Metadata for record file management

You use metadata attributes to control how the trading engine handles the file records that are transported in messages.

You can set these attributes:

• In the Message Handler. See Configure record transformation in message handler.
• In a Message Attributes Template. See Message attributes templates.

Local and virtual attributes

Metadata attributes for file records are classed as either local or virtual attributes:

• Local attributes (for example, LocalFileRecordFormat) apply to document files stored on the Interchange file system. Local attributes describe how file records are structured and in what character set the record is encoded. This enables Interchange to process documents correctly.
• Virtual attributes (for example, VirtualFileRecordFormat) are used by file-transfer protocols, such as OFTP and PeSIT, to describe the files being transferred. Virtual attributes are conveyed by a protocol during the exchange to the partner. This tells the partner what is being transferred and how to process the file once received.

Sent messages

For sending messages, file attributes are defined in a message attributes template or in the message handler:

• If LocalFileRecordFormat is not given, OCTET_STREAM is assumed (the default value).
• If LocalFileRecordFormat is FIXED_TEXT or FIXED_BINARY, LocalRecordLength is required.
• If LocalFileRecordFormat is VARIABLE_TEXT or VARIABLE_BINARY, LocalRecordLength is optional.
• However, if not given, an internal default is assumed. In the case of OFTP, 2048 for VARIABLE_TEXT, 32000 for VARIABLE_BINARY.
• If LocalFileCharSet is not given, ASCII is assumed.
• LocalFilePaddingCode is required only in case of record transcoding.
• Virtual file attributes are optional. If virtual file attributes are not given, the corresponding local file attributes are assumed.
• If VirtualFileRecordFormat is different than LocalFileRecordFormat or the LocalFileChatSet is different than VirtualFileChatset, the file undergoes transcoding before being sent.

Consumed messages

For consumed messages, virtual file attributes are provided by the protocol elements (metadata), as conveyed during the protocol exchange. Local file attributes are assumed to be the same as virtual file attributes received. However, you can use the record transformation options of the message handler to override these attributes and set file transcoding as needed. Additionally, for PeSIT and OFTP message consumption, virtual and local file attribute values can be overridden by applying a message attributes template on the PeSIT or OFTP pickup.

Transcoding

Transcoding applies only to files that have a record structure and not to OCTET_STREAM (unstructured) files. Transcoding occurs when LocalFileRecordFormat is different from VirtualFileRecordFormat or LcoalFileCharSet is different from VirtualFileCharset. File records can be transformed from FIX_ to VARIABLE_ format or vice-versa.

For outbound messages, transformation takes local file attributes as source attributes and virtual file attributes as target attributes. For inbound message, it is the other way round.

When transformed from FIX_ to VARIABLE_, trailing padding characters (as defined in LocalFilePaddingChar or VirtualFilePaddingChar) are stripped off to make the record in variable format.

When transformed from VARIABLE_ to FIX_ , padding characters (as defined in LocalFilePaddingChar or VirtualFilePaddingChar) are added to make the record in fixed format. The process assumes fixed format record length is at least as long as the maximum variable format record.

Attributes