aermicioi.aedi.container.singleton

1 /**
2 
3 License:
4 	Boost Software License - Version 1.0 - August 17th, 2003
5     
6     Permission is hereby granted, free of charge, to any person or organization
7     obtaining a copy of the software and accompanying documentation covered by
8     this license (the "Software") to use, reproduce, display, distribute,
9     execute, and transmit the Software, and to prepare derivative works of the
10     Software, and to permit third-parties to whom the Software is furnished to
11     do so, all subject to the following:
12     
13     The copyright notices in the Software and this entire statement, including
14     the above license grant, this restriction and the following disclaimer,
15     must be included in all copies of the Software, in whole or in part, and
16     all derivative works of the Software, unless such copies or derivative
17     works are solely in the form of machine-executable object code generated by
18     a source language processor.
19     
20     THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
21     IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
22     FITNESS FOR A PARTICULAR PURPOSE, TITLE AND NON-INFRINGEMENT. IN NO EVENT
23     SHALL THE COPYRIGHT HOLDERS OR ANYONE DISTRIBUTING THE SOFTWARE BE LIABLE
24     FOR ANY DAMAGES OR OTHER LIABILITY, WHETHER IN CONTRACT, TORT OR OTHERWISE,
25     ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER
26     DEALINGS IN THE SOFTWARE.
27 
28 Authors:
29 	Alexandru Ermicioi
30 **/
31 module aermicioi.aedi.container.singleton_container;
32 
33 import aermicioi.aedi.container.container;
34 import aermicioi.aedi.storage.object_storage;
35 import aermicioi.aedi.storage.locator_aware;
36 import aermicioi.aedi.storage.locator;
37 import aermicioi.aedi.factory.factory;
38 import aermicioi.aedi.exception;
39 import aermicioi.aedi.container.factory;
40 
41 import std.range.interfaces;
42 import std.typecons;
43 
44 /**
45  Singleton container.
46  
47  It creates objects from ObjectFactory implementations and sets them as long as it lives in application.
48 **/
49 class SingletonContainer : ConfigurableContainer {
50     
51     private {
52         
53         ObjectStorage!() singletons;
54         ObjectStorage!(ObjectFactory, string) factories;
55     }
56     
57     public {
58         
59         this() {
60             this.singletons = new ObjectStorage!();
61             this.factories = new ObjectStorage!(ObjectFactory, string);
62         }
63         
64         SingletonContainer set(ObjectFactory object, string key) {
65             this.factories.set(new ExceptionChainingObjectFactory(new InProcessObjectFactoryDecorator(object), key), key);
66             
67             return this;
68         }
69         
70         SingletonContainer remove(string key) {
71             this.factories.remove(key);
72             this.singletons.remove(key);
73             
74             return this;
75         }
76         
77         Object get(string key) {
78             
79             if (!this.singletons.has(key)) {
80                 if (!this.factories.has(key)) {
81                     throw new NotFoundException("Object with id " ~ key ~ " not found.");
82                 }
83                 
84                 this.singletons.set( 
85                     this.factories.get(key).factory(),
86                     this.resolve(key),
87                 );
88             }
89             
90             return this.singletons.get(key);
91         }
92         
93         bool has(in string key) inout {
94             return this.factories.has(key);
95         }
96         
97         SingletonContainer instantiate() {
98             import std.algorithm : filter;
99             foreach (pair; this.factories.contents.byKeyValue.filter!((pair) => pair.key !in this.singletons.contents)) {
100                 this.singletons.set(
101                     pair.value.factory,
102                     pair.key,
103                 );
104             }
105             
106             return this;
107         }
108         
109         SingletonContainer link(string key, string alias_) {
110             this.singletons.link(key, alias_);
111             this.factories.link(key, alias_);
112             
113             return this;
114         }
115         
116         SingletonContainer unlink(string alias_) {
117             this.singletons.unlink(alias_);
118             this.factories.unlink(alias_);
119             
120             return this;
121         }
122         
123         const(string) resolve(in string key) const {
124             return this.factories.resolve(key);
125         }
126         
127         
128         ObjectFactory getFactory(string identity) {
129             return this.factories.get(identity);
130         }
131         
132         InputRange!(Tuple!(ObjectFactory, string)) getFactories() {
133             import std.algorithm;
134             
135             return this.factories.contents.byKeyValue.map!(
136                 a => tuple(a.value, a.key)
137             ).inputRangeObject;
138         }
139     }
140 }