Emulate unsigned numbers Java 8 API.

Some code and tests adapted from google guava libraries.

Change-Id: Ibcc1a9253f734a11e08c964b5fc067c234ddf8ac

Author: korzha

user/super/com/google/gwt/emul/java/lang/Byte.java

@@ -31,7 +31,7 @@ public final class Byte extends Number implements Comparable<Byte> {
    */
   private static class BoxedValues {
     // Box all values according to JLS
-    private static Byte[] boxedValues = new Byte[256];
+    private static final Byte[] boxedValues = new Byte[256];
 
     // This method should be marked with @HasNoSideEffects but it seems to trigger a bug
     // in the optimizing pipeling and breaks one test.
@@ -70,6 +70,14 @@ public static String toString(byte b) {
     return String.valueOf(b);
   }
 
+  public static int toUnsignedInt(byte b) {
+    return b & 0xff;
+  }
+
+  public static long toUnsignedLong(byte b) {
+    return toUnsignedInt(b);
+  }
+
   public static Byte valueOf(byte b) {
     return BoxedValues.get(b);
   }

user/super/com/google/gwt/emul/java/lang/Character.java

@@ -104,7 +104,7 @@ public java.lang.CharSequence subSequence(int start, int end) {
    */
   private static class BoxedValues {
     // Box values according to JLS - from \u0000 to \u007f
-    private static Character[] boxedValues = new Character[128];
+    private static final Character[] boxedValues = new Character[128];
 
     @HasNoSideEffects
     private static Character get(char c) {

user/super/com/google/gwt/emul/java/lang/Integer.java

@@ -17,6 +17,8 @@
 
 import javaemul.internal.JsUtils;
 import javaemul.internal.annotations.HasNoSideEffects;
+import static javaemul.internal.Coercions.ensureInt;
+import static javaemul.internal.Coercions.toUnsignedInt;
 
 /**
  * Wraps a primitive <code>int</code> as an object.
@@ -34,7 +36,7 @@ public final class Integer extends Number implements Comparable<Integer> {
    */
   private static class BoxedValues {
     // Box values according to JLS - between -128 and 127
-    private static Integer[] boxedValues = new Integer[256];
+    private final static Integer[] boxedValues = new Integer[256];
 
     @HasNoSideEffects
     private static Integer get(int i) {
@@ -81,10 +83,18 @@ public static int compare(int x, int y) {
     }
   }
 
+  public static int compareUnsigned(int a, int b) {
+    return compare(a ^ MIN_VALUE, b ^ MIN_VALUE);
+  }
+
   public static Integer decode(String s) throws NumberFormatException {
     return Integer.valueOf(__decodeAndValidateInt(s, MIN_VALUE, MAX_VALUE));
   }
 
+  public static int divideUnsigned(int dividend, int divisor) {
+    return ensureInt(toUnsignedInt(dividend) / toUnsignedInt(divisor));
+  }
+
   public static int hashCode(int i) {
     return i;
   }
@@ -170,6 +180,37 @@ public static int parseInt(String s, int radix) throws NumberFormatException {
     return __parseAndValidateInt(s, radix, MIN_VALUE, MAX_VALUE);
   }
 
+  public static int parseUnsignedInt(String s) throws NumberFormatException {
+    return parseUnsignedInt(s, 10);
+  }
+
+  public static int parseUnsignedInt(String s, int radix) throws NumberFormatException {
+    if (s == null) {
+      throw NumberFormatException.forNullInputString();
+    }
+
+    int len = s.length();
+    if (len == 0 || s.charAt(0) == '-') {
+      throw NumberFormatException.forInputString(s);
+    }
+
+    // Integer.MAX_VALUE in Character.MAX_RADIX is 6 digits
+    // Integer.MAX_VALUE in base 10 is 10 digits
+    if (len <= 5 || (radix == 10 && len <= 9)) {
+      return parseInt(s, radix);
+    }
+
+    long value = Long.parseLong(s, radix);
+    if (!Long.fitsInUint(value)) {
+      throw NumberFormatException.forInputString(s);
+    }
+    return (int) value;
+  }
+
+  public static int remainderUnsigned(int dividend, int divisor) {
+    return ensureInt(toUnsignedInt(dividend) % toUnsignedInt(divisor));
+  }
+
   public static int reverse(int i) {
     int[] nibbles = ReverseNibbles.reverseNibbles;
     return (nibbles[i >>> 28]) | (nibbles[(i >> 24) & 0xf] << 4)
@@ -249,13 +290,20 @@ public static Integer valueOf(int i) {
     return new Integer(i);
   }
 
+  public static long toUnsignedLong(int x) {
+    return x & 0xffff_ffffL;
+  }
+
+  public static String toUnsignedString(int x) {
+    return toUnsignedString(x, 10);
+  }
+
   public static Integer valueOf(String s) throws NumberFormatException {
     return valueOf(s, 10);
   }
 
-  public static Integer valueOf(String s, int radix)
-      throws NumberFormatException {
-    return Integer.valueOf(Integer.parseInt(s, radix));
+  public static Integer valueOf(String s, int radix) throws NumberFormatException {
+    return valueOf(parseInt(s, radix));
   }
 
   private final transient int value;

user/super/com/google/gwt/emul/java/lang/Long.java

@@ -24,7 +24,7 @@ public final class Long extends Number implements Comparable<Long> {
   /** Use nested class to avoid clinit on outer. */
   static class BoxedValues {
     // Box values according to JLS - between -128 and 127
-    static Long[] boxedValues = new Long[256];
+    static final Long[] boxedValues = new Long[256];
 
     @HasNoSideEffects
     private static Long get(long l) {
@@ -59,11 +59,44 @@ public static int compare(long x, long y) {
     }
   }
 
+  public static int compareUnsigned(long a, long b) {
+    return compare(a ^ MIN_VALUE, b ^ MIN_VALUE);
+  }
+
   public static Long decode(String s) throws NumberFormatException {
     __Decode decode = __decodeNumberString(s);
     return valueOf(decode.payload, decode.radix);
   }
 
+  public static long divideUnsigned(long dividend, long divisor) {
+    if (divisor < 0) { // i.e., divisor >= 2^63:
+      if (compare(dividend, divisor) < 0) {
+        return 0; // dividend < divisor
+      } else {
+        return 1; // dividend >= divisor
+      }
+    }
+
+    // Optimization - use signed division if dividend < 2^63
+    if (dividend >= 0) {
+      return dividend / divisor;
+    }
+
+    /*
+     * Otherwise, approximate the quotient, check, and correct if necessary. Our approximation is
+     * guaranteed to be either exact or one less than the correct value. This follows from fact
+     * that floor(floor(x)/i) == floor(x/i) for any real x and integer i != 0. The proof is not
+     * quite trivial.
+     */
+    long quotient = ((dividend >>> 1) / divisor) << 1;
+    long rem = dividend - quotient * divisor;
+    if (compare(rem, divisor) >= 0) {
+      return quotient + 1;
+    } else {
+      return quotient;
+    }
+  }
+
   public static int hashCode(long l) {
     return LongUtils.getHighBits(l) ^ (int) l;
   }
@@ -121,6 +154,43 @@ public static long reverse(long l) {
     return LongUtils.fromBits(Integer.reverse(high), Integer.reverse(low));
   }
 
+  public static long parseUnsignedLong(String s) throws NumberFormatException {
+    return parseUnsignedLong(s, 10);
+  }
+
+  public static long parseUnsignedLong(String s, int radix) throws NumberFormatException {
+    return __parseAndValidateUnsignedLong(s, radix);
+  }
+
+  public static long remainderUnsigned(long dividend, long divisor) {
+    if (divisor < 0) { // i.e., divisor >= 2^63:
+      if (compare(dividend, divisor) < 0) {
+        return dividend; // dividend < divisor
+      } else {
+        return dividend - divisor; // dividend >= divisor
+      }
+    }
+
+    // Optimization - use signed modulus if dividend < 2^63
+    if (dividend >= 0) {
+      return dividend % divisor;
+    }
+
+    /*
+     * Otherwise, approximate the quotient, check, and correct if necessary. Our approximation is
+     * guaranteed to be either exact or one less than the correct value. This follows from fact
+     * that floor(floor(x)/i) == floor(x/i) for any real x and integer i != 0. The proof is not
+     * quite trivial.
+     */
+    long quotient = ((dividend >>> 1) / divisor) << 1;
+    long rem = dividend - quotient * divisor;
+    if (compare(rem, divisor) >= 0) {
+      return rem - divisor;
+    } else {
+      return rem;
+    }
+  }
+
   public static long reverseBytes(long l) {
     int high = LongUtils.getHighBits(l);
     int low = (int) l;
@@ -163,15 +233,15 @@ public static long sum(long a, long b) {
   }
 
   public static String toBinaryString(long value) {
-    return toPowerOfTwoUnsignedString(value, 1);
+    return toUnsignedString(value, 2);
   }
 
   public static String toHexString(long value) {
-    return toPowerOfTwoUnsignedString(value, 4);
+    return toUnsignedString(value, 16);
   }
 
   public static String toOctalString(long value) {
-    return toPowerOfTwoUnsignedString(value, 3);
+    return toUnsignedString(value, 8);
   }
 
   public static String toString(long value) {
@@ -219,11 +289,89 @@ public static String toString(long value, int intRadix) {
 
   public static Long valueOf(long l) {
     if (l > -129 && l < 128) {
-      return BoxedValues.get(l);
+        return BoxedValues.get(l);
     }
     return new Long(l);
   }
 
+  public static String toUnsignedString(long value) {
+    return toUnsignedString(value, 10);
+  }
+
+  public static String toUnsignedString(long value, int intRadix) {
+    if (fitsInUint(value)) {
+      return Integer.toUnsignedString((int) value, intRadix);
+    }
+
+    if (intRadix < Character.MIN_RADIX || intRadix > Character.MAX_RADIX) {
+      intRadix = 10;
+    }
+
+    if (isPowerOfTwo(intRadix)) {
+      return toPowerOfTwoUnsignedString(value, intRadix);
+    }
+
+    if (value >= 0) {
+      return toString(value, intRadix);
+    }
+
+    // Convert radix to long before hand to avoid costly conversion on each iteration.
+    long radix = intRadix;
+    if (intRadix == 10) {
+      long quotient = divideUnsigned(value, radix);
+      int rem = (int) (value - quotient * radix);
+      return toString(quotient) + rem;
+    }
+
+    int bufLen = intRadix < 8 ? 65 : 23; // Max chars in result (conservative)
+    char[] buf = new char[bufLen];
+    int cursor = bufLen;
+    if (value < 0) {
+      // Separate off the last digit using unsigned division. That will leave
+      // a number that is nonnegative as a signed integer.
+      long quotient = divideUnsigned(value, radix);
+      int rem = (int) (value - quotient * radix);
+      buf[--cursor] = Character.forDigit(rem, intRadix);
+      value = quotient;
+    }
+
+    // Simple modulo/division approach
+    while (value > 0) {
+      buf[--cursor] = Character.forDigit((int) (value % radix), intRadix);
+      value /= radix;
+    }
+
+    return new String(buf, cursor, buf.length - cursor);
+  }
+
+  private static String toPowerOfTwoUnsignedString(long value, int radix) {
+    final int shift = log2(radix);
+
+    final int mask = radix - 1;
+    final int bufSize = 64 / shift + 1;
+    char[] buf = new char[bufSize];
+    int pos = bufSize;
+    do {
+      buf[--pos] = Character.forDigit(((int) value) & mask);
+      value >>>= shift;
+    } while (value != 0);
+
+    return String.valueOf(buf, pos, bufSize - pos);
+  }
+
+  private static boolean isPowerOfTwo(int x) {
+    return (x & (x - 1)) == 0;
+  }
+
+  private static int log2(int x) {
+    return (Integer.SIZE - 1) - Integer.numberOfLeadingZeros(x);
+  }
+
+  static boolean fitsInUint(long value) {
+    int highBits = (int) (value >> 32);
+    return highBits == 0;
+  }
+
   public static Long valueOf(String s) throws NumberFormatException {
     return valueOf(s, 10);
   }