unpack2() public static méthode

public static unpack2 ( byte arr, int offs ) : short
arr byte
offs int
Résultat short
        internal void getStr(Page pg, int i)
        {
            int len  = OldBtreePage.getKeyStrSize(pg, i);
            int offs = OldBtreePage.firstKeyOffs + OldBtreePage.getKeyStrOffs(pg, i);

            char[] sval = new char[len];
            for (int j = 0; j < len; j++)
            {
                sval[j] = (char)Bytes.unpack2(pg.data, offs);
                offs   += 2;
            }
            key = new Key(sval);
        }
        protected override object unpackByteArrayKey(Page pg, int pos)
        {
            int offs = OldBtreePage.firstKeyOffs + OldBtreePage.getKeyStrOffs(pg, pos);

            byte[]   data   = pg.data;
            Object[] values = new Object[types.Length];

            for (int i = 0; i < types.Length; i++)
            {
                Object v = null;
                switch (types[i])
                {
                case ClassDescriptor.FieldType.tpBoolean:
                    v = data[offs++] != 0;
                    break;

                case ClassDescriptor.FieldType.tpSByte:
                    v = (sbyte)data[offs++];
                    break;

                case ClassDescriptor.FieldType.tpByte:
                    v = data[offs++];
                    break;

                case ClassDescriptor.FieldType.tpShort:
                    v     = Bytes.unpack2(data, offs);
                    offs += 2;
                    break;

                case ClassDescriptor.FieldType.tpUShort:
                    v     = (ushort)Bytes.unpack2(data, offs);
                    offs += 2;
                    break;

                case ClassDescriptor.FieldType.tpChar:
                    v     = (char)Bytes.unpack2(data, offs);
                    offs += 2;
                    break;

                case ClassDescriptor.FieldType.tpInt:
                    v     = Bytes.unpack4(data, offs);
                    offs += 4;
                    break;

                case ClassDescriptor.FieldType.tpEnum:
                    v = Enum.ToObject(mbr[i] is FieldInfo ? ((FieldInfo)mbr[i]).FieldType : ((PropertyInfo)mbr[i]).PropertyType,
                                      Bytes.unpack4(data, offs));
                    offs += 4;
                    break;

                case ClassDescriptor.FieldType.tpUInt:
                    v     = (uint)Bytes.unpack4(data, offs);
                    offs += 4;
                    break;

                case ClassDescriptor.FieldType.tpOid:
                case ClassDescriptor.FieldType.tpObject:
                {
                    int oid = Bytes.unpack4(data, offs);
                    v     = oid == 0 ? null : ((DatabaseImpl)Database).lookupObject(oid, null);
                    offs += 4;
                    break;
                }

                case ClassDescriptor.FieldType.tpLong:
                    v     = Bytes.unpack8(data, offs);
                    offs += 8;
                    break;

                case ClassDescriptor.FieldType.tpDate:
                {
                    v     = new DateTime(Bytes.unpack8(data, offs));
                    offs += 8;
                    break;
                }

                case ClassDescriptor.FieldType.tpULong:
                    v     = (ulong)Bytes.unpack8(data, offs);
                    offs += 8;
                    break;

                case ClassDescriptor.FieldType.tpFloat:
                    v     = Bytes.unpackF4(data, offs);
                    offs += 4;
                    break;

                case ClassDescriptor.FieldType.tpDouble:
                    v     = Bytes.unpackF8(data, offs);
                    offs += 8;
                    break;

                case ClassDescriptor.FieldType.tpDecimal:
                    v     = Bytes.unpackDecimal(data, offs);
                    offs += 16;
                    break;

                case ClassDescriptor.FieldType.tpGuid:
                    v     = Bytes.unpackGuid(data, offs);
                    offs += 16;
                    break;

                case ClassDescriptor.FieldType.tpString:
                {
                    int len = Bytes.unpack4(data, offs);
                    offs += 4;
                    char[] sval = new char[len];
                    for (int j = 0; j < len; j++)
                    {
                        sval[j] = (char)Bytes.unpack2(pg.data, offs);
                        offs   += 2;
                    }
                    v = new String(sval);
                    break;
                }

                case ClassDescriptor.FieldType.tpArrayOfByte:
                {
                    int len = Bytes.unpack4(data, offs);
                    offs += 4;
                    byte[] val = new byte[len];
                    Array.Copy(pg.data, offs, val, 0, len);
                    offs += len;
                    v     = val;
                    break;
                }

                default:
                    Debug.Assert(false, "Invalid type");
                    break;
                }
                values[i] = v;
            }
            return(values);
        }
        public override int compareByteArrays(byte[] key, byte[] item, int offs, int lengtn)
        {
            int o1 = 0;
            int o2 = offs;

            byte[] a1 = key;
            byte[] a2 = item;
            for (int i = 0; i < types.Length && o1 < key.Length; i++)
            {
                int diff = 0;
                switch (types[i])
                {
                case ClassDescriptor.FieldType.tpBoolean:
                case ClassDescriptor.FieldType.tpByte:
                    diff = a1[o1++] - a2[o2++];
                    break;

                case ClassDescriptor.FieldType.tpSByte:
                    diff = (sbyte)a1[o1++] - (sbyte)a2[o2++];
                    break;

                case ClassDescriptor.FieldType.tpShort:
                    diff = Bytes.unpack2(a1, o1) - Bytes.unpack2(a2, o2);
                    o1  += 2;
                    o2  += 2;
                    break;

                case ClassDescriptor.FieldType.tpUShort:
                    diff = (ushort)Bytes.unpack2(a1, o1) - (ushort)Bytes.unpack2(a2, o2);
                    o1  += 2;
                    o2  += 2;
                    break;

                case ClassDescriptor.FieldType.tpChar:
                    diff = (char)Bytes.unpack2(a1, o1) - (char)Bytes.unpack2(a2, o2);
                    o1  += 2;
                    o2  += 2;
                    break;

                case ClassDescriptor.FieldType.tpInt:
                {
                    int i1 = Bytes.unpack4(a1, o1);
                    int i2 = Bytes.unpack4(a2, o2);
                    diff = i1 < i2 ? -1 : i1 == i2 ? 0 : 1;
                    o1  += 4;
                    o2  += 4;
                    break;
                }

                case ClassDescriptor.FieldType.tpUInt:
                case ClassDescriptor.FieldType.tpEnum:
                case ClassDescriptor.FieldType.tpObject:
                case ClassDescriptor.FieldType.tpOid:
                {
                    uint u1 = (uint)Bytes.unpack4(a1, o1);
                    uint u2 = (uint)Bytes.unpack4(a2, o2);
                    diff = u1 < u2 ? -1 : u1 == u2 ? 0 : 1;
                    o1  += 4;
                    o2  += 4;
                    break;
                }

                case ClassDescriptor.FieldType.tpLong:
                {
                    long l1 = Bytes.unpack8(a1, o1);
                    long l2 = Bytes.unpack8(a2, o2);
                    diff = l1 < l2 ? -1 : l1 == l2 ? 0 : 1;
                    o1  += 8;
                    o2  += 8;
                    break;
                }

                case ClassDescriptor.FieldType.tpULong:
                case ClassDescriptor.FieldType.tpDate:
                {
                    ulong l1 = (ulong)Bytes.unpack8(a1, o1);
                    ulong l2 = (ulong)Bytes.unpack8(a2, o2);
                    diff = l1 < l2 ? -1 : l1 == l2 ? 0 : 1;
                    o1  += 8;
                    o2  += 8;
                    break;
                }

                case ClassDescriptor.FieldType.tpFloat:
                {
                    float f1 = Bytes.unpackF4(a1, o1);
                    float f2 = Bytes.unpackF4(a2, o2);
                    diff = f1 < f2 ? -1 : f1 == f2 ? 0 : 1;
                    o1  += 4;
                    o2  += 4;
                    break;
                }

                case ClassDescriptor.FieldType.tpDouble:
                {
                    double d1 = Bytes.unpackF8(a1, o1);
                    double d2 = Bytes.unpackF8(a2, o2);
                    diff = d1 < d2 ? -1 : d1 == d2 ? 0 : 1;
                    o1  += 8;
                    o2  += 8;
                    break;
                }

                case ClassDescriptor.FieldType.tpDecimal:
                {
                    decimal d1 = Bytes.unpackDecimal(a1, o1);
                    decimal d2 = Bytes.unpackDecimal(a2, o2);
                    diff = d1.CompareTo(d2);
                    o1  += 16;
                    o2  += 16;
                    break;
                }

                case ClassDescriptor.FieldType.tpGuid:
                {
                    Guid g1 = Bytes.unpackGuid(a1, o1);
                    Guid g2 = Bytes.unpackGuid(a2, o2);
                    diff = g1.CompareTo(g2);
                    o1  += 16;
                    o2  += 16;
                    break;
                }

                case ClassDescriptor.FieldType.tpString:
                {
                    string s1, s2;
                    o1   = Bytes.unpackString(a1, o1, out s1);
                    o2   = Bytes.unpackString(a2, o2, out s2);
                    diff = String.CompareOrdinal(s1, s2);

                    /* TODO: old version, remove
                     * int len1 = Bytes.unpack4(a1, o1);
                     * int len2 = Bytes.unpack4(a2, o2);
                     * o1 += 4;
                     * o2 += 4;
                     * int len = len1 < len2 ? len1 : len2;
                     * while (--len >= 0)
                     * {
                     *  diff = (char)Bytes.unpack2(a1, o1) - (char)Bytes.unpack2(a2, o2);
                     *  if (diff != 0)
                     *  {
                     *      return diff;
                     *  }
                     *  o1 += 2;
                     *  o2 += 2;
                     * }
                     * diff = len1 - len2;
                     */
                    break;
                }

                case ClassDescriptor.FieldType.tpArrayOfByte:
                {
                    int len1 = Bytes.unpack4(a1, o1);
                    int len2 = Bytes.unpack4(a2, o2);
                    o1 += 4;
                    o2 += 4;
                    int len = len1 < len2 ? len1 : len2;
                    while (--len >= 0)
                    {
                        diff = a1[o1++] - a2[o2++];
                        if (diff != 0)
                        {
                            return(diff);
                        }
                    }
                    diff = len1 - len2;
                    break;
                }

                default:
                    Debug.Assert(false, "Invalid type");
                    break;
                }
                if (diff != 0)
                {
                    return(diff);
                }
            }
            return(0);
        }
        internal void extract(Page pg, int offs, ClassDescriptor.FieldType type)
        {
            byte[] data = pg.data;

            switch (type)
            {
            case ClassDescriptor.FieldType.tpBoolean:
                key = new Key(data[offs] != 0);
                break;

            case ClassDescriptor.FieldType.tpSByte:
                key = new Key((sbyte)data[offs]);
                break;

            case ClassDescriptor.FieldType.tpByte:
                key = new Key(data[offs]);
                break;

            case ClassDescriptor.FieldType.tpShort:
                key = new Key(Bytes.unpack2(data, offs));
                break;

            case ClassDescriptor.FieldType.tpUShort:
                key = new Key((ushort)Bytes.unpack2(data, offs));
                break;

            case ClassDescriptor.FieldType.tpChar:
                key = new Key((char)Bytes.unpack2(data, offs));
                break;

            case ClassDescriptor.FieldType.tpInt:
                key = new Key(Bytes.unpack4(data, offs));
                break;

            case ClassDescriptor.FieldType.tpEnum:
            case ClassDescriptor.FieldType.tpUInt:
            case ClassDescriptor.FieldType.tpObject:
            case ClassDescriptor.FieldType.tpOid:
                key = new Key((uint)Bytes.unpack4(data, offs));
                break;

            case ClassDescriptor.FieldType.tpLong:
                key = new Key(Bytes.unpack8(data, offs));
                break;

            case ClassDescriptor.FieldType.tpDate:
            case ClassDescriptor.FieldType.tpULong:
                key = new Key((ulong)Bytes.unpack8(data, offs));
                break;

            case ClassDescriptor.FieldType.tpFloat:
                key = new Key(Bytes.unpackF4(data, offs));
                break;

            case ClassDescriptor.FieldType.tpDouble:
                key = new Key(Bytes.unpackF8(data, offs));
                break;

            case ClassDescriptor.FieldType.tpGuid:
                key = new Key(Bytes.unpackGuid(data, offs));
                break;

            case ClassDescriptor.FieldType.tpDecimal:
                key = new Key(Bytes.unpackDecimal(data, offs));
                break;

            default:
                Debug.Assert(false, "Invalid type");
                break;
            }
        }