private void decompressVerbatimBlock()

in tika-parsers/tika-parsers-standard/tika-parsers-standard-modules/tika-parser-microsoft-module/src/main/java/org/apache/tika/parser/microsoft/chm/ChmLzxBlock.java [453:558]
101 lines of code
28 McCabe index (conditional complexity)

    private void decompressVerbatimBlock(int len, byte[] prevcontent) throws TikaException {
        short s;
        int x, i;
        int matchlen = 0, matchfooter = 0, extra, rundest, runsrc;
        int matchoffset = 0;
        for (i = getContentLength(); i < len; i++) {
            int f = getChmSection().peekBits(ChmConstants.LZX_MAINTREE_TABLEBITS);
            assertShortArrayNotNull(getState().getMainTreeTable());
            s = getState().getMainTreeTable()[f];
            if (s >= ChmConstants.LZX_MAIN_MAXSYMBOLS) {
                x = ChmConstants.LZX_MAINTREE_TABLEBITS;
                do {
                    x++;
                    s <<= 1;
                    s += getChmSection().checkBit(x);
                } while ((s = getState().getMainTreeTable()[s]) >=
                        ChmConstants.LZX_MAIN_MAXSYMBOLS);
            }
            getChmSection().getSyncBits(getState().getMainTreeLengtsTable()[s]);
            if (s < ChmConstants.LZX_NUM_CHARS) {
                content[i] = (byte) s;
            } else {
                s -= ChmConstants.LZX_NUM_CHARS;
                matchlen = s & ChmConstants.LZX_NUM_PRIMARY_LENGTHS;
                if (matchlen == ChmConstants.LZX_NUM_PRIMARY_LENGTHS) {
                    matchfooter = getState().getLengthTreeTable()[getChmSection()
                            .peekBits(ChmConstants.LZX_LENGTH_TABLEBITS)];
                    if (matchfooter >= ChmConstants.LZX_NUM_SECONDARY_LENGTHS) {
                        x = ChmConstants.LZX_LENGTH_TABLEBITS;
                        do {
                            x++;
                            matchfooter <<= 1;
                            matchfooter += getChmSection().checkBit(x);
                        } while ((matchfooter = getState().getLengthTreeTable()[matchfooter]) >=
                                ChmConstants.LZX_NUM_SECONDARY_LENGTHS);
                    }
                    getChmSection().getSyncBits(getState().getLengthTreeLengtsTable()[matchfooter]);
                    matchlen += matchfooter;
                }
                matchlen += ChmConstants.LZX_MIN_MATCH;
                // shorter than 2
                matchoffset = s >>> 3;
                if (matchoffset > 2) {
                    if (matchoffset != 3) { // should get other bits to retrieve
                        // offset
                        extra = ChmConstants.EXTRA_BITS[matchoffset];
                        long l = getChmSection().getSyncBits(extra);
                        matchoffset = (int) (ChmConstants.POSITION_BASE[matchoffset] - 2 + l);
                    } else {
                        matchoffset = 1;
                    }
                    getState().setR2(getState().getR1());
                    getState().setR1(getState().getR0());
                    getState().setR0(matchoffset);
                } else if (matchoffset == 0) {
                    matchoffset = (int) getState().getR0();
                } else if (matchoffset == 1) {
                    matchoffset = (int) getState().getR1();
                    getState().setR1(getState().getR0());
                    getState().setR0(matchoffset);
                } else /* match_offset == 2 */ {
                    matchoffset = (int) getState().getR2();
                    getState().setR2(getState().getR0());
                    getState().setR0(matchoffset);
                }
                rundest = i;
                runsrc = rundest - matchoffset;
                i += (matchlen - 1);
                if (i > len) {
                    break;
                }
                if (runsrc < 0) {
                    if (matchlen + runsrc <= 0) {
                        runsrc = prevcontent.length + runsrc;
                        while ((matchlen-- > 0) && (prevcontent != null) && ((runsrc + 1) > 0))
                            if ((rundest < content.length) && (runsrc < content.length)) {
                                content[rundest++] = prevcontent[runsrc++];
                            }
                    } else {
                        runsrc = prevcontent.length + runsrc;
                        while (runsrc < prevcontent.length)
                            if ((rundest < content.length) && (runsrc < content.length)) {
                                content[rundest++] = prevcontent[runsrc++];
                            }
                        matchlen = matchlen + runsrc - prevcontent.length;
                        runsrc = 0;
                        while (matchlen-- > 0) content[rundest++] = content[runsrc++];
                    }

                } else {
                    /* copies any wrapped source data */
                    while ((runsrc < 0) && (matchlen-- > 0)) {
                        content[rundest++] = content[(int) (runsrc + getBlockLength())];
                        runsrc++;
                    }
                    /* copies match data - no worries about destination wraps */
                    while (matchlen-- > 0) {
                        if ((rundest < content.length) && (runsrc < content.length)) {
                            content[rundest++] = content[runsrc++];
                        }
                    }
                }
            }
        }
        setContentLength(len);
    }