Method ToOrderedBytes
ToOrderedBytes()
Returns the 16-byte ordered encoding of the file ID, under which sequential (version 7) IDs sort in the order they were created and after every secure (version 4) ID.
Declaration
public byte[] ToOrderedBytes()Returns
| Type | Description |
|---|---|
| byte[] |
Remarks
The encoding is for storing file IDs in an ordered binary database column, so that an index over the column receives new sequential IDs at its end
instead of throughout it. Store it in a fixed 16-byte binary column: binary(16) on SQL Server, whose uniqueidentifier type orders values
by their last six bytes first, and bytea or BLOB on other databases.
Under ordinal comparison of the bytes (unsigned, first byte first, as databases compare binary values), the encoding of every version 7 ID is greater
than the encoding of every version 4 ID, and version 7 IDs compare by their timestamp and then their counter, so the IDs from one
FileIdGenerator compare in the order they were created. A repository that switches its FileIdMode from secure to sequential IDs
therefore adds its new IDs after all of its old ones. In RFC 9562 byte order the same version 7 IDs would fall in a narrow band in the middle of the
version 4 IDs, whose bytes are random, because a version 7 ID starts with the high byte of its timestamp, which is 0x01 from late 2004 to late
2039.
The encoding is not RFC 9562 byte order: it moves the version nibble in front of the timestamp. Do not store values in this encoding and in RFC 9562
byte order in the same column; the same ID has different bytes in each, and the two orders disagree. Callers that want RFC 9562 byte order instead
can use ToByteArray(bool) on Guid with bigEndian set to true. Use
FromOrderedBytes(ReadOnlySpan<byte>) to create a file ID from its ordered encoding.
ToOrderedBytes(Span<byte>)
Writes the 16-byte ordered encoding of the file ID to the specified span. See ToOrderedBytes() for the order and its use.
Declaration
public void ToOrderedBytes(Span<byte> destination)Parameters
| Type | Name | Description |
|---|---|---|
| Span<byte> | destination | The span to write the 16 bytes to. |
Exceptions
| Type | Condition |
|---|---|
| ArgumentException |
|