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Diffstat (limited to 'ex_temp.h')
| -rw-r--r-- | ex_temp.h | 191 |
1 files changed, 191 insertions, 0 deletions
diff --git a/ex_temp.h b/ex_temp.h new file mode 100644 index 0000000..8bbb1d1 --- /dev/null +++ b/ex_temp.h @@ -0,0 +1,191 @@ +/* + * This code contains changes by + * Gunnar Ritter, Freiburg i. Br., Germany, 2002. All rights reserved. + * + * Conditions 1, 2, and 4 and the no-warranty notice below apply + * to these changes. + * + * + * Copyright (c) 1980, 1993 + * The Regents of the University of California. All rights reserved. + * + * Redistribution and use in source and binary forms, with or without + * modification, are permitted provided that the following conditions + * are met: + * 1. Redistributions of source code must retain the above copyright + * notice, this list of conditions and the following disclaimer. + * 2. Redistributions in binary form must reproduce the above copyright + * notice, this list of conditions and the following disclaimer in the + * documentation and/or other materials provided with the distribution. + * 3. All advertising materials mentioning features or use of this software + * must display the following acknowledgement: + * This product includes software developed by the University of + * California, Berkeley and its contributors. + * 4. Neither the name of the University nor the names of its contributors + * may be used to endorse or promote products derived from this software + * without specific prior written permission. + * + * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND + * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE + * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE + * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE + * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL + * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS + * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) + * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT + * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY + * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF + * SUCH DAMAGE. + * + * + * Copyright(C) Caldera International Inc. 2001-2002. All rights reserved. + * + * Redistribution and use in source and binary forms, with or without + * modification, are permitted provided that the following conditions + * are met: + * Redistributions of source code and documentation must retain the + * above copyright notice, this list of conditions and the following + * disclaimer. + * Redistributions in binary form must reproduce the above copyright + * notice, this list of conditions and the following disclaimer in the + * documentation and/or other materials provided with the distribution. + * All advertising materials mentioning features or use of this software + * must display the following acknowledgement: + * This product includes software developed or owned by Caldera + * International, Inc. + * Neither the name of Caldera International, Inc. nor the names of + * other contributors may be used to endorse or promote products + * derived from this software without specific prior written permission. + * + * USE OF THE SOFTWARE PROVIDED FOR UNDER THIS LICENSE BY CALDERA + * INTERNATIONAL, INC. AND CONTRIBUTORS ``AS IS'' AND ANY EXPRESS OR + * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED + * WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE + * ARE DISCLAIMED. IN NO EVENT SHALL CALDERA INTERNATIONAL, INC. BE + * LIABLE FOR ANY DIRECT, INDIRECT INCIDENTAL, SPECIAL, EXEMPLARY, OR + * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF + * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR + * BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, + * WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE + * OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, + * EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. + * + * from ex_temp.h 7.4 (Berkeley) 5/31/85 + * + * @(#)ex_temp.h 1.8 (gritter) 1/26/02 + */ + +/* + * The editor uses a temporary file for files being edited, in a structure + * similar to that of ed. The first block of the file is used for a header + * block which guides recovery after editor/system crashes. + * Lines are represented in core by a pointer into the temporary file which + * is packed into 16 bits (32 on VMUNIX). All but the low bit index the temp + * file; the last is used by global commands. The parameters below control + * how much the other bits are shifted left before they index the temp file. + * Larger shifts give more slop in the temp file but allow larger files + * to be edited. + * + * The editor does not garbage collect the temporary file. When a new + * file is edited, the temporary file is rather discarded and a new one + * created for the new file. Garbage collection would be rather complicated + * in ex because of the general undo, and in any case would require more + * work when throwing lines away because marks would have be carefully + * checked before reallocating temporary file space. Said another way, + * each time you create a new line in the temporary file you get a unique + * number back, and this is a property used by marks. + * + * The following temp file parameters allow 256k bytes in the temporary + * file. By changing to the numbers in comments you can get 512k. + * For VMUNIX you get more than you could ever want. + * VMUNIX uses long (32 bit) integers giving much more + * space in the temp file and no waste. This doubles core + * requirements but allows files of essentially unlimited size to be edited. + */ +#ifndef VMUNIX +#define BLKMSK 0777 /* 01777 */ +#define BNDRY 8 /* 16 */ +#define INCRMT 0200 /* 0100 */ +#define LBTMSK 0770 /* 0760 */ +#define NMBLKS 506 /* 1018 */ +#define OFFBTS 7 /* 6 */ +#define OFFMSK 0177 /* 077 */ +#define SHFT 2 /* 3 */ +#else +#ifdef LARGEF +#define BLKMSK 017777777777 +#else +#define BLKMSK 077777 +#endif +#define BNDRY 2 +#define INCRMT 02000 +#define LBTMSK 01776 +#ifdef LARGEF +#define NMBLKS 017777777770 +#else +#define NMBLKS 077770 +#endif +#define OFFBTS 10 +#define OFFMSK 01777 +#define SHFT 0 +#endif + +/* + * The editor uses three buffers into the temporary file (ed uses two + * and is very similar). These are two read buffers and one write buffer. + * Basically, the editor deals with the file as a sequence of BUFSIZ character + * blocks. Each block contains some number of lines (and lines + * can run across block boundaries. + * + * New lines are written into the last block in the temporary file + * which is in core as obuf. When a line is needed which isn't in obuf, + * then it is brought into an input buffer. As there are two, the choice + * is to take the buffer into which the last read (of the two) didn't go. + * Thus this is a 2 buffer LRU replacement strategy. Measurement + * shows that this saves roughly 25% of the buffer reads over a one + * input buffer strategy. Since the editor (on our VAX over 1 week) + * spends (spent) roughly 30% of its time in the system read routine, + * this can be a big help. + */ +var bool hitin2; /* Last read hit was ibuff2 not ibuff */ +var bool ichang2; /* Have actually changed ibuff2 */ +var bool ichanged; /* Have actually changed ibuff */ +var bloc iblock; /* Temp file block number of ibuff (or -1) */ +var bloc iblock2; /* Temp file block number of ibuff2 (or -1) */ +var bloc ninbuf; /* Number useful chars left in input buffer */ +var bloc nleft; /* Number usable chars left in output buffer */ +var bloc oblock; /* Temp file block number of obuff (or -1) */ +var bbloc tline; /* Current temp file ptr */ + +var char ibuff[BUFSIZ]; +var char ibuff2[BUFSIZ]; +var char obuff[BUFSIZ]; + +/* + * Structure of the descriptor block which resides + * in the first block of the temporary file and is + * the guiding light for crash recovery. + * + * As the Blocks field below implies, there are temporary file blocks + * devoted to (some) image of the incore array of pointers into the temp + * file. Thus, to recover from a crash we use these indices to get the + * line pointers back, and then use the line pointers to get the text back. + * Except for possible lost lines due to sandbagged I/O, the entire + * file (at the time of the last editor "sync") can be recovered from + * the temp file. + */ + +/* This definition also appears in expreserve.c... beware */ +struct header { + time_t Time; /* Time temp file last updated */ + uid_t Uid; + bbloc Flines; /* Number of lines in file */ + char Savedfile[FNSIZE]; /* The current file name */ + bloc Blocks[LBLKS]; /* Blocks where line pointers stashed */ +}; +var struct header H; + +#define uid H.Uid +#define flines H.Flines +#define savedfile H.Savedfile +#define blocks H.Blocks |