Mercurial > projects > dwt2
view org.eclipse.swt.win32.win32.x86/src/org/eclipse/swt/internal/image/TIFFRandomFileAccess.d @ 4:6bf2837c50fe
Created own class for Math
author | Frank Benoit <benoit@tionex.de> |
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date | Wed, 04 Mar 2009 23:46:02 +0100 |
parents | 6dd524f61e62 |
children | f36c67707cb3 |
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/******************************************************************************* * Copyright (c) 2000, 2003 IBM Corporation and others. * All rights reserved. This program and the accompanying materials * are made available under the terms of the Eclipse Public License v1.0 * which accompanies this distribution, and is available at * http://www.eclipse.org/legal/epl-v10.html * * Contributors: * IBM Corporation - initial API and implementation * Port to the D programming language: * Frank Benoit <benoit@tionex.de> *******************************************************************************/ module org.eclipse.swt.internal.image.TIFFRandomFileAccess; import org.eclipse.swt.internal.image.LEDataInputStream; import tango.core.Exception; import java.lang.all; final class TIFFRandomFileAccess { LEDataInputStream inputStream; int start, current, next; byte[][] buffers; static final int CHUNK_SIZE = 8192; static final int LIST_SIZE = 128; public this(LEDataInputStream stream) { inputStream = stream; start = current = next = inputStream.getPosition(); buffers = new byte[][](LIST_SIZE); } void seek(int pos) { if (pos is current) return; if (pos < start) throw new IOException( "pos < start" ); current = pos; if (current > next) { int n = current - next; /* store required bytes */ int index = next / CHUNK_SIZE; int offset = next % CHUNK_SIZE; while (n > 0) { if (index >= buffers.length) { byte[][] oldBuffers = buffers; buffers = new byte[][]( Math.max(index + 1, oldBuffers.length + LIST_SIZE) ); System.arraycopy(oldBuffers, 0, buffers, 0, oldBuffers.length); } if (buffers[index] is null) buffers[index] = new byte[CHUNK_SIZE]; int cnt = inputStream.read(buffers[index], offset, Math.min(n, CHUNK_SIZE - offset)); n -= cnt; next += cnt; index++; offset = 0; } } } void read(byte b[]) { int size = b.length; int nCached = Math.min(size, next - current); int nMissing = size - next + current; int destNext = 0; if (nCached > 0) { /* Get cached bytes */ int index = current / CHUNK_SIZE; int offset = current % CHUNK_SIZE; while (nCached > 0) { int cnt = Math.min(nCached, CHUNK_SIZE - offset); System.arraycopy(buffers[index], offset, b, destNext, cnt); nCached -= cnt; destNext += cnt; index++; offset = 0; } } if (nMissing > 0) { /* Read required bytes */ int index = next / CHUNK_SIZE; int offset = next % CHUNK_SIZE; while (nMissing > 0) { if (index >= buffers.length) { byte[][] oldBuffers = buffers; buffers = new byte[][](Math.max(index, oldBuffers.length + LIST_SIZE)); System.arraycopy(oldBuffers, 0, buffers, 0, oldBuffers.length); } if (buffers[index] is null) buffers[index] = new byte[CHUNK_SIZE]; int cnt = inputStream.read(buffers[index], offset, Math.min(nMissing, CHUNK_SIZE - offset)); System.arraycopy(buffers[index], offset, b, destNext, cnt); nMissing -= cnt; next += cnt; destNext += cnt; index++; offset = 0; } } current += size; } }