diff options
Diffstat (limited to 'libio/editbuf.cc')
| -rw-r--r-- | libio/editbuf.cc | 717 |
1 files changed, 717 insertions, 0 deletions
diff --git a/libio/editbuf.cc b/libio/editbuf.cc new file mode 100644 index 00000000000..22304820f8f --- /dev/null +++ b/libio/editbuf.cc @@ -0,0 +1,717 @@ +/* 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). */ + +#ifdef __GNUG__ +#pragma implementation +#endif +#include "libioP.h" +#include "editbuf.h" +#include <stddef.h> +#include <stdlib.h> + +/* NOTE: Some of the code here is taken from GNU emacs */ +/* Hence this file falls under the GNU License! */ + +// Invariants for edit_streambuf: +// An edit_streambuf is associated with a specific edit_string, +// which again is a sub-string of a specific edit_buffer. +// An edit_streambuf is always in either get mode or put mode, never both. +// In get mode, gptr() is the current position, +// and pbase(), pptr(), and epptr() are all NULL. +// In put mode, pptr() is the current position, +// and eback(), gptr(), and egptr() are all NULL. +// Any edit_streambuf that is actively doing insertion (as opposed to +// replacing) // must have its pptr() pointing to the start of the gap. +// Only one edit_streambuf can be actively inserting into a specific +// edit_buffer; the edit_buffer's _writer field points to that edit_streambuf. +// That edit_streambuf "owns" the gap, and the actual start of the +// gap is the pptr() of the edit_streambuf; the edit_buffer::_gap_start pointer +// will only be updated on an edit_streambuf::overflow(). + +int edit_streambuf::truncate() +{ + str->buffer->delete_range(str->buffer->tell((buf_char*)pptr()), + str->buffer->tell(str->end)); + return 0; +} + +#ifdef OLD_STDIO +inline void disconnect_gap_from_file(edit_buffer* buffer, FILE* fp) +{ + if (buffer->gap_start_ptr != &fp->__bufp) + return; + buffer->gap_start_normal = fp->__bufp; + buffer->gap_start_ptr = &buffer->gap_start_normal; +} +#endif + +void edit_streambuf::flush_to_buffer(edit_buffer* buffer) +{ + if (pptr() > buffer->_gap_start && pptr() < buffer->gap_end()) + buffer->_gap_start = pptr(); +} + +void edit_streambuf::disconnect_gap_from_file(edit_buffer* buffer) +{ + if (buffer->_writer != this) return; + flush_to_buffer(buffer); + setp(pptr(),pptr()); + buffer->_writer = NULL; +} + +buf_index edit_buffer::tell(buf_char *ptr) +{ + if (ptr <= gap_start()) + return ptr - data; + else + return ptr - gap_end() + size1(); +} + +#if 0 +buf_index buf_cookie::tell() +{ + return str->buffer->tell(file->__bufp); +} +#endif + +buf_index edit_buffer::tell(edit_mark*mark) +{ + return tell(data + mark->index_in_buffer(this)); +} + +// adjust the position of the gap + +void edit_buffer::move_gap(buf_offset pos) +{ + if (pos < size1()) + gap_left (pos); + else if (pos > size1()) + gap_right (pos); +} + +void edit_buffer::gap_left (int pos) +{ + register buf_char *to, *from; + register int i; + int new_s1; + + i = size1(); + from = gap_start(); + to = from + gap_size(); + new_s1 = size1(); + + /* Now copy the characters. To move the gap down, + copy characters up. */ + + for (;;) + { + /* I gets number of characters left to copy. */ + i = new_s1 - pos; + if (i == 0) + break; +#if 0 + /* If a quit is requested, stop copying now. + Change POS to be where we have actually moved the gap to. */ + if (QUITP) + { + pos = new_s1; + break; + } +#endif + /* Move at most 32000 chars before checking again for a quit. */ + if (i > 32000) + i = 32000; + new_s1 -= i; + while (--i >= 0) + *--to = *--from; + } + + /* Adjust markers, and buffer data structure, to put the gap at POS. + POS is where the loop above stopped, which may be what was specified + or may be where a quit was detected. */ + adjust_markers (pos << 1, size1() << 1, gap_size(), data); +#ifndef OLD_STDIO + _gap_start = data + pos; +#else + if (gap_start_ptr == &gap_start_normal) + gap_start_normal = data + pos; +#endif + __gap_end_pos = to - data; +/* QUIT;*/ +} + +void edit_buffer::gap_right (int pos) +{ + register buf_char *to, *from; + register int i; + int new_s1; + + i = size1(); + to = gap_start(); + from = i + gap_end(); + new_s1 = i; + + /* Now copy the characters. To move the gap up, + copy characters down. */ + + while (1) + { + /* I gets number of characters left to copy. */ + i = pos - new_s1; + if (i == 0) + break; +#if 0 + /* If a quit is requested, stop copying now. + Change POS to be where we have actually moved the gap to. */ + if (QUITP) + { + pos = new_s1; + break; + } +#endif + /* Move at most 32000 chars before checking again for a quit. */ + if (i > 32000) + i = 32000; + new_s1 += i; + while (--i >= 0) + *to++ = *from++; + } + + adjust_markers ((size1() + gap_size()) << 1, (pos + gap_size()) << 1, + - gap_size(), data); +#ifndef OLD_STDIO + _gap_start = data+pos; +#else + if (gap_start_ptr == &gap_start_normal) + gap_start_normal = data + pos; +#endif + __gap_end_pos = from - data; +/* QUIT;*/ +} + +/* make sure that the gap in the current buffer is at least k + characters wide */ + +void edit_buffer::make_gap(buf_offset k) +{ + register buf_char *p1, *p2, *lim; + buf_char *old_data = data; + int s1 = size1(); + + if (gap_size() >= k) + return; + + /* Get more than just enough */ + if (buf_size > 1000) k += 2000; + else k += /*200;*/ 20; // for testing! + + p1 = (buf_char *) realloc (data, s1 + size2() + k); + if (p1 == 0) + abort(); /*memory_full ();*/ + + k -= gap_size(); /* Amount of increase. */ + + /* Record new location of text */ + data = p1; + + /* Transfer the new free space from the end to the gap + by shifting the second segment upward */ + p2 = data + buf_size; + p1 = p2 + k; + lim = p2 - size2(); + while (lim < p2) + *--p1 = *--p2; + + /* Finish updating text location data */ + __gap_end_pos += k; + +#ifndef OLD_STDIO + _gap_start = data + s1; +#else + if (gap_start_ptr == &gap_start_normal) + gap_start_normal = data + s1; +#endif + + /* adjust markers */ + adjust_markers (s1 << 1, (buf_size << 1) + 1, k, old_data); + buf_size += k; +} + +/* Add `amount' to the position of every marker in the current buffer + whose current position is between `from' (exclusive) and `to' (inclusive). + Also, any markers past the outside of that interval, in the direction + of adjustment, are first moved back to the near end of the interval + and then adjusted by `amount'. */ + +void edit_buffer::adjust_markers(register mark_pointer low, + register mark_pointer high, + int amount, buf_char *old_data) +{ + register struct edit_mark *m; + register mark_pointer mpos; + /* convert to mark_pointer */ + amount <<= 1; + + if (_writer) + _writer->disconnect_gap_from_file(this); + + for (m = mark_list(); m != NULL; m = m->chain) + { + mpos = m->_pos; + if (amount > 0) + { + if (mpos > high && mpos < high + amount) + mpos = high + amount; + } + else + { + if (mpos > low + amount && mpos <= low) + mpos = low + amount; + } + if (mpos > low && mpos <= high) + mpos += amount; + m->_pos = mpos; + } + + // Now adjust files + edit_streambuf *file; + + for (file = files; file != NULL; file = file->next) { + mpos = file->current() - old_data; + if (amount > 0) + { + if (mpos > high && mpos < high + amount) + mpos = high + amount; + } + else + { + if (mpos > low + amount && mpos <= low) + mpos = low + amount; + } + if (mpos > low && mpos <= high) + mpos += amount; + char* new_pos = data + mpos; + file->set_current(new_pos, file->is_reading()); + } +} + +#if 0 +stdio_ + __off == index at start of buffer (need only be valid after seek ? ) + __buf == + +if read/read_delete/overwrite mode: + __endp <= min(*gap_start_ptr, edit_string->end->ptr(buffer)) + +if inserting: + must have *gap_start_ptr == __bufp && *gap_start_ptr+gap == __endp + file->edit_string->end->ptr(buffer) == *gap_start_ptr+end +if write_mode: + if before gap +#endif + +int edit_streambuf::underflow() +{ + if (!(_mode & ios::in)) + return EOF; + struct edit_buffer *buffer = str->buffer; + if (!is_reading()) { // Must switch from put to get mode. + disconnect_gap_from_file(buffer); + set_current(pptr(), 1); + } + buf_char *str_end = str->end->ptr(buffer); + retry: + if (gptr() < egptr()) { + return *gptr(); + } + if ((buf_char*)gptr() == str_end) + return EOF; + if (str_end <= buffer->gap_start()) { + setg(eback(), gptr(), str_end); + goto retry; + } + if (gptr() < buffer->gap_start()) { + setg(eback(), gptr(), buffer->gap_start()); + goto retry; + } + if (gptr() == buffer->gap_start()) { + disconnect_gap_from_file(buffer); +// fp->__offset += fp->__bufp - fp->__buffer; + setg(buffer->gap_end(), buffer->gap_end(), str_end); + } + else + setg(eback(), gptr(), str_end); + goto retry; +} + +int edit_streambuf::overflow(int ch) +{ + if (_mode == ios::in) + return EOF; + struct edit_buffer *buffer = str->buffer; + flush_to_buffer(buffer); + if (ch == EOF) + return 0; + if (is_reading()) { // Must switch from get to put mode. + set_current(gptr(), 0); + } + buf_char *str_end = str->end->ptr(buffer); + retry: + if (pptr() < epptr()) { + *pptr() = ch; + pbump(1); + return (unsigned char)ch; + } + if ((buf_char*)pptr() == str_end || inserting()) { + /* insert instead */ + if (buffer->_writer) + buffer->_writer->flush_to_buffer(); // Redundant? + buffer->_writer = NULL; + if (pptr() >= buffer->gap_end()) + buffer->move_gap(pptr() - buffer->gap_size()); + else + buffer->move_gap(pptr()); + buffer->make_gap(1); + setp(buffer->gap_start(), buffer->gap_end()); + buffer->_writer = this; + *pptr() = ch; + pbump(1); + return (unsigned char)ch; + } + if (str_end <= buffer->gap_start()) { + // Entire string is left of gap. + setp(pptr(), str_end); + } + else if (pptr() < buffer->gap_start()) { + // Current pos is left of gap. + setp(pptr(), buffer->gap_start()); + goto retry; + } + else if (pptr() == buffer->gap_start()) { + // Current pos is at start of gap; move to end of gap. +// disconnect_gap_from_file(buffer); + setp(buffer->gap_end(), str_end); +// __offset += __bufp - __buffer; + } + else { + // Otherwise, current pos is right of gap. + setp(pptr(), str_end); + } + goto retry; +} + +void edit_streambuf::set_current(char *new_pos, int reading) +{ + if (reading) { + setg(new_pos, new_pos, new_pos); + setp(NULL, NULL); + } + else { + setg(NULL, NULL, NULL); + setp(new_pos, new_pos); + } +} + +// Called by fseek(fp, pos, whence) if fp is bound to a edit_buffer. + +streampos edit_streambuf::seekoff(streamoff offset, _seek_dir dir, + int /* =ios::in|ios::out*/) +{ + struct edit_buffer *buffer = str->buffer; + disconnect_gap_from_file(buffer); + buf_index cur_pos = buffer->tell((buf_char*)current());; + buf_index start_pos = buffer->tell(str->start); + buf_index end_pos = buffer->tell(str->end); + switch (dir) { + case ios::beg: + offset += start_pos; + break; + case ios::cur: + offset += cur_pos; + break; + case ios::end: + offset += end_pos; + break; + } + if (offset < start_pos || offset > end_pos) + return EOF; + buf_char *new_pos = buffer->data + offset; + buf_char* gap_start = buffer->gap_start(); + if (new_pos > gap_start) { + buf_char* gap_end = buffer->gap_end(); + new_pos += gap_end - gap_start; + if (new_pos >= buffer->data + buffer->buf_size) abort(); // Paranoia. + } + set_current(new_pos, is_reading()); + return EOF; +} + +#if 0 +int buf_seek(void *arg_cookie, fpos_t * pos, int whence) +{ + struct buf_cookie *cookie = arg_cookie; + FILE *file = cookie->file; + struct edit_buffer *buffer = cookie->str->buffer; + buf_char *str_start = cookie->str->start->ptr(buffer); + disconnect_gap_from_file(buffer, cookie->file); + fpos_t cur_pos, new_pos; + if (file->__bufp <= *buffer->gap_start_ptr + || str_start >= buffer->__gap_end) + cur_pos = str_start - file->__bufp; + else + cur_pos = + (*buffer->gap_start_ptr - str_start) + (file->__bufp - __gap_end); + end_pos = ...; + switch (whence) { + case SEEK_SET: + new_pos = *pos; + break; + case SEEK_CUR: + new_pos = cur_pos + *pos; + break; + case SEEK_END: + new_pos = end_pos + *pos; + break; + } + if (new_pos > end_pos) { + seek to end_pos; + insert_nulls(new_pos - end_pos); + return; + } + if (str_start + new_pos <= *gap_start_ptr &* *gap_start_ptr < end) { + __buffer = str_start; + __off = 0; + __bufp = str_start + new_pos; + file->__get_limit = + *buffer->gap_start_ptr; /* what if gap_start_ptr == &bufp ??? */ + } else if () { + + } + *pos = new_pos; +} +#endif + +/* Delete characters from `from' up to (but not incl) `to' */ + +void edit_buffer::delete_range (buf_index from, buf_index to) +{ + register int numdel; + + if ((numdel = to - from) <= 0) + return; + + /* Make sure the gap is somewhere in or next to what we are deleting */ + if (from > size1()) + gap_right (from); + if (to < size1()) + gap_left (to); + + /* Relocate all markers pointing into the new, larger gap + to point at the end of the text before the gap. */ + adjust_markers ((to + gap_size()) << 1, (to + gap_size()) << 1, + - numdel - gap_size(), data); + + __gap_end_pos = to + gap_size(); + _gap_start = data + from; +} + +void edit_buffer::delete_range(struct edit_mark *start, struct edit_mark *end) +{ + delete_range(tell(start), tell(end)); +} + +void buf_delete_chars(struct edit_buffer *, struct edit_mark *, size_t) +{ + abort(); +} + +edit_streambuf::edit_streambuf(edit_string* bstr, int mode) +{ + _mode = mode; + str = bstr; + edit_buffer* buffer = bstr->buffer; + next = buffer->files; + buffer->files = this; + char* buf_ptr = bstr->start->ptr(buffer); + _inserting = 0; +// setb(buf_ptr, buf_ptr, 0); + set_current(buf_ptr, !(mode & ios::out+ios::trunc+ios::app)); + if (_mode & ios::trunc) + truncate(); + if (_mode & ios::ate) + seekoff(0, ios::end); +} + +// Called by fclose(fp) if fp is bound to a edit_buffer. + +#if 0 +static int buf_close(void *arg) +{ + register struct buf_cookie *cookie = arg; + struct edit_buffer *buffer = cookie->str->buffer; + struct buf_cookie **ptr; + for (ptr = &buffer->files; *ptr != cookie; ptr = &(*ptr)->next) ; + *ptr = cookie->next; + disconnect_gap_from_file(buffer, cookie->file); + free (cookie); + return 0; +} +#endif + +edit_streambuf::~edit_streambuf() +{ + if (_mode == ios::out) + truncate(); + // Unlink this from list of files associated with bstr->buffer. + edit_streambuf **ptr = &str->buffer->files; + for (; *ptr != this; ptr = &(*ptr)->next) { } + *ptr = next; + + disconnect_gap_from_file(str->buffer); +} + +edit_buffer::edit_buffer() +{ + buf_size = /*200;*/ 15; /* for testing! */ + data = (buf_char*)malloc(buf_size); + files = NULL; +#ifndef OLD_STDIO + _gap_start = data; + _writer = NULL; +#else + gap_start_normal = data; + gap_start_ptr = &gap_start_normal; +#endif + __gap_end_pos = buf_size; + start_mark.chain = &end_mark; + start_mark._pos = 0; + end_mark.chain = NULL; + end_mark._pos = 2 * buf_size + 1; +} + +// Allocate a new mark, which is adjusted by 'delta' bytes from 'this'. +// Restrict new mark to lie within 'str'. + +edit_mark::edit_mark(struct edit_string *str, long delta) +{ + struct edit_buffer *buf = str->buffer; + chain = buf->start_mark.chain; + buf->start_mark.chain = this; + mark_pointer size1 = buf->size1() << 1; + int gap_size = buf->gap_size() << 1; + delta <<= 1; + + // check if new and old marks are opposite sides of gap + if (_pos <= size1 && _pos + delta > size1) + delta += gap_size; + else if (_pos >= size1 + gap_size && _pos + delta < size1 + gap_size) + delta -= gap_size; + + _pos = _pos + delta; + if (_pos < str->start->_pos & ~1) + _pos = (str->start->_pos & ~ 1) + (_pos & 1); + else if (_pos >= str->end->_pos) + _pos = (str->end->_pos & ~ 1) + (_pos & 1); +} + +// A (slow) way to find the buffer a mark belongs to. + +edit_buffer * edit_mark::buffer() +{ + struct edit_mark *mark; + for (mark = this; mark->chain != NULL; mark = mark->chain) ; + // Assume that the last mark on the chain is the end_mark. + return (edit_buffer *)((char*)mark - offsetof(edit_buffer, end_mark)); +} + +edit_mark::~edit_mark() +{ + // Must unlink mark from chain of owning buffer + struct edit_buffer *buf = buffer(); + if (this == &buf->start_mark || this == &buf->end_mark) abort(); + edit_mark **ptr; + for (ptr = &buf->start_mark.chain; *ptr != this; ptr = &(*ptr)->chain) ; + *ptr = this->chain; +} + +int edit_string::length() const +{ + ptrdiff_t delta = end->ptr(buffer) - start->ptr(buffer); + if (end->ptr(buffer) <= buffer->gap_start() || + start->ptr(buffer) >= buffer->gap_end()) + return delta; + return delta - buffer->gap_size(); +} + +buf_char * edit_string::copy_bytes(int *lenp) const +{ + char *new_str; + int len1, len2; + buf_char *start1, *start2; + start1 = start->ptr(buffer); + if (end->ptr(buffer) <= buffer->gap_start() + || start->ptr(buffer) >= buffer->gap_end()) { + len1 = end->ptr(buffer) - start1; + len2 = 0; + start2 = NULL; // To avoid a warning from g++. + } + else { + len1 = buffer->gap_start() - start1; + start2 = buffer->gap_end(); + len2 = end->ptr(buffer) - start2; + } + new_str = (char*)malloc(len1 + len2 + 1); + memcpy(new_str, start1, len1); + if (len2 > 0) memcpy(new_str + len1, start2, len2); + new_str[len1+len2] = '\0'; + *lenp = len1+len2; + return new_str; +} + +// Replace the buf_chars in 'this' with ones from 'src'. +// Equivalent to deleting this, then inserting src, except tries +// to leave marks in place: Marks whose offset from the start +// of 'this' is less than 'src->length()' will still have the +// same offset in 'this' when done. + +void edit_string::assign(struct edit_string *src) +{ + edit_streambuf dst_file(this, ios::out); + if (buffer == src->buffer /*&& ???*/) { /* overly conservative */ + int src_len; + buf_char *new_str; + new_str = src->copy_bytes(&src_len); + dst_file.sputn(new_str, src_len); + free (new_str); + } else { + edit_streambuf src_file(src, ios::in); + for ( ; ; ) { + int ch = src_file.sbumpc(); + if (ch == EOF) break; + dst_file.sputc(ch); + } + } +} |