blob: 941ef8a107882de00a27c1799599b66e07c53e3f (
plain)
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
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
|
// Copyright (c) Microsoft Corporation. All rights reserved. See License.txt in the project root for license information.
using System.Collections.Generic;
using System.Web.Razor.Resources;
using System.Web.Razor.Utils;
namespace System.Web.Razor.Text
{
public class TextBufferReader : LookaheadTextReader
{
private Stack<BacktrackContext> _bookmarks = new Stack<BacktrackContext>();
private SourceLocationTracker _tracker = new SourceLocationTracker();
public TextBufferReader(ITextBuffer buffer)
{
if (buffer == null)
{
throw new ArgumentNullException("buffer");
}
InnerBuffer = buffer;
}
internal ITextBuffer InnerBuffer { get; private set; }
public override SourceLocation CurrentLocation
{
get { return _tracker.CurrentLocation; }
}
public override int Peek()
{
return InnerBuffer.Peek();
}
public override int Read()
{
int read = InnerBuffer.Read();
if (read != -1)
{
char nextChar = '\0';
int next = Peek();
if (next != -1)
{
nextChar = (char)next;
}
_tracker.UpdateLocation((char)read, nextChar);
}
return read;
}
protected override void Dispose(bool disposing)
{
if (disposing)
{
IDisposable disposable = InnerBuffer as IDisposable;
if (disposable != null)
{
disposable.Dispose();
}
}
base.Dispose(disposing);
}
public override IDisposable BeginLookahead()
{
BacktrackContext context = new BacktrackContext() { Location = CurrentLocation };
_bookmarks.Push(context);
return new DisposableAction(() =>
{
EndLookahead(context);
});
}
public override void CancelBacktrack()
{
if (_bookmarks.Count == 0)
{
throw new InvalidOperationException(RazorResources.CancelBacktrack_Must_Be_Called_Within_Lookahead);
}
_bookmarks.Pop();
}
private void EndLookahead(BacktrackContext context)
{
if (_bookmarks.Count > 0 && ReferenceEquals(_bookmarks.Peek(), context))
{
// Backtrack wasn't cancelled, so pop it
_bookmarks.Pop();
// Set the new current location
_tracker.CurrentLocation = context.Location;
InnerBuffer.Position = context.Location.AbsoluteIndex;
}
}
/// <summary>
/// Need a class for reference equality to support cancelling backtrack.
/// </summary>
private class BacktrackContext
{
public SourceLocation Location { get; set; }
}
}
}
|
