// test-properties.h
// Licensed under the Apache License, Version 2.0 (the "License");
// you may not use this file except in compliance with the License.
// You may obtain a copy of the License at
//
// http://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS IS" BASIS,
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
// See the License for the specific language governing permissions and
// limitations under the License.
//
// Copyright 2005-2010 Google, Inc.
// Author: [email protected] (Michael Riley)
//
// \file
// Functions to manipulate and test property bits
#ifndef FST_LIB_TEST_PROPERTIES_H__
#define FST_LIB_TEST_PROPERTIES_H__
#include <tr1/unordered_set>
using std::tr1::unordered_set;
using std::tr1::unordered_multiset;
#include <fst/dfs-visit.h>
#include <fst/connect.h>
DECLARE_bool(fst_verify_properties);
namespace fst {
// For a binary property, the bit is always returned set.
// For a trinary (i.e. two-bit) property, both bits are
// returned set iff either corresponding input bit is set.
inline uint64 KnownProperties(uint64 props) {
return kBinaryProperties | (props & kTrinaryProperties) |
((props & kPosTrinaryProperties) << 1) |
((props & kNegTrinaryProperties) >> 1);
}
// Tests compatibility between two sets of properties
inline bool CompatProperties(uint64 props1, uint64 props2) {
uint64 known_props1 = KnownProperties(props1);
uint64 known_props2 = KnownProperties(props2);
uint64 known_props = known_props1 & known_props2;
uint64 incompat_props = (props1 & known_props) ^ (props2 & known_props);
if (incompat_props) {
uint64 prop = 1;
for (int i = 0; i < 64; ++i, prop <<= 1)
if (prop & incompat_props)
LOG(ERROR) << "CompatProperties: mismatch: " << PropertyNames[i]
<< ": props1 = " << (props1 & prop ? "true" : "false")
<< ", props2 = " << (props2 & prop ? "true" : "false");
return false;
} else {
return true;
}
}
// Computes FST property values defined in properties.h. The value of
// each property indicated in the mask will be determined and returned
// (these will never be unknown here). In the course of determining
// the properties specifically requested in the mask, certain other
// properties may be determined (those with little additional expense)
// and their values will be returned as well. The complete set of
// known properties (whether true or false) determined by this
// operation will be assigned to the the value pointed to by KNOWN.
// If 'use_stored' is true, pre-computed FST properties may be used
// when possible. This routine is seldom called directly; instead it
// is used to implement fst.Properties(mask, true).
template<class Arc>
uint64 ComputeProperties(const Fst<Arc> &fst, uint64 mask, uint64 *known,
bool use_stored) {
typedef typename Arc::Label Label;
typedef typename Arc::Weight Weight;
typedef typename Arc::StateId StateId;
uint64 fst_props = fst.Properties(kFstProperties, false); // Fst-stored
// Check stored FST properties first if allowed.
if (use_stored) {
uint64 known_props = KnownProperties(fst_props);
// If FST contains required info, return it.
if ((known_props & mask) == mask) {
*known = known_props;
return fst_props;
}
}
// Compute (trinary) properties explicitly.
// Initialize with binary properties (already known).
uint64 comp_props = fst_props & kBinaryProperties;
// Compute these trinary properties with a DFS. We compute only those
// that need a DFS here, since we otherwise would like to avoid a DFS
// since its stack could grow large.
uint64 dfs_props = kCyclic | kAcyclic | kInitialCyclic | kInitialAcyclic |
kAccessible | kNotAccessible |
kCoAccessible | kNotCoAccessible;
if (mask & dfs_props) {
SccVisitor<Arc> scc_visitor(&comp_props);
DfsVisit(fst, &scc_visitor);
}
// Compute any remaining trinary properties via a state and arcs iterations
if (mask & ~(kBinaryProperties | dfs_props)) {
comp_props |= kAcceptor | kNoEpsilons | kNoIEpsilons | kNoOEpsilons |
kILabelSorted | kOLabelSorted | kUnweighted | kTopSorted | kString;
if (mask & (kIDeterministic | kNonIDeterministic))
comp_props |= kIDeterministic;
if (mask & (kODeterministic | kNonODeterministic))
comp_props |= kODeterministic;
unordered_set<Label> *ilabels = 0;
unordered_set<Label> *olabels = 0;
StateId nfinal = 0;
for (StateIterator< Fst<Arc> > siter(fst);
!siter.Done();
siter.Next()) {
StateId s = siter.Value();
Arc prev_arc;
// Create these only if we need to
if (mask & (kIDeterministic | kNonIDeterministic))
ilabels = new unordered_set<Label>;
if (mask & (kODeterministic | kNonODeterministic))
olabels = new unordered_set<Label>;
bool first_arc = true;
for (ArcIterator< Fst<Arc> > aiter(fst, s);
!aiter.Done();
aiter.Next()) {
const Arc &arc =aiter.Value();
if (ilabels && ilabels->find(arc.ilabel) != ilabels->end()) {
comp_props |= kNonIDeterministic;
comp_props &= ~kIDeterministic;
}
if (olabels && olabels->find(arc.olabel) != olabels->end()) {
comp_props |= kNonODeterministic;
comp_props &= ~kODeterministic;
}
if (arc.ilabel != arc.olabel) {
comp_props |= kNotAcceptor;
comp_props &= ~kAcceptor;
}
if (arc.ilabel == 0 && arc.olabel == 0) {
comp_props |= kEpsilons;
comp_props &= ~kNoEpsilons;
}
if (arc.ilabel == 0) {
comp_props |= kIEpsilons;
comp_props &= ~kNoIEpsilons;
}
if (arc.olabel == 0) {
comp_props |= kOEpsilons;
comp_props &= ~kNoOEpsilons;
}
if (!first_arc) {
if (arc.ilabel < prev_arc.ilabel) {
comp_props |= kNotILabelSorted;
comp_props &= ~kILabelSorted;
}
if (arc.olabel < prev_arc.olabel) {
comp_props |= kNotOLabelSorted;
comp_props &= ~kOLabelSorted;
}
}
if (arc.weight != Weight::One() && arc.weight != Weight::Zero()) {
comp_props |= kWeighted;
comp_props &= ~kUnweighted;
}
if (arc.nextstate <= s) {
comp_props |= kNotTopSorted;
comp_props &= ~kTopSorted;
}
if (arc.nextstate != s + 1) {
comp_props |= kNotString;
comp_props &= ~kString;
}
prev_arc = arc;
first_arc = false;
if (ilabels)
ilabels->insert(arc.ilabel);
if (olabels)
olabels->insert(arc.olabel);
}
if (nfinal > 0) { // final state not last
comp_props |= kNotString;
comp_props &= ~kString;
}
Weight final = fst.Final(s);
if (final != Weight::Zero()) { // final state
if (final != Weight::One()) {
comp_props |= kWeighted;
comp_props &= ~kUnweighted;
}
++nfinal;
} else { // non-final state
if (fst.NumArcs(s) != 1) {
comp_props |= kNotString;
comp_props &= ~kString;
}
}
delete ilabels;
delete olabels;
}
if (fst.Start() != kNoStateId && fst.Start() != 0) {
comp_props |= kNotString;
comp_props &= ~kString;
}
}
*known = KnownProperties(comp_props);
return comp_props;
}
// This is a wrapper around ComputeProperties that will cause a fatal
// error if the stored properties and the computed properties are
// incompatible when 'FLAGS_fst_verify_properties' is true. This
// routine is seldom called directly; instead it is used to implement
// fst.Properties(mask, true).
template<class Arc>
uint64 TestProperties(const Fst<Arc> &fst, uint64 mask, uint64 *known) {
if (FLAGS_fst_verify_properties) {
uint64 stored_props = fst.Properties(kFstProperties, false);
uint64 computed_props = ComputeProperties(fst, mask, known, false);
if (!CompatProperties(stored_props, computed_props))
LOG(FATAL) << "TestProperties: stored Fst properties incorrect"
<< " (stored: props1, computed: props2)";
return computed_props;
} else {
return ComputeProperties(fst, mask, known, true);
}
}
} // namespace fst
#endif // FST_LIB_TEST_PROPERTIES_H__