1.1 --- /dev/null	Thu Jan 01 00:00:00 1970 +0000
     1.2 +++ b/javap/src/main/java/org/apidesign/javap/StackMapIterator.java	Thu Nov 29 20:19:00 2012 +0100
     1.3 @@ -0,0 +1,94 @@
     1.4 +/*
     1.5 + * Copyright (c) 2012, Oracle and/or its affiliates. All rights reserved.
     1.6 + * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
     1.7 + *
     1.8 + * This code is free software; you can redistribute it and/or modify it
     1.9 + * under the terms of the GNU General Public License version 2 only, as
    1.10 + * published by the Free Software Foundation.  Oracle designates this
    1.11 + * particular file as subject to the "Classpath" exception as provided
    1.12 + * by Oracle in the LICENSE file that accompanied this code.
    1.13 + *
    1.14 + * This code is distributed in the hope that it will be useful, but WITHOUT
    1.15 + * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
    1.16 + * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
    1.17 + * version 2 for more details (a copy is included in the LICENSE file that
    1.18 + * accompanied this code).
    1.19 + *
    1.20 + * You should have received a copy of the GNU General Public License version
    1.21 + * 2 along with this work; if not, write to the Free Software Foundation,
    1.22 + * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
    1.23 + *
    1.24 + * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
    1.25 + * or visit www.oracle.com if you need additional information or have any
    1.26 + * questions.
    1.27 + */
    1.28 +
    1.29 +package org.apidesign.javap;
    1.30 +
    1.31 +public final class StackMapIterator {
    1.32 +    private static final StackMapTableData INITIAL_FRAME =
    1.33 +            new StackMapTableData(-1) {
    1.34 +                @Override
    1.35 +                int getStackItemsCount() {
    1.36 +                    return 0;
    1.37 +                }
    1.38 +
    1.39 +                @Override
    1.40 +                public String toString() {
    1.41 +                    return "INITIAL(0)";
    1.42 +                }
    1.43 +            };
    1.44 +
    1.45 +    private final StackMapTableData[] stackMapTable;
    1.46 +
    1.47 +    private int nextFrameIndex;
    1.48 +    private int lastFrameByteCodeOffset;
    1.49 +
    1.50 +    private int byteCodeOffset;
    1.51 +
    1.52 +    StackMapIterator(final StackMapTableData[] stackMapTable) {
    1.53 +        this.stackMapTable = (stackMapTable != null)
    1.54 +                                 ? stackMapTable
    1.55 +                                 : new StackMapTableData[0];
    1.56 +        this.lastFrameByteCodeOffset = -1;
    1.57 +        advanceBy(0);
    1.58 +    }
    1.59 +
    1.60 +    public String getFrameAsString() {
    1.61 +        return getCurrentFrame().toString();
    1.62 +    }
    1.63 +
    1.64 +    public int getFrameIndex() {
    1.65 +        return nextFrameIndex;
    1.66 +    }
    1.67 +
    1.68 +    public int getFrameStackItemsCount() {
    1.69 +        return getCurrentFrame().getStackItemsCount();
    1.70 +    }
    1.71 +
    1.72 +    public void advanceBy(final int numByteCodes) {
    1.73 +        if (numByteCodes < 0) {
    1.74 +            throw new IllegalStateException("Forward only iterator");
    1.75 +        }
    1.76 +
    1.77 +        byteCodeOffset += numByteCodes;
    1.78 +        while ((nextFrameIndex < stackMapTable.length)
    1.79 +                    && ((byteCodeOffset - lastFrameByteCodeOffset)
    1.80 +                            >= (stackMapTable[nextFrameIndex].offsetDelta
    1.81 +                                    + 1))) {
    1.82 +            lastFrameByteCodeOffset +=
    1.83 +                    stackMapTable[nextFrameIndex].offsetDelta + 1;
    1.84 +            ++nextFrameIndex;
    1.85 +        }
    1.86 +    }
    1.87 +
    1.88 +    public void advanceTo(final int nextByteCodeOffset) {
    1.89 +        advanceBy(nextByteCodeOffset - byteCodeOffset);
    1.90 +    }
    1.91 +
    1.92 +    private StackMapTableData getCurrentFrame() {
    1.93 +        return (nextFrameIndex == 0)
    1.94 +                ? INITIAL_FRAME
    1.95 +                : stackMapTable[nextFrameIndex - 1];
    1.96 +    }
    1.97 +}