##// END OF EJS Templates
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1 1 using System;
2 2 using Implab.Automaton.RegularExpressions;
3 3 using Implab.Automaton;
4 using System.Diagnostics;
4 5
5 6 namespace Implab.Formats {
6 7 public struct BufferScanner<TTag> {
7 char[] m_buffer;
8 int m_offset;
9 int m_position;
10 int m_hi;
11
12 readonly int m_chunk;
13 readonly int m_limit;
14
15 8 readonly DFAStateDescriptor<TTag>[] m_dfa;
16 9 int m_state;
10 int m_pos;
17 11
18 public BufferScanner(DFAStateDescriptor<TTag>[] dfa, int initialState, int chunk, int limit) {
12 public BufferScanner(DFAStateDescriptor<TTag>[] dfa, int initialState) {
19 13 m_dfa = dfa;
20 14 m_state = initialState;
21 m_chunk = chunk;
22 m_limit = limit;
23 m_buffer = null;
24 m_offset = 0;
25 m_position = 0;
26 m_hi = 0;
27 }
28
29 public char[] Buffer {
30 get {
31 return m_buffer;
32 }
33 }
34
35 public int HiMark {
36 get {
37 return m_hi;
38 }
39 15 }
40 16
41 17 public int Position {
42 get {
43 return m_position;
44 }
45 }
46
47 public int Length {
48 get {
49 return m_hi - m_position;
50 }
51 }
52
53 public int TokenOffset {
54 get {
55 return m_offset;
56 }
57 }
58
59 public int TokenLength {
60 get {
61 return m_position - m_offset;
62 }
63 }
64
65 public void Init(char[] buffer, int position, int length) {
66 m_buffer = buffer;
67 m_position = position;
68 m_offset = position;
69 m_hi = position + length;
70 }
71
72 public int Extend() {
73 // free space
74 var free = m_buffer.Length - m_hi;
75
76 // if the buffer have enough free space
77 if (free > 0)
78 return free;
79
80 // effective size of the buffer
81 var size = m_buffer.Length - m_offset;
82
83 // calculate the new size
84 int grow = Math.Min(m_limit - size, m_chunk);
85 if (grow <= 0)
86 throw new ParserException(String.Format("Input buffer {0} bytes limit exceeded", m_limit));
87
88 var temp = new char[size + grow];
89 Array.Copy(m_buffer, m_offset, temp, 0, m_hi - m_offset);
90 m_position -= m_offset;
91 m_hi -= m_offset;
92 m_offset = 0;
93 m_buffer = temp;
94
95 return free + grow;
96 }
97
98 public void RaiseMark(int size) {
99 m_hi += size;
18 get { return m_pos; }
100 19 }
101 20
102 21 /// <summary>
103 22 /// Scan this instance.
104 23 /// </summary>
105 24 /// <returns><c>true</c> - additional data required</returns>
106 public bool Scan() {
107 while (m_position < m_hi) {
108 var ch = m_buffer[m_position];
109 var next = m_dfa[m_state].transitions[(int)ch];
25 public bool Scan(int[] buffer, int position, int length) {
26 var hi = position + length;
27 m_pos = position;
28
29 while (position < hi) {
30 var next = m_dfa[m_state].transitions[buffer[position]];
110 31 if (next == DFAConst.UNREACHABLE_STATE) {
111 32 if (m_dfa[m_state].final)
112 33 return false;
113 34
114 35 throw new ParserException(
115 36 String.Format(
116 "Unexpected token '{0}'",
117 new string(m_buffer, m_offset, m_position - m_offset)
37 "Unexpected symbol"
118 38 )
119 39 );
120 40 }
41 m_pos++;
121 42 m_state = next;
122 m_position++;
123 43 }
124 44
125 45 return true;
126 46 }
127 47
128 48 public void Eof() {
129 49 if (!m_dfa[m_state].final)
130 50 throw new ParserException(
131 51 String.Format(
132 "Unexpected token '{0}'",
133 new string(m_buffer, m_offset, m_position - m_offset)
52 "Unexpected EOF"
134 53 )
135 54 );
136 55 }
137 56
138 57 public TTag[] GetTokenTags() {
139 58 return m_dfa[m_state].tags;
140 59 }
141 60 }
142 61 }
143 62
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@@ -1,72 +1,61
1 1 using System;
2 2 using Implab.Components;
3 3
4 4 namespace Implab.Formats {
5 5 public abstract class TextScanner<TTag> : Disposable {
6 6
7 char[] m_buffer;
8 int m_offset;
9 int m_length;
10 int m_tokenOffset;
7 readonly int[] m_buffer;
8 int m_bufferOffset;
9 int m_dataLength;
11 10 int m_tokenLength;
11
12 12 TTag[] m_tags;
13 13
14 14 BufferScanner<TTag> m_scanner;
15 15
16 16 protected bool ReadTokenInternal() {
17 17 if (EOF)
18 18 return false;
19 19
20 // create a new scanner from template (scanners are structs)
20 // create a new scanner from template (scanners are value types)
21 21 var inst = m_scanner;
22 22
23 // initialize the scanner
24 inst.Init(m_buffer, m_offset, m_length);
23 m_tokenLength = 0;
24
25 while (inst.Scan(m_buffer, m_bufferOffset, m_dataLength)) {
26 m_tokenLength += m_dataLength;
27
28 var actual = Read(m_buffer, 0, m_buffer.Length);
29
30 m_bufferOffset = 0;
31 m_dataLength = actual;
25 32
26 // do work
27 while (inst.Scan())
28 Feed(ref inst);
33 if (actual == 0) {
34 inst.Eof();
35 break;
36 }
37 }
38
39 var len = inst.Position - m_bufferOffset;
40 m_tokenLength += len;
41 m_dataLength -= len;
42 m_bufferOffset = inst.Position;
29 43
30 44 // save result;
31 m_buffer = inst.Buffer;
32 m_length = inst.Length;
33 m_offset = inst.Position;
34 m_tokenOffset = inst.TokenOffset;
35 m_tokenLength = inst.TokenLength;
36 45
37 46 m_tags = inst.GetTokenTags();
38 47 }
39 48
40 protected string GetToken() {
41 return new String(m_buffer, m_tokenOffset, m_tokenLength);
42 }
49 protected abstract int Read(int[] buffer, int offset, int size);
43 50
44 51 protected TTag[] Tags {
45 52 get {
46 53 return m_tags;
47 54 }
48 55 }
49 56
50 /// <summary>
51 /// Feed the specified scanner.
52 /// </summary>
53 /// <param name="scanner">Scanner.</param>
54 /// <example>
55 /// protected override void Feed(ref BufferScanner<TTag> scanner) {
56 /// var size = scanner.Extend();
57 /// var actual = m_reader.Read(scanner.Buffer, scanner.HiMark, size);
58 /// if (actual == 0) {
59 /// m_eof = true;
60 /// scanner.Eof();
61 /// } else {
62 /// scanner.RaiseHiMark(actual);
63 /// }
64 /// }
65 /// </example>
66 protected abstract void Feed(ref BufferScanner<TTag> scanner);
67
68 57 public abstract bool EOF { get; }
69 58
70 59 }
71 60 }
72 61
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