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Add per-top findMinWidth etc for NFA graphs

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This commit is contained in:
Justin Viiret 2015-12-02 18:16:49 +11:00 committed by Matthew Barr
parent 748d46c124
commit 8c09d054c9
3 changed files with 75 additions and 27 deletions
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68
src/nfagraph/ng_width.cpp
View File

@ -51,10 +51,16 @@ namespace ue2 {
namespace {
/** Filter out edges from start-to-start or accept-to-accept. */
/**
* Filter out special edges, or in the top-specific variant, start edges that
* don't have the right top set.
*/
struct SpecialEdgeFilter {
SpecialEdgeFilter() {}
explicit SpecialEdgeFilter(const NGHolder *h_in) : h(h_in) {}
explicit SpecialEdgeFilter(const NGHolder &h_in) : h(&h_in) {}
explicit SpecialEdgeFilter(const NGHolder &h_in, u32 top_in)
: h(&h_in), single_top(true), top(top_in) {}
bool operator()(const NFAEdge &e) const {
const NFAGraph &g = h->g;
NFAVertex u = source(e, g), v = target(e, g);
@ -62,23 +68,33 @@ struct SpecialEdgeFilter {
(is_any_accept(u, g) && is_any_accept(v, g))) {
return false;
}
if (single_top) {
if (u == h->start && g[e].top != top) {
return false;
}
if (u == h->startDs) {
return false;
}
}
return true;
}
private:
const NGHolder *h = nullptr;
bool single_top = false;
u32 top = 0;
};
} // namespace
static
depth findMinWidth(const NGHolder &h, NFAVertex src) {
depth findMinWidth(const NGHolder &h, const SpecialEdgeFilter &filter,
NFAVertex src) {
if (isLeafNode(src, h)) {
return depth::unreachable();
}
typedef boost::filtered_graph<NFAGraph, SpecialEdgeFilter> StartGraph;
StartGraph g(h.g, SpecialEdgeFilter(&h));
boost::filtered_graph<NFAGraph, SpecialEdgeFilter> g(h.g, filter);
assert(hasCorrectlyNumberedVertices(h));
const size_t num = num_vertices(h);
@ -112,7 +128,8 @@ depth findMinWidth(const NGHolder &h, NFAVertex src) {
}
static
depth findMaxWidth(const NGHolder &h, NFAVertex src) {
depth findMaxWidth(const NGHolder &h, const SpecialEdgeFilter &filter,
NFAVertex src) {
if (isLeafNode(src, h.g)) {
return depth::unreachable();
}
@ -122,8 +139,7 @@ depth findMaxWidth(const NGHolder &h, NFAVertex src) {
return depth::infinity();
}
typedef boost::filtered_graph<NFAGraph, SpecialEdgeFilter> NodeFilteredGraph;
NodeFilteredGraph g(h.g, SpecialEdgeFilter(&h));
boost::filtered_graph<NFAGraph, SpecialEdgeFilter> g(h.g, filter);
assert(hasCorrectlyNumberedVertices(h));
const size_t num = num_vertices(h);
@ -164,7 +180,7 @@ depth findMaxWidth(const NGHolder &h, NFAVertex src) {
if (d.is_unreachable()) {
// If we're actually reachable, we'll have a min width, so we can
// return infinity in this case.
if (findMinWidth(h, src).is_reachable()) {
if (findMinWidth(h, filter, src).is_reachable()) {
return depth::infinity();
}
return d;
@ -175,11 +191,10 @@ depth findMaxWidth(const NGHolder &h, NFAVertex src) {
return d - depth(1);
}
/** Returns the minimum width in bytes of an input that will match the given
* graph. */
depth findMinWidth(const NGHolder &h) {
depth startDepth = findMinWidth(h, h.start);
depth dotstarDepth = findMinWidth(h, h.startDs);
static
depth findMinWidth(const NGHolder &h, const SpecialEdgeFilter &filter) {
depth startDepth = findMinWidth(h, filter, h.start);
depth dotstarDepth = findMinWidth(h, filter, h.startDs);
DEBUG_PRINTF("startDepth=%s, dotstarDepth=%s\n", startDepth.str().c_str(),
dotstarDepth.str().c_str());
if (startDepth.is_unreachable()) {
@ -194,11 +209,18 @@ depth findMinWidth(const NGHolder &h) {
}
}
/** Returns the maximum width in bytes of an input that will match the given
* graph. If there is no maximum width, returns infinity. */
depth findMaxWidth(const NGHolder &h) {
depth startDepth = findMaxWidth(h, h.start);
depth dotstarDepth = findMaxWidth(h, h.startDs);
depth findMinWidth(const NGHolder &h) {
return findMinWidth(h, SpecialEdgeFilter(h));
}
depth findMinWidth(const NGHolder &h, u32 top) {
return findMinWidth(h, SpecialEdgeFilter(h, top));
}
static
depth findMaxWidth(const NGHolder &h, const SpecialEdgeFilter &filter) {
depth startDepth = findMaxWidth(h, filter, h.start);
depth dotstarDepth = findMaxWidth(h, filter, h.startDs);
DEBUG_PRINTF("startDepth=%s, dotstarDepth=%s\n", startDepth.str().c_str(),
dotstarDepth.str().c_str());
if (startDepth.is_unreachable()) {
@ -210,4 +232,12 @@ depth findMaxWidth(const NGHolder &h) {
}
}
depth findMaxWidth(const NGHolder &h) {
return findMaxWidth(h, SpecialEdgeFilter(h));
}
depth findMaxWidth(const NGHolder &h, u32 top) {
return findMaxWidth(h, SpecialEdgeFilter(h, top));
}
} // namespace ue2

28
src/nfagraph/ng_width.h
View File

@ -41,14 +41,34 @@ namespace ue2 {
class NGHolder;
/** Returns the minimum width in bytes of an input that will match the given
* graph. */
/**
* \brief Compute the minimum width in bytes of an input that will match the
* given graph.
*/
depth findMinWidth(const NGHolder &h);
/** Returns the maximum width in bytes of an input that will match the given
* graph. If there is no maximum width, returns infinity. */
/**
* \brief Compute the minimum width in bytes of an input that will match the
* given graph, considering only paths activated by the given top.
*/
depth findMinWidth(const NGHolder &h, u32 top);
/**
* \brief Compute the maximum width in bytes of an input that will match the
* given graph.
*
* If there is no bound on the maximum width, returns infinity.
*/
depth findMaxWidth(const NGHolder &h);
/**
* \brief Compute the maximum width in bytes of an input that will match the
* given graph, considering only paths activated by the given top.
*
* If there is no bound on the maximum width, returns infinity.
*/
depth findMaxWidth(const NGHolder &h, u32 top);
} // namespace ue2
#endif // NG_WIDTH_H

6
src/rose/rose_build_misc.cpp
View File

@ -910,9 +910,8 @@ depth findMinWidth(const suffix_id &s) {
depth findMinWidth(const suffix_id &s, u32 top) {
assert(s.graph() || s.castle() || s.haig() || s.dfa());
// TODO: take top into account for non-castle suffixes.
if (s.graph()) {
return findMinWidth(*s.graph());
return findMinWidth(*s.graph(), top);
} else if (s.castle()) {
return findMinWidth(*s.castle(), top);
} else {
@ -933,9 +932,8 @@ depth findMaxWidth(const suffix_id &s) {
depth findMaxWidth(const suffix_id &s, u32 top) {
assert(s.graph() || s.castle() || s.haig() || s.dfa());
// TODO: take top into account for non-castle suffixes.
if (s.graph()) {
return findMaxWidth(*s.graph());
return findMaxWidth(*s.graph(), top);
} else if (s.castle()) {
return findMaxWidth(*s.castle(), top);
} else {