Component bmqa_messageproperties [Package bmqa]

Provide a VST representing message properties. More...

Namespaces
namespace	bmqp
namespace	bmqa

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Detailed Description

Outline

• Purpose
• Classes
• Description
  • Restrictions on Property Names
  • Restrictions on Property Values

Purpose:

Provide a VST representing message properties.

Classes:

bmqa::MessageProperties	VST representing message properties.
bmqa::MessagePropertiesIterator	Mechanism to iterate over properties.

See also:

bmqt::PropertyType

Description:

bmqa::MessageProperties provides a VST representing message properties. Message properties are a collection of name-value pairs that producer can associate with a message, and consumer can retrieve from the corresponding message. In order to keep their usage flexible, no schema is enforced for the message properties, and their format (names and data types) should be negotiated by producers and consumers. Message properties can be used for routing, pipelining or filtering messages within the application. It can be efficient to specify such message attributes in the properties instead of the message payload, because application does not have to decode entire payload to retrieve these attributes. bmqa::MessagePropertiesIterator provides a mechanism to iterate over all the properties of a bmqa::MessageProperties object.

Restrictions on Property Names:

• Length of a property name must be greater than zero and must not exceed bmqa::MessageProperties::k_MAX_PROPERTY_NAME_LENGTH

• First character of the property name must be alpha-numeric.

Restrictions on Property Values:

• Length of a property value must be non-negative (ie, can be zero) and must not exceed bmqa::MessageProperties::k_MAX_PROPERTY_VALUE_LENGTH. Note that this restriction is obviously applicable to property values with types bmqt::PropertyType::e_STRING and bmqt::PropertyType::e_BINARY, because for all other property value types, size is implicitly applicable based on the type (see 'Data Types and Size' section in bmqt::PropertyType component).