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Diffstat (limited to 'libio/editbuf.h')
| -rw-r--r-- | libio/editbuf.h | 185 |
1 files changed, 185 insertions, 0 deletions
diff --git a/libio/editbuf.h b/libio/editbuf.h new file mode 100644 index 00000000000..d15758f257e --- /dev/null +++ b/libio/editbuf.h @@ -0,0 +1,185 @@ +/* This is part of libio/iostream, providing -*- C++ -*- input/output. +Copyright (C) 1993 Free Software Foundation + +This file is part of the GNU IO Library. This library is free +software; you can redistribute it and/or modify it under the +terms of the GNU General Public License as published by the +Free Software Foundation; either version 2, or (at your option) +any later version. + +This library is distributed in the hope that it will be useful, +but WITHOUT ANY WARRANTY; without even the implied warranty of +MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the +GNU General Public License for more details. + +You should have received a copy of the GNU General Public License +along with this library; see the file COPYING. If not, write to the Free +Software Foundation, 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA. + +As a special exception, if you link this library with files +compiled with a GNU compiler to produce an executable, this does not cause +the resulting executable to be covered by the GNU General Public License. +This exception does not however invalidate any other reasons why +the executable file might be covered by the GNU General Public License. + +Written by Per Bothner (bothner@cygnus.com). */ + +#ifndef _EDITBUF_H +#define _EDITBUF_H +#ifdef __GNUG__ +#pragma interface +#endif +#include <stdio.h> +#include <fstream.h> + +extern "C++" { +typedef unsigned long mark_pointer; +// At some point, it might be nice to parameterize this code +// in terms of buf_char. +typedef /*unsigned*/ char buf_char; + +// Logical pos from start of buffer (does not count gap). +typedef long buf_index; + +// Pos from start of buffer, possibly including gap_size. +typedef long buf_offset; + +#if 0 +struct buf_cookie { + FILE *file; + struct edit_string *str; + struct buf_cookie *next; + buf_index tell(); +}; +#endif + +struct edit_buffer; +struct edit_mark; + +// A edit_string is defined as the region between the 'start' and 'end' marks. +// Normally (always?) 'start->insert_before()' should be false, +// and 'end->insert_before()' should be true. + +struct edit_string { + struct edit_buffer *buffer; // buffer that 'start' and 'end' belong to + struct edit_mark *start, *end; + int length() const; // count of buf_chars currently in string + edit_string(struct edit_buffer *b, + struct edit_mark *ms, struct edit_mark *me) + { buffer = b; start = ms; end = me; } +/* Make a fresh, contiguous copy of the data in STR. + Assign length of STR to *LENP. + (Output has extra NUL at out[*LENP].) */ + buf_char *copy_bytes(int *lenp) const; +// FILE *open_file(char *mode); + void assign(struct edit_string *src); // copy bytes from src to this +}; + +struct edit_streambuf : public streambuf { + friend edit_buffer; + edit_string *str; + edit_streambuf* next; // Chain of edit_streambuf's for a edit_buffer. + short _mode; + edit_streambuf(edit_string* bstr, int mode); + ~edit_streambuf(); + virtual int underflow(); + virtual int overflow(int c = EOF); + virtual streampos seekoff(streamoff, _seek_dir, int mode=ios::in|ios::out); + void flush_to_buffer(); + void flush_to_buffer(edit_buffer* buffer); + int _inserting; + int inserting() { return _inserting; } + void inserting(int i) { _inserting = i; } +// int delete_chars(int count, char* cut_buf); Not implemented. + int truncate(); + int is_reading() { return gptr() != NULL; } + buf_char* current() { return is_reading() ? gptr() : pptr(); } + void set_current(char *p, int is_reading); + protected: + void disconnect_gap_from_file(edit_buffer* buffer); +}; + +// A 'edit_mark' indicates a position in a buffer. +// It is "attached" the text (rather than the offset). +// There are two kinds of mark, which have different behavior +// when text is inserted at the mark: +// If 'insert_before()' is true the mark will be adjusted to be +// *after* the new text. + +struct edit_mark { + struct edit_mark *chain; + mark_pointer _pos; + inline int insert_before() { return _pos & 1; } + inline unsigned long index_in_buffer(struct edit_buffer *) + { return _pos >> 1; } + inline buf_char *ptr(struct edit_buffer *buf); + buf_index tell(); + edit_mark() { } + edit_mark(struct edit_string *str, long delta); + edit_buffer *buffer(); + ~edit_mark(); +}; + +// A 'edit_buffer' consists of a sequence of buf_chars (the data), +// a list of edit_marks pointing into the data, and a list of FILEs +// also pointing into the data. +// A 'edit_buffer' coerced to a edit_string is the string of +// all the buf_chars in the buffer. + +// This implementation uses a conventional buffer gap (as in Emacs). +// The gap start is defined by de-referencing a (buf_char**). +// This is because sometimes a FILE is inserting into the buffer, +// so rather than having each putc adjust the gap, we use indirection +// to have the gap be defined as the write pointer of the FILE. +// (This assumes that putc adjusts a pointer (as in GNU's libc), not an index.) + +struct edit_buffer { + buf_char *data; /* == emacs buffer_text.p1+1 */ + buf_char *_gap_start; + edit_streambuf* _writer; // If non-NULL, currently writing stream + inline buf_char *gap_start() + { return _writer ? _writer->pptr() : _gap_start; } + buf_offset __gap_end_pos; // size of part 1 + size of gap + /* int gap; implicit: buf_size - size1 - size2 */ + int buf_size; + struct edit_streambuf *files; + struct edit_mark start_mark; + struct edit_mark end_mark; + edit_buffer(); + inline buf_offset gap_end_pos() { return __gap_end_pos; } + inline struct edit_mark *start_marker() { return &start_mark; } + inline struct edit_mark *end_marker() { return &end_mark; } +/* these should be protected, ultimately */ + buf_index tell(edit_mark*); + buf_index tell(buf_char*); + inline buf_char *gap_end() { return data + gap_end_pos(); } + inline int gap_size() { return gap_end() - gap_start(); } + inline int size1() { return gap_start() - data; } + inline int size2() { return buf_size - gap_end_pos(); } + inline struct edit_mark * mark_list() { return &start_mark; } + void make_gap (buf_offset); + void move_gap (buf_offset pos); + void move_gap (buf_char *pos) { move_gap(pos - data); } + void gap_left (int pos); + void gap_right (int pos); + void adjust_markers(mark_pointer low, mark_pointer high, + int amount, buf_char *old_data); + void delete_range(buf_index from, buf_index to); + void delete_range(struct edit_mark *start, struct edit_mark *end); +}; + +extern buf_char * bstr_copy(struct edit_string *str, int *lenp); + +// Convert a edit_mark to a (buf_char*) + +inline buf_char *edit_mark::ptr(struct edit_buffer *buf) + { return buf->data + index_in_buffer(buf); } + +inline void edit_streambuf::flush_to_buffer() +{ + edit_buffer* buffer = str->buffer; + if (buffer->_writer == this) flush_to_buffer(buffer); +} +} // extern "C++" +#endif /* !_EDITBUF_H*/ + |