path: root/src/mongo/db/matcher/expression_leaf.cpp

// expression_leaf.cpp

/**
 *    Copyright (C) 2013 10gen Inc.
 *
 *    This program is free software: you can redistribute it and/or  modify
 *    it under the terms of the GNU Affero General Public License, version 3,
 *    as published by the Free Software Foundation.
 *
 *    This program is distributed in the hope that it will be useful,
 *    but WITHOUT ANY WARRANTY; without even the implied warranty of
 *    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 *    GNU Affero General Public License for more details.
 *
 *    You should have received a copy of the GNU Affero General Public License
 *    along with this program.  If not, see <http://www.gnu.org/licenses/>.
 *
 *    As a special exception, the copyright holders give permission to link the
 *    code of portions of this program with the OpenSSL library under certain
 *    conditions as described in each individual source file and distribute
 *    linked combinations including the program with the OpenSSL library. You
 *    must comply with the GNU Affero General Public License in all respects for
 *    all of the code used other than as permitted herein. If you modify file(s)
 *    with this exception, you may extend this exception to your version of the
 *    file(s), but you are not obligated to do so. If you do not wish to do so,
 *    delete this exception statement from your version. If you delete this
 *    exception statement from all source files in the program, then also delete
 *    it in the license file.
 */

#include "mongo/db/matcher/expression_leaf.h"

#include <cmath>
#include <pcrecpp.h>

#include "mongo/bson/bsonobj.h"
#include "mongo/bson/bsonmisc.h"
#include "mongo/db/field_ref.h"
#include "mongo/db/jsobj.h"
#include "mongo/db/matcher/path.h"
#include "mongo/stdx/memory.h"

namespace mongo {

Status LeafMatchExpression::initPath(StringData path) {
    _path = path;
    return _elementPath.init(_path);
}


bool LeafMatchExpression::matches(const MatchableDocument* doc, MatchDetails* details) const {
    MatchableDocument::IteratorHolder cursor(doc, &_elementPath);
    while (cursor->more()) {
        ElementIterator::Context e = cursor->next();
        if (!matchesSingleElement(e.element()))
            continue;
        if (details && details->needRecord() && !e.arrayOffset().eoo()) {
            details->setElemMatchKey(e.arrayOffset().fieldName());
        }
        return true;
    }
    return false;
}

// -------------

bool ComparisonMatchExpression::equivalent(const MatchExpression* other) const {
    if (other->matchType() != matchType())
        return false;
    const ComparisonMatchExpression* realOther =
        static_cast<const ComparisonMatchExpression*>(other);

    return path() == realOther->path() && _rhs.valuesEqual(realOther->_rhs);
}


Status ComparisonMatchExpression::init(StringData path, const BSONElement& rhs) {
    _rhs = rhs;

    if (rhs.eoo()) {
        return Status(ErrorCodes::BadValue, "need a real operand");
    }

    if (rhs.type() == Undefined) {
        return Status(ErrorCodes::BadValue, "cannot compare to undefined");
    }

    switch (matchType()) {
        case LT:
        case LTE:
        case EQ:
        case GT:
        case GTE:
            break;
        default:
            return Status(ErrorCodes::BadValue, "bad match type for ComparisonMatchExpression");
    }

    return initPath(path);
}


bool ComparisonMatchExpression::matchesSingleElement(const BSONElement& e) const {
    // log() << "\t ComparisonMatchExpression e: " << e << " _rhs: " << _rhs << "\n"
    //<< toString() << std::endl;

    if (e.canonicalType() != _rhs.canonicalType()) {
        // some special cases
        //  jstNULL and undefined are treated the same
        if (e.canonicalType() + _rhs.canonicalType() == 5) {
            return matchType() == EQ || matchType() == LTE || matchType() == GTE;
        }

        if (_rhs.type() == MaxKey || _rhs.type() == MinKey) {
            return matchType() != EQ;
        }

        return false;
    }

    // Special case handling for NaN. NaN is equal to NaN but
    // otherwise always compares to false.
    if (std::isnan(e.numberDouble()) || std::isnan(_rhs.numberDouble())) {
        bool bothNaN = std::isnan(e.numberDouble()) && std::isnan(_rhs.numberDouble());
        switch (matchType()) {
            case LT:
                return false;
            case LTE:
                return bothNaN;
            case EQ:
                return bothNaN;
            case GT:
                return false;
            case GTE:
                return bothNaN;
            default:
                // This is a comparison match expression, so it must be either
                // a $lt, $lte, $gt, $gte, or equality expression.
                fassertFailed(17448);
        }
    }

    int x = compareElementValues(e, _rhs);

    // log() << "\t\t" << x << endl;

    switch (matchType()) {
        case LT:
            return x < 0;
        case LTE:
            return x <= 0;
        case EQ:
            return x == 0;
        case GT:
            return x > 0;
        case GTE:
            return x >= 0;
        default:
            // This is a comparison match expression, so it must be either
            // a $lt, $lte, $gt, $gte, or equality expression.
            fassertFailed(16828);
    }
}

void ComparisonMatchExpression::debugString(StringBuilder& debug, int level) const {
    _debugAddSpace(debug, level);
    debug << path() << " ";
    switch (matchType()) {
        case LT:
            debug << "$lt";
            break;
        case LTE:
            debug << "$lte";
            break;
        case EQ:
            debug << "==";
            break;
        case GT:
            debug << "$gt";
            break;
        case GTE:
            debug << "$gte";
            break;
        default:
            debug << " UNKNOWN - should be impossible";
            break;
    }
    debug << " " << _rhs.toString(false);

    MatchExpression::TagData* td = getTag();
    if (NULL != td) {
        debug << " ";
        td->debugString(&debug);
    }

    debug << "\n";
}

void ComparisonMatchExpression::toBSON(BSONObjBuilder* out) const {
    string opString = "";
    switch (matchType()) {
        case LT:
            opString = "$lt";
            break;
        case LTE:
            opString = "$lte";
            break;
        case EQ:
            opString = "$eq";
            break;
        case GT:
            opString = "$gt";
            break;
        case GTE:
            opString = "$gte";
            break;
        default:
            opString = " UNKNOWN - should be impossible";
            break;
    }

    out->append(path(), BSON(opString << _rhs));
}

// ---------------

// TODO: move
inline pcrecpp::RE_Options flags2options(const char* flags) {
    pcrecpp::RE_Options options;
    options.set_utf8(true);
    while (flags && *flags) {
        if (*flags == 'i')
            options.set_caseless(true);
        else if (*flags == 'm')
            options.set_multiline(true);
        else if (*flags == 'x')
            options.set_extended(true);
        else if (*flags == 's')
            options.set_dotall(true);
        flags++;
    }
    return options;
}

RegexMatchExpression::RegexMatchExpression() : LeafMatchExpression(REGEX) {}

RegexMatchExpression::~RegexMatchExpression() {}

bool RegexMatchExpression::equivalent(const MatchExpression* other) const {
    if (matchType() != other->matchType())
        return false;

    const RegexMatchExpression* realOther = static_cast<const RegexMatchExpression*>(other);
    return path() == realOther->path() && _regex == realOther->_regex &&
        _flags == realOther->_flags;
}


Status RegexMatchExpression::init(StringData path, const BSONElement& e) {
    if (e.type() != RegEx)
        return Status(ErrorCodes::BadValue, "regex not a regex");
    return init(path, e.regex(), e.regexFlags());
}


Status RegexMatchExpression::init(StringData path, StringData regex, StringData options) {
    if (regex.size() > MaxPatternSize) {
        return Status(ErrorCodes::BadValue, "Regular expression is too long");
    }

    _regex = regex.toString();
    _flags = options.toString();
    _re.reset(new pcrecpp::RE(_regex.c_str(), flags2options(_flags.c_str())));

    return initPath(path);
}

bool RegexMatchExpression::matchesSingleElement(const BSONElement& e) const {
    // log() << "RegexMatchExpression::matchesSingleElement _regex: " << _regex << " e: " << e <<
    // std::endl;
    switch (e.type()) {
        case String:
        case Symbol:
            // TODO
            // if (rm._prefix.empty())
            return _re->PartialMatch(e.valuestr());
        // else
        // return !strncmp(e.valuestr(), rm._prefix.c_str(), rm._prefix.size());
        case RegEx:
            return _regex == e.regex() && _flags == e.regexFlags();
        default:
            return false;
    }
}

void RegexMatchExpression::debugString(StringBuilder& debug, int level) const {
    _debugAddSpace(debug, level);
    debug << path() << " regex /" << _regex << "/" << _flags;

    MatchExpression::TagData* td = getTag();
    if (NULL != td) {
        debug << " ";
        td->debugString(&debug);
    }
    debug << "\n";
}

void RegexMatchExpression::toBSON(BSONObjBuilder* out) const {
    out->appendRegex(path(), _regex, _flags);
}

void RegexMatchExpression::shortDebugString(StringBuilder& debug) const {
    debug << "/" << _regex << "/" << _flags;
}

// ---------

Status ModMatchExpression::init(StringData path, int divisor, int remainder) {
    if (divisor == 0)
        return Status(ErrorCodes::BadValue, "divisor cannot be 0");
    _divisor = divisor;
    _remainder = remainder;
    return initPath(path);
}

bool ModMatchExpression::matchesSingleElement(const BSONElement& e) const {
    if (!e.isNumber())
        return false;
    return e.numberLong() % _divisor == _remainder;
}

void ModMatchExpression::debugString(StringBuilder& debug, int level) const {
    _debugAddSpace(debug, level);
    debug << path() << " mod " << _divisor << " % x == " << _remainder;
    MatchExpression::TagData* td = getTag();
    if (NULL != td) {
        debug << " ";
        td->debugString(&debug);
    }
    debug << "\n";
}

void ModMatchExpression::toBSON(BSONObjBuilder* out) const {
    out->append(path(), BSON("$mod" << BSON_ARRAY(_divisor << _remainder)));
}

bool ModMatchExpression::equivalent(const MatchExpression* other) const {
    if (matchType() != other->matchType())
        return false;

    const ModMatchExpression* realOther = static_cast<const ModMatchExpression*>(other);
    return path() == realOther->path() && _divisor == realOther->_divisor &&
        _remainder == realOther->_remainder;
}


// ------------------

Status ExistsMatchExpression::init(StringData path) {
    return initPath(path);
}

bool ExistsMatchExpression::matchesSingleElement(const BSONElement& e) const {
    return !e.eoo();
}

void ExistsMatchExpression::debugString(StringBuilder& debug, int level) const {
    _debugAddSpace(debug, level);
    debug << path() << " exists";
    MatchExpression::TagData* td = getTag();
    if (NULL != td) {
        debug << " ";
        td->debugString(&debug);
    }
    debug << "\n";
}

void ExistsMatchExpression::toBSON(BSONObjBuilder* out) const {
    out->append(path(), BSON("$exists" << true));
}

bool ExistsMatchExpression::equivalent(const MatchExpression* other) const {
    if (matchType() != other->matchType())
        return false;

    const ExistsMatchExpression* realOther = static_cast<const ExistsMatchExpression*>(other);
    return path() == realOther->path();
}


// ----

Status TypeMatchExpression::init(StringData path, int type) {
    _path = path;
    _type = type;
    return _elementPath.init(_path);
}

bool TypeMatchExpression::matchesSingleElement(const BSONElement& e) const {
    return e.type() == _type;
}

bool TypeMatchExpression::matches(const MatchableDocument* doc, MatchDetails* details) const {
    MatchableDocument::IteratorHolder cursor(doc, &_elementPath);
    while (cursor->more()) {
        ElementIterator::Context e = cursor->next();

        // In the case where _elementPath is referring to an array,
        // $type should match elements of that array only.
        // outerArray() helps to identify elements of the array
        // and the containing array itself.
        // This matters when we are looking for {$type: Array}.
        // Example (_elementPath refers to field 'a' and _type is Array):
        // a : [        // outer array. should not match
        //     123,     // inner array
        //     [ 456 ], // inner array. should match
        //     ...
        // ]
        if (_type == mongo::Array && e.outerArray()) {
            continue;
        }

        if (!matchesSingleElement(e.element())) {
            continue;
        }

        if (details && details->needRecord() && !e.arrayOffset().eoo()) {
            details->setElemMatchKey(e.arrayOffset().fieldName());
        }
        return true;
    }
    return false;
}

void TypeMatchExpression::debugString(StringBuilder& debug, int level) const {
    _debugAddSpace(debug, level);
    debug << _path << " type: " << _type;
    MatchExpression::TagData* td = getTag();
    if (NULL != td) {
        debug << " ";
        td->debugString(&debug);
    }
    debug << "\n";
}

void TypeMatchExpression::toBSON(BSONObjBuilder* out) const {
    out->append(path(), BSON("$type" << _type));
}

bool TypeMatchExpression::equivalent(const MatchExpression* other) const {
    if (matchType() != other->matchType())
        return false;

    const TypeMatchExpression* realOther = static_cast<const TypeMatchExpression*>(other);
    return _path == realOther->_path && _type == realOther->_type;
}


// --------

ArrayFilterEntries::ArrayFilterEntries() {
    _hasNull = false;
    _hasEmptyArray = false;
}

ArrayFilterEntries::~ArrayFilterEntries() {
    for (unsigned i = 0; i < _regexes.size(); i++)
        delete _regexes[i];
    _regexes.clear();
}

Status ArrayFilterEntries::addEquality(const BSONElement& e) {
    if (e.type() == RegEx)
        return Status(ErrorCodes::BadValue, "ArrayFilterEntries equality cannot be a regex");

    if (e.type() == Undefined) {
        return Status(ErrorCodes::BadValue, "ArrayFilterEntries equality cannot be undefined");
    }

    if (e.type() == jstNULL) {
        _hasNull = true;
    }

    if (e.type() == Array && e.Obj().isEmpty())
        _hasEmptyArray = true;

    _equalities.insert(e);
    return Status::OK();
}

Status ArrayFilterEntries::addRegex(RegexMatchExpression* expr) {
    _regexes.push_back(expr);
    return Status::OK();
}

bool ArrayFilterEntries::equivalent(const ArrayFilterEntries& other) const {
    if (_hasNull != other._hasNull)
        return false;

    if (_regexes.size() != other._regexes.size())
        return false;
    for (unsigned i = 0; i < _regexes.size(); i++)
        if (!_regexes[i]->equivalent(other._regexes[i]))
            return false;

    return _equalities == other._equalities;
}

void ArrayFilterEntries::copyTo(ArrayFilterEntries& toFillIn) const {
    toFillIn._hasNull = _hasNull;
    toFillIn._hasEmptyArray = _hasEmptyArray;
    toFillIn._equalities = _equalities;
    for (unsigned i = 0; i < _regexes.size(); i++)
        toFillIn._regexes.push_back(
            static_cast<RegexMatchExpression*>(_regexes[i]->shallowClone().release()));
}

void ArrayFilterEntries::debugString(StringBuilder& debug) const {
    debug << "[ ";
    for (BSONElementSet::const_iterator it = _equalities.begin(); it != _equalities.end(); ++it) {
        debug << it->toString(false) << " ";
    }
    for (size_t i = 0; i < _regexes.size(); ++i) {
        _regexes[i]->shortDebugString(debug);
        debug << " ";
    }
    debug << "]";
}

void ArrayFilterEntries::toBSON(BSONArrayBuilder* out) const {
    for (BSONElementSet::const_iterator it = _equalities.begin(); it != _equalities.end(); ++it) {
        out->append(*it);
    }
    for (size_t i = 0; i < _regexes.size(); ++i) {
        BSONObjBuilder regexBob;
        _regexes[i]->toBSON(&regexBob);
        out->append(regexBob.obj().firstElement());
    }
    out->doneFast();
}

// -----------

Status InMatchExpression::init(StringData path) {
    return initPath(path);
}

bool InMatchExpression::_matchesRealElement(const BSONElement& e) const {
    if (_arrayEntries.contains(e))
        return true;

    for (unsigned i = 0; i < _arrayEntries.numRegexes(); i++) {
        if (_arrayEntries.regex(i)->matchesSingleElement(e))
            return true;
    }

    return false;
}

bool InMatchExpression::matchesSingleElement(const BSONElement& e) const {
    if (_arrayEntries.hasNull() && e.eoo())
        return true;

    if (_matchesRealElement(e))
        return true;

    /*
    if ( e.type() == Array ) {
        BSONObjIterator i( e.Obj() );
        while ( i.more() ) {
            BSONElement sub = i.next();
            if ( _matchesRealElement( sub ) )
                return true;
        }
    }
    */

    return false;
}

void InMatchExpression::debugString(StringBuilder& debug, int level) const {
    _debugAddSpace(debug, level);
    debug << path() << " $in ";
    _arrayEntries.debugString(debug);
    MatchExpression::TagData* td = getTag();
    if (NULL != td) {
        debug << " ";
        td->debugString(&debug);
    }
    debug << "\n";
}

void InMatchExpression::toBSON(BSONObjBuilder* out) const {
    BSONObjBuilder inBob(out->subobjStart(path()));
    BSONArrayBuilder arrBob(inBob.subarrayStart("$in"));
    _arrayEntries.toBSON(&arrBob);
    inBob.doneFast();
}

bool InMatchExpression::equivalent(const MatchExpression* other) const {
    if (matchType() != other->matchType())
        return false;
    const InMatchExpression* realOther = static_cast<const InMatchExpression*>(other);
    return path() == realOther->path() && _arrayEntries.equivalent(realOther->_arrayEntries);
}

std::unique_ptr<MatchExpression> InMatchExpression::shallowClone() const {
    std::unique_ptr<InMatchExpression> next = stdx::make_unique<InMatchExpression>();
    copyTo(next.get());
    if (getTag()) {
        next->setTag(getTag()->clone());
    }
    return std::move(next);
}

void InMatchExpression::copyTo(InMatchExpression* toFillIn) const {
    toFillIn->init(path());
    _arrayEntries.copyTo(toFillIn->_arrayEntries);
}
}