void
fmerge(struct filelist *filelist, int nfiles, FILE *outfp, struct field *ftbl)
{
get_func_t get = SINGL_FLD ? makeline : makekey;
FILE *fp;
int i;
for (i = 0; i < nfiles; i++) {
fp = fopen(filelist->names[i], "r");
if (fp == NULL)
err(2, "%s", filelist->names[i]);
save_for_merge(fp, get, ftbl);
}
merge_sort(outfp, putline, ftbl);
}
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;
int max_recs = DEBUG('m') ? 16 : MAXNUM;
buffer = allocrec(NULL, bufsize);
bufend = (u_char *)buffer + bufsize;
/* Allocate double length keymap for radix_sort */
keylist = malloc(2 * max_recs * sizeof(*keylist));
if (buffer == NULL || keylist == NULL)
err(2, "failed to malloc initial buffer or keylist");
if (SINGL_FLD)
/* Key and data are one! */
get = makeline;
else
/* Key (merged key fields) added before data */
get = makekey;
file_no = 0;
fp = fopen(filelist->names[0], "r");
if (fp == NULL)
err(2, "%s", filelist->names[0]);
/* Loop through reads of chunk of input files that get sorted
* and then merged together. */
for (;;) {
keypos = keylist;
nelem = 0;
crec = buffer;
makeline_copydown(crec);
/* Loop reading records */
for (;;) {
c = get(fp, crec, bufend, ftbl);
/* 'c' is 0, EOF or BUFFEND */
if (c == 0) {
/* Save start of key in input buffer */
*keypos++ = crec;
if (++nelem == max_recs) {
c = BUFFEND;
break;
}
crec = (RECHEADER *)(crec->data + SALIGN(crec->length));
continue;
}
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);
}
/* patch up keylist[] */
for (keyp = &keypos[-1]; keyp >= keylist; keyp--)
*keyp = nbuffer + (*keyp - buffer);
crec = nbuffer + (crec - buffer);
buffer = nbuffer;
bufend = (u_char *)buffer + bufsize;
}
/* Sort this set of records */
radix_sort(keylist, keylist + max_recs, nelem);
if (c == EOF && mfct == 0) {
/* 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) {
tmp_fp = ftmp();
append(keylist, nelem, tmp_fp, putrec);
save_for_merge(tmp_fp, geteasy, ftbl);
}
mfct = 1;
if (c == EOF) {
/* merge to output file */
merge_sort(outfp,
DEBUG('k') ? putkeydump : putline, ftbl);
break;
}
}
free(keylist);
keylist = NULL;
free(buffer);
buffer = NULL;
}
