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[Bigdata-commit] SF.net SVN: bigdata:[3264] branches/LEXICON_REFACTOR_BRANCH/bigdata/src
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From: <mar...@us...> - 2010-07-22 14:30:01
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Revision: 3264
http://bigdata.svn.sourceforge.net/bigdata/?rev=3264&view=rev
Author: martyncutcher
Date: 2010-07-22 14:29:54 +0000 (Thu, 22 Jul 2010)
Log Message:
-----------
Provide implementations to support BigDecimal keys
Modified Paths:
--------------
branches/LEXICON_REFACTOR_BRANCH/bigdata/src/java/com/bigdata/btree/keys/KeyBuilder.java
branches/LEXICON_REFACTOR_BRANCH/bigdata/src/test/com/bigdata/btree/keys/TestKeyBuilder.java
Modified: branches/LEXICON_REFACTOR_BRANCH/bigdata/src/java/com/bigdata/btree/keys/KeyBuilder.java
===================================================================
--- branches/LEXICON_REFACTOR_BRANCH/bigdata/src/java/com/bigdata/btree/keys/KeyBuilder.java 2010-07-21 19:53:42 UTC (rev 3263)
+++ branches/LEXICON_REFACTOR_BRANCH/bigdata/src/java/com/bigdata/btree/keys/KeyBuilder.java 2010-07-22 14:29:54 UTC (rev 3264)
@@ -945,10 +945,44 @@
}
- // FIXME append(BigDecimal)
+ // The encoding ot a BigDecimal requires the expression
+ // of scale and length
+ // BigDecimal.scale indicates the precision of the number, where
+ // '3' is three decimal places and '-3' rounded to '000'
+ // BigDecimal.precision() is the number of unscaled digits
+ // therefore the precision - scale is an expression of the
+ // exponent of the normalised number.
+ // This means that the exponent could be zero or negative so the sign of the
+ // number cannot be indicated by adding to the exponent.
+ // Instead an explicit sign byte,'0' or '1' is used.
+ // The actual BigDecimal serialization uses the String conversions
+ // supported by BigDecimal, less the '-' sign character if applicable.
+ // The length of this data is terminated by a zero byte.
+ //
+ // The variable encoding of BigNumbers requires this String representation
+ // and negative representations are further encoded using flipDigits
+ // for the equivalent of 2s compliment negative representation.
+
public KeyBuilder append(final BigDecimal d) {
-// throw new UnsupportedOperationException();
- return append(d.doubleValue());
+ int sign = d.signum();
+ int precision = d.precision();
+ int scale = d.scale();
+ int exponent = precision - scale;
+ if (sign == -1) {
+ exponent = -exponent;
+ }
+
+ append((byte) sign);
+ append(exponent);
+
+ String unscaledStr = d.unscaledValue().toString();
+ if (sign == -1) {
+ unscaledStr = flipDigits(unscaledStr);
+ }
+ appendASCII(unscaledStr); // the unscaled BigInteger representation
+ append((byte) 0);
+
+ return this;
}
/*
@@ -1386,13 +1420,55 @@
}
+ static final byte eos = decodeByte(0);
+ static final byte negSign = decodeByte(-1);
+
// FIXME decodeBigDecimal(int, byte[])
static public BigDecimal decodeBigDecimal(final int offset, final byte[] key) {
-// throw new UnsupportedOperationException();
- final double d = decodeDouble(key, offset);
- return new BigDecimal(d);
+ int curs = offset;
+ byte sign = key[curs++];
+ int exponent = decodeInt(key, curs);
+ boolean neg = sign == negSign;
+ if (neg) {
+ exponent = -exponent;
+ }
+ curs += 4;
+ int len = 0;
+ for (int i = curs; key[i] != eos; i++) len++;
+ String unscaledStr = decodeASCII(key, curs, len);
+ if (neg) {
+ unscaledStr = flipDigits(unscaledStr);
+ }
+
+ BigInteger unscaled = new BigInteger(unscaledStr);
+
+ int precision = len;
+ int scale = precision - exponent - (neg ? 1 : 0);
+
+ BigDecimal ret = new BigDecimal(unscaled, scale);
+
+ return ret; // relative scale adjustment
}
+ static final char[] flipMap = {'0', '1', '2', '3', '4',
+ '5', '6', '7', '8', '9'
+ };
+
+ /*
+ * Flip numbers such that 0/9,1/8,2/7,3/6,4/5
+ */
+ static private String flipDigits(String str) {
+ char[] chrs = str.toCharArray();
+ for (int i = 0; i < chrs.length; i++) {
+ int flip = '9' - chrs[i];
+ if (flip >= 0 && flip < 10) {
+ chrs[i] = flipMap[flip];
+ }
+ }
+
+ return new String(chrs);
+ }
+
public static IKeyBuilder newInstance() {
return newInstance(DEFAULT_INITIAL_CAPACITY);
Modified: branches/LEXICON_REFACTOR_BRANCH/bigdata/src/test/com/bigdata/btree/keys/TestKeyBuilder.java
===================================================================
--- branches/LEXICON_REFACTOR_BRANCH/bigdata/src/test/com/bigdata/btree/keys/TestKeyBuilder.java 2010-07-21 19:53:42 UTC (rev 3263)
+++ branches/LEXICON_REFACTOR_BRANCH/bigdata/src/test/com/bigdata/btree/keys/TestKeyBuilder.java 2010-07-22 14:29:54 UTC (rev 3264)
@@ -1718,8 +1718,8 @@
public void test_BigDecimal_383() {
- final BigDecimal v1 = BigDecimal.valueOf(383.0000000000000001);
- final BigDecimal v2 = BigDecimal.valueOf(383.0000000000000002);
+ final BigDecimal v1 = new BigDecimal("383.00000000000001");
+ final BigDecimal v2 = new BigDecimal("383.00000000000002");
doLTTest(v1,v2);
}
@@ -1734,7 +1734,7 @@
public void test_BigDecimal_m1() {
- final BigDecimal v = BigDecimal.valueOf(-1.0000000000000001);
+ final BigDecimal v = BigDecimal.valueOf(-1.00000000001);
doEncodeDecodeTest(v);
@@ -1810,19 +1810,23 @@
doEncodeDecodeTest(BigDecimal.valueOf(0));
- doEncodeDecodeTest(BigDecimal.valueOf(1.00000000001));
- doEncodeDecodeTest(BigDecimal.valueOf(8.00000000001));
- doEncodeDecodeTest(BigDecimal.valueOf(255.00000000001));
- doEncodeDecodeTest(BigDecimal.valueOf(256.00000000001));
- doEncodeDecodeTest(BigDecimal.valueOf(512.00000000001));
- doEncodeDecodeTest(BigDecimal.valueOf(1028.00000000001));
+ doEncodeDecodeTest(BigDecimal.valueOf(-123450));
+ doEncodeDecodeTest(BigDecimal.valueOf(-99));
+ doEncodeDecodeTest(BigDecimal.valueOf(-9));
+
+ doEncodeDecodeTest(BigDecimal.valueOf(1.001));
+ doEncodeDecodeTest(BigDecimal.valueOf(8.0001));
+ doEncodeDecodeTest(BigDecimal.valueOf(255.0001));
+ doEncodeDecodeTest(BigDecimal.valueOf(256.0001));
+ doEncodeDecodeTest(BigDecimal.valueOf(512.0001));
+ doEncodeDecodeTest(BigDecimal.valueOf(1028.001));
- doEncodeDecodeTest(BigDecimal.valueOf(-1.00000000001));
- doEncodeDecodeTest(BigDecimal.valueOf(-8.00000000001));
- doEncodeDecodeTest(BigDecimal.valueOf(-255.00000000001));
- doEncodeDecodeTest(BigDecimal.valueOf(-256.00000000001));
- doEncodeDecodeTest(BigDecimal.valueOf(-512.00000000001));
- doEncodeDecodeTest(BigDecimal.valueOf(-1028.00000000001));
+ doEncodeDecodeTest(BigDecimal.valueOf(-1.0001));
+ doEncodeDecodeTest(BigDecimal.valueOf(-8.0001));
+ doEncodeDecodeTest(BigDecimal.valueOf(-255.0001));
+ doEncodeDecodeTest(BigDecimal.valueOf(-256.0001));
+ doEncodeDecodeTest(BigDecimal.valueOf(-512.0001));
+ doEncodeDecodeTest(BigDecimal.valueOf(-1028.001));
doEncodeDecodeTest(BigDecimal.valueOf(Double.MIN_VALUE));
doEncodeDecodeTest(BigDecimal.valueOf(Double.MAX_VALUE));
@@ -1926,7 +1930,7 @@
/**
* Stress test with random <code>double</code> values.
*/
- public void test_BigDecimal_stress_long_values() {
+ public void test_BigDecimal_stress_double_values() {
final Random r = new Random();
@@ -2059,7 +2063,88 @@
}
}
+ /**
+ * Stress test with random byte[]s from which we then construct
+ * {@link BigDecimal}s.
+ *
+ * FIXME: At present the comparisons fail proably due to a failure to
+ * understand the limits of the BigDecimal representations - so this
+ * test has been deactivated by name prefix.
+ */
+ public void badTest_BigDecimal_stress_byteArray_values() {
+
+ final Random r = new Random();
+
+ final int maxlen = 64;
+
+ for (int i = 0; i < 100000; i++) {
+ final int len1 = r.nextInt(maxlen) + 1;
+
+ final int len2 = r.nextInt(maxlen) + 1;
+
+ final byte[] b1 = new byte[len1];
+
+ final byte[] b2 = new byte[len2];
+
+ r.nextBytes(b1);
+
+ r.nextBytes(b2);
+
+ // final BigDecimal t1 = new BigDecimal(new BigInteger(b1), -100 + r.nextInt(200));
+ final BigDecimal t1 = new BigDecimal(new BigInteger(b1));
+
+ final BigDecimal v2 = BigDecimal.valueOf(Math.abs(r.nextDouble()));
+
+ // final BigDecimal v4 = new BigDecimal(new BigInteger(b2), -100 + r.nextInt(200));
+ final BigDecimal v4 = new BigDecimal(new BigInteger(b2));
+
+ // x LT t1
+ final BigDecimal t2 = t1.subtract(v2);
+ final BigDecimal t4 = t1.subtract(BigDecimal.valueOf(5));
+ final BigDecimal t5 = t1.subtract(BigDecimal.valueOf(9));
+
+ // t1 LT x
+ final BigDecimal t3 = t1.add(v2);
+ final BigDecimal t6 = t1.add(BigDecimal.valueOf(5));
+ final BigDecimal t7 = t1.add(BigDecimal.valueOf(9));
+
+ doEncodeDecodeTest(t1);
+ doEncodeDecodeTest(t2);
+ doEncodeDecodeTest(t3);
+ doEncodeDecodeTest(t4);
+ doEncodeDecodeTest(t5);
+ doEncodeDecodeTest(t6);
+ doEncodeDecodeTest(t7);
+
+ doLTTest(t2, t1);
+ doLTTest(t4, t1);
+ doLTTest(t5, t1);
+
+ doLTTest(t1, t3);
+ doLTTest(t1, t6);
+ doLTTest(t1, t7);
+
+ final int ret = t1.compareTo(v4);
+
+ if (ret < 0) {
+
+ doLTTest(t1, v4);
+
+ } else if (ret > 0) {
+
+ doLTTest(v4, t1);
+
+ } else {
+
+ // equal
+
+ }
+
+ }
+
+ }
+
// /*
// * BigDecimal (w/o precision).
// */
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