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Fix decimal decoding (#401)
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@ilovesoup
ilovesoup authored Jul 23, 2018
1 parent ab74c19 commit dfe8f3e
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Showing 2 changed files with 91 additions and 66 deletions.
62 changes: 35 additions & 27 deletions tikv-client/src/main/java/com/pingcap/tikv/codec/MyDecimal.java
View file
Original file line number Diff line number Diff line change
Expand Up @@ -15,6 +15,7 @@

package com.pingcap.tikv.codec;

import com.google.common.annotations.VisibleForTesting;
import java.math.BigDecimal;
import java.util.Arrays;

Expand Down Expand Up @@ -58,12 +59,12 @@ public class MyDecimal {
/*
* Returns total precision of this decimal. Basically, it is sum of digitsInt and digitsFrac. But there
* are some special cases need to be token care of such as 000.001.
* Precision reflects the actual effective precision without leading zero
*/
public int precision() {
int frac = this.digitsFrac;
int digitsInt =
this.removeLeadingZeros()[
1]; /*this function return an array and the second element is digitsInt*/
this.removeLeadingZeros()[1]; /*this function return an array and the second element is digitsInt*/
int precision = digitsInt + frac;
// if no precision, it is just 0.
if (precision == 0) {
Expand All @@ -72,7 +73,10 @@ public int precision() {
return precision;
}

/** Returns fraction digits that counts how many digits after ".". */
/**
* Returns fraction digits that counts how many digits after ".".
* frac() reflects the actual effective fraction without trailing zero
*/
public int frac() {
return digitsFrac;
}
Expand All @@ -92,8 +96,7 @@ public void fromDecimal(double value) {
*
* @param precision precision specifies total digits that this decimal will be..
* @param frac frac specifies how many fraction digits
* @param bin bin is binary string which represents a decimal value. TODO: (zhexuany) overflow and
* truncated exception need to be done later.
* @param bin bin is binary string which represents a decimal value.
*/
public int fromBin(int precision, int frac, int[] bin) {
if (bin.length == 0) {
Expand Down Expand Up @@ -134,13 +137,13 @@ public int fromBin(int precision, int frac, int[] bin) {
wordsIntTo = wordBufLen;
wordsFracTo = 0;
overflow = true;
} else {
wordsIntTo = wordsInt;
wordsFracTo = wordBufLen - wordsInt;
truncated = true;
}
wordsIntTo = wordsInt;
wordsFracTo = wordBufLen - wordsInt;
truncated = true;
}
wordsIntTo = wordsInt;
wordsFracTo = wordsFrac;

if (overflow || truncated) {
if (wordsIntTo < oldWordsIntTo) {
binIdx += dig2bytes[leadingDigits] + (wordsInt - wordsIntTo) * wordSize;
Expand All @@ -151,8 +154,8 @@ public int fromBin(int precision, int frac, int[] bin) {
}

this.negative = mask != 0;
this.digitsInt = wordsInt * digitsPerWord + leadingDigits;
this.digitsFrac = wordsFrac * digitsPerWord + trailingDigits;
this.digitsInt = (byte)(wordsInt * digitsPerWord + leadingDigits);
this.digitsFrac = (byte)(wordsFrac * digitsPerWord + trailingDigits);

int wordIdx = 0;
if (leadingDigits > 0) {
Expand Down Expand Up @@ -264,25 +267,26 @@ private int digitsToWords(int digits) {
/**
* Reads a word from a array at given size.
*
* @param b b is source data.
* @param b b is source data of unsigned byte as int[]
* @param size is word size which can be used in switch statement.
* @param start start indicates the where start to read.
*/
private int readWord(int[] b, int size, int start) {
@VisibleForTesting
public static int readWord(int[] b, int size, int start) {
int x = 0;
switch (size) {
case 1:
x = b[start];
x = (byte)b[start];
break;
case 2:
x = (b[start] << 8) + b[start + 1];
x = (((byte)b[start]) << 8) + (b[start + 1] & 0xFF);
break;
case 3:
int sign = b[start] & 128;
if (sign > 0) {
x = 255 << 24 | (b[start] & 0xFF) << 16 | (b[start + 1] & 0xFF) << 8 | (b[start + 2]);
x = 0xFF << 24 | (b[start] << 16) | (b[start + 1] << 8) | (b[start + 2]);
} else {
x = b[start] << 16 | b[start + 1] << 8 | b[start + 2];
x = b[start] << 16 | (b[start + 1] << 8) | b[start + 2];
}
break;
case 4:
Expand All @@ -292,6 +296,12 @@ private int readWord(int[] b, int size, int start) {
return x;
}

public static void main(String args[]) {
int[] b = new int[]{250,250,250};
int x = 255 << 24 | (b[0] << 16) | (b[0 + 1] << 8) | (b[0 + 2]);
System.out.println(x);
}

/**
* parser a decimal value from a string.
*
Expand Down Expand Up @@ -320,7 +330,7 @@ private void fromCharArray(char[] str) {
// [-, 1, 2, 3]
// [+, 1, 2, 3]
// for +/-, we need skip them and record sign information into negative field.
switch (str[0]) {
switch (str[startIdx]) {
case '-':
this.negative = true;
startIdx++;
Expand All @@ -335,8 +345,8 @@ private void fromCharArray(char[] str) {
}
// we initialize strIdx in case of sign notation, here we need substract startIdx from strIdx casue strIdx is used for counting the number of digits.
int digitsInt = strIdx - startIdx;
int digitsFrac = 0;
int endIdx = 0;
int digitsFrac;
int endIdx;
if (strIdx < str.length && str[strIdx] == '.') {
endIdx = strIdx + 1;
// detect where is the end index of this char array.
Expand All @@ -363,13 +373,12 @@ private void fromCharArray(char[] str) {
wordsInt = wordBufLen;
wordsFrac = 0;
overflow = true;
} else {
wordsFrac = wordBufLen - wordsInt;
truncated = true;
}
// wordsIntTo = wordsInt;
wordsFrac = wordBufLen - wordsInt;
truncated = true;

}
// wordsIntTo = wordsInt;
// wordsFracTo = wordsFrac;

if (overflow || truncated) {
digitsFrac = wordsFrac * digitsPerWord;
Expand Down Expand Up @@ -700,7 +709,6 @@ public int[] toBin(int precision, int frac) {
int originFracSize = fracSize;
int[] bin = new int[intSize + fracSize];
int binIdx = 0;
//TODO, overflow and truncated later
int[] res = this.removeLeadingZeros();
int wordIdxFrom = res[0];
int digitsIntFrom = res[1];
Expand Down
95 changes: 56 additions & 39 deletions tikv-client/src/test/java/com/pingcap/tikv/codec/MyDecimalTest.java
View file
Original file line number Diff line number Diff line change
Expand Up @@ -27,48 +27,66 @@
public class MyDecimalTest {
@Test
public void fromStringTest() throws Exception {
List<MyDecimalTestStruct> test = new ArrayList<>();
test.add(new MyDecimalTestStruct("12345", "12345", 5, 0));
test.add(new MyDecimalTestStruct("12345.", "12345", 5, 0));
test.add(new MyDecimalTestStruct("123.45", "123.45", 5, 2));
test.add(new MyDecimalTestStruct("-123.45", "-123.45", 5, 2));
test.add(new MyDecimalTestStruct(".00012345000098765", "0.00012345000098765", 17, 17));
test.add(new MyDecimalTestStruct(".12345000098765", "0.12345000098765", 14, 14));
test.add(
List<MyDecimalTestStruct> tests = new ArrayList<>();
tests.add(new MyDecimalTestStruct("1111111111111111111111111.111111111111111111111111111111",
"1111111111111111111111111.111111111111111111111111111111", 65, 30));
tests.add(new MyDecimalTestStruct("12345", "12345", 5, 0));
tests.add(new MyDecimalTestStruct("12345.", "12345", 5, 0));
tests.add(new MyDecimalTestStruct("123.45", "123.45", 5, 2));
tests.add(new MyDecimalTestStruct("-123.45", "-123.45", 5, 2));
tests.add(new MyDecimalTestStruct(".00012345000098765", "0.00012345000098765", 17, 17));
tests.add(new MyDecimalTestStruct(".12345000098765", "0.12345000098765", 14, 14));
tests.add(
new MyDecimalTestStruct("-.000000012345000098765", "-0.000000012345000098765", 21, 21));
test.add(new MyDecimalTestStruct("0000000.001", "0.001", 3, 3));
test.add(new MyDecimalTestStruct("1234500009876.5", "1234500009876.5", 14, 1));
test.forEach(
(a) -> {
MyDecimal dec = new MyDecimal();
dec.fromString(a.in);
assertEquals(a.precision, dec.precision());
assertEquals(a.frac, dec.frac());
assertEquals(a.out, dec.toString());
});
tests.add(
new MyDecimalTestStruct("-.000000012345000098765", "-0.000000012345000098765", 2, 21));
tests.add(
new MyDecimalTestStruct("-.000000012345000098765", "-0.000000012345000098765", 21, 2));
tests.add(new MyDecimalTestStruct("0000000.001", "0.001", 3, 3));
tests.add(new MyDecimalTestStruct("1234500009876.5", "1234500009876.5", 14, 1));
for(MyDecimalTestStruct t : tests) {
MyDecimal dec = new MyDecimal();
dec.fromString(t.in);
assertEquals(t.out, dec.toString());
}
}

@Test
public void readWordTest() throws Exception {
assertEquals(MyDecimal.readWord(new int[]{250}, 1, 0), -6);
assertEquals(MyDecimal.readWord(new int[]{50}, 1, 0), 50);

assertEquals(MyDecimal.readWord(new int[]{250, 250}, 2, 0), -1286);
assertEquals(MyDecimal.readWord(new int[]{50, 50}, 2, 0), 12850);

assertEquals(MyDecimal.readWord(new int[]{250, 250, 250}, 3, 0), -328966);
assertEquals(MyDecimal.readWord(new int[]{50, 50, 50}, 3, 0), 3289650);

assertEquals(MyDecimal.readWord(new int[]{250, 250, 250, 250}, 4, 0), -84215046);
assertEquals(MyDecimal.readWord(new int[]{50, 50, 50, 50}, 4, 0), 842150450);
}

@Test
public void toBinToBinFromBinTest() throws Exception {
List<MyDecimalTestStruct> test = new ArrayList<>();
test.add(new MyDecimalTestStruct("-10.55", "-10.55", 4, 2));
test.add(new MyDecimalTestStruct("12345", "12345", 5, 0));
test.add(new MyDecimalTestStruct("-12345", "-12345", 5, 0));
test.add(new MyDecimalTestStruct("0000000.001", "0.001", 3, 3));
test.add(new MyDecimalTestStruct("0.00012345000098765", "0.00012345000098765", 17, 17));
test.add(new MyDecimalTestStruct("-0.00012345000098765", "-0.00012345000098765", 17, 17));
test.forEach(
(a) -> {
MyDecimal dec = new MyDecimal();
dec.fromString(a.in);
assertEquals(a.out, dec.toString());
int[] bin = dec.toBin(dec.precision(), dec.frac());
dec.clear();
dec.fromBin(a.precision, a.frac, bin);
assertEquals(a.precision, dec.precision());
assertEquals(a.frac, dec.frac());
assertEquals(a.out, dec.toString());
});
public void toBinFromBinTest() throws Exception {
List<MyDecimalTestStruct> tests = new ArrayList<>();
String decValStr = "11111111111111111111111111111111111.111111111111111111111111111111";
tests.add(new MyDecimalTestStruct(decValStr, decValStr, 65, 30));
tests.add(new MyDecimalTestStruct("12345000098765", "12345000098765", 14, 0));
tests.add(new MyDecimalTestStruct("-10.55", "-10.55", 4, 2));
tests.add(new MyDecimalTestStruct("12345", "12345", 5, 0));
tests.add(new MyDecimalTestStruct("-12345", "-12345", 5, 0));
tests.add(new MyDecimalTestStruct("0000000.001", "0.001", 3, 3));
tests.add(new MyDecimalTestStruct("0.00012345000098765", "0.00012345000098765", 17, 17));
tests.add(new MyDecimalTestStruct("-0.00012345000098765", "-0.00012345000098765", 17, 17));
for (MyDecimalTestStruct a : tests) {
MyDecimal dec = new MyDecimal();
dec.fromString(a.in);
assertEquals(a.out, dec.toString());
int[] bin = dec.toBin(a.precision, a.frac);
dec.clear();
dec.fromBin(a.precision, a.frac, bin);
assertEquals(a.out, dec.toString());
}
}

@Test
Expand All @@ -80,7 +98,6 @@ public void toBinTest() throws Exception {
new int[] {
0x7E, 0xF2, 0x04, 0xC7, 0x2D, 0xFB, 0x2D,
};
// something wrong with toBin and fromBin
assertArrayEquals(expected, data);
}

Expand Down

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