|
|
1.1 root 1: /* This is part of libio/iostream, providing -*- C++ -*- input/output.
2: Copyright (C) 1993 Free Software Foundation
3:
4: This file is part of the GNU IO Library. This library is free
5: software; you can redistribute it and/or modify it under the
6: terms of the GNU General Public License as published by the
7: Free Software Foundation; either version 2, or (at your option)
8: any later version.
9:
10: This library is distributed in the hope that it will be useful,
11: but WITHOUT ANY WARRANTY; without even the implied warranty of
12: MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
13: GNU General Public License for more details.
14:
15: You should have received a copy of the GNU General Public License
16: along with GNU CC; see the file COPYING. If not, write to
17: the Free Software Foundation, 675 Mass Ave, Cambridge, MA 02139, USA.
18:
19: As a special exception, if you link this library with files
20: compiled with a GNU compiler to produce an executable, this does not cause
21: the resulting executable to be covered by the GNU General Public License.
22: This exception does not however invalidate any other reasons why
23: the executable file might be covered by the GNU General Public License.
24:
25: Written by Per Bothner ([email protected]). */
26:
27: #ifndef _EDITBUF_H
28: #define _EDITBUF_H
29: #ifdef __GNUG__
30: #pragma interface
31: #pragma cplusplus
32: #endif
33: #include <stdio.h>
34: #include <fstream.h>
35:
36: typedef unsigned long mark_pointer;
37: // At some point, it might be nice to parameterize this code
38: // in terms of buf_char.
39: typedef /*unsigned*/ char buf_char;
40:
41: // Logical pos from start of buffer (does not count gap).
42: typedef long buf_index;
43:
44: // Pos from start of buffer, possibly including gap_size.
45: typedef long buf_offset;
46:
47: #if 0
48: struct buf_cookie {
49: FILE *file;
50: struct edit_string *str;
51: struct buf_cookie *next;
52: buf_index tell();
53: };
54: #endif
55:
56: struct edit_buffer;
57: struct edit_mark;
58:
59: // A edit_string is defined as the region between the 'start' and 'end' marks.
60: // Normally (always?) 'start->insert_before()' should be false,
61: // and 'end->insert_before()' should be true.
62:
63: struct edit_string {
64: struct edit_buffer *buffer; // buffer that 'start' and 'end' belong to
65: struct edit_mark *start, *end;
66: int length() const; // count of buf_chars currently in string
67: edit_string(struct edit_buffer *b,
68: struct edit_mark *ms, struct edit_mark *me)
69: { buffer = b; start = ms; end = me; }
70: /* Make a fresh, contiguous copy of the data in STR.
71: Assign length of STR to *LENP.
72: (Output has extra NUL at out[*LENP].) */
73: buf_char *copy_bytes(int *lenp) const;
74: // FILE *open_file(char *mode);
75: void assign(struct edit_string *src); // copy bytes from src to this
76: };
77:
78: struct edit_streambuf : public streambuf {
79: friend edit_buffer;
80: edit_string *str;
81: edit_streambuf* next; // Chain of edit_streambuf's for a edit_buffer.
82: short _mode;
83: edit_streambuf(edit_string* bstr, int mode);
84: ~edit_streambuf();
85: virtual int underflow();
86: virtual int overflow(int c = EOF);
87: virtual streampos seekoff(streamoff, _seek_dir, int mode=ios::in|ios::out);
88: void flush_to_buffer();
89: void flush_to_buffer(edit_buffer* buffer);
90: int _inserting;
91: int inserting() { return _inserting; }
92: void inserting(int i) { _inserting = i; }
93: // int delete_chars(int count, char* cut_buf); Not implemented.
94: int truncate();
95: int is_reading() { return gptr() != NULL; }
96: buf_char* current() { return is_reading() ? gptr() : pptr(); }
97: void set_current(char *p, int is_reading);
98: protected:
99: void disconnect_gap_from_file(edit_buffer* buffer);
100: };
101:
102: // A 'edit_mark' indicates a position in a buffer.
103: // It is "attached" the text (rather than the offset).
104: // There are two kinds of mark, which have different behavior
105: // when text is inserted at the mark:
106: // If 'insert_before()' is true the mark will be adjusted to be
107: // *after* the new text.
108:
109: struct edit_mark {
110: struct edit_mark *chain;
111: mark_pointer _pos;
112: inline int insert_before() { return _pos & 1; }
113: inline unsigned long index_in_buffer(struct edit_buffer *buffer)
114: { return _pos >> 1; }
115: inline buf_char *ptr(struct edit_buffer *buf);
116: buf_index tell();
117: edit_mark() { }
118: edit_mark(struct edit_string *str, long delta);
119: edit_buffer *buffer();
120: ~edit_mark();
121: };
122:
123: // A 'edit_buffer' consists of a sequence of buf_chars (the data),
124: // a list of edit_marks pointing into the data, and a list of FILEs
125: // also pointing into the data.
126: // A 'edit_buffer' coerced to a edit_string is the string of
127: // all the buf_chars in the buffer.
128:
129: // This implementation uses a conventional buffer gap (as in Emacs).
130: // The gap start is defined by de-referencing a (buf_char**).
131: // This is because sometimes a FILE is inserting into the buffer,
132: // so rather than having each putc adjust the gap, we use indirection
133: // to have the gap be defined as the write pointer of the FILE.
134: // (This assumes that putc adjusts a pointer (as in GNU's libc), not an index.)
135:
136: struct edit_buffer {
137: buf_char *data; /* == emacs buffer_text.p1+1 */
138: buf_char *_gap_start;
139: edit_streambuf* _writer; // If non-NULL, currently writing stream
140: inline buf_char *gap_start()
141: { return _writer ? _writer->pptr() : _gap_start; }
142: buf_offset __gap_end_pos; // size of part 1 + size of gap
143: /* int gap; implicit: buf_size - size1 - size2 */
144: int buf_size;
145: struct edit_streambuf *files;
146: struct edit_mark start_mark;
147: struct edit_mark end_mark;
148: edit_buffer();
149: inline buf_offset gap_end_pos() { return __gap_end_pos; }
150: inline struct edit_mark *start_marker() { return &start_mark; }
151: inline struct edit_mark *end_marker() { return &end_mark; }
152: /* these should be protected, ultimately */
153: buf_index tell(edit_mark*);
154: buf_index tell(buf_char*);
155: inline buf_char *gap_end() { return data + gap_end_pos(); }
156: inline int gap_size() { return gap_end() - gap_start(); }
157: inline int size1() { return gap_start() - data; }
158: inline int size2() { return buf_size - gap_end_pos(); }
159: inline struct edit_mark * mark_list() { return &start_mark; }
160: void make_gap (buf_offset);
161: void move_gap (buf_offset pos);
162: void move_gap (buf_char *pos) { move_gap(pos - data); }
163: void gap_left (int pos);
164: void gap_right (int pos);
165: void adjust_markers(mark_pointer low, mark_pointer high,
166: int amount, buf_char *old_data);
167: void delete_range(buf_index from, buf_index to);
168: void delete_range(struct edit_mark *start, struct edit_mark *end);
169: };
170:
171: extern buf_char * bstr_copy(struct edit_string *str, int *lenp);
172:
173: // Convert a edit_mark to a (buf_char*)
174:
175: inline buf_char *edit_mark::ptr(struct edit_buffer *buf)
176: { return buf->data + index_in_buffer(buf); }
177:
178: inline void edit_streambuf::flush_to_buffer()
179: {
180: edit_buffer* buffer = str->buffer;
181: if (buffer->_writer == this) flush_to_buffer(buffer);
182: }
183: #endif /* !_EDITBUF_H*/
184:
This archive runs on limited infrastructure. Preserving old code on modern bandwidth. Automated agents are requested to crawl responsibly.