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z3/lib/dl_base.cpp
Leonardo de Moura e9eab22e5c Z3 sources
Signed-off-by: Leonardo de Moura <leonardo@microsoft.com>
2012-10-02 11:35:25 -07:00

491 lines
15 KiB
C++

/*++
Copyright (c) 2006 Microsoft Corporation
Module Name:
dl_base.cpp
Abstract:
<abstract>
Author:
Krystof Hoder (t-khoder) 2010-09-14.
Revision History:
--*/
#include"ast_pp.h"
#include"union_find.h"
#include"vector.h"
#include"dl_context.h"
#include"dl_base.h"
#include"bool_rewriter.h"
#include<sstream>
namespace datalog {
context & get_context_from_rel_manager(const relation_manager & rm) {
return rm.get_context();
}
ast_manager & get_ast_manager_from_rel_manager(const relation_manager & rm) {
return rm.get_context().get_manager();
}
#if DL_LEAK_HUNTING
void leak_guard_check(const symbol & s) {
}
#endif
void relation_signature::output(ast_manager & m, std::ostream & out) const {
unsigned sz=size();
out<<"(";
for(unsigned i=0; i<sz; i++) {
if(i) { out<<","; }
out<<ast_pp((*this)[i], m);
}
out<<")";
}
relation_fact::relation_fact(context & ctx) : app_ref_vector(ctx.get_manager()) {}
void relation_base::reset() {
ast_manager & m = get_plugin().get_ast_manager();
app_ref bottom_ref(m.mk_false(), m);
scoped_ptr<relation_mutator_fn> reset_fn =
get_manager().mk_filter_interpreted_fn(static_cast<relation_base &>(*this), bottom_ref);
if(!reset_fn) {
NOT_IMPLEMENTED_YET();
}
(*reset_fn)(*this);
}
void table_signature::from_join(const table_signature & s1, const table_signature & s2, unsigned col_cnt,
const unsigned * cols1, const unsigned * cols2, table_signature & result) {
result.reset();
unsigned s1sz=s1.size();
unsigned s2sz=s2.size();
unsigned s1first_func=s1sz-s1.functional_columns();
unsigned s2first_func=s2sz-s2.functional_columns();
for(unsigned i=0; i<s1first_func; i++) {
result.push_back(s1[i]);
}
for(unsigned i=0; i<s2first_func; i++) {
result.push_back(s2[i]);
}
for(unsigned i=s1first_func; i<s1sz; i++) {
result.push_back(s1[i]);
}
for(unsigned i=s2first_func; i<s2sz; i++) {
result.push_back(s2[i]);
}
result.set_functional_columns(s1.functional_columns()+s2.functional_columns());
}
void table_signature::from_project(const table_signature & src, unsigned col_cnt,
const unsigned * removed_cols, table_signature & result) {
signature_base::from_project(src, col_cnt, removed_cols, result);
unsigned func_cnt = src.functional_columns();
if(removed_cols==0) {
result.set_functional_columns(func_cnt);
return;
}
unsigned first_src_fun = src.first_functional();
if(removed_cols[0]<first_src_fun) {
//if we remove at least one non-functional column, all the columns in the result are non-functional
result.set_functional_columns(0);
}
else {
//all columns we are removing are functional
SASSERT(func_cnt>=col_cnt);
result.set_functional_columns(func_cnt-col_cnt);
}
}
void table_signature::from_project_with_reduce(const table_signature & src, unsigned col_cnt,
const unsigned * removed_cols, table_signature & result) {
signature_base::from_project(src, col_cnt, removed_cols, result);
unsigned remaining_fun = src.functional_columns();
unsigned first_src_fun = src.first_functional();
for(int i=col_cnt-1; i>=0; i--) {
if(removed_cols[i]<first_src_fun) {
break;
}
remaining_fun--;
}
result.set_functional_columns(remaining_fun);
}
void table_signature::from_join_project(const table_signature & s1, const table_signature & s2,
unsigned joined_col_cnt, const unsigned * cols1, const unsigned * cols2, unsigned removed_col_cnt,
const unsigned * removed_cols, table_signature & result) {
table_signature aux;
from_join(s1, s2, joined_col_cnt, cols1, cols2, aux);
//after the join the column order is
//(non-functional of s1)(non-functional of s2)(functional of s1)(functional of s2)
if(s1.functional_columns()==0 && s2.functional_columns()==0) {
from_project(aux, removed_col_cnt, removed_cols, result);
SASSERT(result.functional_columns()==0);
return;
}
unsigned join_sig_sz = s1.size()+s2.size();
unsigned s1_first_func = s1.first_functional();
unsigned s2_first_func = s2.first_functional();
unsigned second_ofs = s1_first_func;
unsigned first_func_ofs = second_ofs + s2_first_func;
unsigned second_func_ofs = second_ofs + s1.functional_columns();
svector<unsigned> remaining_in_equivalence_class;
remaining_in_equivalence_class.resize(join_sig_sz, 0);
bool merging_rows_can_happen = false;
union_find_default_ctx uf_ctx;
union_find<> uf(uf_ctx); //the numbers in uf correspond to column indexes after the join
for(unsigned i=0; i<join_sig_sz; i++) {
unsigned v = uf.mk_var();
SASSERT(v==i);
}
for(unsigned i=0; i<joined_col_cnt; i++) {
unsigned idx1 = (s1_first_func>cols1[i]) ? cols1[i] : (first_func_ofs+cols1[i]-s1_first_func);
unsigned idx2 = (s2_first_func>cols2[i]) ? (second_ofs+cols2[i]) : (second_func_ofs+cols2[i]-s2_first_func);
uf.merge(idx1, idx2);
}
for(unsigned i=0; i<first_func_ofs; i++) { //we only count the non-functional columns
remaining_in_equivalence_class[uf.find(i)]++;
}
for(unsigned i=0; i<removed_col_cnt; i++) {
unsigned rc = removed_cols[i];
if(rc>=first_func_ofs) {
//removing functional columns won't make us merge rows
continue;
}
unsigned eq_class_idx = uf.find(rc);
if(remaining_in_equivalence_class[eq_class_idx]>1) {
remaining_in_equivalence_class[eq_class_idx]--;
}
else {
merging_rows_can_happen = true;
break;
}
}
if(merging_rows_can_happen) {
//this one marks all columns as non-functional
from_project(aux, removed_col_cnt, removed_cols, result);
SASSERT(result.functional_columns()==0);
}
else {
//this one preserves columns to be functional
from_project_with_reduce(aux, removed_col_cnt, removed_cols, result);
}
}
// -----------------------------------
//
// table_base
//
// -----------------------------------
//here we give generic implementation of table operations using iterators
bool table_base::empty() const {
return begin()==end();
}
void table_base::remove_facts(unsigned fact_cnt, const table_fact * facts) {
for(unsigned i=0; i<fact_cnt; i++) {
remove_fact(facts[i]);
}
}
void table_base::remove_facts(unsigned fact_cnt, const table_element * facts) {
for(unsigned i=0; i<fact_cnt; i++) {
remove_fact(facts + i*get_signature().size());
}
}
void table_base::reset() {
vector<table_fact> to_remove;
table_base::iterator it = begin();
table_base::iterator iend = end();
table_fact row;
for(; it!=iend; ++it) {
it->get_fact(row);
to_remove.append(row);
}
remove_facts(to_remove.size(), to_remove.c_ptr());
}
bool table_base::contains_fact(const table_fact & f) const {
iterator it = begin();
iterator iend = end();
table_fact row;
for(; it!=iend; ++it) {
it->get_fact(row);
if(vectors_equal(row, f)) {
return true;
}
}
return false;
}
bool table_base::fetch_fact(table_fact & f) const {
if(get_signature().functional_columns()==0) {
return contains_fact(f);
}
else {
unsigned sig_sz = get_signature().size();
unsigned non_func_cnt = sig_sz-get_signature().functional_columns();
table_base::iterator it = begin();
table_base::iterator iend = end();
table_fact row;
for(; it!=iend; ++it) {
it->get_fact(row);
bool differs = false;
for(unsigned i=0; i<non_func_cnt; i++) {
if(row[i]!=f[i]) {
differs = true;
}
}
if(differs) {
continue;
}
for(unsigned i=non_func_cnt; i<sig_sz; i++) {
f[i]=row[i];
}
return true;
}
return false;
}
}
bool table_base::suggest_fact(table_fact & f) {
if(get_signature().functional_columns()==0) {
if(contains_fact(f)) {
return false;
}
add_new_fact(f);
return true;
}
else {
if(fetch_fact(f)) {
return false;
}
add_new_fact(f);
return true;
}
}
void table_base::ensure_fact(const table_fact & f) {
if(get_signature().functional_columns()==0) {
add_fact(f);
}
else {
remove_fact(f);
add_fact(f);
}
}
table_base * table_base::clone() const {
table_base * res = get_plugin().mk_empty(get_signature());
iterator it = begin();
iterator iend = end();
table_fact row;
for(; it!=iend; ++it) {
it->get_fact(row);
res->add_new_fact(row);
}
return res;
}
table_base * table_base::complement(func_decl* p, const table_element * func_columns) const {
const table_signature & sig = get_signature();
SASSERT(sig.functional_columns()==0 || func_columns!=0);
table_base * res = get_plugin().mk_empty(sig);
table_fact fact;
fact.resize(sig.first_functional());
fact.append(sig.functional_columns(), func_columns);
if(sig.first_functional()==0) {
if(empty()) {
res->add_fact(fact);
}
return res;
}
if(sig.first_functional()!=1) { //now we support only tables with one non-functional column
NOT_IMPLEMENTED_YET();
}
uint64 upper_bound = get_signature()[0];
bool empty_table = empty();
if (upper_bound > (1 << 18)) {
std::ostringstream buffer;
buffer << "creating large table of size " << upper_bound;
if (p) buffer << " for relation " << p->get_name();
warning_msg(buffer.str().c_str());
}
for(table_element i=0; i<upper_bound; i++) {
fact[0]=i;
if(empty_table || !contains_fact(fact)) {
res->add_fact(fact);
}
}
return res;
#if 0
svector<unsigned> var_arg_indexes(arity);
var_arg_indexes.fill(0);
svector<unsigned> var_arg_domain_sizes = s;
unsigned var_cnt=var_arg_indexes.size();
table_fact fact;
fact.resize(arity);
fact.fill(0);
unsigned depth=arity;
while(true) {
if(depth==arity) {
SASSERT(!res->contains_fact(fact));
if(empty_table || !contains_fact(fact)) {
res->add_fact(fact);
}
depth--;
}
else if(fact[depth]==s[depth]-1) {
val_indexes[depth]=0;
if(depth==0) {
break;
}
depth--;
}
else {
SASSERT(val_indexes[depth]<var_arg_domain_sizes[depth]);
unsigned arg_idx = var_arg_indexes[depth];
unsigned val_idx = val_indexes[depth]++;
head_args[arg_idx]=ctx.get_arith().mk_numeral(rational(val_idx), true);
depth++;
}
}
return res;
#endif
}
void table_base::display(std::ostream & out) const {
out << "table with signature ";
print_container(get_signature(), out);
out << ":\n";
iterator it = begin();
iterator iend = end();
for(; it!=iend; ++it) {
const row_interface & r = *it;
r.display(out);
}
out << "\n";
}
class table_base::row_interface::fact_row_iterator : public table_base::row_iterator_core {
const row_interface & m_parent;
unsigned m_index;
protected:
virtual bool is_finished() const { return m_index==m_parent.size(); }
public:
fact_row_iterator(const row_interface & row, bool finished)
: m_parent(row), m_index(finished ? row.size() : 0) {}
virtual table_element operator*() {
SASSERT(!is_finished());
return m_parent[m_index];
}
virtual void operator++() {
m_index++;
SASSERT(m_index<=m_parent.size());
}
};
table_base::row_iterator table_base::row_interface::begin() const {
return row_iterator(alloc(fact_row_iterator, *this, false));
}
table_base::row_iterator table_base::row_interface::end() const {
return row_iterator(alloc(fact_row_iterator, *this, true));
}
void table_base::row_interface::get_fact(table_fact & result) const {
result.reset();
unsigned n=size();
for(unsigned i=0; i<n; i++) {
result.push_back((*this)[i]);
}
}
void table_base::row_interface::display(std::ostream & out) const {
table_fact fact;
get_fact(fact);
print_container(fact, out);
out << "\n";
}
void table_base::to_formula(relation_signature const& sig, expr_ref& fml) const {
// iterate over rows and build disjunction
ast_manager & m = fml.get_manager();
expr_ref_vector disjs(m);
expr_ref_vector conjs(m);
dl_decl_util util(m);
table_fact fact;
iterator it = begin();
iterator iend = end();
for(; it!=iend; ++it) {
const row_interface & r = *it;
r.get_fact(fact);
conjs.reset();
for (unsigned i = 0; i < fact.size(); ++i) {
conjs.push_back(m.mk_eq(m.mk_var(i, sig[i]), util.mk_numeral(fact[i], sig[i])));
}
switch(conjs.size()) {
case 0: disjs.push_back(m.mk_true()); break;
case 1: disjs.push_back(conjs[0].get()); break;
default: disjs.push_back(m.mk_and(conjs.size(), conjs.c_ptr())); break;
}
}
bool_rewriter(m).mk_or(disjs.size(), disjs.c_ptr(), fml);
}
}