public int read()

in pdfbox/src/main/java/org/apache/pdfbox/filter/ASCII85InputStream.java [69:166]
94 lines of code
21 McCabe index (conditional complexity)

    public int read() throws IOException
    {
        if (index >= n)
        {
            if (eof)
            {
                return -1;
            }
            index = 0;
            int k;
            byte z;
            do
            {
                int zz = (byte) in.read();
                if (zz == -1)
                {
                    eof = true;
                    return -1;
                }
                z = (byte) zz;
            } while (z == NEWLINE || z == RETURN || z == SPACE);

            if (z == TERMINATOR)
            {
                eof = true;
                ascii = b = null;
                n = 0;
                return -1;
            }
            else if (z == Z)
            {
                b[0] = b[1] = b[2] = b[3] = 0;
                n = 4;
            }
            else
            {
                ascii[0] = z; // may be EOF here....
                for (k = 1; k < 5; ++k)
                {
                    do
                    {
                        int zz = (byte) in.read();
                        if (zz == -1)
                        {
                            eof = true;
                            return -1;
                        }
                        z = (byte) zz;
                    } while (z == NEWLINE || z == RETURN || z == SPACE);
                    ascii[k] = z;
                    if (z == TERMINATOR)
                    {
                        // don't include ~ as padding byte
                        ascii[k] = (byte) PADDING_U;
                        break;
                    }
                }
                n = k - 1;
                if (n == 0)
                {
                    eof = true;
                    ascii = null;
                    b = null;
                    return -1;
                }
                if (k < 5)
                {
                    for (++k; k < 5; ++k)
                    {
                        // use 'u' for padding
                        ascii[k] = (byte) PADDING_U;
                    }
                    eof = true;
                }
                // decode stream
                long t = 0;
                for (k = 0; k < 5; ++k)
                {
                    z = (byte) (ascii[k] - OFFSET);
                    if (z < 0 || z > 93)
                    {
                        n = 0;
                        eof = true;
                        ascii = null;
                        b = null;
                        throw new IOException("Invalid data in Ascii85 stream");
                    }
                    t = (t * 85L) + z;
                }
                for (k = 3; k >= 0; --k)
                {
                    b[k] = (byte) (t & 0xFFL);
                    t >>>= 8;
                }
            }
        }
        return b[index++] & 0xFF;
    }