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#ifndef lint |
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static const char RCSid[] = "$Id$"; |
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#endif |
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/* |
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* Sorting routines for meta-files |
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*/ |
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|
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|
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#define PBSIZE 1000 /* max size of sort block */ |
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/* maxalloc must be >= this */ |
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|
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|
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#define NFILES 4 /* number of sort files */ |
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|
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#include "meta.h" |
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|
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/* |
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* This sort routine does a combination quicksort and |
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* n-ary mergesort |
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*/ |
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|
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|
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sort(infp, pcmp) /* sort primitives according to pcmp */ |
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|
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FILE *infp; |
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int (*pcmp)(); /* compares pointers to pointers to primitives! */ |
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|
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{ |
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PRIMITIVE *prims[PBSIZE]; /* pointers to primitives */ |
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PLIST primlist; /* our primitives list */ |
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int nprims; |
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short done; |
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|
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do { |
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|
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for (nprims = 0; nprims < PBSIZE; nprims++) { /* read to global */ |
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|
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if ((prims[nprims] = palloc()) == NULL) |
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error(SYSTEM, "memory exhausted in sort"); |
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|
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readp(prims[nprims], infp); |
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|
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if (isglob(prims[nprims]->com)) |
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break; |
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} |
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|
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qsort(prims, nprims, sizeof(*prims), pcmp); /* sort pointer array */ |
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|
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if (nprims < PBSIZE) /* tack on global if one */ |
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nprims++; |
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|
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order(prims, nprims, &primlist); /* make array into list */ |
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|
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sendsort(&primlist, pcmp); /* send to merge sorter */ |
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|
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done = primlist.pbot->com == PEOF; |
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|
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plfree(&primlist); /* free up array */ |
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|
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} while (!done); |
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|
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} |
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|
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|
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|
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|
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/* |
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* The following routine merges up to NFILES sorted primitive files |
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* with 0 or 1 primitive lists. Each set of primitives can end with |
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* 0 or 1 global commands. |
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*/ |
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|
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mergesort(fi, nf, pl, pcmp, ofp) /* merge sorted files with list */ |
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|
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FILE *fi[]; /* array of input files */ |
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int nf; /* number of input files */ |
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PLIST *pl; /* sorted list */ |
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int (*pcmp)(); /* comparison function, takes primitive handles */ |
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FILE *ofp; /* output file */ |
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|
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{ |
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PRIMITIVE *plp; /* position in list */ |
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PRIMITIVE *pp[NFILES]; /* input primitives */ |
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int minf; |
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PRIMITIVE *minp; |
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register int i; |
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|
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if (pl == NULL) |
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plp = NULL; /* initialize list */ |
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else |
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plp = pl->ptop; |
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|
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for (i = 0; i < nf; i++) { /* initialize input files */ |
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if ((pp[i] = palloc()) == NULL) |
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error(SYSTEM, "memory exhausted in mergesort"); |
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readp(pp[i], fi[i]); |
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} |
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|
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for ( ; ; ) { |
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|
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if (plp != NULL && isprim(plp->com)) |
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minp = plp; |
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else |
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minp = NULL; |
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|
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for (i = 0; i < nf; i++) |
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if (isprim(pp[i]->com) && |
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(minp == NULL || (*pcmp)(&pp[i], &minp) < 0)) |
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minp = pp[minf=i]; |
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|
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if (minp == NULL) |
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break; |
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|
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writep(minp, ofp); |
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|
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if (minp == plp) |
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plp = plp->pnext; |
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else { |
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fargs(pp[minf]); |
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readp(pp[minf], fi[minf]); |
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} |
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} |
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|
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if (plp != NULL && plp->com != PEOF) |
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writep(plp, ofp); |
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|
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for (i = 0; i < nf; i++) { |
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if (pp[i]->com != PEOF) |
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writep(pp[i], ofp); |
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pfree(pp[i]); |
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} |
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|
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} |
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|
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|
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|
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static |
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treemerge(height, nt, nf, pl, pcmp, ofp) /* merge into one file */ |
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|
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int height, nt, nf; |
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PLIST *pl; |
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int (*pcmp)(); |
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FILE *ofp; |
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|
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{ |
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char *tfname(); |
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FILE *fi[NFILES], *fp; |
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int i; |
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|
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if (nf <= NFILES) { |
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|
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for (i = 0; i < nf; i++) |
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fi[i] = efopen(tfname(height, i + nt*NFILES), "r"); |
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|
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if ((fp = ofp) == NULL) |
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fp = efopen(tfname(height + 1, nt), "w"); |
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|
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mergesort(fi, nf, pl, pcmp, fp); |
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for (i = 0; i < nf; i++) { |
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fclose(fi[i]); |
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unlink(tfname(height, i + nt*NFILES)); |
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} |
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if (ofp == NULL) { |
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writeof(fp); |
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fclose(fp); |
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} |
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|
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} else { |
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|
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for (i = 0; i < (nf-1)/NFILES; i++) |
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treemerge(height, i, NFILES, NULL, pcmp, NULL); |
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|
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treemerge(height, (nf-1)/NFILES, (nf-1)%NFILES + 1, pl, pcmp, NULL); |
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|
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treemerge(height + 1, 0, (nf-1)/NFILES + 1, NULL, pcmp, ofp); |
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|
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} |
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|
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} |
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|
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|
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|
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|
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static |
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sendsort(pl, pcmp) /* send a sorted list */ |
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|
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PLIST *pl; |
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int (*pcmp)(); |
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|
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{ |
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static int nf = 0, |
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intree = FALSE; |
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FILE *fp; |
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|
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if (isglob(pl->pbot->com)) { |
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|
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/* send sorted output to stdout */ |
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if (intree && nf <= NFILES) |
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treemerge(0, 0, nf, pl, pcmp, stdout); |
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else if (nf%NFILES == 0) |
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|
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if (intree) { |
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treemerge(0, nf/NFILES - 1, NFILES, pl, pcmp, NULL); |
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treemerge(1, 0, nf/NFILES, NULL, pcmp, stdout); |
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} else |
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treemerge(1, 0, nf/NFILES, pl, pcmp, stdout); |
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|
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else { |
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treemerge(0, nf/NFILES, nf%NFILES, pl, pcmp, NULL); |
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treemerge(1, 0, nf/NFILES + 1, NULL, pcmp, stdout); |
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|
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} |
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nf = 0; /* all done */ |
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intree = FALSE; /* reset for next time */ |
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|
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} else if (intree && nf%NFILES == 0) { |
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|
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/* merge NFILES with list */ |
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treemerge(0, nf/NFILES - 1, NFILES, pl, pcmp, NULL); |
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intree = FALSE; |
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|
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} else { |
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|
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/* output straight to temp file */ |
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treemerge(-1, nf++, 0, pl, pcmp, NULL); |
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intree = TRUE; |
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|
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} |
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|
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} |
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|
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static |
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order(pa, n, pl) /* order the first n array primitives into list */ |
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|
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PRIMITIVE *pa[]; |
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int n; |
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PLIST *pl; |
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|
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{ |
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register int i; |
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|
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for (i = 1; i < n; i++) |
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pa[i-1]->pnext = pa[i]; |
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pa[n-1]->pnext = NULL; |
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pl->ptop = pa[0]; |
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pl->pbot = pa[n-1]; |
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|
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} |
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|
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|
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|
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|
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static char * |
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tfname(lvl, num) /* create temporary file name */ |
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|
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int lvl, num; |
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|
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{ |
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static char fnbuf[32]; |
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|
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sprintf(fnbuf, "%sS%d%c%d", TDIR, getpid(), lvl+'A', num); |
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|
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return(fnbuf); |
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} |