1*0Sstevel@tonic-gate /* 2*0Sstevel@tonic-gate * CDDL HEADER START 3*0Sstevel@tonic-gate * 4*0Sstevel@tonic-gate * The contents of this file are subject to the terms of the 5*0Sstevel@tonic-gate * Common Development and Distribution License, Version 1.0 only 6*0Sstevel@tonic-gate * (the "License"). You may not use this file except in compliance 7*0Sstevel@tonic-gate * with the License. 8*0Sstevel@tonic-gate * 9*0Sstevel@tonic-gate * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE 10*0Sstevel@tonic-gate * or http://www.opensolaris.org/os/licensing. 11*0Sstevel@tonic-gate * See the License for the specific language governing permissions 12*0Sstevel@tonic-gate * and limitations under the License. 13*0Sstevel@tonic-gate * 14*0Sstevel@tonic-gate * When distributing Covered Code, include this CDDL HEADER in each 15*0Sstevel@tonic-gate * file and include the License file at usr/src/OPENSOLARIS.LICENSE. 16*0Sstevel@tonic-gate * If applicable, add the following below this CDDL HEADER, with the 17*0Sstevel@tonic-gate * fields enclosed by brackets "[]" replaced with your own identifying 18*0Sstevel@tonic-gate * information: Portions Copyright [yyyy] [name of copyright owner] 19*0Sstevel@tonic-gate * 20*0Sstevel@tonic-gate * CDDL HEADER END 21*0Sstevel@tonic-gate */ 22*0Sstevel@tonic-gate /* Copyright (c) 1984, 1986, 1987, 1988, 1989 AT&T */ 23*0Sstevel@tonic-gate /* All Rights Reserved */ 24*0Sstevel@tonic-gate 25*0Sstevel@tonic-gate 26*0Sstevel@tonic-gate /* Copyright (c) 1981 Regents of the University of California */ 27*0Sstevel@tonic-gate #ident "%Z%%M% %I% %E% SMI" /* SVr4.0 1.7 */ 28*0Sstevel@tonic-gate /* 29*0Sstevel@tonic-gate * The editor uses a temporary file for files being edited, in a structure 30*0Sstevel@tonic-gate * similar to that of ed. The first block of the file is used for a header 31*0Sstevel@tonic-gate * block which guides recovery after editor/system crashes. 32*0Sstevel@tonic-gate * Lines are represented in core by a pointer into the temporary file which 33*0Sstevel@tonic-gate * is packed into 16 bits (32 on VMUNIX). All but the low bit index the temp 34*0Sstevel@tonic-gate * file; the last is used by global commands. The parameters below control 35*0Sstevel@tonic-gate * how much the other bits are shifted left before they index the temp file. 36*0Sstevel@tonic-gate * Larger shifts give more slop in the temp file but allow larger files 37*0Sstevel@tonic-gate * to be edited. 38*0Sstevel@tonic-gate * 39*0Sstevel@tonic-gate * The editor does not garbage collect the temporary file. When a new 40*0Sstevel@tonic-gate * file is edited, the temporary file is rather discarded and a new one 41*0Sstevel@tonic-gate * created for the new file. Garbage collection would be rather complicated 42*0Sstevel@tonic-gate * in ex because of the general undo, and in any case would require more 43*0Sstevel@tonic-gate * work when throwing lines away because marks would have be carefully 44*0Sstevel@tonic-gate * checked before reallocating temporary file space. Said another way, 45*0Sstevel@tonic-gate * each time you create a new line in the temporary file you get a unique 46*0Sstevel@tonic-gate * number back, and this is a property used by marks. 47*0Sstevel@tonic-gate * 48*0Sstevel@tonic-gate * The following temp file parameters allow 256k bytes in the temporary 49*0Sstevel@tonic-gate * file. By changing to the numbers in comments you can get 512k. 50*0Sstevel@tonic-gate * For VMUNIX you get more than you could ever want. 51*0Sstevel@tonic-gate * VMUNIX uses long (32 bit) integers giving much more 52*0Sstevel@tonic-gate * space in the temp file and no waste. This doubles core 53*0Sstevel@tonic-gate * requirements but allows files of essentially unlimited size to be edited. 54*0Sstevel@tonic-gate */ 55*0Sstevel@tonic-gate #ifndef VMUNIX 56*0Sstevel@tonic-gate #define BLKMSK 0777 /* 01777 */ 57*0Sstevel@tonic-gate #define BNDRY 8 /* 16 */ 58*0Sstevel@tonic-gate #define INCRMT 0200 /* 0100 */ 59*0Sstevel@tonic-gate #define LBTMSK 0770 /* 0760 */ 60*0Sstevel@tonic-gate #define NMBLKS 506 /* 1018 */ 61*0Sstevel@tonic-gate #define OFFBTS 7 /* 6 */ 62*0Sstevel@tonic-gate #define OFFMSK 0177 /* 077 */ 63*0Sstevel@tonic-gate #define SHFT 2 /* 3 */ 64*0Sstevel@tonic-gate #else 65*0Sstevel@tonic-gate #define BLKMSK 077777 66*0Sstevel@tonic-gate #define BNDRY 2 67*0Sstevel@tonic-gate #define INCRMT 04000 /* 02000 */ 68*0Sstevel@tonic-gate #define LBTMSK 03776 /* 01776 */ 69*0Sstevel@tonic-gate #define NMBLKS 077770 70*0Sstevel@tonic-gate #define OFFBTS 11 /* 10 */ 71*0Sstevel@tonic-gate #define OFFMSK 03777 /* 01777 */ 72*0Sstevel@tonic-gate #define SHFT 0 73*0Sstevel@tonic-gate #endif 74*0Sstevel@tonic-gate 75*0Sstevel@tonic-gate /* 76*0Sstevel@tonic-gate * The editor uses three buffers into the temporary file (ed uses two 77*0Sstevel@tonic-gate * and is very similar). These are two read buffers and one write buffer. 78*0Sstevel@tonic-gate * Basically, the editor deals with the file as a sequence of BUFSIZE character 79*0Sstevel@tonic-gate * blocks. Each block contains some number of lines (and lines 80*0Sstevel@tonic-gate * can run across block boundaries. 81*0Sstevel@tonic-gate * 82*0Sstevel@tonic-gate * New lines are written into the last block in the temporary file 83*0Sstevel@tonic-gate * which is in core as obuf. When a line is needed which isn't in obuf, 84*0Sstevel@tonic-gate * then it is brought into an input buffer. As there are two, the choice 85*0Sstevel@tonic-gate * is to take the buffer into which the last read (of the two) didn't go. 86*0Sstevel@tonic-gate * Thus this is a 2 buffer LRU replacement strategy. Measurement 87*0Sstevel@tonic-gate * shows that this saves roughly 25% of the buffer reads over a one 88*0Sstevel@tonic-gate * input buffer strategy. Since the editor (on our VAX over 1 week) 89*0Sstevel@tonic-gate * spends (spent) roughly 30% of its time in the system read routine, 90*0Sstevel@tonic-gate * this can be a big help. 91*0Sstevel@tonic-gate */ 92*0Sstevel@tonic-gate var bool hitin2; /* Last read hit was ibuff2 not ibuff */ 93*0Sstevel@tonic-gate var bool ichang2; /* Have actually changed ibuff2 */ 94*0Sstevel@tonic-gate var bool ichanged; /* Have actually changed ibuff */ 95*0Sstevel@tonic-gate var short iblock; /* Temp file block number of ibuff (or -1) */ 96*0Sstevel@tonic-gate var short iblock2; /* Temp file block number of ibuff2 (or -1) */ 97*0Sstevel@tonic-gate var short ninbuf; /* Number useful chars left in input buffer */ 98*0Sstevel@tonic-gate var short nleft; /* Number usable chars left in output buffer */ 99*0Sstevel@tonic-gate var short oblock; /* Temp file block number of obuff (or -1) */ 100*0Sstevel@tonic-gate #ifndef VMUNIX 101*0Sstevel@tonic-gate var short tline; /* Current temp file ptr */ 102*0Sstevel@tonic-gate #else 103*0Sstevel@tonic-gate var int tline; 104*0Sstevel@tonic-gate #endif 105*0Sstevel@tonic-gate 106*0Sstevel@tonic-gate var unsigned char ibuff[BUFSIZE]; 107*0Sstevel@tonic-gate var unsigned char ibuff2[BUFSIZE]; 108*0Sstevel@tonic-gate var unsigned char obuff[BUFSIZE]; 109*0Sstevel@tonic-gate 110*0Sstevel@tonic-gate /* 111*0Sstevel@tonic-gate * Structure of the descriptor block which resides 112*0Sstevel@tonic-gate * in the first block of the temporary file and is 113*0Sstevel@tonic-gate * the guiding light for crash recovery. 114*0Sstevel@tonic-gate * 115*0Sstevel@tonic-gate * As the Blocks field below implies, there are temporary file blocks 116*0Sstevel@tonic-gate * devoted to (some) image of the incore array of pointers into the temp 117*0Sstevel@tonic-gate * file. Thus, to recover from a crash we use these indices to get the 118*0Sstevel@tonic-gate * line pointers back, and then use the line pointers to get the text back. 119*0Sstevel@tonic-gate * Except for possible lost lines due to sandbagged I/O, the entire 120*0Sstevel@tonic-gate * file (at the time of the last editor "sync") can be recovered from 121*0Sstevel@tonic-gate * the temp file. 122*0Sstevel@tonic-gate */ 123*0Sstevel@tonic-gate 124*0Sstevel@tonic-gate /* This definition also appears in expreserve.c... beware */ 125*0Sstevel@tonic-gate struct header { 126*0Sstevel@tonic-gate time_t Time; /* Time temp file last updated */ 127*0Sstevel@tonic-gate int Uid; 128*0Sstevel@tonic-gate #ifndef VMUNIX 129*0Sstevel@tonic-gate short Flines; /* Number of lines in file */ 130*0Sstevel@tonic-gate #else 131*0Sstevel@tonic-gate int Flines; 132*0Sstevel@tonic-gate #endif 133*0Sstevel@tonic-gate unsigned char Savedfile[FNSIZE]; /* The current file name */ 134*0Sstevel@tonic-gate short Blocks[LBLKS]; /* Blocks where line pointers stashed */ 135*0Sstevel@tonic-gate short encrypted; /* Encrypted temp file flag */ 136*0Sstevel@tonic-gate }; 137*0Sstevel@tonic-gate var struct header H; 138*0Sstevel@tonic-gate 139*0Sstevel@tonic-gate #define uid H.Uid 140*0Sstevel@tonic-gate #define flines H.Flines 141*0Sstevel@tonic-gate #define savedfile H.Savedfile 142*0Sstevel@tonic-gate #define blocks H.Blocks 143