Current location - Trademark Inquiry Complete Network - Futures platform - What is aggregation?
What is aggregation?
Gather together: gather together in a scattered way.

[Polymerization]: Chemical combination of [small molecules] into macromolecules, especially very large molecules; Terminology of aggregate futures market affected by aggregate. It means that as the futures contract approaches the expiration date, the spot price and futures price tend to converge, that is, the basis will tend to zero.

Aggregation network terminology. Refers to the collection of all kinds of information on the Internet.

English: Aggregation

It refers to the related websites that screen, analyze and classify the massive information on the Internet (such as blogs, forums, movies, music, supply and demand information, etc.). ), and finally provide excellent and useful more targeted information for netizens.

For example, the process of collecting and sorting websites or blogs with RSS subscription function. The aggregated content can be read through online tools (online reader websites such as Youdao Reader or Google Reader) or directly through the news reader on the computer desktop.

COM technology:

To expose the interface of a COM class and treat it as implemented on a second COM class, the second class will aggregate the first class. COM objects can be aggregated. NET object, in this case, all interfaces of the object (including its class interface) can be used through external objects. Inside. NET object delegates the call to its IUnknown method to the control IUnknown.

Aggregation is slightly more complicated than inclusion (explained in the next section). It is usually used to make an external object expose the interface implementation of another object without modification. All managed objects automatically support using managed objects as internal objects of COM-style aggregations. In order to aggregate managed objects, unmanaged external objects will create managed internal objects by calling CoCreateInstance, and then pass the IUnknown of external objects as the OuterUnknown parameter. When an external IUnknown is passed to a managed object during construction, the managed object caches the interface and uses it as follows:

The external object is linked to the non-delegated IUnknown of the internal IUnknown. The operation mode of inactive IUnknown is the same as that of conventional IUnknown; That is, if the object implements the interface, the non-delegate IUnknown will succeed, otherwise it will fail. Non-delegate IUnknown does not forward calls to external objects.

If the internal object is queried for an interface it does not support, the internal object will delegate the call to the IUnknown interface of the external object.

All calls to the QueryInterface, AddRef and Release methods of the internal object will be delegated to the IUnknown of the external object.

Through these three behaviors, you can aggregate any managed object. Using this aggregation relationship, a single COM object can be partially implemented in managed code (internal part) and partially implemented in unmanaged code (external part).