From c0f38b3f8d862d8ce38c36ad7459494a11d833e3 Mon Sep 17 00:00:00 2001
From: Sven Gothel <sgothel@jausoft.com>
Date: Fri, 31 Jul 2015 04:55:06 +0200
Subject: Bitfield: Refine impl. complete get/put 32bit, add copy*(..), add
synchronized delegation; TODO: Unit tests.
---
src/java/jogamp/common/util/Int32Bitfield.java | 83 +++++++++++++++++++-------
1 file changed, 63 insertions(+), 20 deletions(-)
(limited to 'src/java/jogamp/common/util/Int32Bitfield.java')
diff --git a/src/java/jogamp/common/util/Int32Bitfield.java b/src/java/jogamp/common/util/Int32Bitfield.java
index f81b486..6119a00 100644
--- a/src/java/jogamp/common/util/Int32Bitfield.java
+++ b/src/java/jogamp/common/util/Int32Bitfield.java
@@ -49,22 +49,55 @@ public class Int32Bitfield implements Bitfield {
return UNIT_SIZE;
}
- private final void check(final int limit, final int bitnum) throws IndexOutOfBoundsException {
- if( 0 > bitnum || bitnum >= limit ) {
- throw new IndexOutOfBoundsException("Bitnum should be within [0.."+(limit-1)+"], but is "+bitnum);
+ private static final void check(final int size, final int bitnum) throws IndexOutOfBoundsException {
+ if( 0 > bitnum || bitnum >= size ) {
+ throw new IndexOutOfBoundsException("Bitnum should be within [0.."+(size-1)+"], but is "+bitnum);
}
}
@Override
- public final int getInt32(final int rightBitnum) throws IndexOutOfBoundsException {
- check(UNIT_SIZE-31, rightBitnum);
- return storage;
+ public final int get32(final int lowBitnum, final int length) throws IndexOutOfBoundsException {
+ if( 0 > length || length > 32 ) {
+ throw new IndexOutOfBoundsException("length should be within [0..32], but is "+length);
+ }
+ check(UNIT_SIZE-length+1, lowBitnum);
+ final int left = 32 - lowBitnum; // remaining bits of first chunk
+ if( 32 == left ) {
+ // fast path
+ final int m = ( 1 << length ) - 1;
+ return m & storage;
+ } else {
+ // slow path
+ final int l = Math.min(length, left); // length of first chunk
+ final int m = ( 1 << l ) - 1; // mask of first chunk
+ return m & ( storage >>> lowBitnum );
+ }
}
-
@Override
- public final void putInt32(final int rightBitnum, final int mask) throws IndexOutOfBoundsException {
- check(UNIT_SIZE-31, rightBitnum);
- storage = mask;
+ public final void put32(final int lowBitnum, final int length, final int data) throws IndexOutOfBoundsException {
+ if( 0 > length || length > 32 ) {
+ throw new IndexOutOfBoundsException("length should be within [0..32], but is "+length);
+ }
+ check(UNIT_SIZE-length+1, lowBitnum);
+ final int left = 32 - lowBitnum; // remaining bits of first chunk storage
+ if( 32 == left ) {
+ // fast path
+ final int m = ( 1 << length ) - 1; // mask of chunk
+ storage = ( ( ~m ) & storage ) // keep non-written storage bits
+ | ( m & data ); // overwrite storage w/ used data bits
+ } else {
+ // slow path
+ final int l = Math.min(length, left); // length of first chunk
+ final int m = ( 1 << l ) - 1; // mask of first chunk
+ storage = ( ( ~( m << lowBitnum ) ) & storage ) // keep non-written storage bits
+ | ( ( m & data ) << lowBitnum ); // overwrite storage w/ used data bits
+ }
+ }
+ @Override
+ public final int copy32(final int srcBitnum, final int dstBitnum, final int length) throws IndexOutOfBoundsException {
+ final int data = get32(srcBitnum, length);
+ put32(dstBitnum, length, data);
+ return data;
}
@Override
@@ -72,20 +105,15 @@ public class Int32Bitfield implements Bitfield {
check(UNIT_SIZE, bitnum);
return 0 != ( storage & ( 1 << bitnum ) ) ;
}
-
@Override
- public final boolean put(final int bitnum, final boolean bit) throws IndexOutOfBoundsException {
+ public final void put(final int bitnum, final boolean bit) throws IndexOutOfBoundsException {
check(UNIT_SIZE, bitnum);
final int m = 1 << bitnum;
- final boolean prev = 0 != ( storage & m ) ;
- if( prev != bit ) {
- if( bit ) {
- storage |= m;
- } else {
- storage &= ~m;
- }
+ if( bit ) {
+ storage |= m;
+ } else {
+ storage &= ~m;
}
- return prev;
}
@Override
public final void set(final int bitnum) throws IndexOutOfBoundsException {
@@ -99,6 +127,21 @@ public class Int32Bitfield implements Bitfield {
final int m = 1 << bitnum;
storage &= ~m;
}
+ @Override
+ public final boolean copy(final int srcBitnum, final int dstBitnum) throws IndexOutOfBoundsException {
+ check(UNIT_SIZE, srcBitnum);
+ check(UNIT_SIZE, dstBitnum);
+ // get
+ final boolean bit = 0 != ( storage & ( 1 << srcBitnum ) ) ;
+ // put
+ final int m = 1 << dstBitnum;
+ if( bit ) {
+ storage |= m;
+ } else {
+ storage &= ~m;
+ }
+ return bit;
+ }
@Override
public int getBitCount() {
--
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