C   19

fsort.c

Guest on 14th January 2022 06:24:28 PM

  1. /*      $NetBSD: fsort.c,v 1.47  enami Exp $    */ /*- * Copyright (c) 2000-2003 The NetBSD Foundation, Inc. * All rights reserved. * * This code is derived from software contributed to The NetBSD Foundation * by Ben Harris and Jaromir Dolecek. * * 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. * * THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, 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 THE FOUNDATION 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. */
  2. /*- * Copyright (c) The Regents of the University of California. All rights reserved. * * This code is derived from software contributed to Berkeley by * Peter McIlroy. * * 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. 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. */
  3. /* * Read in a block of records (until 'enough'). * sort, write to temp file. * Merge sort temp files into output file * Small files miss out the temp file stage. * Large files might get multiple merges. */ #include "sort.h" #include "fsort.h" __RCSID("$NetBSD: fsort.c,v 1.47 2010/02/05 21:58:41 enami Exp $"); #include <stdlib.h> #include <string.h> #define SALIGN(n) ((n+sizeof(length_t)-1) & ~(sizeof(length_t)-1))
  4. void fsort(struct filelist *filelist, int nfiles, FILE *outfp, struct field *ftbl) {    RECHEADER **keylist;    RECHEADER **keypos, **keyp;     RECHEADER *buffer;      size_t bufsize = DEFBUFSIZE;    u_char *bufend;         int mfct = 0;   int c, nelem;   get_func_t get;         RECHEADER *crec;        RECHEADER *nbuffer;     FILE *fp, *tmp_fp;      int file_no;
  5. int max_recs = DEBUG('m') ? 16 : MAXNUM;
  6. buffer = allocrec(NULL, bufsize);       bufend = (u_char *)buffer + bufsize;
  7.         /* Allocate double length keymap for radix_sort */
  8. keylist = malloc(2 * max_recs * sizeof(*keylist));      if (buffer == NULL || keylist == NULL)          err(2, "failed to malloc initial buffer or keylist");   if (SINGL_FLD)         
  9. /* Key and data are one! */
  10. get = makeline;         else
  11.         /* Key (merged key fields) added before data */                 get = makekey;  file_no = 0;    fp = fopen(filelist->names[0], "r");
  12. if (fp == NULL)                
  13. err(2, "%s", filelist->names[0]);
  14.         /* Loop through reads of chunk of input files that get sorted    * and then merged together. */         for (;;) {             
  15. keypos = keylist;               nelem = 0;              crec = buffer;          makeline_copydown(crec);               
  16. /* Loop reading records */              for (;;) {      
  17. c = get(fp, crec, bufend, ftbl);                        /* 'c' is 0, EOF or BUFFEND */                  if (c == 0) {                           /* Save start of key in input buffer */                                 *keypos++ = crec;                              
  18. if (++nelem == max_recs) {                             
  19.         c = BUFFEND;    
  20.                                 break;                          }                               crec = (RECHEADER *)(crec->data + SALIGN(crec->length));                                continue;      
  21.                 }                       if (c == EOF) {                                 /* try next file */                             if (++file_no >= nfiles)                                        /* no more files */                                     break;                          fp = fopen(filelist->names[file_no], "r");                              if (fp == NULL)                                         err(2, "%s", filelist->names[file_no]);                                 continue;                       }                       if (nelem >= max_recs                    || (bufsize >= MAXBUFSIZE && nelem > 8))                               /* Need to sort and save this lot of data */                            break;                  /* c == BUFFEND, and we can process more data */                        /* Allocate a larger buffer for this lot of data */                     bufsize *= 2;                   nbuffer = allocrec(buffer, bufsize);                    if (!nbuffer) {                                 err(2, "failed to realloc buffer to %zu bytes",                                         bufsize);                       }              
  22.         /* patch up keylist[] */                       
  23. for (keyp = &keypos[-1]; keyp >= keylist; keyp--)                              
  24. *keyp = nbuffer + (*keyp - buffer);
  25.  
  26. crec = nbuffer + (crec - buffer);                       buffer = nbuffer;      
  27.                 bufend = (u_char *)buffer + bufsize;            }               /* Sort this set of records */          radix_sort(keylist, keylist + max_recs, nelem);                 if (c == EOF && mfct == 0) {           
  28.         /* all the data is (sorted) in the buffer */                    append(keylist, nelem, outfp,                    DEBUG('k') ? putkeydump : putline);                    break;          }               /* Save current data to a temporary file for a later merge */           if (nelem != 0) {                      
  29. tmp_fp = ftmp();                       
  30. append(keylist, nelem, tmp_fp, putrec);                         save_for_merge(tmp_fp, geteasy, ftbl);          }              
  31. mfct = 1;              
  32. if (c == EOF) {                        
  33. /* merge to output file */                      merge_sort(outfp,                        DEBUG('k') ? putkeydump : putline, ftbl);                      break;          }       }       free(keylist);  keylist = NULL;
  34.         free(buffer);   buffer = NULL; }

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