| /** |
| ******************************************************************************* |
| * Copyright (C) 1996-2005, International Business Machines Corporation and * |
| * others. All Rights Reserved. * |
| ******************************************************************************* |
| * |
| * |
| ******************************************************************************* |
| */ |
| |
| package libcore.icu; |
| |
| import java.text.CollationKey; |
| |
| /** |
| * A concrete implementation of the abstract java.text.CollationKey. |
| */ |
| public final class CollationKeyICU extends CollationKey { |
| /** |
| * The key. |
| */ |
| private final byte[] bytes; |
| |
| /** |
| * Cached hash value. |
| */ |
| private int hashCode; |
| |
| CollationKeyICU(String source, byte[] bytes) { |
| super(source); |
| this.bytes = bytes; |
| } |
| |
| @Override public int compareTo(CollationKey other) { |
| // Get the bytes from the other collation key. |
| final byte[] rhsBytes; |
| if (other instanceof CollationKeyICU) { |
| rhsBytes = ((CollationKeyICU) other).bytes; |
| } else { |
| rhsBytes = other.toByteArray(); |
| } |
| |
| if (bytes == null || bytes.length == 0) { |
| if (rhsBytes == null || rhsBytes.length == 0) { |
| return 0; |
| } |
| return -1; |
| } else { |
| if (rhsBytes == null || rhsBytes.length == 0) { |
| return 1; |
| } |
| } |
| |
| int count = Math.min(bytes.length, rhsBytes.length); |
| for (int i = 0; i < count; ++i) { |
| int s = bytes[i] & 0xff; |
| int t = rhsBytes[i] & 0xff; |
| if (s < t) { |
| return -1; |
| } |
| if (s > t) { |
| return 1; |
| } |
| } |
| if (bytes.length < rhsBytes.length) { |
| return -1; |
| } |
| if (bytes.length > rhsBytes.length) { |
| return 1; |
| } |
| return 0; |
| } |
| |
| @Override public boolean equals(Object object) { |
| if (object == this) { |
| return true; |
| } |
| if (!(object instanceof CollationKey)) { |
| return false; |
| } |
| return compareTo((CollationKey) object) == 0; |
| } |
| |
| /** |
| * Creates a hash code for this CollationKey. |
| * Compute the hash by iterating sparsely over about 32 (up to 63) bytes |
| * spaced evenly through the string. For each byte, multiply the previous |
| * hash value by a prime number and add the new byte in, like a linear |
| * congruential random number generator, producing a pseudo-random |
| * deterministic value well distributed over the output range. |
| * @return hash value of collation key. Hash value is never 0. |
| * @stable ICU 2.4 |
| */ |
| @Override public int hashCode() { |
| if (hashCode == 0) { |
| if (bytes != null && bytes.length != 0) { |
| int len = bytes.length; |
| int inc = ((len - 32) / 32) + 1; |
| for (int i = 0; i < len;) { |
| hashCode = (hashCode * 37) + bytes[i]; |
| i += inc; |
| } |
| } |
| if (hashCode == 0) { |
| hashCode = 1; |
| } |
| } |
| return hashCode; |
| } |
| |
| @Override public byte[] toByteArray() { |
| if (bytes == null || bytes.length == 0) { |
| return null; |
| } |
| return bytes.clone(); |
| } |
| } |