/* * Copyright (c) 1994, 1995, 1996 * Ohio University. All rights reserved. * * Redistribution and use in source and binary forms, with or without * modification, are permitted provided that: (1) source code * distributions retain the above copyright notice and this paragraph * in its entirety, (2) distributions including binary code include * the above copyright notice and this paragraph in its entirety in * the documentation or other materials provided with the * distribution, and (3) all advertising materials mentioning features * or use of this software display the following acknowledgment: * ``This product includes software developed by the Ohio University * Internetworking Research Laboratory.'' 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 ``AS IS'' AND WITHOUT ANY EXPRESS OR * IMPLIED WARRANTIES, INCLUDING, WITHOUT LIMITATION, THE IMPLIED * WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE. * * Author: Shawn Ostermann * School of Electrical Engineering and Computer Science * Ohio University * Athens, OH * ostermann@cs.ohiou.edu */ static char const copyright[] = "@(#)Copyright (c) 1996 -- Ohio University. All rights reserved.\n"; static char const rcsid[] = "@(#)$Header: /home/sdo/src/tcptrace/RCS/mfiles.c,v 3.7 1997/12/03 19:27:10 sdo Exp $"; /* * tcptrace.c - turn protocol monitor traces into xplot * * this set of functions allows a user to open "many files" * dispite the open file max limit. (Uses LRU) * * Author: Shawn Ostermann * Date: Tue Nov 1, 1994 */ #include "tcptrace.h" #include struct mfile { FILE *stream; char *fname; MFILE *next; MFILE *prev; long fptr; }; /* local static routines */ static void Mcheck(MFILE *pmf); static void Mfopen_internal(MFILE *pmf, char *mode); static void Mf_totail(MFILE *pmf, MFILE *ptail); static void Mf_unlink(MFILE *pmf); /* head and tail of LRU open file list */ MFILE mf_head; /* LEAST recently used */ MFILE mf_tail; /* MOST recently used */ MFILE mfc_head; /* closed files, LEAST recently closed */ MFILE mfc_tail; /* closed files, MOST recently closed */ void Minit(void) { mf_head.next = &mf_tail; mf_tail.prev = &mf_head; mf_head.fname = "HEAD"; mf_tail.fname = "TAIL"; mfc_head.next = &mfc_tail; mfc_tail.prev = &mfc_head; mfc_head.fname = "CLOSED HEAD"; mfc_tail.fname = "CLOSED TAIL"; } MFILE * Mfopen( char *fname, char *mode) { MFILE *pmf; if (strcmp(mode,"w") != 0) { fprintf(stderr,"Sorry, Mfopen works only for mode \"w\"\n"); exit(-1); } pmf = (MFILE *) MallocZ(sizeof(MFILE)); pmf->fname = strdup(fname); Mfopen_internal(pmf,"w+"); /* put at the tail of the LRU list */ Mf_totail(pmf,&mf_tail); return(pmf); } int Mfileno( MFILE *pmf) { /* Warning, I'll GIVE you the fd, but I won't guarantee that it'll stay */ /* where you want it if you call my functions back!!! */ Mcheck(pmf); return(fileno(pmf->stream)); } int Mvfprintf( MFILE *pmf, char *format, va_list ap) { int ret; Mcheck(pmf); ret = vfprintf(pmf->stream,format,ap); return(ret); } int Mfprintf( MFILE *pmf, char *format, ...) { va_list ap; int ret; va_start(ap,format); Mcheck(pmf); ret = vfprintf(pmf->stream,format,ap); va_end(ap); return(ret); } long Mftell( MFILE *pmf) { Mcheck(pmf); return(ftell(pmf->stream)); } int Mfseek( MFILE *pmf, long offset, int ptrname) { Mcheck(pmf); return(fseek(pmf->stream, offset, ptrname)); } int Mfwrite( char *buf, u_long size, u_long nitems, MFILE *pmf) { Mcheck(pmf); return(fwrite(buf,size,nitems,pmf->stream)); } int Mfclose( MFILE *pmf) { int ret; if (debug>1) fprintf(stderr,"Mfclose: called for file '%s'\n", pmf->fname); Mcheck(pmf); ret=fclose(pmf->stream); pmf->stream = NULL; return(ret); } int Mfflush( MFILE *pmf) { Mcheck(pmf); return(fflush(pmf->stream)); } static void Mfopen_internal( MFILE *pmf, char *mode) { FILE *stream; MFILE *closehim; stream = fopen(pmf->fname,mode); if (stream == NULL) { if (errno != EMFILE) { perror("fopen"); exit(-1); } /* OK, close a file we haven't used for a while */ closehim = mf_head.next; closehim->fptr = ftell(closehim->stream); /* remember current position */ fclose(closehim->stream); closehim->stream = NULL; /* put closed file at the tail of the closed LRU list */ Mf_unlink(closehim); Mf_totail(closehim,&mfc_tail); if (debug > 1) fprintf(stderr,"Mfiles: too many files open, closed file '%s'\n", closehim->fname); /* now, try again */ stream = fopen(pmf->fname,mode); if (stream == NULL) { perror("fopen (second try)"); exit(-1); } } pmf->stream = stream; /* seek back to where we were last time, if this was previously opened */ if (pmf->fptr != 0) { if (fseek(stream, pmf->fptr, SEEK_SET) != 0) { perror("fseek"); exit(-1); } } return; } static void Mcheck( MFILE *pmf) { /* make sure that it's open */ if (pmf->stream == NULL) { if (debug > 1) fprintf(stderr,"Mcheck: re-opening file '%s'\n", pmf->fname); Mfopen_internal(pmf,"r+"); } /* put at the tail of the LRU list */ if (mf_tail.prev != pmf) { Mf_unlink(pmf); Mf_totail(pmf,&mf_tail); } } #ifdef OLD static void M_printlru(void) { MFILE *pmf; for (pmf = &mf_head; pmf; pmf=pmf->next) fprintf(stderr,"%s ==> ", pmf->fname); fprintf(stderr,"NULL \n"); for (pmf = &mfc_head; pmf; pmf=pmf->next) fprintf(stderr,"%s ==> ", pmf->fname); fprintf(stderr,"NULL \n"); } #endif /* OLD */ static void Mf_unlink( MFILE *pmf) { pmf->prev->next = pmf->next; pmf->next->prev = pmf->prev; } static void Mf_totail( MFILE *pmf, MFILE *ptail) { pmf->next = ptail; pmf->prev = ptail->prev; ptail->prev->next = pmf; ptail->prev = pmf; }