blob: adb9c8890e079209db11dd8615934f765cb81909 (
plain) (
blame)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
|
// Copyright Yahoo. Licensed under the terms of the Apache 2.0 license. See LICENSE in the project root.
#pragma once
#include <memory>
namespace mbus {
class RoutingContext;
/**
* A routing policy selects who should get a message and merges the replies that are returned from those
* recipients. Note that recipient selection is done separately for each path element. This means that a routing policy
* is not selecting recipients directly, but rather the set of strings that should be used for the next service name
* path element. This process is done recursively until a set of actual service names are produced. The merging process
* is similar, but in reverse order.
*/
class IRoutingPolicy {
public:
/**
* Convenience typedefs.
*/
using UP = std::unique_ptr<IRoutingPolicy>;
using SP = std::shared_ptr<IRoutingPolicy>;
IRoutingPolicy(const IRoutingPolicy &) = delete;
IRoutingPolicy & operator = (const IRoutingPolicy &) = delete;
/**
* Destructor. Frees any allocated resources.
*/
virtual ~IRoutingPolicy() { }
/**
* This function must choose a set of services that is to receive the given message from a list of possible
* recipients. This is done by adding child routing contexts to the argument object. These children can then be
* iterated and manipulated even before selection pass is concluded.
*
* @param context The complete context for the invocation of this policy. Contains all available data.
*/
virtual void select(RoutingContext &context) = 0;
/**
* This function is called when all replies have arrived for some message. The implementation is responsible for
* merging multiple replies into a single sensible reply. The replies is contained in the child context objects of
* the argument context, and then response must be set in that context.
*
* @param context The complete context for the invocation of this policy. Contains all available data.
*/
virtual void merge(RoutingContext &context) = 0;
protected:
IRoutingPolicy() = default;
};
} // namespace mbus
|
