--- /dev/null
+/*
+ * DFA routines
+ * This file is #included by regexec.c.
+ *
+ * Copyright (c) 1998, 1999 Henry Spencer. All rights reserved.
+ *
+ * Development of this software was funded, in part, by Cray Research Inc.,
+ * UUNET Communications Services Inc., Sun Microsystems Inc., and Scriptics
+ * Corporation, none of whom are responsible for the results. The author
+ * thanks all of them.
+ *
+ * Redistribution and use in source and binary forms -- with or without
+ * modification -- are permitted for any purpose, provided that
+ * redistributions in source form retain this entire copyright notice and
+ * indicate the origin and nature of any modifications.
+ *
+ * I'd appreciate being given credit for this package in the documentation
+ * of software which uses it, but that is not a requirement.
+ *
+ * THIS SOFTWARE IS PROVIDED ``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
+ * HENRY SPENCER 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.
+ *
+ */
+\f
+/*
+ - longest - longest-preferred matching engine
+ ^ static chr *longest(struct vars *, struct dfa *, chr *, chr *, int *);
+ */
+static chr * /* endpoint, or NULL */
+longest(
+ struct vars *const v, /* used only for debug and exec flags */
+ struct dfa *const d,
+ chr *const start, /* where the match should start */
+ chr *const stop, /* match must end at or before here */
+ int *const hitstopp) /* record whether hit v->stop, if non-NULL */
+{
+ chr *cp;
+ chr *realstop = (stop == v->stop) ? stop : stop + 1;
+ color co;
+ struct sset *css, *ss;
+ chr *post;
+ int i;
+ struct colormap *cm = d->cm;
+
+ /*
+ * Initialize.
+ */
+
+ css = initialize(v, d, start);
+ cp = start;
+ if (hitstopp != NULL) {
+ *hitstopp = 0;
+ }
+
+ /*
+ * Startup.
+ */
+
+ FDEBUG(("+++ startup +++\n"));
+ if (cp == v->start) {
+ co = d->cnfa->bos[(v->eflags®_NOTBOL) ? 0 : 1];
+ FDEBUG(("color %ld\n", (long)co));
+ } else {
+ co = GETCOLOR(cm, *(cp - 1));
+ FDEBUG(("char %c, color %ld\n", (char)*(cp-1), (long)co));
+ }
+ css = miss(v, d, css, co, cp, start);
+ if (css == NULL) {
+ return NULL;
+ }
+ css->lastseen = cp;
+
+ /*
+ * Main loop.
+ */
+
+ if (v->eflags®_FTRACE) {
+ while (cp < realstop) {
+ FDEBUG(("+++ at c%d +++\n", (int) (css - d->ssets)));
+ co = GETCOLOR(cm, *cp);
+ FDEBUG(("char %c, color %ld\n", (char)*cp, (long)co));
+ ss = css->outs[co];
+ if (ss == NULL) {
+ ss = miss(v, d, css, co, cp+1, start);
+ if (ss == NULL) {
+ break; /* NOTE BREAK OUT */
+ }
+ }
+ cp++;
+ ss->lastseen = cp;
+ css = ss;
+ }
+ } else {
+ while (cp < realstop) {
+ co = GETCOLOR(cm, *cp);
+ ss = css->outs[co];
+ if (ss == NULL) {
+ ss = miss(v, d, css, co, cp+1, start);
+ if (ss == NULL) {
+ break; /* NOTE BREAK OUT */
+ }
+ }
+ cp++;
+ ss->lastseen = cp;
+ css = ss;
+ }
+ }
+
+ /*
+ * Shutdown.
+ */
+
+ FDEBUG(("+++ shutdown at c%d +++\n", (int) (css - d->ssets)));
+ if (cp == v->stop && stop == v->stop) {
+ if (hitstopp != NULL) {
+ *hitstopp = 1;
+ }
+ co = d->cnfa->eos[(v->eflags®_NOTEOL) ? 0 : 1];
+ FDEBUG(("color %ld\n", (long)co));
+ ss = miss(v, d, css, co, cp, start);
+
+ /*
+ * Special case: match ended at eol?
+ */
+
+ if (ss != NULL && (ss->flags&POSTSTATE)) {
+ return cp;
+ } else if (ss != NULL) {
+ ss->lastseen = cp; /* to be tidy */
+ }
+ }
+
+ /*
+ * Find last match, if any.
+ */
+
+ post = d->lastpost;
+ for (ss = d->ssets, i = d->nssused; i > 0; ss++, i--) {
+ if ((ss->flags&POSTSTATE) && (post != ss->lastseen) &&
+ (post == NULL || post < ss->lastseen)) {
+ post = ss->lastseen;
+ }
+ }
+ if (post != NULL) { /* found one */
+ return post - 1;
+ }
+
+ return NULL;
+}
+\f
+/*
+ - shortest - shortest-preferred matching engine
+ ^ static chr *shortest(struct vars *, struct dfa *, chr *, chr *, chr *,
+ ^ chr **, int *);
+ */
+static chr * /* endpoint, or NULL */
+shortest(
+ struct vars *const v,
+ struct dfa *const d,
+ chr *const start, /* where the match should start */
+ chr *const min, /* match must end at or after here */
+ chr *const max, /* match must end at or before here */
+ chr **const coldp, /* store coldstart pointer here, if nonNULL */
+ int *const hitstopp) /* record whether hit v->stop, if non-NULL */
+{
+ chr *cp;
+ chr *realmin = (min == v->stop) ? min : min + 1;
+ chr *realmax = (max == v->stop) ? max : max + 1;
+ color co;
+ struct sset *css, *ss;
+ struct colormap *cm = d->cm;
+
+ /*
+ * Initialize.
+ */
+
+ css = initialize(v, d, start);
+ cp = start;
+ if (hitstopp != NULL) {
+ *hitstopp = 0;
+ }
+
+ /*
+ * Startup.
+ */
+
+ FDEBUG(("--- startup ---\n"));
+ if (cp == v->start) {
+ co = d->cnfa->bos[(v->eflags®_NOTBOL) ? 0 : 1];
+ FDEBUG(("color %ld\n", (long)co));
+ } else {
+ co = GETCOLOR(cm, *(cp - 1));
+ FDEBUG(("char %c, color %ld\n", (char)*(cp-1), (long)co));
+ }
+ css = miss(v, d, css, co, cp, start);
+ if (css == NULL) {
+ return NULL;
+ }
+ css->lastseen = cp;
+ ss = css;
+
+ /*
+ * Main loop.
+ */
+
+ if (v->eflags®_FTRACE) {
+ while (cp < realmax) {
+ FDEBUG(("--- at c%d ---\n", (int) (css - d->ssets)));
+ co = GETCOLOR(cm, *cp);
+ FDEBUG(("char %c, color %ld\n", (char)*cp, (long)co));
+ ss = css->outs[co];
+ if (ss == NULL) {
+ ss = miss(v, d, css, co, cp+1, start);
+ if (ss == NULL) {
+ break; /* NOTE BREAK OUT */
+ }
+ }
+ cp++;
+ ss->lastseen = cp;
+ css = ss;
+ if ((ss->flags&POSTSTATE) && cp >= realmin) {
+ break; /* NOTE BREAK OUT */
+ }
+ }
+ } else {
+ while (cp < realmax) {
+ co = GETCOLOR(cm, *cp);
+ ss = css->outs[co];
+ if (ss == NULL) {
+ ss = miss(v, d, css, co, cp+1, start);
+ if (ss == NULL) {
+ break; /* NOTE BREAK OUT */
+ }
+ }
+ cp++;
+ ss->lastseen = cp;
+ css = ss;
+ if ((ss->flags&POSTSTATE) && cp >= realmin) {
+ break; /* NOTE BREAK OUT */
+ }
+ }
+ }
+
+ if (ss == NULL) {
+ return NULL;
+ }
+
+ if (coldp != NULL) { /* report last no-progress state set, if any */
+ *coldp = lastCold(v, d);
+ }
+
+ if ((ss->flags&POSTSTATE) && cp > min) {
+ assert(cp >= realmin);
+ cp--;
+ } else if (cp == v->stop && max == v->stop) {
+ co = d->cnfa->eos[(v->eflags®_NOTEOL) ? 0 : 1];
+ FDEBUG(("color %ld\n", (long)co));
+ ss = miss(v, d, css, co, cp, start);
+
+ /*
+ * Match might have ended at eol.
+ */
+
+ if ((ss == NULL || !(ss->flags&POSTSTATE)) && hitstopp != NULL) {
+ *hitstopp = 1;
+ }
+ }
+
+ if (ss == NULL || !(ss->flags&POSTSTATE)) {
+ return NULL;
+ }
+
+ return cp;
+}
+\f
+/*
+ - lastCold - determine last point at which no progress had been made
+ ^ static chr *lastCold(struct vars *, struct dfa *);
+ */
+static chr * /* endpoint, or NULL */
+lastCold(
+ struct vars *const v,
+ struct dfa *const d)
+{
+ struct sset *ss;
+ chr *nopr = d->lastnopr;
+ int i;
+
+ if (nopr == NULL) {
+ nopr = v->start;
+ }
+ for (ss = d->ssets, i = d->nssused; i > 0; ss++, i--) {
+ if ((ss->flags&NOPROGRESS) && nopr < ss->lastseen) {
+ nopr = ss->lastseen;
+ }
+ }
+ return nopr;
+}
+\f
+/*
+ - newDFA - set up a fresh DFA
+ ^ static struct dfa *newDFA(struct vars *, struct cnfa *,
+ ^ struct colormap *, struct smalldfa *);
+ */
+static struct dfa *
+newDFA(
+ struct vars *const v,
+ struct cnfa *const cnfa,
+ struct colormap *const cm,
+ struct smalldfa *sml) /* preallocated space, may be NULL */
+{
+ struct dfa *d;
+ size_t nss = cnfa->nstates * 2;
+ int wordsper = (cnfa->nstates + UBITS - 1) / UBITS;
+ struct smalldfa *smallwas = sml;
+
+ assert(cnfa != NULL && cnfa->nstates != 0);
+
+ if (nss <= FEWSTATES && cnfa->ncolors <= FEWCOLORS) {
+ assert(wordsper == 1);
+ if (sml == NULL) {
+ sml = (struct smalldfa *) MALLOC(sizeof(struct smalldfa));
+ if (sml == NULL) {
+ ERR(REG_ESPACE);
+ return NULL;
+ }
+ }
+ d = &sml->dfa;
+ d->ssets = sml->ssets;
+ d->statesarea = sml->statesarea;
+ d->work = &d->statesarea[nss];
+ d->outsarea = sml->outsarea;
+ d->incarea = sml->incarea;
+ d->cptsmalloced = 0;
+ d->mallocarea = (smallwas == NULL) ? (char *)sml : NULL;
+ } else {
+ d = (struct dfa *) MALLOC(sizeof(struct dfa));
+ if (d == NULL) {
+ ERR(REG_ESPACE);
+ return NULL;
+ }
+ d->ssets = (struct sset *) MALLOC(nss * sizeof(struct sset));
+ d->statesarea = (unsigned *)
+ MALLOC((nss+WORK) * wordsper * sizeof(unsigned));
+ d->work = &d->statesarea[nss * wordsper];
+ d->outsarea = (struct sset **)
+ MALLOC(nss * cnfa->ncolors * sizeof(struct sset *));
+ d->incarea = (struct arcp *)
+ MALLOC(nss * cnfa->ncolors * sizeof(struct arcp));
+ d->cptsmalloced = 1;
+ d->mallocarea = (char *)d;
+ if (d->ssets == NULL || d->statesarea == NULL ||
+ d->outsarea == NULL || d->incarea == NULL) {
+ freeDFA(d);
+ ERR(REG_ESPACE);
+ return NULL;
+ }
+ }
+
+ d->nssets = (v->eflags®_SMALL) ? 7 : nss;
+ d->nssused = 0;
+ d->nstates = cnfa->nstates;
+ d->ncolors = cnfa->ncolors;
+ d->wordsper = wordsper;
+ d->cnfa = cnfa;
+ d->cm = cm;
+ d->lastpost = NULL;
+ d->lastnopr = NULL;
+ d->search = d->ssets;
+
+ /*
+ * Initialization of sset fields is done as needed.
+ */
+
+ return d;
+}
+\f
+/*
+ - freeDFA - free a DFA
+ ^ static void freeDFA(struct dfa *);
+ */
+static void
+freeDFA(
+ struct dfa *const d)
+{
+ if (d->cptsmalloced) {
+ if (d->ssets != NULL) {
+ FREE(d->ssets);
+ }
+ if (d->statesarea != NULL) {
+ FREE(d->statesarea);
+ }
+ if (d->outsarea != NULL) {
+ FREE(d->outsarea);
+ }
+ if (d->incarea != NULL) {
+ FREE(d->incarea);
+ }
+ }
+
+ if (d->mallocarea != NULL) {
+ FREE(d->mallocarea);
+ }
+}
+\f
+/*
+ - hash - construct a hash code for a bitvector
+ * There are probably better ways, but they're more expensive.
+ ^ static unsigned hash(unsigned *, int);
+ */
+static unsigned
+hash(
+ unsigned *const uv,
+ const int n)
+{
+ int i;
+ unsigned h;
+
+ h = 0;
+ for (i = 0; i < n; i++) {
+ h ^= uv[i];
+ }
+ return h;
+}
+\f
+/*
+ - initialize - hand-craft a cache entry for startup, otherwise get ready
+ ^ static struct sset *initialize(struct vars *, struct dfa *, chr *);
+ */
+static struct sset *
+initialize(
+ struct vars *const v, /* used only for debug flags */
+ struct dfa *const d,
+ chr *const start)
+{
+ struct sset *ss;
+ int i;
+
+ /*
+ * Is previous one still there?
+ */
+
+ if (d->nssused > 0 && (d->ssets[0].flags&STARTER)) {
+ ss = &d->ssets[0];
+ } else { /* no, must (re)build it */
+ ss = getVacantSS(v, d, start, start);
+ for (i = 0; i < d->wordsper; i++) {
+ ss->states[i] = 0;
+ }
+ BSET(ss->states, d->cnfa->pre);
+ ss->hash = HASH(ss->states, d->wordsper);
+ assert(d->cnfa->pre != d->cnfa->post);
+ ss->flags = STARTER|LOCKED|NOPROGRESS;
+
+ /*
+ * lastseen dealt with below
+ */
+ }
+
+ for (i = 0; i < d->nssused; i++) {
+ d->ssets[i].lastseen = NULL;
+ }
+ ss->lastseen = start; /* maybe untrue, but harmless */
+ d->lastpost = NULL;
+ d->lastnopr = NULL;
+ return ss;
+}
+\f
+/*
+ - miss - handle a cache miss
+ ^ static struct sset *miss(struct vars *, struct dfa *, struct sset *,
+ ^ pcolor, chr *, chr *);
+ */
+static struct sset * /* NULL if goes to empty set */
+miss(
+ struct vars *const v, /* used only for debug flags */
+ struct dfa *const d,
+ struct sset *const css,
+ const pcolor co,
+ chr *const cp, /* next chr */
+ chr *const start) /* where the attempt got started */
+{
+ struct cnfa *cnfa = d->cnfa;
+ unsigned h;
+ struct carc *ca;
+ struct sset *p;
+ int i, isPost, noProgress, gotState, doLAConstraints, sawLAConstraints;
+
+ /*
+ * For convenience, we can be called even if it might not be a miss.
+ */
+
+ if (css->outs[co] != NULL) {
+ FDEBUG(("hit\n"));
+ return css->outs[co];
+ }
+ FDEBUG(("miss\n"));
+
+ /*
+ * First, what set of states would we end up in?
+ */
+
+ for (i = 0; i < d->wordsper; i++) {
+ d->work[i] = 0;
+ }
+ isPost = 0;
+ noProgress = 1;
+ gotState = 0;
+ for (i = 0; i < d->nstates; i++) {
+ if (ISBSET(css->states, i)) {
+ for (ca = cnfa->states[i]; ca->co != COLORLESS; ca++) {
+ if (ca->co == co) {
+ BSET(d->work, ca->to);
+ gotState = 1;
+ if (ca->to == cnfa->post) {
+ isPost = 1;
+ }
+ if (!(cnfa->stflags[ca->to] & CNFA_NOPROGRESS)) {
+ noProgress = 0;
+ }
+ FDEBUG(("%d -> %d\n", i, ca->to));
+ }
+ }
+ }
+ }
+ doLAConstraints = (gotState ? (cnfa->flags&HASLACONS) : 0);
+ sawLAConstraints = 0;
+ while (doLAConstraints) { /* transitive closure */
+ doLAConstraints = 0;
+ for (i = 0; i < d->nstates; i++) {
+ if (ISBSET(d->work, i)) {
+ for (ca = cnfa->states[i]; ca->co != COLORLESS; ca++) {
+ if (ca->co < cnfa->ncolors) {
+ continue; /* NOTE CONTINUE */
+ }
+ sawLAConstraints = 1;
+ if (ISBSET(d->work, ca->to)) {
+ continue; /* NOTE CONTINUE */
+ }
+ if (!checkLAConstraint(v, cnfa, cp, ca->co)) {
+ continue; /* NOTE CONTINUE */
+ }
+ BSET(d->work, ca->to);
+ doLAConstraints = 1;
+ if (ca->to == cnfa->post) {
+ isPost = 1;
+ }
+ if (!(cnfa->stflags[ca->to] & CNFA_NOPROGRESS)) {
+ noProgress = 0;
+ }
+ FDEBUG(("%d :> %d\n", i, ca->to));
+ }
+ }
+ }
+ }
+ if (!gotState) {
+ return NULL;
+ }
+ h = HASH(d->work, d->wordsper);
+
+ /*
+ * Next, is that in the cache?
+ */
+
+ for (p = d->ssets, i = d->nssused; i > 0; p++, i--) {
+ if (HIT(h, d->work, p, d->wordsper)) {
+ FDEBUG(("cached c%d\n", (int) (p - d->ssets)));
+ break; /* NOTE BREAK OUT */
+ }
+ }
+ if (i == 0) { /* nope, need a new cache entry */
+ p = getVacantSS(v, d, cp, start);
+ assert(p != css);
+ for (i = 0; i < d->wordsper; i++) {
+ p->states[i] = d->work[i];
+ }
+ p->hash = h;
+ p->flags = (isPost ? POSTSTATE : 0);
+ if (noProgress) {
+ p->flags |= NOPROGRESS;
+ }
+
+ /*
+ * lastseen to be dealt with by caller
+ */
+ }
+
+ if (!sawLAConstraints) { /* lookahead conds. always cache miss */
+ FDEBUG(("c%d[%d]->c%d\n",
+ (int) (css - d->ssets), co, (int) (p - d->ssets)));
+ css->outs[co] = p;
+ css->inchain[co] = p->ins;
+ p->ins.ss = css;
+ p->ins.co = (color) co;
+ }
+ return p;
+}
+\f
+/*
+ - checkLAConstraint - lookahead-constraint checker for miss()
+ ^ static int checkLAConstraint(struct vars *, struct cnfa *, chr *, pcolor);
+ */
+static int /* predicate: constraint satisfied? */
+checkLAConstraint(
+ struct vars *const v,
+ struct cnfa *const pcnfa, /* parent cnfa */
+ chr *const cp,
+ const pcolor co) /* "color" of the lookahead constraint */
+{
+ int n;
+ struct subre *sub;
+ struct dfa *d;
+ struct smalldfa sd;
+ chr *end;
+
+ n = co - pcnfa->ncolors;
+ assert(n < v->g->nlacons && v->g->lacons != NULL);
+ FDEBUG(("=== testing lacon %d\n", n));
+ sub = &v->g->lacons[n];
+ d = newDFA(v, &sub->cnfa, &v->g->cmap, &sd);
+ if (d == NULL) {
+ ERR(REG_ESPACE);
+ return 0;
+ }
+ end = longest(v, d, cp, v->stop, NULL);
+ freeDFA(d);
+ FDEBUG(("=== lacon %d match %d\n", n, (end != NULL)));
+ return (sub->subno) ? (end != NULL) : (end == NULL);
+}
+\f
+/*
+ - getVacantSS - get a vacant state set
+ * This routine clears out the inarcs and outarcs, but does not otherwise
+ * clear the innards of the state set -- that's up to the caller.
+ ^ static struct sset *getVacantSS(struct vars *, struct dfa *, chr *, chr *);
+ */
+static struct sset *
+getVacantSS(
+ struct vars *const v, /* used only for debug flags */
+ struct dfa *const d,
+ chr *const cp,
+ chr *const start)
+{
+ int i;
+ struct sset *ss, *p;
+ struct arcp ap, lastap = {NULL, 0}; /* silence gcc 4 warning */
+ color co;
+
+ ss = pickNextSS(v, d, cp, start);
+ assert(!(ss->flags&LOCKED));
+
+ /*
+ * Clear out its inarcs, including self-referential ones.
+ */
+
+ ap = ss->ins;
+ while ((p = ap.ss) != NULL) {
+ co = ap.co;
+ FDEBUG(("zapping c%d's %ld outarc\n", (int) (p - d->ssets), (long)co));
+ p->outs[co] = NULL;
+ ap = p->inchain[co];
+ p->inchain[co].ss = NULL; /* paranoia */
+ }
+ ss->ins.ss = NULL;
+
+ /*
+ * Take it off the inarc chains of the ssets reached by its outarcs.
+ */
+
+ for (i = 0; i < d->ncolors; i++) {
+ p = ss->outs[i];
+ assert(p != ss); /* not self-referential */
+ if (p == NULL) {
+ continue; /* NOTE CONTINUE */
+ }
+ FDEBUG(("del outarc %d from c%d's in chn\n", i, (int) (p - d->ssets)));
+ if (p->ins.ss == ss && p->ins.co == i) {
+ p->ins = ss->inchain[i];
+ } else {
+ assert(p->ins.ss != NULL);
+ for (ap = p->ins; ap.ss != NULL && !(ap.ss == ss && ap.co == i);
+ ap = ap.ss->inchain[ap.co]) {
+ lastap = ap;
+ }
+ assert(ap.ss != NULL);
+ lastap.ss->inchain[lastap.co] = ss->inchain[i];
+ }
+ ss->outs[i] = NULL;
+ ss->inchain[i].ss = NULL;
+ }
+
+ /*
+ * If ss was a success state, may need to remember location.
+ */
+
+ if ((ss->flags&POSTSTATE) && ss->lastseen != d->lastpost &&
+ (d->lastpost == NULL || d->lastpost < ss->lastseen)) {
+ d->lastpost = ss->lastseen;
+ }
+
+ /*
+ * Likewise for a no-progress state.
+ */
+
+ if ((ss->flags&NOPROGRESS) && ss->lastseen != d->lastnopr &&
+ (d->lastnopr == NULL || d->lastnopr < ss->lastseen)) {
+ d->lastnopr = ss->lastseen;
+ }
+
+ return ss;
+}
+\f
+/*
+ - pickNextSS - pick the next stateset to be used
+ ^ static struct sset *pickNextSS(struct vars *, struct dfa *, chr *, chr *);
+ */
+static struct sset *
+pickNextSS(
+ struct vars *const v, /* used only for debug flags */
+ struct dfa *const d,
+ chr *const cp,
+ chr *const start)
+{
+ int i;
+ struct sset *ss, *end;
+ chr *ancient;
+
+ /*
+ * Shortcut for cases where cache isn't full.
+ */
+
+ if (d->nssused < d->nssets) {
+ i = d->nssused;
+ d->nssused++;
+ ss = &d->ssets[i];
+ FDEBUG(("new c%d\n", i));
+
+ /*
+ * Set up innards.
+ */
+
+ ss->states = &d->statesarea[i * d->wordsper];
+ ss->flags = 0;
+ ss->ins.ss = NULL;
+ ss->ins.co = WHITE; /* give it some value */
+ ss->outs = &d->outsarea[i * d->ncolors];
+ ss->inchain = &d->incarea[i * d->ncolors];
+ for (i = 0; i < d->ncolors; i++) {
+ ss->outs[i] = NULL;
+ ss->inchain[i].ss = NULL;
+ }
+ return ss;
+ }
+
+ /*
+ * Look for oldest, or old enough anyway.
+ */
+
+ if (cp - start > d->nssets*2/3) { /* oldest 33% are expendable */
+ ancient = cp - d->nssets*2/3;
+ } else {
+ ancient = start;
+ }
+ for (ss = d->search, end = &d->ssets[d->nssets]; ss < end; ss++) {
+ if ((ss->lastseen == NULL || ss->lastseen < ancient)
+ && !(ss->flags&LOCKED)) {
+ d->search = ss + 1;
+ FDEBUG(("replacing c%d\n", (int) (ss - d->ssets)));
+ return ss;
+ }
+ }
+ for (ss = d->ssets, end = d->search; ss < end; ss++) {
+ if ((ss->lastseen == NULL || ss->lastseen < ancient)
+ && !(ss->flags&LOCKED)) {
+ d->search = ss + 1;
+ FDEBUG(("replacing c%d\n", (int) (ss - d->ssets)));
+ return ss;
+ }
+ }
+
+ /*
+ * Nobody's old enough?!? -- something's really wrong.
+ */
+
+ FDEBUG(("can't find victim to replace!\n"));
+ assert(NOTREACHED);
+ ERR(REG_ASSERT);
+ return d->ssets;
+}
+\f
+/*
+ * Local Variables:
+ * mode: c
+ * c-basic-offset: 4
+ * fill-column: 78
+ * End:
+ */
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