281 lines
10 KiB
C
281 lines
10 KiB
C
/* SB - Copyright 1982 by Ken Harrenstien, SRI International
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* This software is quasi-public; it may be used freely with
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* like software, but may NOT be sold or made part of licensed
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* products without permission of the author. In all cases
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* the source code and any modifications thereto must remain
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* available to any user.
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*
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* This is part of the SB library package.
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* Any software using the SB library must likewise be made
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* quasi-public, with freely available sources.
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*/
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#ifdef COMMENT
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The initials "SB" stand for "String Block" or "String Buffer".
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SBBUFFER - A SB buffer containing a sbstring opened for editing.
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SBFILE - A structure holding file-specific information for all
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SDBLKs pointing to that file.
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SBSTRING - A SB string; conceptually a single string, but actually
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a linked list of SDBLKs. Unless opened by a SBBUFFER,
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only a few operations are allowed on SBSTRINGs (creating,
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copying, deleting).
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SDBLK - One of the linked nodes constituting a sbstring. Each SDBLK
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node points to a continuous string either in memory or
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on disk, or both.
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SBLK - Another name for SDBLK.
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SMBLK - An allocated chunk of memory. Also refers to the node structure
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maintained by the SBM memory management routines, which
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points to the actual chunk of memory.
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SBM - Name of the memory management package. SBM routines are used
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to allocate memory in general, and are not just for
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use by SB routines.
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************ MACHINE DEPENDENT DEFINITIONS **********
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The following compile time definitions represent machine
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dependent parameters which are intended mainly for use only by SBM and
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SBSTR routines. Other programs should use them with caution. Note
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that a great deal of code assumes that type "int" corresponds to a basic
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machine word (as per C Reference Manual).
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The current definitions will only work for machines which have
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1, 2, 4, or 8 "char" bytes in a machine word. Any other size will
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require some changes to the definitions and possibly to some places
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using them.
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WORD - integer-type definition corresponding to machine word.
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WDSIZE - # addressable char bytes in a machine word. (1, 2, 4, 8)
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WDBITS - # low order bits in an address, ie log2(WDSIZE). (0, 1, 2, 3)
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WDMASK - Mask for low order bits of address (0, 1, 3, 7)
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CHAR_MASK - If defined, machine does sign-extension on chars, and
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they must be masked with this value.
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Note that the macro for WDBITS has no mathematical significance
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other than being an expression which happens to evaluate into the right
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constant for the 4 allowed values of WDSIZE, and in fact it is this
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crock which restricts WDSIZE! If C had a base 2 logarithm expression
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then any power of 2 could be used.
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Values for machines
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WORD WDSIZE WDBITS WDMASK
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PDP11, Z8000, I8086 int 2 1 01
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VAX11, M68000, PDP10 int 4 2 03
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#endif /* COMMENT */
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/* First try to define a few things in a semi-portable way
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*/
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#include "eesite.h"
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#ifdef __STDC__ /* Implementation supports ANSI stuff? */
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#include <limits.h> /* Get sizes for char stuff */
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#define _SBMUCHAR 1 /* Can use "unsigned char" */
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#define _SBMCHARSIGN (CHAR_MIN < 0) /* True if "char" is sign-extended */
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#define CHAR_MASK (UCHAR_MAX)
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#else /* not ANSI */
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#ifndef _SBMUCHAR /* Default assumes no "unsigned char" */
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#define _SBMUCHAR 0
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#endif
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#ifndef _SBMCHARSIGN /* Default assumes "char" is sign-extended */
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#define _SBMCHARSIGN 1
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#endif
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#ifndef CHAR_MASK /* Default assumes "char" is 8 bits */
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#define CHAR_MASK 0377
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#endif
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#endif /* not ANSI */
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/* Define "sb_uchartoint" as a macro which ensures that an unsigned
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** character value is converted properly to an int value.
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*/
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#if (_SBMUCHAR || (_SBMCHARSIGN==0))
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#define sb_uchartoint(a) (a) /* No fear of sign extension */
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#else
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#define sb_uchartoint(a) ((a)&CHAR_MASK) /* Bah, sign extension */
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#endif
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/* Defs for machines with a base-2 WDSIZE. Yes, the (int) is indeed necessary
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* (to allow implicit conversion to long where needed - the PDP11 compiler
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* is known to lose without it, because sizeof is cast as "unsigned int"
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* which loses big in long masks!)
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*/
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#define WORD int
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#define WDSIZE ((int)(sizeof(WORD)))
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#define WDMASK (WDSIZE-1)
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#define WDBITS ((WDSIZE>>2)+(1&WDMASK))
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#define rnddiv(a) ((a)>>WDBITS) /* # words, rounded down */
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#define rndrem(a) ((a)&WDMASK) /* # bytes remaining past wd bndary */
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#define rnddwn(a) ((a)&~WDMASK) /* Round down to word boundary */
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#define rndup(a) rnddwn((a)+WDSIZE-1) /* Round up to word boundary */
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#ifdef COMMENT /* The following are for machines without a base-2 WDSIZE */
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#define rnddiv(a) ((a)/WDSIZE)
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#define rndrem(a) ((a)%WDSIZE)
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#define rnddwn(a) ((a)-rndrem(a))
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#define rndup(a) rnddwn((a)+WDSIZE-1)
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#undef WDMASK /* These become meaningless and anything */
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#undef WDBITS /* which uses them should be changed! */
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#endif /* COMMENT */
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/* The following 3 definitions are somewhat machine-dependent,
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* but are specifically intended for general use and work for all
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* currently known C implementations.
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* SBMO must be an integer-type object large enough to hold
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* the largest difference in SBMA pointers, and must not be
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* used in signed comparisons.
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*/
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typedef long chroff; /* CHROFF - Char offset in disk/sbstr */
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typedef unsigned int SBMO; /* SBMO - Char offset in memory */
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typedef
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#if _SBMUCHAR
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unsigned
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#endif
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char *SBMA; /* SBMA - Pointer to char loc in memory */
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/* The following definitions tend to be system-dependent. Only the
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* SBM and SBSTR routines use them.
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*/
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#define SB_NFILES 32 /* # of open files we can hack. Actually
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* this is max FD value plus 1. */
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#define SB_BUFSIZ 512 /* Optimal buffer size (system block size) */
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#define SB_SLOP (16*WDSIZE) /* # slop chars to tolerate for allocations */
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#define SMNODES (20) /* # SM or SD nodes to create when needed */
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#define SMCHUNKSIZ (16*512) /* # bytes of mem to create (via sbrk) " " */
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#define MAXSBMO ((SBMO)-1) /* Used in SBM only */
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/* MAXSBMO should be the largest possible SBMO value. */
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#define EOF (-1)
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#define SBFILE struct sbfile
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#define SBBUF struct sbbuffer
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#define SBSTR struct sdblk /* Start of a sbstring */
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struct sbfile {
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int sfflags; /* Various flags */
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int sffd; /* FD for file (-1 if none) */
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struct sdblk *sfptr1; /* Ptr to 1st node in phys list */
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chroff sflen; /* Original length of file FD is for */
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};
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/* Definition of SBBUF string/buffer */
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struct sbbuffer {
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SBMA sbiop; /* I/O pointer into in-core text */
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int sbrleft; /* # chars left for reading */
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int sbwleft; /* # chars left for writing */
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int sbflags; /* Various flags */
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chroff sbdot; /* Logical pos for start of current sdblk */
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chroff sboff; /* Offset into current sdblk (if no smblk)*/
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struct sdblk *sbcur; /* Pointer to current SD block of string */
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};
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/* Flags for "sbflags" */
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#define SB_OVW 01 /* Over-write mode */
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#define SB_WRIT 02 /* Written; smuse needs to be updated from sbiop */
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/* NOTE: An unused sbbuf structure should be completely zeroed.
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* This will cause routines to handle it properly
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* if they are accidentally pointed at it.
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*/
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/* Definition of SDBLK */
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struct sdblk {
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struct sdblk *slforw; /* Logical sequence forward link */
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struct sdblk *slback; /* Logical sequence backward link */
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int sdflags;
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struct sdblk *sdforw; /* Physical sequence (disk) */
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struct sdblk *sdback; /* ditto - backptr for easy flushing */
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struct smblk *sdmem; /* Mem pointer, 0 if no in-core version */
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SBFILE *sdfile; /* File pointer, 0 if no disk version */
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chroff sdlen; /* # chars in disk text */
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chroff sdaddr; /* Disk address of text */
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};
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/* Flags for "sdflags" */
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#define SD_LOCK 0100000 /* Locked because opened by a SBBUF */
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#define SD_LCK2 0040000 /* Locked for other reasons */
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#define SD_MOD 0020000 /* Modified, mem blk is real stuff */
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#define SD_NID 0323 /* Node ID marks active (not on freelist) */
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#define SD_LOCKS (SD_LOCK|SD_LCK2)
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/* Note sdback is ONLY needed for fixing up phys list when a sdblk is
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* deleted (so as to find previous blk in phys list). Perhaps it shd
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* be flushed (ie only use SDFORW)? How to do deletions - use circular
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* list? Sigh.
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*/
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/* Definition of SMBLK (used by SBM routines) */
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struct smblk {
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struct smblk *smforw; /* Links to other mem blks, in phys order */
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struct smblk *smback;
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int smflags; /* Type, in-use flags */
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SBMA smaddr; /* Mem address of text */
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SBMO smlen; /* # bytes in mem block */
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SBMO smuse; /* # bytes "used" in block */
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};
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/* Flags for "smflags" */
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#define SM_USE 0100000 /* Block is in use (mem free if off) */
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#define SM_NXM 040000 /* Block mem is non-existent */
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#define SM_EXT 020000 /* Block mem owned by external (non-SBM) rtn*/
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#define SM_MNODS 010000 /* Block holds SMBLK nodes */
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#define SM_DNODS 04000 /* Block holds SDBLK nodes */
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#define SM_NID 0315 /* Node in-use identifier (low byte) */
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/* Error handler type values */
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#define SBMERR 0 /* Error in SBM package */
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#define SBXERR 1 /* Error in SBSTR package */
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#define SBFERR 2 /* "Error" - SBSTR package found a file overwritten.
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* Non-zero return will continue normally. */
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/* Redefine certain external symbols to be unique in the first 6 chars
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** to conform with ANSI requirements.
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*/
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#define sbm_nfre sbmnfre /* SBM stuff */
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#define sbm_nfor sbmnfor
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#define sbm_nmov sbmnmov
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#define sbm_ngc sbmngc
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#define sbx_ndget sbxndg /* SBSTR stuff */
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#define sbx_ndel sbxnde
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#define sbx_ndfre sbxndf
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#define sbx_sdcpy sbxsdc
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#define sbx_sdgc sbxsdg
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#define sbe_sdlist sbesls /* SBERR stuff */
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#define sbe_sdtab sbestb
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#define sbe_sds sbesds
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#define sbe_sbvfy sbesbv
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#define sbe_sbs sbesbs
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/* Forward declarations */
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extern SBMA sbm_lowaddr; /* For roundoff purposes */
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extern SBFILE sbv_tf; /* SBFILE for temp swapout file */
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extern int (*sbv_debug)(); /* Error handler address */
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extern off_t lseek(); /* For sbstr code mostly */
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extern char *mktemp();
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extern char *malloc();
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extern char *calloc();
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extern SBBUF *sb_open();
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extern SBSTR *sb_close(), *sb_fduse(), *sbs_cpy(), *sbs_app(), *sb_cpyn(),
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*sb_killn();
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extern struct sdblk *sbx_ready();
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extern chroff sb_tell(), sb_ztell(), sbs_len();
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/* Definition of SB_GETC, SB_PUTC, SB_BACKC macros */
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#define sb_putc(s,c) (--((s)->sbwleft) >= 0 ? \
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(*(s)->sbiop++ = c) : sb_sputc(s,c))
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#define sb_getc(s) (--((s)->sbrleft) >= 0 ? \
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sb_uchartoint(*(s)->sbiop++) : sb_sgetc(s))
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#define sb_peekc(s) ((s)->sbrleft > 0 ? \
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sb_uchartoint(*(s)->sbiop) : sb_speekc(s))
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/* WARNING - sb_backc must ONLY be used if last operation was a
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* successful sb_getc!! For slow but sure invocation use sb_rgetc.
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*/
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#define sb_backc(s) (++(s->sbrleft), --(s->sbiop))
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#include "sbproto.h" /* function prototypes */
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