z3/src/muz/rel/rel_context.cpp

/*++
Copyright (c) 2012 Microsoft Corporation

Module Name:

    rel_context.cpp

Abstract:

    context for relational datalog engine.

Author:

    Nikolaj Bjorner (nbjorner) 2012-12-3.

Revision History:

    Extracted from dl_context

--*/


#include "muz/rel/rel_context.h"
#include "util/stopwatch.h"
#include "muz/base/dl_context.h"
#include "muz/rel/dl_compiler.h"
#include "muz/rel/dl_instruction.h"
#include "muz/rel/dl_mk_explanations.h"
#include "muz/transforms/dl_mk_magic_sets.h"
#include "muz/rel/dl_product_relation.h"
#include "muz/rel/dl_bound_relation.h"
#include "muz/rel/dl_interval_relation.h"
#include "muz/rel/karr_relation.h"
#include "muz/rel/dl_finite_product_relation.h"
#include "muz/rel/udoc_relation.h"
#include "muz/rel/check_relation.h"
#include "muz/rel/dl_lazy_table.h"
#include "muz/rel/dl_sparse_table.h"
#include "muz/rel/dl_table.h"
#include "muz/rel/dl_table_relation.h"
#include "muz/rel/aig_exporter.h"
#include "muz/rel/dl_mk_simple_joins.h"
#include "muz/rel/dl_mk_similarity_compressor.h"
#include "muz/transforms/dl_mk_unbound_compressor.h"
#include "muz/transforms/dl_mk_subsumption_checker.h"
#include "muz/transforms/dl_mk_coi_filter.h"
#include "muz/transforms/dl_mk_filter_rules.h"
#include "muz/transforms/dl_mk_rule_inliner.h"
#include "muz/transforms/dl_mk_interp_tail_simplifier.h"
#include "muz/transforms/dl_mk_bit_blast.h"
#include "muz/transforms/dl_mk_separate_negated_tails.h"
#include "ast/ast_util.h"


namespace datalog {

    class rel_context::scoped_query {
        context&  m_ctx;
        rule_set  m_rules;
        decl_set  m_preds;
        bool      m_was_closed;                        

    public:

        scoped_query(context& ctx):
            m_ctx(ctx),
            m_rules(ctx.get_rules()),
            m_preds(ctx.get_predicates()),
            m_was_closed(ctx.is_closed())
        {
            if (m_was_closed) {
                ctx.reopen();
            }
        }

        ~scoped_query() {
            m_ctx.ensure_opened();                                
            m_ctx.restrict_predicates(m_preds);
            m_ctx.replace_rules(m_rules);
            if (m_was_closed) {
                m_ctx.close();                                  
            }          
        }

        void reset() {        
            m_ctx.reopen();
            m_ctx.restrict_predicates(m_preds);
            m_ctx.replace_rules(m_rules);
            m_ctx.close();
        }
    };

    rel_context::rel_context(context& ctx)
        : rel_context_base(ctx.get_manager(), "datalog"), 
          m_context(ctx), 
          m(ctx.get_manager()),
          m_rmanager(ctx),
          m_answer(m), 
          m_last_result_relation(nullptr),
          m_ectx(ctx),
          m_sw(0) {

        // register plugins for builtin tables

        relation_manager& rm = get_rmanager();

        rm.register_plugin(alloc(sparse_table_plugin, rm));
        rm.register_plugin(alloc(hashtable_table_plugin, rm));
        rm.register_plugin(alloc(bitvector_table_plugin, rm));
        rm.register_plugin(lazy_table_plugin::mk_sparse(rm));

        // register plugins for builtin relations

        rm.register_plugin(alloc(bound_relation_plugin, rm));
        rm.register_plugin(alloc(interval_relation_plugin, rm));
        if (m_context.karr()) rm.register_plugin(alloc(karr_relation_plugin, rm));
        rm.register_plugin(alloc(udoc_plugin, rm));
        rm.register_plugin(alloc(check_relation_plugin, rm));
    }

    rel_context::~rel_context() {
        if (m_last_result_relation) {
            m_last_result_relation->deallocate();
            m_last_result_relation = nullptr;
        }        
    }

    lbool rel_context::saturate() {
        scoped_query sq(m_context);
        return saturate(sq);
    }

    lbool rel_context::saturate(scoped_query& sq) {
        m_context.ensure_closed();        
        unsigned remaining_time_limit = m_context.soft_timeout();
        unsigned restart_time = m_context.initial_restart_timeout();
        bool time_limit = remaining_time_limit != 0;
                        
        instruction_block termination_code;

        lbool result;

        TRACE("dl", m_context.display(tout););

        while (true) {
            m_ectx.reset();
            m_code.reset();
            termination_code.reset();
            m_context.ensure_closed();
            transform_rules();
            if (m_context.canceled()) {
                TRACE("dl", tout << "canceled\n";);
                result = l_undef;
                break;
            }
            TRACE("dl", m_context.display(tout););
            //IF_VERBOSE(3, m_context.display_smt2(0,0,verbose_stream()););

            if (m_context.print_aig().is_non_empty_string()) {
                const char *filename = m_context.print_aig().bare_str();
                aig_exporter aig(m_context.get_rules(), get_context(), &m_table_facts);
                std::ofstream strm(filename, std::ios_base::binary);
                aig(strm);
                exit(0);
            }

            ::stopwatch sw;
            sw.start();

            compiler::compile(m_context, m_context.get_rules(), m_code, termination_code);

            bool timeout_after_this_round = time_limit && (restart_time==0 || remaining_time_limit<=restart_time);

            if (time_limit || restart_time!=0) {
                unsigned timeout = time_limit ? (restart_time!=0) ? 
                    std::min(remaining_time_limit, restart_time)
                    : remaining_time_limit : restart_time;
                m_ectx.set_timelimit(timeout);
            }

            bool early_termination = !m_code.perform(m_ectx);
            m_ectx.reset_timelimit();
            VERIFY( termination_code.perform(m_ectx) || m_context.canceled());

            m_code.process_all_costs();
            sw.stop();
            m_sw += sw.get_seconds();


            IF_VERBOSE(10, m_ectx.report_big_relations(1000, verbose_stream()););

            if (m_context.canceled()) {
                TRACE("dl", tout << "canceled\n";);
                result = l_undef;
                break;
            }
            if (!early_termination) {
                m_context.set_status(OK);
                result = l_true;
                break;
            }
            if (memory::above_high_watermark()) {
                m_context.set_status(MEMOUT);
                result = l_undef;
                break;
            }
            if (timeout_after_this_round) {
                m_context.set_status(TIMEOUT);
                TRACE("dl", tout << "timeout\n";);
                result = l_undef;
                break;
            }
            SASSERT(restart_time != 0);
            if (time_limit) {
                SASSERT(remaining_time_limit>restart_time);
                remaining_time_limit -= restart_time;
            }
            uint64_t new_restart_time = static_cast<uint64_t>(restart_time)*m_context.initial_restart_timeout();
            if (new_restart_time > UINT_MAX) {
                restart_time = UINT_MAX;
            }
            else {
                restart_time = static_cast<unsigned>(new_restart_time);
            }
            sq.reset();
        }
        m_context.record_transformed_rules();
        TRACE("dl", display_profile(tout););
        return result;
    }
 
    lbool rel_context::query(unsigned num_rels, func_decl * const* rels) {
        setup_default_relation();
        get_rmanager().reset_saturated_marks();
        scoped_query _scoped_query(m_context);
        for (unsigned i = 0; i < num_rels; ++i) {
            m_context.set_output_predicate(rels[i]);
        }
        m_context.close();
        reset_negated_tables();
        lbool res = saturate(_scoped_query);

        switch(res) {
        case l_true: {
            const rule_set& rules = m_context.get_rules();
            expr_ref_vector ans(m);
            expr_ref e(m);
            bool some_non_empty = num_rels == 0;
            bool is_approx = false;
            for (unsigned i = 0; i < num_rels; ++i) {
                func_decl* q = rules.get_pred(rels[i]);
                relation_base& rel = get_relation(q);
                if (!rel.empty()) {
                    some_non_empty = true;
                }
                if (!rel.is_precise()) {
                    is_approx = true;
                }
                rel.to_formula(e);
#if 0
                // Alternative format: 
                // List the signature of the relation as 
                // part of the answer.
                expr_ref_vector args(m);
                for (unsigned j = 0; j < q->get_arity(); ++j) {
                    args.push_back(m.mk_var(j, q->get_domain(j)));
                }
                e = m.mk_implies(m.mk_app(q, args.size(), args.c_ptr()), e);
#endif
                ans.push_back(e);
            }
            SASSERT(!m_last_result_relation);
            if (some_non_empty) {
                m_answer = mk_and(m, ans.size(), ans.c_ptr());
                if (is_approx) {
                    TRACE("dl", tout << "approx\n";);
                    res = l_undef;
                    m_context.set_status(APPROX);
                }
            }
            else {
                m_answer = m.mk_false();
                res = l_false;
            }
            break;
        }            
        case l_false:
            m_answer = m.mk_false();
            break;
        case l_undef:
            TRACE("dl", tout << "saturation in undef\n";);
            break;
        }
        return res;
    }

    void rel_context::transform_rules() {
        rule_transformer transf(m_context);
        transf.register_plugin(alloc(mk_coi_filter, m_context));
        transf.register_plugin(alloc(mk_filter_rules, m_context));        
        transf.register_plugin(alloc(mk_simple_joins, m_context));
        if (m_context.unbound_compressor()) {
            transf.register_plugin(alloc(mk_unbound_compressor, m_context));
        }
        if (m_context.similarity_compressor()) {
            transf.register_plugin(alloc(mk_similarity_compressor, m_context)); 
        }
        transf.register_plugin(alloc(mk_rule_inliner, m_context));
        transf.register_plugin(alloc(mk_interp_tail_simplifier, m_context));
        transf.register_plugin(alloc(mk_separate_negated_tails, m_context));

        if (m_context.xform_bit_blast()) {
            transf.register_plugin(alloc(mk_bit_blast, m_context, 22000));
            transf.register_plugin(alloc(mk_interp_tail_simplifier, m_context, 21000));
        }
        m_context.transform_rules(transf);
    }

    bool rel_context::try_get_size(func_decl* p, unsigned& rel_size) const {
        relation_base* rb = try_get_relation(p);
        if (rb && rb->knows_exact_size()) {
            rel_size = rb->get_size_estimate_rows();
            return true;
        }
        else {
            return false;
        }
    }

    lbool rel_context::query(expr* query) {
        setup_default_relation();
        get_rmanager().reset_saturated_marks();
        scoped_query _scoped_query(m_context);
        rule_manager& rm = m_context.get_rule_manager();
        func_decl_ref query_pred(m);
        try {
            query_pred = rm.mk_query(query, m_context.get_rules());
        }
        catch (default_exception& exn) {
            m_context.set_status(INPUT_ERROR);
            throw exn;
        }
        
        m_context.close();
        reset_negated_tables();
        
        if (m_context.generate_explanations()) {
            m_context.transform_rules(alloc(mk_explanations, m_context));
        }

        query_pred = m_context.get_rules().get_pred(query_pred);

        if (m_context.magic_sets_for_queries()) {
            m_context.transform_rules(alloc(mk_magic_sets, m_context, query_pred));
            query_pred = m_context.get_rules().get_pred(query_pred);
        }

        lbool res = saturate(_scoped_query);
        
        query_pred = m_context.get_rules().get_pred(query_pred);

        if (res != l_undef) {            
            m_last_result_relation = get_relation(query_pred).clone();
            if (m_last_result_relation->empty()) {
                res = l_false;
                m_answer = m.mk_false();
            }
            else {
                m_last_result_relation->to_formula(m_answer);
                if (!m_last_result_relation->is_precise()) {
                    m_context.set_status(APPROX);
                    TRACE("dl", tout << "approx\n";);
                    res = l_undef;
                }
            }
        }
        
        return res;
    }

    void rel_context::reset_negated_tables() {
        const rule_set& all_rules = m_context.get_rules();
        rule_set::pred_set_vector const & pred_sets = all_rules.get_strats();
        bool non_empty = false;
        for (unsigned i = 1; i < pred_sets.size(); ++i) {
            func_decl_set::iterator it = pred_sets[i]->begin(), end = pred_sets[i]->end();
            for (; it != end; ++it) {
                func_decl* pred = *it;
                relation_base & rel = get_relation(pred);
                if (!rel.fast_empty()) {
                    non_empty = true;
                    break;
                }
            }
        }
        if (!non_empty) {
            return;
        }
        // collect predicates that depend on negation.
        func_decl_set depends_on_negation;
        for (unsigned i = 1; i < pred_sets.size(); ++i) {
            bool change = true;
            while (change) {
                change = false;
                func_decl_set::iterator it = pred_sets[i]->begin(), end = pred_sets[i]->end();
                for (; it != end; ++it) {
                    func_decl* pred = *it;
                    if (depends_on_negation.contains(pred)) {
                        continue;
                    }
                    rule_vector const& rules = all_rules.get_predicate_rules(pred);
                    bool inserted = false;
                    for (unsigned j = 0; !inserted && j < rules.size(); ++j) {
                        rule* r = rules[j];
                        unsigned psz = r->get_positive_tail_size();
                        unsigned tsz = r->get_uninterpreted_tail_size();
                        if (psz < tsz) {
                            depends_on_negation.insert(pred);
                            change = true;
                            inserted = true;
                        }
                        for (unsigned k = 0; !inserted && k < tsz; ++k) {
                            func_decl* tail_decl = r->get_tail(k)->get_decl();
                            if (depends_on_negation.contains(tail_decl)) {
                                depends_on_negation.insert(pred);
                                change   = true;
                                inserted = true;
                            }
                        }
                    }
                }
            }
        }        
        func_decl_set::iterator it = depends_on_negation.begin(), end = depends_on_negation.end();
        for (; it != end; ++it) {
            func_decl* pred = *it;
            relation_base & rel = get_relation(pred);
            
            if (!rel.empty()) {
                TRACE("dl", tout << "Resetting: " << mk_ismt2_pp(pred, m) << "\n";);
                rel.reset();
            }
        }
    }

    void rel_context::restrict_predicates(func_decl_set const& predicates) {
        get_rmanager().restrict_predicates(predicates);
    }

    relation_base & rel_context::get_relation(func_decl * pred)  { return get_rmanager().get_relation(pred); }
    relation_base * rel_context::try_get_relation(func_decl * pred) const { return get_rmanager().try_get_relation(pred); }

    expr_ref rel_context::try_get_formula(func_decl* p) const {
        expr_ref result(m);        
        relation_base* rb = try_get_relation(p);
        if (rb) {
            rb->to_formula(result);
        }
        return result;
    }

    bool rel_context::is_empty_relation(func_decl* pred) const {
        relation_base* rb = try_get_relation(pred);
        return !rb || rb->fast_empty();
    }

    relation_manager & rel_context::get_rmanager() { return m_rmanager; }

    const relation_manager & rel_context::get_rmanager() const { return m_rmanager; }

    bool rel_context::output_profile() const { return m_context.output_profile(); }


    void rel_context::set_predicate_representation(func_decl * pred, unsigned relation_name_cnt, 
                                                   symbol const * relation_names) {

        TRACE("dl", 
              tout << pred->get_name() << ": ";
              for (unsigned i = 0; i < relation_name_cnt; ++i) {
                  tout << relation_names[i] << " ";
              }
              tout << "\n";
              );

        relation_manager & rmgr = get_rmanager();
        family_id target_kind = null_family_id;
        switch (relation_name_cnt) {
        case 0: 
            return;
        case 1:
            target_kind = get_ordinary_relation_plugin(relation_names[0]).get_kind();
            break;
        default: {
            rel_spec rel_kinds; // kinds of plugins that are not table plugins
            family_id rel_kind;           // the aggregate kind of non-table plugins
            for (unsigned i = 0; i < relation_name_cnt; i++) {
                relation_plugin & p = get_ordinary_relation_plugin(relation_names[i]);
                rel_kinds.push_back(p.get_kind());                
            }
            if (rel_kinds.size() == 1) {
                rel_kind = rel_kinds[0];
            }
            else {
                relation_signature rel_sig;
                rmgr.from_predicate(pred, rel_sig);
                product_relation_plugin & prod_plugin = product_relation_plugin::get_plugin(rmgr);
                rel_kind = prod_plugin.get_relation_kind(rel_sig, rel_kinds);
            }
            target_kind = rel_kind;
            break;
        }       
        }

        SASSERT(target_kind != null_family_id);
        get_rmanager().set_predicate_kind(pred, target_kind);
    }


    void rel_context::setup_default_relation() {
        if (m_context.default_relation() == symbol("doc")) {
            m_context.set_unbound_compressor(false);
        }
    }

    relation_plugin & rel_context::get_ordinary_relation_plugin(symbol relation_name) {
        relation_plugin * plugin = get_rmanager().get_relation_plugin(relation_name);
        if (!plugin) {
            std::stringstream sstm;
            sstm << "relation plugin " << relation_name << " does not exist";
            throw default_exception(sstm.str());
        }
        if (plugin->is_product_relation()) {
            throw default_exception("cannot request product relation directly");
        }
        if (plugin->is_sieve_relation()) {
            throw default_exception("cannot request sieve relation directly");
        }
        if (plugin->is_finite_product_relation()) {
            throw default_exception("cannot request finite product relation directly");
        }
        return *plugin;
    }

    bool rel_context::result_contains_fact(relation_fact const& f) {
        SASSERT(m_last_result_relation);
        return m_last_result_relation->contains_fact(f);
    }
 
    void rel_context::add_fact(func_decl* pred, relation_fact const& fact) {
        get_rmanager().reset_saturated_marks();
        get_relation(pred).add_fact(fact);
        if (!m_context.print_aig().is_null()) {
            m_table_facts.push_back(std::make_pair(pred, fact));
        }
    }

    void rel_context::add_fact(func_decl* pred, table_fact const& fact) {
        get_rmanager().reset_saturated_marks();
        relation_base & rel0 = get_relation(pred);
        if (rel0.from_table()) {
            table_relation & rel = static_cast<table_relation &>(rel0);
            rel.add_table_fact(fact);
            // TODO: table facts?
        }
        else {
            relation_fact rfact(m);
            for (unsigned i = 0; i < fact.size(); ++i) {
                rfact.push_back(m_context.get_decl_util().mk_numeral(fact[i], pred->get_domain()[i]));
            }
            add_fact(pred, rfact);
        }
    }

    bool rel_context::has_facts(func_decl * pred) const {
        relation_base* r = try_get_relation(pred);
        return r && !r->empty();
    }

    void rel_context::store_relation(func_decl * pred, relation_base * rel) {
        get_rmanager().store_relation(pred, rel);
    }

    void rel_context::collect_statistics(statistics& st) const {
        st.update("saturation time", m_sw);
        m_code.collect_statistics(st);
        m_ectx.collect_statistics(st);
    }

    void rel_context::updt_params() {
        if (m_context.check_relation() != symbol::null &&
            m_context.check_relation() != symbol("null")) {
            symbol cr("check_relation");
            m_context.set_default_relation(cr);
            relation_plugin* p = get_rmanager().get_relation_plugin(cr);
            SASSERT(p);
            check_relation_plugin* p1 = dynamic_cast<check_relation_plugin*>(p);
            relation_plugin* p2 = get_rmanager().get_relation_plugin(m_context.check_relation());
            SASSERT(p2);
            SASSERT(p1 != p2);
            p1->set_plugin(p2);
            get_rmanager().set_favourite_plugin(p1);
            if (m_context.check_relation() == symbol("doc")) {
                m_context.set_unbound_compressor(false);
            }
        }
    }

    void rel_context::inherit_predicate_kind(func_decl* new_pred, func_decl* orig_pred) {
        if (orig_pred) {
            family_id target_kind = get_rmanager().get_requested_predicate_kind(orig_pred);            
            if (target_kind != null_family_id) {
                get_rmanager().set_predicate_kind(new_pred, target_kind);
            }
        }
    }

    void rel_context::display_output_facts(rule_set const& rules, std::ostream & out) const {
        get_rmanager().display_output_tables(rules, out);
    }

    void rel_context::display_facts(std::ostream& out) const {
        get_rmanager().display(out);
    }

    void rel_context::display_profile(std::ostream& out) {
        m_code.make_annotations(m_ectx);
        m_code.process_all_costs();  

        out << "Big relations\n";
        m_ectx.report_big_relations(1000, out);

        get_rmanager().display_relation_sizes(out);
    }


};