Ray's playground

摘要： You’d think about using the pattern when all of the following applies: 􀀁 You need to save the object’s state as a snapshot or a portion of it,which can be restored later. 􀀁 You need to hide the interface with which obtaining the state wouldexpose the implantation details. 阅读全文

摘要： You’d naturally think about using the pattern when 􀀁 You need a remote proxy that provides a local representative for anobject in a different address space or in the network. 􀀁 You need a virtual proxy to create heavy-weighted objects on demand.We will implement that kind of proxy in a code examp. 阅读全文

摘要： You’d naturally think about using it when all of the following are true: 􀀁 Your app uses a lot of objects. 􀀁 Keeping objects in memory can affect memory performance. 􀀁 Most of the object’s unique state (extrinsic state) can be externalizedand lightweight. 􀀁 Relatively few shared objects can rep. 阅读全文