ae.sys.net source code

1 /**
2  * Abstract interface for basic network operations.
3  * Import ae.sys.net.* to select an implementation.
4  *
5  * License:
6  *   This Source Code Form is subject to the terms of
7  *   the Mozilla Public License, v. 2.0. If a copy of
8  *   the MPL was not distributed with this file, You
9  *   can obtain one at http://mozilla.org/MPL/2.0/.
10  *
11  * Authors:
12  *   Vladimir Panteleev <vladimir@thecybershadow.net>
13  */
14 
15 module ae.sys.net;
16 
17 import std.functional;
18 import std.path;
19 
20 import ae.net.ietf.url;
21 import ae.sys.file;
22 
23 class Network
24 {
25 	/// Download file located at the indicated URL,
26 	/// unless the target file already exists.
27 	void downloadFile(string url, string target)
28 	{
29 		notImplemented();
30 	}
31 
32 	/// Get resource located at the indicated URL.
33 	void[] getFile(string url)
34 	{
35 		notImplemented();
36 		assert(false);
37 	}
38 
39 	/// Post data to the specified URL.
40 	// TODO: Content-Type?
41 	void[] post(string url, in void[] data)
42 	{
43 		notImplemented();
44 		assert(false);
45 	}
46 
47 	/// Check if the resource exists and is downloadable.
48 	/// E.g. the HTTP status code for a HEAD request should be 200.
49 	bool urlOK(string url)
50 	{
51 		notImplemented();
52 		assert(false);
53 	}
54 
55 	/// Get the destination of an HTTP redirect.
56 	string resolveRedirect(string url)
57 	{
58 		notImplemented();
59 		assert(false);
60 	}
61 
62 	private final void notImplemented()
63 	{
64 		assert(false, "Not implemented or Network implementation not set");
65 	}
66 }
67 
68 /// The instance of the selected Network implementation.
69 Network net;
70 
71 static this()
72 {
73 	assert(!net);
74 	net = new Network();
75 }
76 
77 /// UFCS-able global synonym functions.
78 void downloadFile(string url, string target) { net.downloadFile(url, target); }
79 void[] getFile(string url) { return net.getFile(url); } /// ditto
80 void[] post(string url, void[] data) { return net.post(url, data); }
81 bool urlOK(string url) { return net.urlOK(url); } /// ditto
82 string resolveRedirect(string url) { return net.resolveRedirect(url); } /// ditto