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Diffstat (limited to 'src/undo.c')
| -rw-r--r-- | src/undo.c | 1380 |
1 files changed, 1380 insertions, 0 deletions
diff --git a/src/undo.c b/src/undo.c new file mode 100644 index 000000000..6efcffab4 --- /dev/null +++ b/src/undo.c @@ -0,0 +1,1380 @@ +/* vi:set ts=8 sts=4 sw=4: + * + * VIM - Vi IMproved by Bram Moolenaar + * + * Do ":help uganda" in Vim to read copying and usage conditions. + * Do ":help credits" in Vim to see a list of people who contributed. + * See README.txt for an overview of the Vim source code. + */ + +/* + * undo.c: multi level undo facility + * + * The saved lines are stored in a list of lists (one for each buffer): + * + * b_u_oldhead------------------------------------------------+ + * | + * V + * +--------------+ +--------------+ +--------------+ + * b_u_newhead--->| u_header | | u_header | | u_header | + * | uh_next------>| uh_next------>| uh_next---->NULL + * NULL<--------uh_prev |<---------uh_prev |<---------uh_prev | + * | uh_entry | | uh_entry | | uh_entry | + * +--------|-----+ +--------|-----+ +--------|-----+ + * | | | + * V V V + * +--------------+ +--------------+ +--------------+ + * | u_entry | | u_entry | | u_entry | + * | ue_next | | ue_next | | ue_next | + * +--------|-----+ +--------|-----+ +--------|-----+ + * | | | + * V V V + * +--------------+ NULL NULL + * | u_entry | + * | ue_next | + * +--------|-----+ + * | + * V + * etc. + * + * Each u_entry list contains the information for one undo or redo. + * curbuf->b_u_curhead points to the header of the last undo (the next redo), + * or is NULL if nothing has been undone. + * + * All data is allocated with u_alloc_line(), thus it will be freed as soon as + * we switch files! + */ + +#include "vim.h" + +static u_entry_T *u_get_headentry __ARGS((void)); +static void u_getbot __ARGS((void)); +static int u_savecommon __ARGS((linenr_T, linenr_T, linenr_T)); +static void u_doit __ARGS((int count)); +static void u_undoredo __ARGS((void)); +static void u_undo_end __ARGS((void)); +static void u_freelist __ARGS((struct u_header *)); +static void u_freeentry __ARGS((u_entry_T *, long)); + +static char_u *u_blockalloc __ARGS((long_u)); +static void u_free_line __ARGS((char_u *, int keep)); +static char_u *u_alloc_line __ARGS((unsigned)); +static char_u *u_save_line __ARGS((linenr_T)); + +static long u_newcount, u_oldcount; + +/* + * When 'u' flag included in 'cpoptions', we behave like vi. Need to remember + * the action that "u" should do. + */ +static int undo_undoes = FALSE; + +/* + * save the current line for both the "u" and "U" command + */ + int +u_save_cursor() +{ + return (u_save((linenr_T)(curwin->w_cursor.lnum - 1), + (linenr_T)(curwin->w_cursor.lnum + 1))); +} + +/* + * Save the lines between "top" and "bot" for both the "u" and "U" command. + * "top" may be 0 and bot may be curbuf->b_ml.ml_line_count + 1. + * Returns FAIL when lines could not be saved, OK otherwise. + */ + int +u_save(top, bot) + linenr_T top, bot; +{ + if (undo_off) + return OK; + + if (top > curbuf->b_ml.ml_line_count || + top >= bot || bot > curbuf->b_ml.ml_line_count + 1) + return FALSE; /* rely on caller to do error messages */ + + if (top + 2 == bot) + u_saveline((linenr_T)(top + 1)); + + return (u_savecommon(top, bot, (linenr_T)0)); +} + +/* + * save the line "lnum" (used by ":s" and "~" command) + * The line is replaced, so the new bottom line is lnum + 1. + */ + int +u_savesub(lnum) + linenr_T lnum; +{ + if (undo_off) + return OK; + + return (u_savecommon(lnum - 1, lnum + 1, lnum + 1)); +} + +/* + * a new line is inserted before line "lnum" (used by :s command) + * The line is inserted, so the new bottom line is lnum + 1. + */ + int +u_inssub(lnum) + linenr_T lnum; +{ + if (undo_off) + return OK; + + return (u_savecommon(lnum - 1, lnum, lnum + 1)); +} + +/* + * save the lines "lnum" - "lnum" + nlines (used by delete command) + * The lines are deleted, so the new bottom line is lnum, unless the buffer + * becomes empty. + */ + int +u_savedel(lnum, nlines) + linenr_T lnum; + long nlines; +{ + if (undo_off) + return OK; + + return (u_savecommon(lnum - 1, lnum + nlines, + nlines == curbuf->b_ml.ml_line_count ? 2 : lnum)); +} + + static int +u_savecommon(top, bot, newbot) + linenr_T top, bot; + linenr_T newbot; +{ + linenr_T lnum; + long i; + struct u_header *uhp; + u_entry_T *uep; + u_entry_T *prev_uep; + long size; + + /* + * Don't allow changes when 'modifiable' is off. Letting the + * undo fail is a crude way to make all change commands fail. + */ + if (!curbuf->b_p_ma) + { + EMSG(_(e_modifiable)); + return FAIL; + } + +#ifdef HAVE_SANDBOX + /* + * In the sandbox it's not allowed to change the text. Letting the + * undo fail is a crude way to make all change commands fail. + */ + if (sandbox != 0) + { + EMSG(_(e_sandbox)); + return FAIL; + } +#endif + +#ifdef FEAT_NETBEANS_INTG + /* + * Netbeans defines areas that cannot be modified. Bail out here when + * trying to change text in a guarded area. + */ + if (usingNetbeans && netbeans_is_guarded(top, bot)) + { + EMSG(_(e_guarded)); + return FAIL; + } +#endif + +#ifdef FEAT_AUTOCMD + /* + * Saving text for undo means we are going to make a change. Give a + * warning for a read-only file before making the change, so that the + * FileChangedRO event can replace the buffer with a read-write version + * (e.g., obtained from a source control system). + */ + change_warning(0); +#endif + + size = bot - top - 1; + + /* + * if curbuf->b_u_synced == TRUE make a new header + */ + if (curbuf->b_u_synced) + { +#ifdef FEAT_JUMPLIST + /* Need to create new entry in b_changelist. */ + curbuf->b_new_change = TRUE; +#endif + + /* + * if we undid more than we redid, free the entry lists before and + * including curbuf->b_u_curhead + */ + while (curbuf->b_u_curhead != NULL) + u_freelist(curbuf->b_u_newhead); + + /* + * free headers to keep the size right + */ + while (curbuf->b_u_numhead > p_ul && curbuf->b_u_oldhead != NULL) + u_freelist(curbuf->b_u_oldhead); + + if (p_ul < 0) /* no undo at all */ + { + curbuf->b_u_synced = FALSE; + return OK; + } + + /* + * make a new header entry + */ + uhp = (struct u_header *)u_alloc_line((unsigned) + sizeof(struct u_header)); + if (uhp == NULL) + goto nomem; + uhp->uh_prev = NULL; + uhp->uh_next = curbuf->b_u_newhead; + if (curbuf->b_u_newhead != NULL) + curbuf->b_u_newhead->uh_prev = uhp; + uhp->uh_entry = NULL; + uhp->uh_getbot_entry = NULL; + uhp->uh_cursor = curwin->w_cursor; /* save cursor pos. for undo */ +#ifdef FEAT_VIRTUALEDIT + if (virtual_active() && curwin->w_cursor.coladd > 0) + uhp->uh_cursor_vcol = getviscol(); + else + uhp->uh_cursor_vcol = -1; +#endif + + /* save changed and buffer empty flag for undo */ + uhp->uh_flags = (curbuf->b_changed ? UH_CHANGED : 0) + + ((curbuf->b_ml.ml_flags & ML_EMPTY) ? UH_EMPTYBUF : 0); + + /* save named marks for undo */ + mch_memmove(uhp->uh_namedm, curbuf->b_namedm, sizeof(pos_T) * NMARKS); + curbuf->b_u_newhead = uhp; + if (curbuf->b_u_oldhead == NULL) + curbuf->b_u_oldhead = uhp; + ++curbuf->b_u_numhead; + } + else + { + if (p_ul < 0) /* no undo at all */ + return OK; + + /* + * When saving a single line, and it has been saved just before, it + * doesn't make sense saving it again. Saves a lot of memory when + * making lots of changes inside the same line. + * This is only possible if the previous change didn't increase or + * decrease the number of lines. + * Check the ten last changes. More doesn't make sense and takes too + * long. + */ + if (size == 1) + { + uep = u_get_headentry(); + prev_uep = NULL; + for (i = 0; i < 10; ++i) + { + if (uep == NULL) + break; + + /* If lines have been inserted/deleted we give up. + * Also when the line was included in a multi-line save. */ + if ((curbuf->b_u_newhead->uh_getbot_entry != uep + ? (uep->ue_top + uep->ue_size + 1 + != (uep->ue_bot == 0 + ? curbuf->b_ml.ml_line_count + 1 + : uep->ue_bot)) + : uep->ue_lcount != curbuf->b_ml.ml_line_count) + || (uep->ue_size > 1 + && top >= uep->ue_top + && top + 2 <= uep->ue_top + uep->ue_size + 1)) + break; + + /* If it's the same line we can skip saving it again. */ + if (uep->ue_size == 1 && uep->ue_top == top) + { + if (i > 0) + { + /* It's not the last entry: get ue_bot for the last + * entry now. Following deleted/inserted lines go to + * the re-used entry. */ + u_getbot(); + curbuf->b_u_synced = FALSE; + + /* Move the found entry to become the last entry. The + * order of undo/redo doesn't matter for the entries + * we move it over, since they don't change the line + * count and don't include this line. It does matter + * for the found entry if the line count is changed by + * the executed command. */ + prev_uep->ue_next = uep->ue_next; + uep->ue_next = curbuf->b_u_newhead->uh_entry; + curbuf->b_u_newhead->uh_entry = uep; + } + + /* The executed command may change the line count. */ + if (newbot != 0) + uep->ue_bot = newbot; + else if (bot > curbuf->b_ml.ml_line_count) + uep->ue_bot = 0; + else + { + uep->ue_lcount = curbuf->b_ml.ml_line_count; + curbuf->b_u_newhead->uh_getbot_entry = uep; + } + return OK; + } + prev_uep = uep; + uep = uep->ue_next; + } + } + + /* find line number for ue_bot for previous u_save() */ + u_getbot(); + } + +#if !defined(UNIX) && !defined(DJGPP) && !defined(WIN32) && !defined(__EMX__) + /* + * With Amiga and MSDOS 16 bit we can't handle big undo's, because + * then u_alloc_line would have to allocate a block larger than 32K + */ + if (size >= 8000) + goto nomem; +#endif + + /* + * add lines in front of entry list + */ + uep = (u_entry_T *)u_alloc_line((unsigned)sizeof(u_entry_T)); + if (uep == NULL) + goto nomem; + + uep->ue_size = size; + uep->ue_top = top; + if (newbot != 0) + uep->ue_bot = newbot; + /* + * Use 0 for ue_bot if bot is below last line. + * Otherwise we have to compute ue_bot later. + */ + else if (bot > curbuf->b_ml.ml_line_count) + uep->ue_bot = 0; + else + { + uep->ue_lcount = curbuf->b_ml.ml_line_count; + curbuf->b_u_newhead->uh_getbot_entry = uep; + } + + if (size) + { + if ((uep->ue_array = (char_u **)u_alloc_line( + (unsigned)(sizeof(char_u *) * size))) == NULL) + { + u_freeentry(uep, 0L); + goto nomem; + } + for (i = 0, lnum = top + 1; i < size; ++i) + { + if ((uep->ue_array[i] = u_save_line(lnum++)) == NULL) + { + u_freeentry(uep, i); + goto nomem; + } + } + } + uep->ue_next = curbuf->b_u_newhead->uh_entry; + curbuf->b_u_newhead->uh_entry = uep; + curbuf->b_u_synced = FALSE; + undo_undoes = FALSE; + + return OK; + +nomem: + msg_silent = 0; /* must display the prompt */ + if (ask_yesno((char_u *)_("No undo possible; continue anyway"), TRUE) + == 'y') + { + undo_off = TRUE; /* will be reset when character typed */ + return OK; + } + do_outofmem_msg((long_u)0); + return FAIL; +} + +/* + * If 'cpoptions' contains 'u': Undo the previous undo or redo (vi compatible). + * If 'cpoptions' does not contain 'u': Always undo. + */ + void +u_undo(count) + int count; +{ + /* + * If we get an undo command while executing a macro, we behave like the + * original vi. If this happens twice in one macro the result will not + * be compatible. + */ + if (curbuf->b_u_synced == FALSE) + { + u_sync(); + count = 1; + } + + if (vim_strchr(p_cpo, CPO_UNDO) == NULL) + undo_undoes = TRUE; + else + undo_undoes = !undo_undoes; + u_doit(count); +} + +/* + * If 'cpoptions' contains 'u': Repeat the previous undo or redo. + * If 'cpoptions' does not contain 'u': Always redo. + */ + void +u_redo(count) + int count; +{ + if (vim_strchr(p_cpo, CPO_UNDO) == NULL) + undo_undoes = FALSE; + u_doit(count); +} + +/* + * Undo or redo, depending on 'undo_undoes', 'count' times. + */ + static void +u_doit(count) + int count; +{ + /* Don't allow changes when 'modifiable' is off. */ + if (!curbuf->b_p_ma) + { + EMSG(_(e_modifiable)); + return; + } +#ifdef HAVE_SANDBOX + /* In the sandbox it's not allowed to change the text. */ + if (sandbox != 0) + { + EMSG(_(e_sandbox)); + return; + } +#endif + + u_newcount = 0; + u_oldcount = 0; + while (count--) + { + if (undo_undoes) + { + if (curbuf->b_u_curhead == NULL) /* first undo */ + curbuf->b_u_curhead = curbuf->b_u_newhead; + else if (p_ul > 0) /* multi level undo */ + /* get next undo */ + curbuf->b_u_curhead = curbuf->b_u_curhead->uh_next; + /* nothing to undo */ + if (curbuf->b_u_numhead == 0 || curbuf->b_u_curhead == NULL) + { + /* stick curbuf->b_u_curhead at end */ + curbuf->b_u_curhead = curbuf->b_u_oldhead; + beep_flush(); + break; + } + + u_undoredo(); + } + else + { + if (curbuf->b_u_curhead == NULL || p_ul <= 0) + { + beep_flush(); /* nothing to redo */ + break; + } + + u_undoredo(); + /* advance for next redo */ + curbuf->b_u_curhead = curbuf->b_u_curhead->uh_prev; + } + } + u_undo_end(); +} + +/* + * u_undoredo: common code for undo and redo + * + * The lines in the file are replaced by the lines in the entry list at + * curbuf->b_u_curhead. The replaced lines in the file are saved in the entry + * list for the next undo/redo. + */ + static void +u_undoredo() +{ + char_u **newarray = NULL; + linenr_T oldsize; + linenr_T newsize; + linenr_T top, bot; + linenr_T lnum; + linenr_T newlnum = MAXLNUM; + long i; + u_entry_T *uep, *nuep; + u_entry_T *newlist = NULL; + int old_flags; + int new_flags; + pos_T namedm[NMARKS]; + int empty_buffer; /* buffer became empty */ + + old_flags = curbuf->b_u_curhead->uh_flags; + new_flags = (curbuf->b_changed ? UH_CHANGED : 0) + + ((curbuf->b_ml.ml_flags & ML_EMPTY) ? UH_EMPTYBUF : 0); + setpcmark(); + + /* + * save marks before undo/redo + */ + mch_memmove(namedm, curbuf->b_namedm, sizeof(pos_T) * NMARKS); + curbuf->b_op_start.lnum = curbuf->b_ml.ml_line_count; + curbuf->b_op_start.col = 0; + curbuf->b_op_end.lnum = 0; + curbuf->b_op_end.col = 0; + + for (uep = curbuf->b_u_curhead->uh_entry; uep != NULL; uep = nuep) + { + top = uep->ue_top; + bot = uep->ue_bot; + if (bot == 0) + bot = curbuf->b_ml.ml_line_count + 1; + if (top > curbuf->b_ml.ml_line_count || top >= bot + || bot > curbuf->b_ml.ml_line_count + 1) + { + EMSG(_("E438: u_undo: line numbers wrong")); + changed(); /* don't want UNCHANGED now */ + return; + } + + oldsize = bot - top - 1; /* number of lines before undo */ + newsize = uep->ue_size; /* number of lines after undo */ + + if (top < newlnum) + { + /* If the saved cursor is somewhere in this undo block, move it to + * the remembered position. Makes "gwap" put the cursor back + * where it was. */ + lnum = curbuf->b_u_curhead->uh_cursor.lnum; + if (lnum >= top && lnum <= top + newsize + 1) + { + curwin->w_cursor = curbuf->b_u_curhead->uh_cursor; + newlnum = curwin->w_cursor.lnum - 1; + } + else + { + /* Use the first line that actually changed. Avoids that + * undoing auto-formatting puts the cursor in the previous + * line. */ + for (i = 0; i < newsize && i < oldsize; ++i) + if (STRCMP(uep->ue_array[i], ml_get(top + 1 + i)) != 0) + break; + if (i == newsize && newlnum == MAXLNUM && uep->ue_next == NULL) + { + newlnum = top; + curwin->w_cursor.lnum = newlnum + 1; + } + else if (i < newsize) + { + newlnum = top + i; + curwin->w_cursor.lnum = newlnum + 1; + } + } + } + + empty_buffer = FALSE; + + /* delete the lines between top and bot and save them in newarray */ + if (oldsize) + { + if ((newarray = (char_u **)u_alloc_line( + (unsigned)(sizeof(char_u *) * oldsize))) == NULL) + { + do_outofmem_msg((long_u)(sizeof(char_u *) * oldsize)); + /* + * We have messed up the entry list, repair is impossible. + * we have to free the rest of the list. + */ + while (uep != NULL) + { + nuep = uep->ue_next; + u_freeentry(uep, uep->ue_size); + uep = nuep; + } + break; + } + /* delete backwards, it goes faster in most cases */ + for (lnum = bot - 1, i = oldsize; --i >= 0; --lnum) + { + /* what can we do when we run out of memory? */ + if ((newarray[i] = u_save_line(lnum)) == NULL) + do_outofmem_msg((long_u)0); + /* remember we deleted the last line in the buffer, and a + * dummy empty line will be inserted */ + if (curbuf->b_ml.ml_line_count == 1) + empty_buffer = TRUE; + ml_delete(lnum, FALSE); + } + } + + /* insert the lines in u_array between top and bot */ + if (newsize) + { + for (lnum = top, i = 0; i < newsize; ++i, ++lnum) + { + /* + * If the file is empty, there is an empty line 1 that we + * should get rid of, by replacing it with the new line + */ + if (empty_buffer && lnum == 0) + ml_replace((linenr_T)1, uep->ue_array[i], TRUE); + else + ml_append(lnum, uep->ue_array[i], (colnr_T)0, FALSE); + u_free_line(uep->ue_array[i], FALSE); + } + u_free_line((char_u *)uep->ue_array, FALSE); + } + + /* adjust marks */ + if (oldsize != newsize) + { + mark_adjust(top + 1, top + oldsize, (long)MAXLNUM, + (long)newsize - (long)oldsize); + if (curbuf->b_op_start.lnum > top + oldsize) + curbuf->b_op_start.lnum += newsize - oldsize; + if (curbuf->b_op_end.lnum > top + oldsize) + curbuf->b_op_end.lnum += newsize - oldsize; + } + + changed_lines(top + 1, 0, bot, newsize - oldsize); + + /* set '[ and '] mark */ + if (top + 1 < curbuf->b_op_start.lnum) + curbuf->b_op_start.lnum = top + 1; + if (newsize == 0 && top + 1 > curbuf->b_op_end.lnum) + curbuf->b_op_end.lnum = top + 1; + else if (top + newsize > curbuf->b_op_end.lnum) + curbuf->b_op_end.lnum = top + newsize; + + u_newcount += newsize; + u_oldcount += oldsize; + uep->ue_size = oldsize; + uep->ue_array = newarray; + uep->ue_bot = top + newsize + 1; + + /* + * insert this entry in front of the new entry list + */ + nuep = uep->ue_next; + uep->ue_next = newlist; + newlist = uep; + } + + curbuf->b_u_curhead->uh_entry = newlist; + curbuf->b_u_curhead->uh_flags = new_flags; + if ((old_flags & UH_EMPTYBUF) && bufempty()) + curbuf->b_ml.ml_flags |= ML_EMPTY; + if (old_flags & UH_CHANGED) + changed(); + else + unchanged(curbuf, FALSE); + + /* + * restore marks from before undo/redo + */ + for (i = 0; i < NMARKS; ++i) + if (curbuf->b_u_curhead->uh_namedm[i].lnum) + { + curbuf->b_namedm[i] = curbuf->b_u_curhead->uh_namedm[i]; + curbuf->b_u_curhead->uh_namedm[i] = namedm[i]; + } + + /* + * If the cursor is only off by one line, put it at the same position as + * before starting the change (for the "o" command). + * Otherwise the cursor should go to the first undone line. + */ + if (curbuf->b_u_curhead->uh_cursor.lnum + 1 == curwin->w_cursor.lnum + && curwin->w_cursor.lnum > 1) + --curwin->w_cursor.lnum; + if (curbuf->b_u_curhead->uh_cursor.lnum == curwin->w_cursor.lnum) + { + curwin->w_cursor.col = curbuf->b_u_curhead->uh_cursor.col; +#ifdef FEAT_VIRTUALEDIT + if (virtual_active() && curbuf->b_u_curhead->uh_cursor_vcol >= 0) + coladvance((colnr_T)curbuf->b_u_curhead->uh_cursor_vcol); + else + curwin->w_cursor.coladd = 0; +#endif + } + else if (curwin->w_cursor.lnum <= curbuf->b_ml.ml_line_count) + beginline(BL_SOL | BL_FIX); + else + { + /* We get here with the current cursor line being past the end (eg + * after adding lines at the end of the file, and then undoing it). + * check_cursor() will move the cursor to the last line. Move it to + * the first column here. */ + curwin->w_cursor.col = 0; +#ifdef FEAT_VIRTUALEDIT + curwin->w_cursor.coladd = 0; +#endif + } + + /* Make sure the cursor is on an existing line and column. */ + check_cursor(); +} + +/* + * If we deleted or added lines, report the number of less/more lines. + * Otherwise, report the number of changes (this may be incorrect + * in some cases, but it's better than nothing). + */ + static void +u_undo_end() +{ + if ((u_oldcount -= u_newcount) != 0) + msgmore(-u_oldcount); + else if (u_newcount > p_report) + { + if (u_newcount == 1) + MSG(_("1 change")); + else + smsg((char_u *)_("%ld changes"), u_newcount); + } +#ifdef FEAT_FOLDING + if ((fdo_flags & FDO_UNDO) && KeyTyped) + foldOpenCursor(); +#endif +} + +/* + * u_sync: stop adding to the current entry list + */ + void +u_sync() +{ + if (curbuf->b_u_synced) + return; /* already synced */ +#if defined(FEAT_XIM) && defined(FEAT_GUI_GTK) + if (im_is_preediting()) + return; /* XIM is busy, don't break an undo sequence */ +#endif + if (p_ul < 0) + curbuf->b_u_synced = TRUE; /* no entries, nothing to do */ + else + { + u_getbot(); /* compute ue_bot of previous u_save */ + curbuf->b_u_curhead = NULL; + } +} + +/* + * Called after writing the file and setting b_changed to FALSE. + * Now an undo means that the buffer is modified. + */ + void +u_unchanged(buf) + buf_T *buf; +{ + struct u_header *uh; + + for (uh = buf->b_u_newhead; uh; uh = uh->uh_next) + uh->uh_flags |= UH_CHANGED; + buf->b_did_warn = FALSE; +} + +/* + * Get pointer to last added entry. + * If it's not valid, give an error message and return NULL. + */ + static u_entry_T * +u_get_headentry() +{ + if (curbuf->b_u_newhead == NULL || curbuf->b_u_newhead->uh_entry == NULL) + { + EMSG(_("E439: undo list corrupt")); + return NULL; + } + return curbuf->b_u_newhead->uh_entry; +} + +/* + * u_getbot(): compute the line number of the previous u_save + * It is called only when b_u_synced is FALSE. + */ + static void +u_getbot() +{ + u_entry_T *uep; + linenr_T extra; + + uep = u_get_headentry(); /* check for corrupt undo list */ + if (uep == NULL) + return; + + uep = curbuf->b_u_newhead->uh_getbot_entry; + if (uep != NULL) + { + /* + * the new ue_bot is computed from the number of lines that has been + * inserted (0 - deleted) since calling u_save. This is equal to the + * old line count subtracted from the current line count. + */ + extra = curbuf->b_ml.ml_line_count - uep->ue_lcount; + uep->ue_bot = uep->ue_top + uep->ue_size + 1 + extra; + if (uep->ue_bot < 1 || uep->ue_bot > curbuf->b_ml.ml_line_count) + { + EMSG(_("E440: undo line missing")); + uep->ue_bot = uep->ue_top + 1; /* assume all lines deleted, will + * get all the old lines back + * without deleting the current + * ones */ + } + + curbuf->b_u_newhead->uh_getbot_entry = NULL; + } + + curbuf->b_u_synced = TRUE; +} + +/* + * u_freelist: free one entry list and adjust the pointers + */ + static void +u_freelist(uhp) + struct u_header *uhp; +{ + u_entry_T *uep, *nuep; + + for (uep = uhp->uh_entry; uep != NULL; uep = nuep) + { + nuep = uep->ue_next; + u_freeentry(uep, uep->ue_size); + } + + if (curbuf->b_u_curhead == uhp) + curbuf->b_u_curhead = NULL; + + if (uhp->uh_next == NULL) + curbuf->b_u_oldhead = uhp->uh_prev; + else + uhp->uh_next->uh_prev = uhp->uh_prev; + + if (uhp->uh_prev == NULL) + curbuf->b_u_newhead = uhp->uh_next; + else + uhp->uh_prev->uh_next = uhp->uh_next; + + u_free_line((char_u *)uhp, FALSE); + --curbuf->b_u_numhead; +} + +/* + * free entry 'uep' and 'n' lines in uep->ue_array[] + */ + static void +u_freeentry(uep, n) + u_entry_T *uep; + long n; +{ + while (n) + u_free_line(uep->ue_array[--n], FALSE); + u_free_line((char_u *)uep, FALSE); +} + +/* + * invalidate the undo buffer; called when storage has already been released + */ + void +u_clearall(buf) + buf_T *buf; +{ + buf->b_u_newhead = buf->b_u_oldhead = buf->b_u_curhead = NULL; + buf->b_u_synced = TRUE; + buf->b_u_numhead = 0; + buf->b_u_line_ptr = NULL; + buf->b_u_line_lnum = 0; +} + +/* + * save the line "lnum" for the "U" command + */ + void +u_saveline(lnum) + linenr_T lnum; +{ + if (lnum == curbuf->b_u_line_lnum) /* line is already saved */ + return; + if (lnum < 1 || lnum > curbuf->b_ml.ml_line_count) /* should never happen */ + return; + u_clearline(); + curbuf->b_u_line_lnum = lnum; + if (curwin->w_cursor.lnum == lnum) + curbuf->b_u_line_colnr = curwin->w_cursor.col; + else + curbuf->b_u_line_colnr = 0; + if ((curbuf->b_u_line_ptr = u_save_line(lnum)) == NULL) + do_outofmem_msg((long_u)0); +} + +/* + * clear the line saved for the "U" command + * (this is used externally for crossing a line while in insert mode) + */ + void +u_clearline() +{ + if (curbuf->b_u_line_ptr != NULL) + { + u_free_line(curbuf->b_u_line_ptr, FALSE); + curbuf->b_u_line_ptr = NULL; + curbuf->b_u_line_lnum = 0; + } +} + +/* + * Implementation of the "U" command. + * Differentiation from vi: "U" can be undone with the next "U". + * We also allow the cursor to be in another line. + */ + void +u_undoline() +{ + colnr_T t; + char_u *oldp; + + if (undo_off) + return; + + if (curbuf->b_u_line_ptr == NULL || + curbuf->b_u_line_lnum > curbuf->b_ml.ml_line_count) + { + beep_flush(); + return; + } + /* first save the line for the 'u' command */ + if (u_savecommon(curbuf->b_u_line_lnum - 1, + curbuf->b_u_line_lnum + 1, (linenr_T)0) == FAIL) + return; + oldp = u_save_line(curbuf->b_u_line_lnum); + if (oldp == NULL) + { + do_outofmem_msg((long_u)0); + return; + } + ml_replace(curbuf->b_u_line_lnum, curbuf->b_u_line_ptr, TRUE); + changed_bytes(curbuf->b_u_line_lnum, 0); + u_free_line(curbuf->b_u_line_ptr, FALSE); + curbuf->b_u_line_ptr = oldp; + + t = curbuf->b_u_line_colnr; + if (curwin->w_cursor.lnum == curbuf->b_u_line_lnum) + curbuf->b_u_line_colnr = curwin->w_cursor.col; + curwin->w_cursor.col = t; + curwin->w_cursor.lnum = curbuf->b_u_line_lnum; +} + +/* + * storage allocation for the undo lines and blocks of the current file + */ + +/* + * Memory is allocated in relatively large blocks. These blocks are linked + * in the allocated block list, headed by curbuf->b_block_head. They are all + * freed when abandoning a file, so we don't have to free every single line. + * The list is kept sorted on memory address. + * block_alloc() allocates a block. + * m_blockfree() frees all blocks. + * + * The available chunks of memory are kept in free chunk lists. There is + * one free list for each block of allocated memory. The list is kept sorted + * on memory address. + * u_alloc_line() gets a chunk from the free lists. + * u_free_line() returns a chunk to the free lists. + * curbuf->b_m_search points to the chunk before the chunk that was + * freed/allocated the last time. + * curbuf->b_mb_current points to the b_head where curbuf->b_m_search + * points into the free list. + * + * + * b_block_head /---> block #1 /---> block #2 + * mb_next ---/ mb_next ---/ mb_next ---> NULL + * mb_info mb_info mb_info + * | | | + * V V V + * NULL free chunk #1.1 free chunk #2.1 + * | | + * V V + * free chunk #1.2 NULL + * | + * V + * NULL + * + * When a single free chunk list would have been used, it could take a lot + * of time in u_free_line() to find the correct place to insert a chunk in the + * free list. The single free list would become very long when many lines are + * changed (e.g. with :%s/^M$//). + */ + + /* + * this blocksize is used when allocating new lines + */ +#define MEMBLOCKSIZE 2044 + +/* + * The size field contains the size of the chunk, including the size field + * itself. + * + * When the chunk is not in-use it is preceded with the m_info structure. + * The m_next field links it in one of the free chunk lists. + * + * On most unix systems structures have to be longword (32 or 64 bit) aligned. + * On most other systems they are short (16 bit) aligned. + */ + +/* the structure definitions are now in structs.h */ + +#ifdef ALIGN_LONG + /* size of m_size */ +# define M_OFFSET (sizeof(long_u)) +#else + /* size of m_size */ +# define M_OFFSET (sizeof(short_u)) +#endif + +/* + * Allocate a block of memory and link it in the allocated block list. + */ + static char_u * +u_blockalloc(size) + long_u size; +{ + mblock_T *p; + mblock_T *mp, *next; + + p = (mblock_T *)lalloc(size + sizeof(mblock_T), FALSE); + if (p != NULL) + { + /* Insert the block into the allocated block list, keeping it + sorted on address. */ + for (mp = &curbuf->b_block_head; + (next = mp->mb_next) != NULL && next < p; + mp = next) + ; + p->mb_next = next; /* link in block list */ + p->mb_size = size; + mp->mb_next = p; + p->mb_info.m_next = NULL; /* clear free list */ + p->mb_info.m_size = 0; + curbuf->b_mb_current = p; /* remember current block */ + curbuf->b_m_search = NULL; + p++; /* return usable memory */ + } + return (char_u *)p; +} + +/* + * free all allocated memory blocks for the buffer 'buf' + */ + void +u_blockfree(buf) + buf_T *buf; +{ + mblock_T *p, *np; + + for (p = buf->b_block_head.mb_next; p != NULL; p = np) + { + np = p->mb_next; + vim_free(p); + } + buf->b_block_head.mb_next = NULL; + buf->b_m_search = NULL; + buf->b_mb_current = NULL; +} + +/* + * Free a chunk of memory for the current buffer. + * Insert the chunk into the correct free list, keeping it sorted on address. + */ + static void +u_free_line(ptr, keep) + char_u *ptr; + int keep; /* don't free the block when it's empty */ +{ + minfo_T *next; + minfo_T *prev, *curr; + minfo_T *mp; + mblock_T *nextb; + mblock_T *prevb; + + if (ptr == NULL || ptr == IObuff) + return; /* illegal address can happen in out-of-memory situations */ + + mp = (minfo_T *)(ptr - M_OFFSET); + + /* find block where chunk could be a part off */ + /* if we change curbuf->b_mb_current, curbuf->b_m_search is set to NULL */ + if (curbuf->b_mb_current == NULL || mp < (minfo_T *)curbuf->b_mb_current) + { + curbuf->b_mb_current = curbuf->b_block_head.mb_next; + curbuf->b_m_search = NULL; + } + if ((nextb = curbuf->b_mb_current->mb_next) != NULL + && (minfo_T *)nextb < mp) + { + curbuf->b_mb_current = nextb; + curbuf->b_m_search = NULL; + } + while ((nextb = curbuf->b_mb_current->mb_next) != NULL + && (minfo_T *)nextb < mp) + curbuf->b_mb_current = nextb; + + curr = NULL; + /* + * If mp is smaller than curbuf->b_m_search->m_next go to the start of + * the free list + */ + if (curbuf->b_m_search == NULL || mp < (curbuf->b_m_search->m_next)) + next = &(curbuf->b_mb_current->mb_info); + else + next = curbuf->b_m_search; + /* + * The following loop is executed very often. + * Therefore it has been optimized at the cost of readability. + * Keep it fast! + */ +#ifdef SLOW_BUT_EASY_TO_READ + do + { + prev = curr; + curr = next; + next = next->m_next; + } + while (mp > next && next != NULL); +#else + do /* first, middle, last */ + { + prev = next->m_next; /* curr, next, prev */ + if (prev == NULL || mp <= prev) + { + prev = curr; + curr = next; + next = next->m_next; + break; + } + curr = prev->m_next; /* next, prev, curr */ + if (curr == NULL || mp <= curr) + { + prev = next; + curr = prev->m_next; + next = curr->m_next; + break; + } + next = curr->m_next; /* prev, curr, next */ + } + while (mp > next && next != NULL); +#endif + + /* if *mp and *next are concatenated, join them into one chunk */ + if ((char_u *)mp + mp->m_size == (char_u *)next) + { + mp->m_size += next->m_size; + mp->m_next = next->m_next; + } + else + mp->m_next = next; + + /* if *curr and *mp are concatenated, join them */ + if (prev != NULL && (char_u *)curr + curr->m_size == (char_u *)mp) + { + curr->m_size += mp->m_size; + curr->m_next = mp->m_next; + curbuf->b_m_search = prev; + } + else + { + curr->m_next = mp; + curbuf->b_m_search = curr; /* put curbuf->b_m_search before freed + chunk */ + } + + /* + * If the block only containes free memory now, release it. + */ + if (!keep && curbuf->b_mb_current->mb_size + == curbuf->b_mb_current->mb_info.m_next->m_size) + { + /* Find the block before the current one to be able to unlink it from + * the list of blocks. */ + prevb = &curbuf->b_block_head; + for (nextb = prevb->mb_next; nextb != curbuf->b_mb_current; + nextb = nextb->mb_next) + prevb = nextb; + prevb->mb_next = nextb->mb_next; + vim_free(nextb); + curbuf->b_mb_current = NULL; + curbuf->b_m_search = NULL; + } +} + +/* + * Allocate and initialize a new line structure with room for at least + * 'size' characters plus a terminating NUL. + */ + static char_u * +u_alloc_line(size) + unsigned size; +{ + minfo_T *mp, *mprev, *mp2; + mblock_T *mbp; + int size_align; + + /* + * Add room for size field and trailing NUL byte. + * Adjust for minimal size (must be able to store minfo_T + * plus a trailing NUL, so the chunk can be released again) + */ + size += M_OFFSET + 1; + if (size < sizeof(minfo_T) + 1) + size = sizeof(minfo_T) + 1; + + /* + * round size up for alignment + */ + size_align = (size + ALIGN_MASK) & ~ALIGN_MASK; + + /* + * If curbuf->b_m_search is NULL (uninitialized free list) start at + * curbuf->b_block_head + */ + if (curbuf->b_mb_current == NULL || curbuf->b_m_search == NULL) + { + curbuf->b_mb_current = &curbuf->b_block_head; + curbuf->b_m_search = &(curbuf->b_block_head.mb_info); + } + + /* search for space in free list */ + mprev = curbuf->b_m_search; + mbp = curbuf->b_mb_current; + mp = curbuf->b_m_search->m_next; + if (mp == NULL) + { + if (mbp->mb_next) + mbp = mbp->mb_next; + else + mbp = &curbuf->b_block_head; + mp = curbuf->b_m_search = &(mbp->mb_info); + } + while (mp->m_size < size) + { + if (mp == curbuf->b_m_search) /* back where we started in free + chunk list */ + { + if (mbp->mb_next) + mbp = mbp->mb_next; + else + mbp = &curbuf->b_block_head; + mp = curbuf->b_m_search = &(mbp->mb_info); + if (mbp == curbuf->b_mb_current) /* back where we started in + block list */ + { + int n = (size_align > (MEMBLOCKSIZE / 4) + ? size_align : MEMBLOCKSIZE); + + mp = (minfo_T *)u_blockalloc((long_u)n); + if (mp == NULL) + return (NULL); + mp->m_size = n; + u_free_line((char_u *)mp + M_OFFSET, TRUE); + mp = curbuf->b_m_search; + mbp = curbuf->b_mb_current; + } + } + mprev = mp; + if ((mp = mp->m_next) == NULL) /* at end of the list */ + mp = &(mbp->mb_info); /* wrap around to begin */ + } + + /* if the chunk we found is large enough, split it up in two */ + if ((long)mp->m_size - size_align >= (long)(sizeof(minfo_T) + 1)) + { + mp2 = (minfo_T *)((char_u *)mp + size_align); + mp2->m_size = mp->m_size - size_align; + mp2->m_next = mp->m_next; + mprev->m_next = mp2; + mp->m_size = size_align; + } + else /* remove *mp from the free list */ + { + mprev->m_next = mp->m_next; + } + curbuf->b_m_search = mprev; + curbuf->b_mb_current = mbp; + + mp = (minfo_T *)((char_u *)mp + M_OFFSET); + *(char_u *)mp = NUL; /* set the first byte to NUL */ + + return ((char_u *)mp); +} + +/* + * u_save_line(): allocate memory with u_alloc_line() and copy line 'lnum' + * into it. + */ + static char_u * +u_save_line(lnum) + linenr_T lnum; +{ + char_u *src; + char_u *dst; + unsigned len; + + src = ml_get(lnum); + len = (unsigned)STRLEN(src); + if ((dst = u_alloc_line(len)) != NULL) + mch_memmove(dst, src, (size_t)(len + 1)); + return (dst); +} + +/* + * Check if the 'modified' flag is set, or 'ff' has changed (only need to + * check the first character, because it can only be "dos", "unix" or "mac"). + * "nofile" and "scratch" type buffers are considered to always be unchanged. + */ + int +bufIsChanged(buf) + buf_T *buf; +{ + return +#ifdef FEAT_QUICKFIX + !bt_dontwrite(buf) && +#endif + (buf->b_changed || file_ff_differs(buf)); +} + + int +curbufIsChanged() +{ + return +#ifdef FEAT_QUICKFIX + !bt_dontwrite(curbuf) && +#endif + (curbuf->b_changed || file_ff_differs(curbuf)); +} |