1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 129 130 131 132 133 134 135 136 137 138 139 140 141 142 143 144 145 146 147 148 149 150 151 152 153 154 155 156 157 158 159 160 161 162 163 164 165 166 167 168 169 170 171 172 173 174 175 176 177 178 179 180 181 182 183 184 185 186 187 188 189 190 191 192 193 194 195 196 197 198 199 200 201 202 203 204 205 206 207 208 209 210 211 212 213 214 215 216 217 218 219 220 221 222 223
|
// queryutil.h
/* Copyright 2009 10gen Inc.
*
* 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.
*/
#pragma once
#include "jsobj.h"
namespace mongo {
struct FieldBound {
BSONElement bound_;
bool inclusive_;
bool operator==( const FieldBound &other ) const {
return bound_.woCompare( other.bound_ ) == 0 &&
inclusive_ == other.inclusive_;
}
};
struct FieldInterval {
FieldInterval(){}
FieldInterval( const BSONElement& e ){
lower_.bound_ = upper_.bound_ = e;
lower_.inclusive_ = upper_.inclusive_ = true;
}
FieldBound lower_;
FieldBound upper_;
bool valid() const {
int cmp = lower_.bound_.woCompare( upper_.bound_, false );
return ( cmp < 0 || ( cmp == 0 && lower_.inclusive_ && upper_.inclusive_ ) );
}
};
// range of a field's value that may be determined from query -- used to
// determine index limits
class FieldRange {
public:
FieldRange( const BSONElement &e = BSONObj().firstElement() , bool isNot=false , bool optimize=true );
const FieldRange &operator&=( const FieldRange &other );
const FieldRange &operator|=( const FieldRange &other );
BSONElement min() const { assert( !empty() ); return intervals_[ 0 ].lower_.bound_; }
BSONElement max() const { assert( !empty() ); return intervals_[ intervals_.size() - 1 ].upper_.bound_; }
bool minInclusive() const { assert( !empty() ); return intervals_[ 0 ].lower_.inclusive_; }
bool maxInclusive() const { assert( !empty() ); return intervals_[ intervals_.size() - 1 ].upper_.inclusive_; }
bool equality() const {
return
!empty() &&
min().woCompare( max(), false ) == 0 &&
maxInclusive() &&
minInclusive();
}
bool nontrivial() const {
return
! empty() &&
( minKey.firstElement().woCompare( min(), false ) != 0 ||
maxKey.firstElement().woCompare( max(), false ) != 0 );
}
bool empty() const { return intervals_.empty(); }
const vector< FieldInterval > &intervals() const { return intervals_; }
string getSpecial() const { return _special; }
private:
BSONObj addObj( const BSONObj &o );
vector< FieldInterval > intervals_;
vector< BSONObj > objData_;
string _special;
};
// implements query pattern matching, used to determine if a query is
// similar to an earlier query and should use the same plan
class QueryPattern {
public:
friend class FieldRangeSet;
enum Type {
Equality,
LowerBound,
UpperBound,
UpperAndLowerBound
};
// for testing only, speed unimportant
bool operator==( const QueryPattern &other ) const {
bool less = operator<( other );
bool more = other.operator<( *this );
assert( !( less && more ) );
return !( less || more );
}
bool operator!=( const QueryPattern &other ) const {
return !operator==( other );
}
bool operator<( const QueryPattern &other ) const {
map< string, Type >::const_iterator i = fieldTypes_.begin();
map< string, Type >::const_iterator j = other.fieldTypes_.begin();
while( i != fieldTypes_.end() ) {
if ( j == other.fieldTypes_.end() )
return false;
if ( i->first < j->first )
return true;
else if ( i->first > j->first )
return false;
if ( i->second < j->second )
return true;
else if ( i->second > j->second )
return false;
++i;
++j;
}
if ( j != other.fieldTypes_.end() )
return true;
return sort_.woCompare( other.sort_ ) < 0;
}
private:
QueryPattern() {}
void setSort( const BSONObj sort ) {
sort_ = normalizeSort( sort );
}
BSONObj static normalizeSort( const BSONObj &spec ) {
if ( spec.isEmpty() )
return spec;
int direction = ( spec.firstElement().number() >= 0 ) ? 1 : -1;
BSONObjIterator i( spec );
BSONObjBuilder b;
while( i.moreWithEOO() ) {
BSONElement e = i.next();
if ( e.eoo() )
break;
b.append( e.fieldName(), direction * ( ( e.number() >= 0 ) ? -1 : 1 ) );
}
return b.obj();
}
map< string, Type > fieldTypes_;
BSONObj sort_;
};
// ranges of fields' value that may be determined from query -- used to
// determine index limits
class FieldRangeSet {
public:
FieldRangeSet( const char *ns, const BSONObj &query , bool optimize=true );
const FieldRange &range( const char *fieldName ) const {
map< string, FieldRange >::const_iterator f = ranges_.find( fieldName );
if ( f == ranges_.end() )
return trivialRange();
return f->second;
}
int nNontrivialRanges() const {
int count = 0;
for( map< string, FieldRange >::const_iterator i = ranges_.begin(); i != ranges_.end(); ++i )
if ( i->second.nontrivial() )
++count;
return count;
}
const char *ns() const { return ns_; }
BSONObj query() const { return query_; }
// if fields is specified, order fields of returned object to match those of 'fields'
BSONObj simplifiedQuery( const BSONObj &fields = BSONObj() ) const;
bool matchPossible() const {
for( map< string, FieldRange >::const_iterator i = ranges_.begin(); i != ranges_.end(); ++i )
if ( i->second.empty() )
return false;
return true;
}
QueryPattern pattern( const BSONObj &sort = BSONObj() ) const;
BoundList indexBounds( const BSONObj &keyPattern, int direction ) const;
string getSpecial() const;
private:
void processOpElement( const char *fieldName, const BSONElement &f, bool isNot, bool optimize );
static FieldRange *trivialRange_;
static FieldRange &trivialRange();
mutable map< string, FieldRange > ranges_;
const char *ns_;
BSONObj query_;
};
/**
used for doing field limiting
*/
class FieldMatcher {
public:
FieldMatcher(bool include=false) : _include(include){}
void add( const BSONObj& o );
void append( BSONObjBuilder& b , const BSONElement& e ) const;
BSONObj getSpec() const;
private:
void add( const string& field, bool include );
void appendArray( BSONObjBuilder& b , const BSONObj& a ) const;
bool _include; // true if default at this level is to include
//TODO: benchmark vector<pair> vs map
typedef map<string, boost::shared_ptr<FieldMatcher> > FieldMap;
FieldMap _fields;
BSONObj _source;
};
/** returns a string that when used as a matcher, would match a super set of regex()
returns "" for complex regular expressions
used to optimize queries in some simple regex cases that start with '^'
if purePrefix != NULL, sets it to whether the regex can be converted to a range query
*/
string simpleRegex(const char* regex, const char* flags, bool* purePrefix=NULL);
/** returns the upper bound of a query that matches prefix */
string simpleRegexEnd( string prefix );
} // namespace mongo
|