add more method for Bits

Author: 15045120

build.gradle

@@ -26,7 +26,7 @@ tasks.withType(JavaCompile) { options.encoding = "UTF-8" }
 
 group = 'com.github.myibu'
 archivesBaseName = "algorithm-java"
-version = "1.0.0e"
+version = "1.0.0f"
 
 repositories {
  mavenCentral()

readme.md

@@ -57,7 +57,7 @@ Reference to: [HoffmanAndGolombCoding.pdf](./docs/HoffmanAndGolombCoding.pdf)
 <dependency>
  <groupId>com.github.myibu</groupId>
  <artifactId>algorithm-java</artifactId>
- <version>1.0.0e</version>
+ <version>1.0.0f</version>
 </dependency>
 ```
 

src/main/java/com/github/myibu/algorithm/data/Bits.java

@@ -3,6 +3,7 @@
 import java.nio.charset.StandardCharsets;
 import java.util.Arrays;
 import java.util.Iterator;
+import java.util.List;
 import java.util.NoSuchElementException;
 
 /**
@@ -546,8 +547,19 @@ static void subBitsRangeCheck(int fromIndex, int toIndex, int size) {
  ") > toIndex(" + toIndex + ")");
  }
 
+ @Deprecated
  public Bit[] table(){
- return this.table;
+ return toArray();
+ }
+
+ public Bit[] toArray() {
+ return Arrays.copyOf(table, used);
+ }
+
+ public List<Bit> toList() {
+ Bit[] usedTable = new Bit[used];
+ System.arraycopy(table, 0, usedTable, 0, used);
+ return Arrays.asList(usedTable);
  }
 
  @Override
@@ -593,6 +605,14 @@ public Bit get(int index) {
  return table[index];
  }
 
+ public Bit set(int index, Bit bit) {
+ if (index < 0 || index >= used)
+ throw new IndexOutOfBoundsException();
+ Bit oldValue = table[index];
+ table[index] = bit;
+ return oldValue;
+ }
+
  @Override
  public Bits clone() {
  Bits dest = null;
@@ -618,4 +638,77 @@ public boolean equals(Object o) {
  public int hashCode() {
  return Arrays.hashCode(table);
  }
+
+ public static void copy(Bits src, int srcPos, Bits dest, int destPos, int length) {
+ System.arraycopy(src.table, srcPos, dest.table, destPos, length);
+ }
+
+ public static class Encoder {
+ public static Bits encodeIntValue(int value) {
+ Bits bits = new Bits();
+ int div = 0;
+ while ((div = (value / 2)) != 0) {
+ int left = value - div * 2;
+ bits.append(left == 0 ? Bit.ZERO : Bit.ONE);
+ value = div;
+ }
+ bits.append(value == 1 ? Bit.ONE : Bit.ZERO);
+ return Bits.reverse(bits);
+ }
+
+ public static Bits encodeDecimalValue(double value) {
+ Bits bits = new Bits();
+ while (!firstNumAfterDotIsZero(value)) {
+ int left = (int)(value * 2);
+ bits.append(left == 0 ? Bit.ZERO : Bit.ONE);
+ value = value * 2 - left;
+ }
+ return bits;
+ }
+
+ private static boolean firstNumAfterDotIsZero(double value) {
+ String doubleValue = "" + value;
+ int dotIndex = -1;
+ if ((dotIndex = doubleValue.indexOf(".")) != -1) {
+ if (dotIndex + 1 < doubleValue.length()) {
+ return doubleValue.charAt(dotIndex+1) == '0';
+ }
+ }
+ return false;
+ }
+
+ public static Bits encodeFloatValue(float value) {
+ int intValue = (int)value;
+ float dotValue = value - intValue;
+ Bits bits1 = encodeIntValue(intValue);
+ Bits bits2 = encodeDecimalValue(dotValue);
+ Bits S = value < 0 ? Bits.ofOne() : Bits.ofZero();
+ Bits E = Bits.ofZero(8);
+ Bits eValue = encodeIntValue(bits1.length() - 1 + 127);
+ Bits.copy(eValue, 0, E, 0,8);
+ Bits M = Bits.ofZero(23);
+ Bits.copy(bits1, 1, M, 0, bits1.length() - 1);
+ Bits.copy(bits2, 0, M, bits1.length() - 1, bits2.length());
+ return S.append(E).append(M);
+ }
+
+ public static Bits encodeDoubleValue(double value) {
+ int intValue = (int)value;
+ double dotValue = value - intValue;
+ Bits bits1 = encodeIntValue(intValue);
+ Bits bits2 = encodeDecimalValue(dotValue);
+ Bits S = value < 0 ? Bits.ofOne() : Bits.ofZero();
+ Bits E = Bits.ofZero(11);
+ Bits eValue = encodeIntValue(bits1.length() - 1 + 1023);
+ Bits.copy(eValue, 0, E, 0,11);
+ Bits M = Bits.ofZero(52);
+ Bits.copy(bits1, 1, M, 0, bits1.length() - 1);
+ Bits.copy(bits2, 0, M, bits1.length() - 1, bits2.length());
+ return S.append(E).append(M);
+ }
+
+ public static Bits encodeStringValue(String value) {
+ return Bits.ofByte(value.getBytes(StandardCharsets.UTF_8));
+ }
+ }
 }