Fix O(N^2) performance problems in regular-expression compiler.
Change the singly-linked in-arc and out-arc lists to be doubly-linked, so that arc deletion is constant time rather than having worst-case time proportional to the number of other arcs on the connected states. Modify the bulk arc transfer operations copyins(), copyouts(), moveins(), moveouts() so that they use a sort-and-merge algorithm whenever there's more than a small number of arcs to be copied or moved. The previous method is O(N^2) in the number of arcs involved, because it performs duplicate checking independently for each copied arc. The new method may change the ordering of existing arcs for the destination state, but nothing really cares about that. Provide another bulk arc copying method mergeins(), which is unused as of this commit but is needed for the next one. It basically is like copyins(), but the source arcs might not all come from the same state. Replace the O(N^2) bubble-sort algorithm used in carcsort() with a qsort() call. These changes greatly improve the performance of regex compilation for large or complex regexes, at the cost of extra space for arc storage during compilation. The original tradeoff was probably fine when it was made, but now we care more about speed and less about memory consumption. Back-patch to all supported branches.
This commit is contained in:
Tom Lane
parent
48789c5d23
commit
579840ca05
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@ -321,6 +321,9 @@ destroystate(struct nfa * nfa,
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/*
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* newarc - set up a new arc within an NFA
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*
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* This function checks to make sure that no duplicate arcs are created.
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* In general we never want duplicates.
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*/
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static void
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newarc(struct nfa * nfa,
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@ -344,11 +347,40 @@ newarc(struct nfa * nfa,
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return;
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}
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/* check for duplicates */
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for (a = from->outs; a != NULL; a = a->outchain)
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if (a->to == to && a->co == co && a->type == t)
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return;
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/* check for duplicate arc, using whichever chain is shorter */
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if (from->nouts <= to->nins)
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{
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for (a = from->outs; a != NULL; a = a->outchain)
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if (a->to == to && a->co == co && a->type == t)
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return;
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}
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else
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{
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for (a = to->ins; a != NULL; a = a->inchain)
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if (a->from == from && a->co == co && a->type == t)
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return;
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}
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/* no dup, so create the arc */
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createarc(nfa, t, co, from, to);
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}
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/*
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* createarc - create a new arc within an NFA
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*
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* This function must *only* be used after verifying that there is no existing
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* identical arc (same type/color/from/to).
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*/
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static void
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createarc(struct nfa * nfa,
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int t,
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pcolor co,
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struct state * from,
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struct state * to)
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{
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struct arc *a;
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/* the arc is physically allocated within its from-state */
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a = allocarc(nfa, from);
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if (NISERR())
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return;
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@ -360,14 +392,19 @@ newarc(struct nfa * nfa,
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a->from = from;
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/*
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* Put the new arc on the beginning, not the end, of the chains. Not only
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* is this easier, it has the very useful side effect that deleting the
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* most-recently-added arc is the cheapest case rather than the most
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* expensive one.
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* Put the new arc on the beginning, not the end, of the chains; it's
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* simpler here, and freearc() is the same cost either way. See also the
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* logic in moveins() and its cohorts, as well as fixempties().
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*/
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a->inchain = to->ins;
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a->inchainRev = NULL;
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if (to->ins)
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to->ins->inchainRev = a;
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to->ins = a;
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a->outchain = from->outs;
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a->outchainRev = NULL;
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if (from->outs)
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from->outs->outchainRev = a;
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from->outs = a;
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from->nouts++;
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@ -433,7 +470,7 @@ freearc(struct nfa * nfa,
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{
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struct state *from = victim->from;
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struct state *to = victim->to;
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struct arc *a;
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struct arc *predecessor;
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assert(victim->type != 0);
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@ -443,44 +480,103 @@ freearc(struct nfa * nfa,
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/* take it off source's out-chain */
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assert(from != NULL);
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assert(from->outs != NULL);
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a = from->outs;
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if (a == victim) /* simple case: first in chain */
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predecessor = victim->outchainRev;
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if (predecessor == NULL)
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{
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assert(from->outs == victim);
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from->outs = victim->outchain;
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}
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else
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{
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for (; a != NULL && a->outchain != victim; a = a->outchain)
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continue;
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assert(a != NULL);
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a->outchain = victim->outchain;
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assert(predecessor->outchain == victim);
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predecessor->outchain = victim->outchain;
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}
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if (victim->outchain != NULL)
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{
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assert(victim->outchain->outchainRev == victim);
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victim->outchain->outchainRev = predecessor;
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}
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from->nouts--;
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/* take it off target's in-chain */
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assert(to != NULL);
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assert(to->ins != NULL);
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a = to->ins;
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if (a == victim) /* simple case: first in chain */
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predecessor = victim->inchainRev;
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if (predecessor == NULL)
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{
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assert(to->ins == victim);
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to->ins = victim->inchain;
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}
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else
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{
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for (; a != NULL && a->inchain != victim; a = a->inchain)
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continue;
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assert(a != NULL);
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a->inchain = victim->inchain;
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assert(predecessor->inchain == victim);
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predecessor->inchain = victim->inchain;
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}
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if (victim->inchain != NULL)
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{
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assert(victim->inchain->inchainRev == victim);
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victim->inchain->inchainRev = predecessor;
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}
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to->nins--;
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/* clean up and place on free list */
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/* clean up and place on from-state's free list */
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victim->type = 0;
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victim->from = NULL; /* precautions... */
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victim->to = NULL;
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victim->inchain = NULL;
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victim->inchainRev = NULL;
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victim->outchain = NULL;
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victim->outchainRev = NULL;
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victim->freechain = from->free;
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from->free = victim;
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}
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/*
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* changearctarget - flip an arc to have a different to state
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*
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* Caller must have verified that there is no pre-existing duplicate arc.
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*
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* Note that because we store arcs in their from state, we can't easily have
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* a similar changearcsource function.
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*/
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static void
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changearctarget(struct arc * a, struct state * newto)
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{
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struct state *oldto = a->to;
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struct arc *predecessor;
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assert(oldto != newto);
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/* take it off old target's in-chain */
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assert(oldto != NULL);
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predecessor = a->inchainRev;
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if (predecessor == NULL)
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{
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assert(oldto->ins == a);
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oldto->ins = a->inchain;
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}
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else
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{
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assert(predecessor->inchain == a);
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predecessor->inchain = a->inchain;
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}
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if (a->inchain != NULL)
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{
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assert(a->inchain->inchainRev == a);
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a->inchain->inchainRev = predecessor;
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}
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oldto->nins--;
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a->to = newto;
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/* prepend it to new target's in-chain */
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a->inchain = newto->ins;
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a->inchainRev = NULL;
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if (newto->ins)
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newto->ins->inchainRev = a;
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newto->ins = a;
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newto->nins++;
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}
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/*
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* hasnonemptyout - Does state have a non-EMPTY out arc?
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*/
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@ -560,28 +656,248 @@ cparc(struct nfa * nfa,
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newarc(nfa, oa->type, oa->co, from, to);
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}
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/*
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* sortins - sort the in arcs of a state by from/color/type
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*/
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static void
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sortins(struct nfa * nfa,
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struct state * s)
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{
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struct arc **sortarray;
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struct arc *a;
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int n = s->nins;
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int i;
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if (n <= 1)
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return; /* nothing to do */
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/* make an array of arc pointers ... */
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sortarray = (struct arc **) MALLOC(n * sizeof(struct arc *));
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if (sortarray == NULL)
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{
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NERR(REG_ESPACE);
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return;
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}
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i = 0;
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for (a = s->ins; a != NULL; a = a->inchain)
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sortarray[i++] = a;
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assert(i == n);
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/* ... sort the array */
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qsort(sortarray, n, sizeof(struct arc *), sortins_cmp);
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/* ... and rebuild arc list in order */
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/* it seems worth special-casing first and last items to simplify loop */
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a = sortarray[0];
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s->ins = a;
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a->inchain = sortarray[1];
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a->inchainRev = NULL;
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for (i = 1; i < n - 1; i++)
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{
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a = sortarray[i];
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a->inchain = sortarray[i + 1];
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a->inchainRev = sortarray[i - 1];
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}
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a = sortarray[i];
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a->inchain = NULL;
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a->inchainRev = sortarray[i - 1];
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FREE(sortarray);
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}
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static int
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sortins_cmp(const void *a, const void *b)
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{
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const struct arc *aa = *((const struct arc * const *) a);
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const struct arc *bb = *((const struct arc * const *) b);
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/* we check the fields in the order they are most likely to be different */
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if (aa->from->no < bb->from->no)
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return -1;
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if (aa->from->no > bb->from->no)
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return 1;
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if (aa->co < bb->co)
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return -1;
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if (aa->co > bb->co)
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return 1;
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if (aa->type < bb->type)
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return -1;
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if (aa->type > bb->type)
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return 1;
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return 0;
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}
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/*
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* sortouts - sort the out arcs of a state by to/color/type
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*/
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static void
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sortouts(struct nfa * nfa,
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struct state * s)
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{
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struct arc **sortarray;
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struct arc *a;
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int n = s->nouts;
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int i;
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if (n <= 1)
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return; /* nothing to do */
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/* make an array of arc pointers ... */
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sortarray = (struct arc **) MALLOC(n * sizeof(struct arc *));
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if (sortarray == NULL)
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{
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NERR(REG_ESPACE);
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return;
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}
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i = 0;
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for (a = s->outs; a != NULL; a = a->outchain)
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sortarray[i++] = a;
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assert(i == n);
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/* ... sort the array */
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qsort(sortarray, n, sizeof(struct arc *), sortouts_cmp);
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/* ... and rebuild arc list in order */
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/* it seems worth special-casing first and last items to simplify loop */
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a = sortarray[0];
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s->outs = a;
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a->outchain = sortarray[1];
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a->outchainRev = NULL;
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for (i = 1; i < n - 1; i++)
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{
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a = sortarray[i];
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a->outchain = sortarray[i + 1];
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a->outchainRev = sortarray[i - 1];
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}
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a = sortarray[i];
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a->outchain = NULL;
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a->outchainRev = sortarray[i - 1];
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FREE(sortarray);
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}
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static int
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sortouts_cmp(const void *a, const void *b)
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{
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const struct arc *aa = *((const struct arc * const *) a);
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const struct arc *bb = *((const struct arc * const *) b);
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/* we check the fields in the order they are most likely to be different */
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if (aa->to->no < bb->to->no)
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return -1;
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if (aa->to->no > bb->to->no)
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return 1;
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if (aa->co < bb->co)
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return -1;
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if (aa->co > bb->co)
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return 1;
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if (aa->type < bb->type)
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return -1;
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if (aa->type > bb->type)
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return 1;
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return 0;
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}
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/*
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* Common decision logic about whether to use arc-by-arc operations or
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* sort/merge. If there's just a few source arcs we cannot recoup the
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* cost of sorting the destination arc list, no matter how large it is.
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* Otherwise, limit the number of arc-by-arc comparisons to about 1000
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* (a somewhat arbitrary choice, but the breakeven point would probably
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* be machine dependent anyway).
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*/
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#define BULK_ARC_OP_USE_SORT(nsrcarcs, ndestarcs) \
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((nsrcarcs) < 4 ? 0 : ((nsrcarcs) > 32 || (ndestarcs) > 32))
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/*
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* moveins - move all in arcs of a state to another state
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*
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* You might think this could be done better by just updating the
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* existing arcs, and you would be right if it weren't for the desire
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* existing arcs, and you would be right if it weren't for the need
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* for duplicate suppression, which makes it easier to just make new
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* ones to exploit the suppression built into newarc.
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*
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* However, if we have a whole lot of arcs to deal with, retail duplicate
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* checks become too slow. In that case we proceed by sorting and merging
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* the arc lists, and then we can indeed just update the arcs in-place.
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*/
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static void
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moveins(struct nfa * nfa,
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struct state * oldState,
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struct state * newState)
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{
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struct arc *a;
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assert(oldState != newState);
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while ((a = oldState->ins) != NULL)
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if (!BULK_ARC_OP_USE_SORT(oldState->nins, newState->nins))
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{
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cparc(nfa, a, a->from, newState);
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freearc(nfa, a);
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/* With not too many arcs, just do them one at a time */
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struct arc *a;
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while ((a = oldState->ins) != NULL)
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{
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cparc(nfa, a, a->from, newState);
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freearc(nfa, a);
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}
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}
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else
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{
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/*
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* With many arcs, use a sort-merge approach. Note changearctarget()
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* will put the arc onto the front of newState's chain, so it does not
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* break our walk through the sorted part of the chain.
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*/
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struct arc *oa;
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struct arc *na;
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/*
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* Because we bypass newarc() in this code path, we'd better include a
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* cancel check.
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*/
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if (CANCEL_REQUESTED(nfa->v->re))
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{
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NERR(REG_CANCEL);
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return;
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}
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sortins(nfa, oldState);
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sortins(nfa, newState);
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if (NISERR())
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return; /* might have failed to sort */
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oa = oldState->ins;
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na = newState->ins;
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while (oa != NULL && na != NULL)
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{
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struct arc *a = oa;
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switch (sortins_cmp(&oa, &na))
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{
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case -1:
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/* newState does not have anything matching oa */
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oa = oa->inchain;
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/*
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* Rather than doing createarc+freearc, we can just unlink
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* and relink the existing arc struct.
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*/
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changearctarget(a, newState);
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break;
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case 0:
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/* match, advance in both lists */
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oa = oa->inchain;
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na = na->inchain;
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/* ... and drop duplicate arc from oldState */
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freearc(nfa, a);
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break;
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case +1:
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/* advance only na; oa might have a match later */
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na = na->inchain;
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break;
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default:
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assert(NOTREACHED);
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}
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}
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while (oa != NULL)
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{
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/* newState does not have anything matching oa */
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struct arc *a = oa;
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oa = oa->inchain;
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changearctarget(a, newState);
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}
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}
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assert(oldState->nins == 0);
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assert(oldState->ins == NULL);
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}
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|
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@ -597,14 +913,187 @@ copyins(struct nfa * nfa,
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struct state * newState,
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int all)
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{
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struct arc *a;
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assert(oldState != newState);
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for (a = oldState->ins; a != NULL; a = a->inchain)
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if (!BULK_ARC_OP_USE_SORT(oldState->nins, newState->nins))
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{
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if (all || a->type != EMPTY)
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cparc(nfa, a, a->from, newState);
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/* With not too many arcs, just do them one at a time */
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struct arc *a;
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for (a = oldState->ins; a != NULL; a = a->inchain)
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if (all || a->type != EMPTY)
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cparc(nfa, a, a->from, newState);
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}
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else
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{
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/*
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* With many arcs, use a sort-merge approach. Note that createarc()
|
||||
* will put new arcs onto the front of newState's chain, so it does
|
||||
* not break our walk through the sorted part of the chain.
|
||||
*/
|
||||
struct arc *oa;
|
||||
struct arc *na;
|
||||
|
||||
/*
|
||||
* Because we bypass newarc() in this code path, we'd better include a
|
||||
* cancel check.
|
||||
*/
|
||||
if (CANCEL_REQUESTED(nfa->v->re))
|
||||
{
|
||||
NERR(REG_CANCEL);
|
||||
return;
|
||||
}
|
||||
|
||||
sortins(nfa, oldState);
|
||||
sortins(nfa, newState);
|
||||
if (NISERR())
|
||||
return; /* might have failed to sort */
|
||||
oa = oldState->ins;
|
||||
na = newState->ins;
|
||||
while (oa != NULL && na != NULL)
|
||||
{
|
||||
struct arc *a = oa;
|
||||
|
||||
if (!all && a->type == EMPTY)
|
||||
{
|
||||
oa = oa->inchain;
|
||||
continue;
|
||||
}
|
||||
|
||||
switch (sortins_cmp(&oa, &na))
|
||||
{
|
||||
case -1:
|
||||
/* newState does not have anything matching oa */
|
||||
oa = oa->inchain;
|
||||
createarc(nfa, a->type, a->co, a->from, newState);
|
||||
break;
|
||||
case 0:
|
||||
/* match, advance in both lists */
|
||||
oa = oa->inchain;
|
||||
na = na->inchain;
|
||||
break;
|
||||
case +1:
|
||||
/* advance only na; oa might have a match later */
|
||||
na = na->inchain;
|
||||
break;
|
||||
default:
|
||||
assert(NOTREACHED);
|
||||
}
|
||||
}
|
||||
while (oa != NULL)
|
||||
{
|
||||
/* newState does not have anything matching oa */
|
||||
struct arc *a = oa;
|
||||
|
||||
if (!all && a->type == EMPTY)
|
||||
{
|
||||
oa = oa->inchain;
|
||||
continue;
|
||||
}
|
||||
|
||||
oa = oa->inchain;
|
||||
createarc(nfa, a->type, a->co, a->from, newState);
|
||||
}
|
||||
}
|
||||
}
|
||||
|
||||
/*
|
||||
* mergeins - merge a list of inarcs into a state
|
||||
*
|
||||
* This is much like copyins, but the source arcs are listed in an array,
|
||||
* and are not guaranteed unique. It's okay to clobber the array contents.
|
||||
*/
|
||||
static void
|
||||
mergeins(struct nfa * nfa,
|
||||
struct state * s,
|
||||
struct arc ** arcarray,
|
||||
int arccount)
|
||||
{
|
||||
struct arc *na;
|
||||
int i;
|
||||
int j;
|
||||
|
||||
if (arccount <= 0)
|
||||
return;
|
||||
|
||||
/*
|
||||
* Because we bypass newarc() in this code path, we'd better include a
|
||||
* cancel check.
|
||||
*/
|
||||
if (CANCEL_REQUESTED(nfa->v->re))
|
||||
{
|
||||
NERR(REG_CANCEL);
|
||||
return;
|
||||
}
|
||||
|
||||
/* Sort existing inarcs as well as proposed new ones */
|
||||
sortins(nfa, s);
|
||||
if (NISERR())
|
||||
return; /* might have failed to sort */
|
||||
|
||||
qsort(arcarray, arccount, sizeof(struct arc *), sortins_cmp);
|
||||
|
||||
/*
|
||||
* arcarray very likely includes dups, so we must eliminate them. (This
|
||||
* could be folded into the next loop, but it's not worth the trouble.)
|
||||
*/
|
||||
j = 0;
|
||||
for (i = 1; i < arccount; i++)
|
||||
{
|
||||
switch (sortins_cmp(&arcarray[j], &arcarray[i]))
|
||||
{
|
||||
case -1:
|
||||
/* non-dup */
|
||||
arcarray[++j] = arcarray[i];
|
||||
break;
|
||||
case 0:
|
||||
/* dup */
|
||||
break;
|
||||
default:
|
||||
/* trouble */
|
||||
assert(NOTREACHED);
|
||||
}
|
||||
}
|
||||
arccount = j + 1;
|
||||
|
||||
/*
|
||||
* Now merge into s' inchain. Note that createarc() will put new arcs
|
||||
* onto the front of s's chain, so it does not break our walk through the
|
||||
* sorted part of the chain.
|
||||
*/
|
||||
i = 0;
|
||||
na = s->ins;
|
||||
while (i < arccount && na != NULL)
|
||||
{
|
||||
struct arc *a = arcarray[i];
|
||||
|
||||
switch (sortins_cmp(&a, &na))
|
||||
{
|
||||
case -1:
|
||||
/* s does not have anything matching a */
|
||||
createarc(nfa, a->type, a->co, a->from, s);
|
||||
i++;
|
||||
break;
|
||||
case 0:
|
||||
/* match, advance in both lists */
|
||||
i++;
|
||||
na = na->inchain;
|
||||
break;
|
||||
case +1:
|
||||
/* advance only na; array might have a match later */
|
||||
na = na->inchain;
|
||||
break;
|
||||
default:
|
||||
assert(NOTREACHED);
|
||||
}
|
||||
}
|
||||
while (i < arccount)
|
||||
{
|
||||
/* s does not have anything matching a */
|
||||
struct arc *a = arcarray[i];
|
||||
|
||||
createarc(nfa, a->type, a->co, a->from, s);
|
||||
i++;
|
||||
}
|
||||
}
|
||||
|
||||
|
|
@ -616,15 +1105,85 @@ moveouts(struct nfa * nfa,
|
|||
struct state * oldState,
|
||||
struct state * newState)
|
||||
{
|
||||
struct arc *a;
|
||||
|
||||
assert(oldState != newState);
|
||||
|
||||
while ((a = oldState->outs) != NULL)
|
||||
if (!BULK_ARC_OP_USE_SORT(oldState->nouts, newState->nouts))
|
||||
{
|
||||
cparc(nfa, a, newState, a->to);
|
||||
freearc(nfa, a);
|
||||
/* With not too many arcs, just do them one at a time */
|
||||
struct arc *a;
|
||||
|
||||
while ((a = oldState->outs) != NULL)
|
||||
{
|
||||
cparc(nfa, a, newState, a->to);
|
||||
freearc(nfa, a);
|
||||
}
|
||||
}
|
||||
else
|
||||
{
|
||||
/*
|
||||
* With many arcs, use a sort-merge approach. Note that createarc()
|
||||
* will put new arcs onto the front of newState's chain, so it does
|
||||
* not break our walk through the sorted part of the chain.
|
||||
*/
|
||||
struct arc *oa;
|
||||
struct arc *na;
|
||||
|
||||
/*
|
||||
* Because we bypass newarc() in this code path, we'd better include a
|
||||
* cancel check.
|
||||
*/
|
||||
if (CANCEL_REQUESTED(nfa->v->re))
|
||||
{
|
||||
NERR(REG_CANCEL);
|
||||
return;
|
||||
}
|
||||
|
||||
sortouts(nfa, oldState);
|
||||
sortouts(nfa, newState);
|
||||
if (NISERR())
|
||||
return; /* might have failed to sort */
|
||||
oa = oldState->outs;
|
||||
na = newState->outs;
|
||||
while (oa != NULL && na != NULL)
|
||||
{
|
||||
struct arc *a = oa;
|
||||
|
||||
switch (sortouts_cmp(&oa, &na))
|
||||
{
|
||||
case -1:
|
||||
/* newState does not have anything matching oa */
|
||||
oa = oa->outchain;
|
||||
createarc(nfa, a->type, a->co, newState, a->to);
|
||||
freearc(nfa, a);
|
||||
break;
|
||||
case 0:
|
||||
/* match, advance in both lists */
|
||||
oa = oa->outchain;
|
||||
na = na->outchain;
|
||||
/* ... and drop duplicate arc from oldState */
|
||||
freearc(nfa, a);
|
||||
break;
|
||||
case +1:
|
||||
/* advance only na; oa might have a match later */
|
||||
na = na->outchain;
|
||||
break;
|
||||
default:
|
||||
assert(NOTREACHED);
|
||||
}
|
||||
}
|
||||
while (oa != NULL)
|
||||
{
|
||||
/* newState does not have anything matching oa */
|
||||
struct arc *a = oa;
|
||||
|
||||
oa = oa->outchain;
|
||||
createarc(nfa, a->type, a->co, newState, a->to);
|
||||
freearc(nfa, a);
|
||||
}
|
||||
}
|
||||
|
||||
assert(oldState->nouts == 0);
|
||||
assert(oldState->outs == NULL);
|
||||
}
|
||||
|
||||
/*
|
||||
|
|
@ -638,14 +1197,87 @@ copyouts(struct nfa * nfa,
|
|||
struct state * newState,
|
||||
int all)
|
||||
{
|
||||
struct arc *a;
|
||||
|
||||
assert(oldState != newState);
|
||||
|
||||
for (a = oldState->outs; a != NULL; a = a->outchain)
|
||||
if (!BULK_ARC_OP_USE_SORT(oldState->nouts, newState->nouts))
|
||||
{
|
||||
if (all || a->type != EMPTY)
|
||||
cparc(nfa, a, newState, a->to);
|
||||
/* With not too many arcs, just do them one at a time */
|
||||
struct arc *a;
|
||||
|
||||
for (a = oldState->outs; a != NULL; a = a->outchain)
|
||||
if (all || a->type != EMPTY)
|
||||
cparc(nfa, a, newState, a->to);
|
||||
}
|
||||
else
|
||||
{
|
||||
/*
|
||||
* With many arcs, use a sort-merge approach. Note that createarc()
|
||||
* will put new arcs onto the front of newState's chain, so it does
|
||||
* not break our walk through the sorted part of the chain.
|
||||
*/
|
||||
struct arc *oa;
|
||||
struct arc *na;
|
||||
|
||||
/*
|
||||
* Because we bypass newarc() in this code path, we'd better include a
|
||||
* cancel check.
|
||||
*/
|
||||
if (CANCEL_REQUESTED(nfa->v->re))
|
||||
{
|
||||
NERR(REG_CANCEL);
|
||||
return;
|
||||
}
|
||||
|
||||
sortouts(nfa, oldState);
|
||||
sortouts(nfa, newState);
|
||||
if (NISERR())
|
||||
return; /* might have failed to sort */
|
||||
oa = oldState->outs;
|
||||
na = newState->outs;
|
||||
while (oa != NULL && na != NULL)
|
||||
{
|
||||
struct arc *a = oa;
|
||||
|
||||
if (!all && a->type == EMPTY)
|
||||
{
|
||||
oa = oa->outchain;
|
||||
continue;
|
||||
}
|
||||
|
||||
switch (sortouts_cmp(&oa, &na))
|
||||
{
|
||||
case -1:
|
||||
/* newState does not have anything matching oa */
|
||||
oa = oa->outchain;
|
||||
createarc(nfa, a->type, a->co, newState, a->to);
|
||||
break;
|
||||
case 0:
|
||||
/* match, advance in both lists */
|
||||
oa = oa->outchain;
|
||||
na = na->outchain;
|
||||
break;
|
||||
case +1:
|
||||
/* advance only na; oa might have a match later */
|
||||
na = na->outchain;
|
||||
break;
|
||||
default:
|
||||
assert(NOTREACHED);
|
||||
}
|
||||
}
|
||||
while (oa != NULL)
|
||||
{
|
||||
/* newState does not have anything matching oa */
|
||||
struct arc *a = oa;
|
||||
|
||||
if (!all && a->type == EMPTY)
|
||||
{
|
||||
oa = oa->outchain;
|
||||
continue;
|
||||
}
|
||||
|
||||
oa = oa->outchain;
|
||||
createarc(nfa, a->type, a->co, newState, a->to);
|
||||
}
|
||||
}
|
||||
}
|
||||
|
||||
|
|
@ -2217,7 +2849,7 @@ compact(struct nfa * nfa,
|
|||
NERR(REG_ASSERT);
|
||||
break;
|
||||
}
|
||||
carcsort(first, ca - 1);
|
||||
carcsort(first, ca - first);
|
||||
ca->co = COLORLESS;
|
||||
ca->to = 0;
|
||||
ca++;
|
||||
|
|
@ -2233,31 +2865,29 @@ compact(struct nfa * nfa,
|
|||
|
||||
/*
|
||||
* carcsort - sort compacted-NFA arcs by color
|
||||
*
|
||||
* Really dumb algorithm, but if the list is long enough for that to matter,
|
||||
* you're in real trouble anyway.
|
||||
*/
|
||||
static void
|
||||
carcsort(struct carc * first,
|
||||
struct carc * last)
|
||||
carcsort(struct carc * first, size_t n)
|
||||
{
|
||||
struct carc *p;
|
||||
struct carc *q;
|
||||
struct carc tmp;
|
||||
if (n > 1)
|
||||
qsort(first, n, sizeof(struct carc), carc_cmp);
|
||||
}
|
||||
|
||||
if (last - first <= 1)
|
||||
return;
|
||||
static int
|
||||
carc_cmp(const void *a, const void *b)
|
||||
{
|
||||
const struct carc *aa = (const struct carc *) a;
|
||||
const struct carc *bb = (const struct carc *) b;
|
||||
|
||||
for (p = first; p <= last; p++)
|
||||
for (q = p; q <= last; q++)
|
||||
if (p->co > q->co ||
|
||||
(p->co == q->co && p->to > q->to))
|
||||
{
|
||||
assert(p != q);
|
||||
tmp = *p;
|
||||
*p = *q;
|
||||
*q = tmp;
|
||||
}
|
||||
if (aa->co < bb->co)
|
||||
return -1;
|
||||
if (aa->co > bb->co)
|
||||
return +1;
|
||||
if (aa->to < bb->to)
|
||||
return -1;
|
||||
if (aa->to > bb->to)
|
||||
return +1;
|
||||
return 0;
|
||||
}
|
||||
|
||||
/*
|
||||
|
|
@ -2337,36 +2967,30 @@ dumparcs(struct state * s,
|
|||
FILE *f)
|
||||
{
|
||||
int pos;
|
||||
struct arc *a;
|
||||
|
||||
assert(s->nouts > 0);
|
||||
/* printing arcs in reverse order is usually clearer */
|
||||
pos = dumprarcs(s->outs, s, f, 1);
|
||||
/* printing oldest arcs first is usually clearer */
|
||||
a = s->outs;
|
||||
assert(a != NULL);
|
||||
while (a->outchain != NULL)
|
||||
a = a->outchain;
|
||||
pos = 1;
|
||||
do
|
||||
{
|
||||
dumparc(a, s, f);
|
||||
if (pos == 5)
|
||||
{
|
||||
fprintf(f, "\n");
|
||||
pos = 1;
|
||||
}
|
||||
else
|
||||
pos++;
|
||||
a = a->outchainRev;
|
||||
} while (a != NULL);
|
||||
if (pos != 1)
|
||||
fprintf(f, "\n");
|
||||
}
|
||||
|
||||
/*
|
||||
* dumprarcs - dump remaining outarcs, recursively, in reverse order
|
||||
*/
|
||||
static int /* resulting print position */
|
||||
dumprarcs(struct arc * a,
|
||||
struct state * s,
|
||||
FILE *f,
|
||||
int pos) /* initial print position */
|
||||
{
|
||||
if (a->outchain != NULL)
|
||||
pos = dumprarcs(a->outchain, s, f, pos);
|
||||
dumparc(a, s, f);
|
||||
if (pos == 5)
|
||||
{
|
||||
fprintf(f, "\n");
|
||||
pos = 1;
|
||||
}
|
||||
else
|
||||
pos++;
|
||||
return pos;
|
||||
}
|
||||
|
||||
/*
|
||||
* dumparc - dump one outarc in readable form, including prefixing tab
|
||||
*/
|
||||
|
|
|
|||
|
|
@ -124,15 +124,22 @@ static void dropstate(struct nfa *, struct state *);
|
|||
static void freestate(struct nfa *, struct state *);
|
||||
static void destroystate(struct nfa *, struct state *);
|
||||
static void newarc(struct nfa *, int, pcolor, struct state *, struct state *);
|
||||
static void createarc(struct nfa *, int, pcolor, struct state *, struct state *);
|
||||
static struct arc *allocarc(struct nfa *, struct state *);
|
||||
static void freearc(struct nfa *, struct arc *);
|
||||
static void changearctarget(struct arc *, struct state *);
|
||||
static int hasnonemptyout(struct state *);
|
||||
static int nonemptyouts(struct state *);
|
||||
static int nonemptyins(struct state *);
|
||||
static struct arc *findarc(struct state *, int, pcolor);
|
||||
static void cparc(struct nfa *, struct arc *, struct state *, struct state *);
|
||||
static void sortins(struct nfa *, struct state *);
|
||||
static int sortins_cmp(const void *, const void *);
|
||||
static void sortouts(struct nfa *, struct state *);
|
||||
static int sortouts_cmp(const void *, const void *);
|
||||
static void moveins(struct nfa *, struct state *, struct state *);
|
||||
static void copyins(struct nfa *, struct state *, struct state *, int);
|
||||
static void mergeins(struct nfa *, struct state *, struct arc **, int);
|
||||
static void moveouts(struct nfa *, struct state *, struct state *);
|
||||
static void copyouts(struct nfa *, struct state *, struct state *, int);
|
||||
static void cloneouts(struct nfa *, struct state *, struct state *, struct state *, int);
|
||||
|
|
@ -168,7 +175,8 @@ static void markreachable(struct nfa *, struct state *, struct state *, struct s
|
|||
static void markcanreach(struct nfa *, struct state *, struct state *, struct state *);
|
||||
static long analyze(struct nfa *);
|
||||
static void compact(struct nfa *, struct cnfa *);
|
||||
static void carcsort(struct carc *, struct carc *);
|
||||
static void carcsort(struct carc *, size_t);
|
||||
static int carc_cmp(const void *, const void *);
|
||||
static void freecnfa(struct cnfa *);
|
||||
static void dumpnfa(struct nfa *, FILE *);
|
||||
|
||||
|
|
|
|||
|
|
@ -289,8 +289,10 @@ struct arc
|
|||
struct state *from; /* where it's from (and contained within) */
|
||||
struct state *to; /* where it's to */
|
||||
struct arc *outchain; /* link in *from's outs chain or free chain */
|
||||
#define freechain outchain
|
||||
struct arc *outchainRev; /* back-link in *from's outs chain */
|
||||
#define freechain outchain /* we do not maintain "freechainRev" */
|
||||
struct arc *inchain; /* link in *to's ins chain */
|
||||
struct arc *inchainRev; /* back-link in *to's ins chain */
|
||||
struct arc *colorchain; /* link in color's arc chain */
|
||||
struct arc *colorchainRev; /* back-link in color's arc chain */
|
||||
};
|
||||
|
|
|
|||
Loading…
Reference in New Issue