In Formula cache Ptg[] instead of constantly (un)serializing it from the byte encoding

This commit is contained in:
Travis Burtrum 2017-05-23 15:32:56 -04:00
parent 00968d5f10
commit 8ab388eb78
1 changed files with 9 additions and 5 deletions

View File

@ -35,15 +35,17 @@ import org.apache.poi.util.LittleEndianOutput;
*/
public class Formula {
private static final Formula EMPTY = new Formula(new byte[0], 0);
private static final Formula EMPTY = new Formula(new byte[0], 0, new Ptg[0]);
/** immutable */
private final byte[] _byteEncoding;
private final int _encodedTokenLen;
private Ptg[] _cache;
private Formula(byte[] byteEncoding, int encodedTokenLen) {
private Formula(byte[] byteEncoding, int encodedTokenLen, Ptg[] cache) {
_byteEncoding = byteEncoding.clone();
_encodedTokenLen = encodedTokenLen;
_cache = cache;
// if (false) { // set to true to eagerly check Ptg decoding
// LittleEndianByteArrayInputStream in = new LittleEndianByteArrayInputStream(byteEncoding);
// Ptg.readTokens(encodedTokenLen, in);
@ -74,12 +76,14 @@ public class Formula {
public static Formula read(int encodedTokenLen, LittleEndianInput in, int totalEncodedLen) {
byte[] byteEncoding = new byte[totalEncodedLen];
in.readFully(byteEncoding);
return new Formula(byteEncoding, encodedTokenLen);
return new Formula(byteEncoding, encodedTokenLen, null);
}
public Ptg[] getTokens() {
if(_cache != null)
return _cache;
LittleEndianInput in = new LittleEndianByteArrayInputStream(_byteEncoding);
return Ptg.readTokens(_encodedTokenLen, in);
return _cache = Ptg.readTokens(_encodedTokenLen, in);
}
/**
* Writes The formula encoding is includes:
@ -140,7 +144,7 @@ public class Formula {
byte[] encodedData = new byte[totalSize];
Ptg.serializePtgs(ptgs, encodedData, 0);
int encodedTokenLen = Ptg.getEncodedSizeWithoutArrayData(ptgs);
return new Formula(encodedData, encodedTokenLen);
return new Formula(encodedData, encodedTokenLen, ptgs); // todo: copy ptgs? don't think we need to
}
/**
* Gets the {@link Ptg} array from the supplied {@link Formula}.