Compressed Macintosh resource data, Apple `'dcmp' (0)` format: Java parsing library

Compressed resource data in 'dcmp' (0) format, as stored in compressed resources with header type 8 and decompressor ID 0.

The 'dcmp' (0) decompressor resource is included in the System file of System 7.0 and later. This compression format is used for most compressed resources in System 7.0's files. This decompressor is also included with and used by some other Apple applications, such as ResEdit.

This compression format supports some basic general-purpose compression schemes, including backreferences to previous data, run-length encoding, and delta encoding. It also includes some types of compression tailored specifically to Mac OS resources, including a set of single-byte codes that correspond to entries in a hard-coded lookup table, and a specialized kind of delta encoding for segment loader jump tables.

Almost all parts of this compression format operate on units of 2 or 4 bytes. As a result, it is nearly impossible to store data with an odd length in this format. To work around this limitation, odd-length resources are padded with an extra byte before compressing them with this format. This extra byte is ignored after decompression, as the real (odd) length of the resource is stored in the compressed resource header.

The 'dcmp' (1) compression format (see dcmp_1.ksy) is very similar to this format, with the main difference that it operates mostly on single bytes rather than two-byte units.

Application

Mac OS

KS implementation details

License: MIT
Minimal Kaitai Struct required: 0.8

This page hosts a formal specification of Compressed Macintosh resource data, Apple `'dcmp' (0)` format using Kaitai Struct. This specification can be automatically translated into a variety of programming languages to get a parsing library.

Usage

Runtime library

All parsing code for Java generated by Kaitai Struct depends on the Java runtime library. You have to install it before you can parse data.

The Java runtime library is published in the Maven Central Repository. Refer to the artifact page for instructions how to add it into your project with the build tool that you use.

Code

Parse a local file and get structure in memory:

Dcmp0 data = Dcmp0.fromFile("path/to/local/file.Compressed Macintosh resource data, Apple `'dcmp' (0)` format");

Or parse structure from a byte array:

byte[] someArray = new byte[] { ... };
Dcmp0 data = new Dcmp0(new ByteBufferKaitaiStream(someArray));

After that, one can get various attributes from the structure by invoking getter methods like:

data.chunks() // => The sequence of chunks that make up the compressed data.

Java source code to parse Compressed Macintosh resource data, Apple `'dcmp' (0)` format

Dcmp0.java

// This is a generated file! Please edit source .ksy file and use kaitai-struct-compiler to rebuild

import io.kaitai.struct.ByteBufferKaitaiStream;
import io.kaitai.struct.KaitaiStruct;
import io.kaitai.struct.KaitaiStream;
import java.io.IOException;
import java.util.ArrayList;
import java.util.Map;
import java.util.HashMap;
import java.util.Arrays;


/**
 * Compressed resource data in `'dcmp' (0)` format,
 * as stored in compressed resources with header type `8` and decompressor ID `0`.
 * 
 * The `'dcmp' (0)` decompressor resource is included in the System file of System 7.0 and later.
 * This compression format is used for most compressed resources in System 7.0's files.
 * This decompressor is also included with and used by some other Apple applications,
 * such as ResEdit.
 * 
 * This compression format supports some basic general-purpose compression schemes,
 * including backreferences to previous data,
 * run-length encoding,
 * and delta encoding.
 * It also includes some types of compression tailored specifically to Mac OS resources,
 * including a set of single-byte codes that correspond to entries in a hard-coded lookup table,
 * and a specialized kind of delta encoding for segment loader jump tables.
 * 
 * Almost all parts of this compression format operate on units of 2 or 4 bytes.
 * As a result,
 * it is nearly impossible to store data with an odd length in this format.
 * To work around this limitation,
 * odd-length resources are padded with an extra byte before compressing them with this format.
 * This extra byte is ignored after decompression,
 * as the real (odd) length of the resource is stored in the compressed resource header.
 * 
 * The `'dcmp' (1)` compression format (see dcmp_1.ksy) is very similar to this format,
 * with the main difference that it operates mostly on single bytes rather than two-byte units.
 * @see <a href="https://github.com/dgelessus/python-rsrcfork/tree/master/rsrcfork/compress/dcmp0.py">Source</a>
 */
public class Dcmp0 extends KaitaiStruct {
    public static Dcmp0 fromFile(String fileName) throws IOException {
        return new Dcmp0(new ByteBufferKaitaiStream(fileName));
    }

    public Dcmp0(KaitaiStream _io) {
        this(_io, null, null);
    }

    public Dcmp0(KaitaiStream _io, KaitaiStruct _parent) {
        this(_io, _parent, null);
    }

    public Dcmp0(KaitaiStream _io, KaitaiStruct _parent, Dcmp0 _root) {
        super(_io);
        this._parent = _parent;
        this._root = _root == null ? this : _root;
        _read();
    }
    private void _read() {
        this.chunks = new ArrayList<Chunk>();
        {
            Chunk _it;
            int i = 0;
            do {
                _it = new Chunk(this._io, this, _root);
                this.chunks.add(_it);
                i++;
            } while (!(_it.tag() == 255));
        }
    }

    /**
     * A single chunk of compressed data.
     * Each chunk in the compressed data expands to a sequence of bytes in the uncompressed data,
     * except when `tag == 0xff`,
     * which marks the end of the data and does not correspond to any bytes in the uncompressed data.
     * 
     * Most chunks are stateless and always expand to the same data,
     * regardless of where the chunk appears in the sequence.
     * However,
     * some chunks affect the behavior of future chunks,
     * or expand to different data depending on which chunks came before them.
     */
    public static class Chunk extends KaitaiStruct {
        public static Chunk fromFile(String fileName) throws IOException {
            return new Chunk(new ByteBufferKaitaiStream(fileName));
        }

        public enum TagKind {
            INVALID(-1),
            LITERAL(0),
            BACKREFERENCE(1),
            TABLE_LOOKUP(2),
            EXTENDED(3),
            END(4);

            private final long id;
            TagKind(long id) { this.id = id; }
            public long id() { return id; }
            private static final Map<Long, TagKind> byId = new HashMap<Long, TagKind>(6);
            static {
                for (TagKind e : TagKind.values())
                    byId.put(e.id(), e);
            }
            public static TagKind byId(long id) { return byId.get(id); }
        }

        public Chunk(KaitaiStream _io) {
            this(_io, null, null);
        }

        public Chunk(KaitaiStream _io, Dcmp0 _parent) {
            this(_io, _parent, null);
        }

        public Chunk(KaitaiStream _io, Dcmp0 _parent, Dcmp0 _root) {
            super(_io);
            this._parent = _parent;
            this._root = _root;
            _read();
        }
        private void _read() {
            this.tag = this._io.readU1();
            {
                TagKind on = ( ((tag() >= 0) && (tag() <= 31))  ? TagKind.LITERAL : ( ((tag() >= 32) && (tag() <= 74))  ? TagKind.BACKREFERENCE : ( ((tag() >= 75) && (tag() <= 253))  ? TagKind.TABLE_LOOKUP : (tag() == 254 ? TagKind.EXTENDED : (tag() == 255 ? TagKind.END : TagKind.INVALID)))));
                if (on != null) {
                    switch (( ((tag() >= 0) && (tag() <= 31))  ? TagKind.LITERAL : ( ((tag() >= 32) && (tag() <= 74))  ? TagKind.BACKREFERENCE : ( ((tag() >= 75) && (tag() <= 253))  ? TagKind.TABLE_LOOKUP : (tag() == 254 ? TagKind.EXTENDED : (tag() == 255 ? TagKind.END : TagKind.INVALID)))))) {
                    case EXTENDED: {
                        this.body = new ExtendedBody(this._io, this, _root);
                        break;
                    }
                    case LITERAL: {
                        this.body = new LiteralBody(this._io, this, _root, tag());
                        break;
                    }
                    case END: {
                        this.body = new EndBody(this._io, this, _root);
                        break;
                    }
                    case TABLE_LOOKUP: {
                        this.body = new TableLookupBody(this._io, this, _root, tag());
                        break;
                    }
                    case BACKREFERENCE: {
                        this.body = new BackreferenceBody(this._io, this, _root, tag());
                        break;
                    }
                    }
                }
            }
        }

        /**
         * The body of a literal data chunk.
         * 
         * The data that this chunk expands to is stored literally in the body (`literal`).
         * Optionally,
         * the literal data may also be stored for use by future backreference chunks (`do_store`).
         * 
         * The length of the literal data is stored as a number of two-byte units.
         * This means that the literal data always has an even length in bytes.
         */
        public static class LiteralBody extends KaitaiStruct {

            public LiteralBody(KaitaiStream _io, int tag) {
                this(_io, null, null, tag);
            }

            public LiteralBody(KaitaiStream _io, Dcmp0.Chunk _parent, int tag) {
                this(_io, _parent, null, tag);
            }

            public LiteralBody(KaitaiStream _io, Dcmp0.Chunk _parent, Dcmp0 _root, int tag) {
                super(_io);
                this._parent = _parent;
                this._root = _root;
                this.tag = tag;
                _read();
            }
            private void _read() {
                if (isLenLiteralDiv2Separate()) {
                    this.lenLiteralDiv2Separate = this._io.readU1();
                }
                this.literal = this._io.readBytes(lenLiteral());
            }
            private Boolean doStore;

            /**
             * Whether this literal should be stored for use by future backreference chunks.
             * 
             * See the documentation of the `backreference_body` type for details about backreference chunks.
             */
            public Boolean doStore() {
                if (this.doStore != null)
                    return this.doStore;
                boolean _tmp = (boolean) ((tag() & 16) != 0);
                this.doStore = _tmp;
                return this.doStore;
            }
            private Integer lenLiteralDiv2;

            /**
             * The length of the literal data,
             * in two-byte units.
             * 
             * In practice,
             * this value is always greater than zero,
             * as there is no use in storing a zero-length literal.
             */
            public Integer lenLiteralDiv2() {
                if (this.lenLiteralDiv2 != null)
                    return this.lenLiteralDiv2;
                int _tmp = (int) ((isLenLiteralDiv2Separate() ? lenLiteralDiv2Separate() : lenLiteralDiv2InTag()));
                this.lenLiteralDiv2 = _tmp;
                return this.lenLiteralDiv2;
            }
            private Integer lenLiteral;

            /**
             * The length of the literal data,
             * in bytes.
             */
            public Integer lenLiteral() {
                if (this.lenLiteral != null)
                    return this.lenLiteral;
                int _tmp = (int) ((lenLiteralDiv2() * 2));
                this.lenLiteral = _tmp;
                return this.lenLiteral;
            }
            private Integer lenLiteralDiv2InTag;

            /**
             * The part of the tag byte that indicates the length of the literal data,
             * in two-byte units.
             * If this value is 0,
             * the length is stored in a separate byte after the tag byte and before the literal data.
             */
            public Integer lenLiteralDiv2InTag() {
                if (this.lenLiteralDiv2InTag != null)
                    return this.lenLiteralDiv2InTag;
                int _tmp = (int) ((tag() & 15));
                this.lenLiteralDiv2InTag = _tmp;
                return this.lenLiteralDiv2InTag;
            }
            private Boolean isLenLiteralDiv2Separate;

            /**
             * Whether the length of the literal is stored separately from the tag.
             */
            public Boolean isLenLiteralDiv2Separate() {
                if (this.isLenLiteralDiv2Separate != null)
                    return this.isLenLiteralDiv2Separate;
                boolean _tmp = (boolean) (lenLiteralDiv2InTag() == 0);
                this.isLenLiteralDiv2Separate = _tmp;
                return this.isLenLiteralDiv2Separate;
            }
            private Integer lenLiteralDiv2Separate;
            private byte[] literal;
            private int tag;
            private Dcmp0 _root;
            private Dcmp0.Chunk _parent;

            /**
             * The length of the literal data,
             * in two-byte units.
             * 
             * This field is only present if the tag byte's low nibble is zero.
             * In practice,
             * this only happens if the length is 0x10 or greater,
             * because smaller lengths can be encoded into the tag byte.
             */
            public Integer lenLiteralDiv2Separate() { return lenLiteralDiv2Separate; }

            /**
             * The literal data.
             */
            public byte[] literal() { return literal; }

            /**
             * The tag byte preceding this chunk body.
             */
            public int tag() { return tag; }
            public Dcmp0 _root() { return _root; }
            public Dcmp0.Chunk _parent() { return _parent; }
        }

        /**
         * The body of a backreference chunk.
         * 
         * This chunk expands to the data stored in a preceding literal chunk,
         * indicated by an index number (`index`).
         */
        public static class BackreferenceBody extends KaitaiStruct {

            public BackreferenceBody(KaitaiStream _io, int tag) {
                this(_io, null, null, tag);
            }

            public BackreferenceBody(KaitaiStream _io, Dcmp0.Chunk _parent, int tag) {
                this(_io, _parent, null, tag);
            }

            public BackreferenceBody(KaitaiStream _io, Dcmp0.Chunk _parent, Dcmp0 _root, int tag) {
                super(_io);
                this._parent = _parent;
                this._root = _root;
                this.tag = tag;
                _read();
            }
            private void _read() {
                if (isIndexSeparate()) {
                    switch (tag()) {
                    case 32: {
                        this.indexSeparateMinus = (int) (this._io.readU1());
                        break;
                    }
                    case 33: {
                        this.indexSeparateMinus = (int) (this._io.readU1());
                        break;
                    }
                    case 34: {
                        this.indexSeparateMinus = this._io.readU2be();
                        break;
                    }
                    }
                }
            }
            private Boolean isIndexSeparate;

            /**
             * Whether the index is stored separately from the tag.
             */
            public Boolean isIndexSeparate() {
                if (this.isIndexSeparate != null)
                    return this.isIndexSeparate;
                boolean _tmp = (boolean) ( ((tag() >= 32) && (tag() <= 34)) );
                this.isIndexSeparate = _tmp;
                return this.isIndexSeparate;
            }
            private Integer indexInTag;

            /**
             * The index of the referenced literal chunk,
             * as stored in the tag byte.
             */
            public Integer indexInTag() {
                if (this.indexInTag != null)
                    return this.indexInTag;
                int _tmp = (int) ((tag() - 35));
                this.indexInTag = _tmp;
                return this.indexInTag;
            }
            private Integer indexSeparate;

            /**
             * The index of the referenced literal chunk,
             * as stored separately from the tag byte,
             * with the implicit offset corrected for.
             */
            public Integer indexSeparate() {
                if (this.indexSeparate != null)
                    return this.indexSeparate;
                if (isIndexSeparate()) {
                    int _tmp = (int) (((indexSeparateMinus() + 40) + (tag() == 33 ? 256 : 0)));
                    this.indexSeparate = _tmp;
                }
                return this.indexSeparate;
            }
            private Integer index;

            /**
             * The index of the referenced literal chunk.
             * 
             * Stored literals are assigned index numbers in the order in which they appear in the compressed data,
             * starting at 0.
             * Non-stored literals are not counted in the numbering and cannot be referenced using backreferences.
             * Once an index is assigned to a stored literal,
             * it is never changed or unassigned for the entire length of the compressed data.
             * 
             * As the name indicates,
             * a backreference can only reference stored literal chunks found *before* the backreference,
             * not ones that come after it.
             */
            public Integer index() {
                if (this.index != null)
                    return this.index;
                int _tmp = (int) ((isIndexSeparate() ? indexSeparate() : indexInTag()));
                this.index = _tmp;
                return this.index;
            }
            private Integer indexSeparateMinus;
            private int tag;
            private Dcmp0 _root;
            private Dcmp0.Chunk _parent;

            /**
             * The index of the referenced literal chunk,
             * stored separately from the tag.
             * The value in this field is stored minus 0x28.
             * If the tag byte is 0x21,
             * the value is also stored minus 0x100,
             * *on top of* the regular offset
             * (i. e. minus 0x128 in total).
             * 
             * In other words,
             * for tag bytes 0x20 and 0x21,
             * the index is actually 9 bits large,
             * with the low 8 bits stored separately and the highest bit stored in the lowest bit of the tag byte.
             * 
             * This field is only present if the tag byte is 0x20 through 0x22.
             * For higher tag bytes,
             * the index is encoded in the tag byte.
             * Values smaller than 0x28 cannot be stored in this field,
             * they must always be encoded in the tag byte.
             */
            public Integer indexSeparateMinus() { return indexSeparateMinus; }

            /**
             * The tag byte preceding this chunk body.
             */
            public int tag() { return tag; }
            public Dcmp0 _root() { return _root; }
            public Dcmp0.Chunk _parent() { return _parent; }
        }

        /**
         * The body of a table lookup chunk.
         * This body is always empty.
         * 
         * This chunk always expands to two bytes (`value`),
         * determined from the tag byte using a fixed lookup table (`lookup_table`).
         * This lookup table is hardcoded in the decompressor and always the same for all compressed data.
         */
        public static class TableLookupBody extends KaitaiStruct {

            public TableLookupBody(KaitaiStream _io, int tag) {
                this(_io, null, null, tag);
            }

            public TableLookupBody(KaitaiStream _io, Dcmp0.Chunk _parent, int tag) {
                this(_io, _parent, null, tag);
            }

            public TableLookupBody(KaitaiStream _io, Dcmp0.Chunk _parent, Dcmp0 _root, int tag) {
                super(_io);
                this._parent = _parent;
                this._root = _root;
                this.tag = tag;
                _read();
            }
            private void _read() {
            }
            private ArrayList<byte[]> lookupTable;

            /**
             * Fixed lookup table that maps tag byte numbers to two bytes each.
             * 
             * The entries in the lookup table are offset -
             * index 0 stands for tag 0x4b, 1 for 0x4c, etc.
             */
            public ArrayList<byte[]> lookupTable() {
                if (this.lookupTable != null)
                    return this.lookupTable;
                this.lookupTable = new ArrayList<byte[]>(Arrays.asList(new byte[] { 0, 0 }, new byte[] { 78, -70 }, new byte[] { 0, 8 }, new byte[] { 78, 117 }, new byte[] { 0, 12 }, new byte[] { 78, -83 }, new byte[] { 32, 83 }, new byte[] { 47, 11 }, new byte[] { 97, 0 }, new byte[] { 0, 16 }, new byte[] { 112, 0 }, new byte[] { 47, 0 }, new byte[] { 72, 110 }, new byte[] { 32, 80 }, new byte[] { 32, 110 }, new byte[] { 47, 46 }, new byte[] { -1, -4 }, new byte[] { 72, -25 }, new byte[] { 63, 60 }, new byte[] { 0, 4 }, new byte[] { -1, -8 }, new byte[] { 47, 12 }, new byte[] { 32, 6 }, new byte[] { 78, -19 }, new byte[] { 78, 86 }, new byte[] { 32, 104 }, new byte[] { 78, 94 }, new byte[] { 0, 1 }, new byte[] { 88, -113 }, new byte[] { 79, -17 }, new byte[] { 0, 2 }, new byte[] { 0, 24 }, new byte[] { 96, 0 }, new byte[] { -1, -1 }, new byte[] { 80, -113 }, new byte[] { 78, -112 }, new byte[] { 0, 6 }, new byte[] { 38, 110 }, new byte[] { 0, 20 }, new byte[] { -1, -12 }, new byte[] { 76, -18 }, new byte[] { 0, 10 }, new byte[] { 0, 14 }, new byte[] { 65, -18 }, new byte[] { 76, -33 }, new byte[] { 72, -64 }, new byte[] { -1, -16 }, new byte[] { 45, 64 }, new byte[] { 0, 18 }, new byte[] { 48, 46 }, new byte[] { 112, 1 }, new byte[] { 47, 40 }, new byte[] { 32, 84 }, new byte[] { 103, 0 }, new byte[] { 0, 32 }, new byte[] { 0, 28 }, new byte[] { 32, 95 }, new byte[] { 24, 0 }, new byte[] { 38, 111 }, new byte[] { 72, 120 }, new byte[] { 0, 22 }, new byte[] { 65, -6 }, new byte[] { 48, 60 }, new byte[] { 40, 64 }, new byte[] { 114, 0 }, new byte[] { 40, 110 }, new byte[] { 32, 12 }, new byte[] { 102, 0 }, new byte[] { 32, 107 }, new byte[] { 47, 7 }, new byte[] { 85, -113 }, new byte[] { 0, 40 }, new byte[] { -1, -2 }, new byte[] { -1, -20 }, new byte[] { 34, -40 }, new byte[] { 32, 11 }, new byte[] { 0, 15 }, new byte[] { 89, -113 }, new byte[] { 47, 60 }, new byte[] { -1, 0 }, new byte[] { 1, 24 }, new byte[] { -127, -31 }, new byte[] { 74, 0 }, new byte[] { 78, -80 }, new byte[] { -1, -24 }, new byte[] { 72, -57 }, new byte[] { 0, 3 }, new byte[] { 0, 34 }, new byte[] { 0, 7 }, new byte[] { 0, 26 }, new byte[] { 103, 6 }, new byte[] { 103, 8 }, new byte[] { 78, -7 }, new byte[] { 0, 36 }, new byte[] { 32, 120 }, new byte[] { 8, 0 }, new byte[] { 102, 4 }, new byte[] { 0, 42 }, new byte[] { 78, -48 }, new byte[] { 48, 40 }, new byte[] { 38, 95 }, new byte[] { 103, 4 }, new byte[] { 0, 48 }, new byte[] { 67, -18 }, new byte[] { 63, 0 }, new byte[] { 32, 31 }, new byte[] { 0, 30 }, new byte[] { -1, -10 }, new byte[] { 32, 46 }, new byte[] { 66, -89 }, new byte[] { 32, 7 }, new byte[] { -1, -6 }, new byte[] { 96, 2 }, new byte[] { 61, 64 }, new byte[] { 12, 64 }, new byte[] { 102, 6 }, new byte[] { 0, 38 }, new byte[] { 45, 72 }, new byte[] { 47, 1 }, new byte[] { 112, -1 }, new byte[] { 96, 4 }, new byte[] { 24, -128 }, new byte[] { 74, 64 }, new byte[] { 0, 64 }, new byte[] { 0, 44 }, new byte[] { 47, 8 }, new byte[] { 0, 17 }, new byte[] { -1, -28 }, new byte[] { 33, 64 }, new byte[] { 38, 64 }, new byte[] { -1, -14 }, new byte[] { 66, 110 }, new byte[] { 78, -71 }, new byte[] { 61, 124 }, new byte[] { 0, 56 }, new byte[] { 0, 13 }, new byte[] { 96, 6 }, new byte[] { 66, 46 }, new byte[] { 32, 60 }, new byte[] { 103, 12 }, new byte[] { 45, 104 }, new byte[] { 102, 8 }, new byte[] { 74, 46 }, new byte[] { 74, -82 }, new byte[] { 0, 46 }, new byte[] { 72, 64 }, new byte[] { 34, 95 }, new byte[] { 34, 0 }, new byte[] { 103, 10 }, new byte[] { 48, 7 }, new byte[] { 66, 103 }, new byte[] { 0, 50 }, new byte[] { 32, 40 }, new byte[] { 0, 9 }, new byte[] { 72, 122 }, new byte[] { 2, 0 }, new byte[] { 47, 43 }, new byte[] { 0, 5 }, new byte[] { 34, 110 }, new byte[] { 102, 2 }, new byte[] { -27, -128 }, new byte[] { 103, 14 }, new byte[] { 102, 10 }, new byte[] { 0, 80 }, new byte[] { 62, 0 }, new byte[] { 102, 12 }, new byte[] { 46, 0 }, new byte[] { -1, -18 }, new byte[] { 32, 109 }, new byte[] { 32, 64 }, new byte[] { -1, -32 }, new byte[] { 83, 64 }, new byte[] { 96, 8 }, new byte[] { 4, -128 }, new byte[] { 0, 104 }, new byte[] { 11, 124 }, new byte[] { 68, 0 }, new byte[] { 65, -24 }, new byte[] { 72, 65 }));
                return this.lookupTable;
            }
            private byte[] value;

            /**
             * The two bytes that the tag byte expands to,
             * based on the fixed lookup table.
             */
            public byte[] value() {
                if (this.value != null)
                    return this.value;
                this.value = lookupTable().get((int) (tag() - 75));
                return this.value;
            }
            private int tag;
            private Dcmp0 _root;
            private Dcmp0.Chunk _parent;

            /**
             * The tag byte preceding this chunk body.
             */
            public int tag() { return tag; }
            public Dcmp0 _root() { return _root; }
            public Dcmp0.Chunk _parent() { return _parent; }
        }

        /**
         * The body of an end chunk.
         * This body is always empty.
         * 
         * The last chunk in the compressed data must always be an end chunk.
         * An end chunk cannot appear elsewhere in the compressed data.
         */
        public static class EndBody extends KaitaiStruct {
            public static EndBody fromFile(String fileName) throws IOException {
                return new EndBody(new ByteBufferKaitaiStream(fileName));
            }

            public EndBody(KaitaiStream _io) {
                this(_io, null, null);
            }

            public EndBody(KaitaiStream _io, Dcmp0.Chunk _parent) {
                this(_io, _parent, null);
            }

            public EndBody(KaitaiStream _io, Dcmp0.Chunk _parent, Dcmp0 _root) {
                super(_io);
                this._parent = _parent;
                this._root = _root;
                _read();
            }
            private void _read() {
            }
            private Dcmp0 _root;
            private Dcmp0.Chunk _parent;
            public Dcmp0 _root() { return _root; }
            public Dcmp0.Chunk _parent() { return _parent; }
        }

        /**
         * The body of an extended chunk.
         * The meaning of this chunk depends on the extended tag byte stored in the chunk data.
         */
        public static class ExtendedBody extends KaitaiStruct {
            public static ExtendedBody fromFile(String fileName) throws IOException {
                return new ExtendedBody(new ByteBufferKaitaiStream(fileName));
            }

            public ExtendedBody(KaitaiStream _io) {
                this(_io, null, null);
            }

            public ExtendedBody(KaitaiStream _io, Dcmp0.Chunk _parent) {
                this(_io, _parent, null);
            }

            public ExtendedBody(KaitaiStream _io, Dcmp0.Chunk _parent, Dcmp0 _root) {
                super(_io);
                this._parent = _parent;
                this._root = _root;
                _read();
            }
            private void _read() {
                this.tag = this._io.readU1();
                switch (tag()) {
                case 0: {
                    this.body = new JumpTableBody(this._io, this, _root);
                    break;
                }
                case 4: {
                    this.body = new DeltaEncoding16BitBody(this._io, this, _root);
                    break;
                }
                case 6: {
                    this.body = new DeltaEncoding32BitBody(this._io, this, _root);
                    break;
                }
                case 3: {
                    this.body = new RepeatBody(this._io, this, _root, tag());
                    break;
                }
                case 2: {
                    this.body = new RepeatBody(this._io, this, _root, tag());
                    break;
                }
                }
            }

            /**
             * The body of a jump table chunk.
             * 
             * This chunk generates parts of a segment loader jump table,
             * in the format found in `'CODE' (0)` resources.
             * It expands to the following data,
             * with all non-constant numbers encoded as unsigned 16-bit big-endian integers:
             * 
             * * `0x3f 0x3c` (push following segment number onto stack)
             * * The segment number
             * * `0xa9 0xf0` (`_LoadSeg` trap)
             * * For each address:
             *   * The address
             *   * `0x3f 0x3c` (push following segment number onto stack)
             *   * The segment number
             *   * `0xa9 0xf0` (`_LoadSeg` trap)
             * 
             * Note that this generates one jump table entry without an address before it,
             * meaning that this address needs to be generated by the preceding chunk.
             * All following jump table entries are generated with the addresses encoded in this chunk.
             */
            public static class JumpTableBody extends KaitaiStruct {
                public static JumpTableBody fromFile(String fileName) throws IOException {
                    return new JumpTableBody(new ByteBufferKaitaiStream(fileName));
                }

                public JumpTableBody(KaitaiStream _io) {
                    this(_io, null, null);
                }

                public JumpTableBody(KaitaiStream _io, Dcmp0.Chunk.ExtendedBody _parent) {
                    this(_io, _parent, null);
                }

                public JumpTableBody(KaitaiStream _io, Dcmp0.Chunk.ExtendedBody _parent, Dcmp0 _root) {
                    super(_io);
                    this._parent = _parent;
                    this._root = _root;
                    _read();
                }
                private void _read() {
                    this.segmentNumberRaw = new DcmpVariableLengthInteger(this._io);
                    this.numAddressesRaw = new DcmpVariableLengthInteger(this._io);
                    addressesRaw = new ArrayList<DcmpVariableLengthInteger>(((Number) (numAddresses())).intValue());
                    for (int i = 0; i < numAddresses(); i++) {
                        this.addressesRaw.add(new DcmpVariableLengthInteger(this._io));
                    }
                }
                private Integer segmentNumber;

                /**
                 * The segment number for all of the generated jump table entries.
                 * 
                 * Although it is stored as a variable-length integer,
                 * the segment number must be in the range `0x0 <= x <= 0xffff`,
                 * i. e. an unsigned 16-bit integer.
                 */
                public Integer segmentNumber() {
                    if (this.segmentNumber != null)
                        return this.segmentNumber;
                    int _tmp = (int) (segmentNumberRaw().value());
                    this.segmentNumber = _tmp;
                    return this.segmentNumber;
                }
                private Integer numAddresses;

                /**
                 * The number of addresses stored in this chunk.
                 * 
                 * This number must be greater than 0.
                 */
                public Integer numAddresses() {
                    if (this.numAddresses != null)
                        return this.numAddresses;
                    int _tmp = (int) (numAddressesRaw().value());
                    this.numAddresses = _tmp;
                    return this.numAddresses;
                }
                private DcmpVariableLengthInteger segmentNumberRaw;
                private DcmpVariableLengthInteger numAddressesRaw;
                private ArrayList<DcmpVariableLengthInteger> addressesRaw;
                private Dcmp0 _root;
                private Dcmp0.Chunk.ExtendedBody _parent;

                /**
                 * Raw variable-length integer representation of `segment_number`.
                 */
                public DcmpVariableLengthInteger segmentNumberRaw() { return segmentNumberRaw; }

                /**
                 * Raw variable-length integer representation of `num_addresses`.
                 */
                public DcmpVariableLengthInteger numAddressesRaw() { return numAddressesRaw; }

                /**
                 * The addresses for each generated jump table entry,
                 * stored as variable-length integers.
                 * 
                 * The first address is stored literally and must be in the range `0x0 <= x <= 0xffff`,
                 * i. e. an unsigned 16-bit integer.
                 * 
                 * All following addresses are stored as deltas relative to the previous address.
                 * Each of these deltas is stored plus 6;
                 * this value needs to be subtracted before (or after) adding it to the previous address.
                 * 
                 * Each delta (after subtracting 6) should be positive,
                 * and adding it to the previous address should not result in a value larger than `0xffff`,
                 * i. e. there should be no 16-bit unsigned integer wraparound.
                 * These conditions are always met in all known jump table chunks,
                 * so it is not known how the original decompressor behaves otherwise.
                 */
                public ArrayList<DcmpVariableLengthInteger> addressesRaw() { return addressesRaw; }
                public Dcmp0 _root() { return _root; }
                public Dcmp0.Chunk.ExtendedBody _parent() { return _parent; }
            }

            /**
             * The body of a repeat chunk.
             * 
             * This chunk expands to a 1-byte or 2-byte value repeated a number of times,
             * i. e. it implements a form of run-length encoding.
             */
            public static class RepeatBody extends KaitaiStruct {

                public RepeatBody(KaitaiStream _io, int tag) {
                    this(_io, null, null, tag);
                }

                public RepeatBody(KaitaiStream _io, Dcmp0.Chunk.ExtendedBody _parent, int tag) {
                    this(_io, _parent, null, tag);
                }

                public RepeatBody(KaitaiStream _io, Dcmp0.Chunk.ExtendedBody _parent, Dcmp0 _root, int tag) {
                    super(_io);
                    this._parent = _parent;
                    this._root = _root;
                    this.tag = tag;
                    _read();
                }
                private void _read() {
                    this.toRepeatRaw = new DcmpVariableLengthInteger(this._io);
                    this.repeatCountM1Raw = new DcmpVariableLengthInteger(this._io);
                }
                private Integer byteCount;

                /**
                 * The length in bytes of the value to be repeated.
                 * Regardless of the byte count,
                 * the value to be repeated is stored as a variable-length integer.
                 */
                public Integer byteCount() {
                    if (this.byteCount != null)
                        return this.byteCount;
                    int _tmp = (int) ((tag() == 2 ? 1 : (tag() == 3 ? 2 : -1)));
                    this.byteCount = _tmp;
                    return this.byteCount;
                }
                private Integer toRepeat;

                /**
                 * The value to repeat.
                 * 
                 * Although it is stored as a variable-length integer,
                 * this value must fit into an unsigned big-endian integer that is as long as `byte_count`,
                 * i. e. either 8 or 16 bits.
                 */
                public Integer toRepeat() {
                    if (this.toRepeat != null)
                        return this.toRepeat;
                    int _tmp = (int) (toRepeatRaw().value());
                    this.toRepeat = _tmp;
                    return this.toRepeat;
                }
                private Integer repeatCountM1;

                /**
                 * The number of times to repeat the value,
                 * minus one.
                 * 
                 * This value must not be negative.
                 */
                public Integer repeatCountM1() {
                    if (this.repeatCountM1 != null)
                        return this.repeatCountM1;
                    int _tmp = (int) (repeatCountM1Raw().value());
                    this.repeatCountM1 = _tmp;
                    return this.repeatCountM1;
                }
                private Integer repeatCount;

                /**
                 * The number of times to repeat the value.
                 * 
                 * This value must be positive.
                 */
                public Integer repeatCount() {
                    if (this.repeatCount != null)
                        return this.repeatCount;
                    int _tmp = (int) ((repeatCountM1() + 1));
                    this.repeatCount = _tmp;
                    return this.repeatCount;
                }
                private DcmpVariableLengthInteger toRepeatRaw;
                private DcmpVariableLengthInteger repeatCountM1Raw;
                private int tag;
                private Dcmp0 _root;
                private Dcmp0.Chunk.ExtendedBody _parent;

                /**
                 * Raw variable-length integer representation of `to_repeat`.
                 */
                public DcmpVariableLengthInteger toRepeatRaw() { return toRepeatRaw; }

                /**
                 * Raw variable-length integer representation of `repeat_count_m1`.
                 */
                public DcmpVariableLengthInteger repeatCountM1Raw() { return repeatCountM1Raw; }

                /**
                 * The extended tag byte preceding this chunk body.
                 */
                public int tag() { return tag; }
                public Dcmp0 _root() { return _root; }
                public Dcmp0.Chunk.ExtendedBody _parent() { return _parent; }
            }

            /**
             * The body of a 16-bit delta encoding chunk.
             * 
             * This chunk expands to a sequence of 16-bit big-endian integer values.
             * The first value is stored literally.
             * All following values are stored as deltas relative to the previous value.
             */
            public static class DeltaEncoding16BitBody extends KaitaiStruct {
                public static DeltaEncoding16BitBody fromFile(String fileName) throws IOException {
                    return new DeltaEncoding16BitBody(new ByteBufferKaitaiStream(fileName));
                }

                public DeltaEncoding16BitBody(KaitaiStream _io) {
                    this(_io, null, null);
                }

                public DeltaEncoding16BitBody(KaitaiStream _io, Dcmp0.Chunk.ExtendedBody _parent) {
                    this(_io, _parent, null);
                }

                public DeltaEncoding16BitBody(KaitaiStream _io, Dcmp0.Chunk.ExtendedBody _parent, Dcmp0 _root) {
                    super(_io);
                    this._parent = _parent;
                    this._root = _root;
                    _read();
                }
                private void _read() {
                    this.firstValueRaw = new DcmpVariableLengthInteger(this._io);
                    this.numDeltasRaw = new DcmpVariableLengthInteger(this._io);
                    deltas = new ArrayList<Byte>(((Number) (numDeltas())).intValue());
                    for (int i = 0; i < numDeltas(); i++) {
                        this.deltas.add(this._io.readS1());
                    }
                }
                private Integer firstValue;

                /**
                 * The first value in the sequence.
                 * 
                 * Although it is stored as a variable-length integer,
                 * this value must be in the range `-0x8000 <= x <= 0x7fff`,
                 * i. e. a signed 16-bit integer.
                 */
                public Integer firstValue() {
                    if (this.firstValue != null)
                        return this.firstValue;
                    int _tmp = (int) (firstValueRaw().value());
                    this.firstValue = _tmp;
                    return this.firstValue;
                }
                private Integer numDeltas;

                /**
                 * The number of deltas stored in this chunk.
                 * 
                 * This number must not be negative.
                 */
                public Integer numDeltas() {
                    if (this.numDeltas != null)
                        return this.numDeltas;
                    int _tmp = (int) (numDeltasRaw().value());
                    this.numDeltas = _tmp;
                    return this.numDeltas;
                }
                private DcmpVariableLengthInteger firstValueRaw;
                private DcmpVariableLengthInteger numDeltasRaw;
                private ArrayList<Byte> deltas;
                private Dcmp0 _root;
                private Dcmp0.Chunk.ExtendedBody _parent;

                /**
                 * Raw variable-length integer representation of `first_value`.
                 */
                public DcmpVariableLengthInteger firstValueRaw() { return firstValueRaw; }

                /**
                 * Raw variable-length integer representation of `num_deltas`.
                 */
                public DcmpVariableLengthInteger numDeltasRaw() { return numDeltasRaw; }

                /**
                 * The deltas for each value relative to the previous value.
                 * 
                 * Each of these deltas is a signed 8-bit value.
                 * When adding the delta to the previous value,
                 * 16-bit integer wraparound is performed if necessary,
                 * so that the resulting value always fits into a 16-bit signed integer.
                 */
                public ArrayList<Byte> deltas() { return deltas; }
                public Dcmp0 _root() { return _root; }
                public Dcmp0.Chunk.ExtendedBody _parent() { return _parent; }
            }

            /**
             * The body of a 32-bit delta encoding chunk.
             * 
             * This chunk expands to a sequence of 32-bit big-endian integer values.
             * The first value is stored literally.
             * All following values are stored as deltas relative to the previous value.
             */
            public static class DeltaEncoding32BitBody extends KaitaiStruct {
                public static DeltaEncoding32BitBody fromFile(String fileName) throws IOException {
                    return new DeltaEncoding32BitBody(new ByteBufferKaitaiStream(fileName));
                }

                public DeltaEncoding32BitBody(KaitaiStream _io) {
                    this(_io, null, null);
                }

                public DeltaEncoding32BitBody(KaitaiStream _io, Dcmp0.Chunk.ExtendedBody _parent) {
                    this(_io, _parent, null);
                }

                public DeltaEncoding32BitBody(KaitaiStream _io, Dcmp0.Chunk.ExtendedBody _parent, Dcmp0 _root) {
                    super(_io);
                    this._parent = _parent;
                    this._root = _root;
                    _read();
                }
                private void _read() {
                    this.firstValueRaw = new DcmpVariableLengthInteger(this._io);
                    this.numDeltasRaw = new DcmpVariableLengthInteger(this._io);
                    deltasRaw = new ArrayList<DcmpVariableLengthInteger>(((Number) (numDeltas())).intValue());
                    for (int i = 0; i < numDeltas(); i++) {
                        this.deltasRaw.add(new DcmpVariableLengthInteger(this._io));
                    }
                }
                private Integer firstValue;

                /**
                 * The first value in the sequence.
                 */
                public Integer firstValue() {
                    if (this.firstValue != null)
                        return this.firstValue;
                    int _tmp = (int) (firstValueRaw().value());
                    this.firstValue = _tmp;
                    return this.firstValue;
                }
                private Integer numDeltas;

                /**
                 * The number of deltas stored in this chunk.
                 * 
                 * This number must not be negative.
                 */
                public Integer numDeltas() {
                    if (this.numDeltas != null)
                        return this.numDeltas;
                    int _tmp = (int) (numDeltasRaw().value());
                    this.numDeltas = _tmp;
                    return this.numDeltas;
                }
                private DcmpVariableLengthInteger firstValueRaw;
                private DcmpVariableLengthInteger numDeltasRaw;
                private ArrayList<DcmpVariableLengthInteger> deltasRaw;
                private Dcmp0 _root;
                private Dcmp0.Chunk.ExtendedBody _parent;

                /**
                 * Raw variable-length integer representation of `first_value`.
                 */
                public DcmpVariableLengthInteger firstValueRaw() { return firstValueRaw; }

                /**
                 * Raw variable-length integer representation of `num_deltas`.
                 */
                public DcmpVariableLengthInteger numDeltasRaw() { return numDeltasRaw; }

                /**
                 * The deltas for each value relative to the previous value,
                 * stored as variable-length integers.
                 * 
                 * Each of these deltas is a signed value.
                 * When adding the delta to the previous value,
                 * 32-bit integer wraparound is performed if necessary,
                 * so that the resulting value always fits into a 32-bit signed integer.
                 */
                public ArrayList<DcmpVariableLengthInteger> deltasRaw() { return deltasRaw; }
                public Dcmp0 _root() { return _root; }
                public Dcmp0.Chunk.ExtendedBody _parent() { return _parent; }
            }
            private int tag;
            private KaitaiStruct body;
            private Dcmp0 _root;
            private Dcmp0.Chunk _parent;

            /**
             * The chunk's extended tag byte.
             * This controls the structure of the body and the meaning of the chunk.
             */
            public int tag() { return tag; }

            /**
             * The chunk's body.
             */
            public KaitaiStruct body() { return body; }
            public Dcmp0 _root() { return _root; }
            public Dcmp0.Chunk _parent() { return _parent; }
        }
        private int tag;
        private KaitaiStruct body;
        private Dcmp0 _root;
        private Dcmp0 _parent;

        /**
         * The chunk's tag byte.
         * This controls the structure of the body and the meaning of the chunk.
         */
        public int tag() { return tag; }

        /**
         * The chunk's body.
         * 
         * Certain chunks do not have any data following the tag byte.
         * In this case,
         * the body is a zero-length structure.
         */
        public KaitaiStruct body() { return body; }
        public Dcmp0 _root() { return _root; }
        public Dcmp0 _parent() { return _parent; }
    }
    private ArrayList<Chunk> chunks;
    private Dcmp0 _root;
    private KaitaiStruct _parent;

    /**
     * The sequence of chunks that make up the compressed data.
     */
    public ArrayList<Chunk> chunks() { return chunks; }
    public Dcmp0 _root() { return _root; }
    public KaitaiStruct _parent() { return _parent; }
}