styx2000.protobj.nwqid source code

1 // Written in the D programming language.
2 
3 /**
4 A type for representing the nwqid object of the 9P / Styx protocol. 
5 
6 Copyright: LightHouse Software, 2021
7 License:   $(HTTP https://github.com/aquaratixc/ESL-License, Experimental Software License 1.0).
8 Authors:   Oleg Bakharev,
9 		   Ilya Pertsev
10 */
11 module styx2000.protobj.nwqid;
12 
13 private {
14 	import std.conv : to;
15 	import std..string : format;
16 	
17 	import styx2000.lowlevel.endianness;
18 	
19 	import styx2000.protobj.styxobject;
20 }
21 
22 public {
23 	import styx2000.protobj.qid;
24 }
25 
26 /**
27 	A class that provides a type for the Nwqid field in some Styx messages. Inherits methods from the StyxObject class. 
28 	See_Also:
29 		https://web.archive.org/web/20201029184954/https://powerman.name/Inferno/man/5/0intro.html
30 */
31 class Nwqid : StyxObject
32 {
33 	protected {
34 		Qid[] _nwqid;
35 		
36 		ubyte[] _representation;
37 	}
38 	
39 	private {
40 		// update qids list
41 		void updateQids()
42 		{
43 			if (_nwqid.length == 0)
44 			{
45 				_representation = [0, 0];
46 			}
47 			else
48 			{
49 				_representation = toLEBytes!ushort(
50 					cast(ushort) _nwqid.length
51 				);
52 				foreach (e; _nwqid)
53 				{
54 					_representation ~= e.pack;
55 				}
56 			}
57 		}
58 	}
59 	
60 	/**
61 	A constructor that creates an object of the Nwqid class with the given parameter in the form of qid's array. 
62 	If called without parameters, then the default parameter is empty qid's array. 
63     Params:
64     nwname = Full file path as qid's array.
65     
66     Typical usage:
67     ----
68     Nwqid nwqid = new Nwqid([new Qid, new Qid]);
69     ----
70     */
71 	this(Qid[] nwqid = [])
72 	{
73 		_nwqid = nwqid;
74 		_representation = [];
75 		updateQids;
76 	}
77 	
78 	/// Get all qids in path as qid's array
79 	Qid[] getQid()
80 	{
81 		return _nwqid;
82 	}
83 	
84 	/// Number of qids
85 	ushort countOfQids()
86 	{
87 		return fromLEBytes!ushort(_representation[0..2]);
88 	}
89 	
90 	/// Set all qids in path as qid's array
91 	void setQid(Qid[] nwqid...)
92 	{
93 		_nwqid = nwqid;
94 		_representation = [];
95 		updateQids;
96 	}
97 	
98 	/// Pack to bytes array
99 	ubyte[] pack()
100 	{
101 		return _representation;
102 	}
103 	
104 	/// Unpack from bytes array
105 	void unpack(ubyte[] bytes...)
106 	{
107 		_representation = bytes;
108 		_nwqid = [];
109 		ushort length = fromLEBytes!ushort(bytes[0..2]);
110 		auto vlsPosition = 2;
111 		
112 		foreach (_; 0..length)
113 		{
114 			Qid qid = new Qid;
115 			qid.unpack(bytes[vlsPosition..$]);
116 			_nwqid ~= qid;
117 			vlsPosition += 13;
118 		}
119 	}
120 	
121 	/// Convenient string representation of an object for printing
122 	override string toString()
123 	{
124 		return format(
125 			`Nwqid(nwqid=%d, wqid=%s)`,
126 			fromLEBytes!ushort(_representation[0..2]),
127 			_nwqid.to!string
128 		);
129 	}
130 	
131 	/// An alias for easier packing into a byte array without having to manually call the pack() method
132 	alias pack this;
133 }