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// @file bsonobj.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 <set>
#include <list>
#include <vector>
#include "util/builder.h"
#include "stringdata.h"
namespace mongo {
typedef set< BSONElement, BSONElementCmpWithoutField > BSONElementSet;
/**
C++ representation of a "BSON" object -- that is, an extended JSON-style
object in a binary representation.
See bsonspec.org.
Note that BSONObj's have a smart pointer capability built in -- so you can
pass them around by value. The reference counts used to implement this
do not use locking, so copying and destroying BSONObj's are not thread-safe
operations.
BSON object format:
\code
<unsigned totalSize> {<byte BSONType><cstring FieldName><Data>}* EOO
totalSize includes itself.
Data:
Bool: <byte>
EOO: nothing follows
Undefined: nothing follows
OID: an OID object
NumberDouble: <double>
NumberInt: <int32>
String: <unsigned32 strsizewithnull><cstring>
Date: <8bytes>
Regex: <cstring regex><cstring options>
Object: a nested object, leading with its entire size, which terminates with EOO.
Array: same as object
DBRef: <strlen> <cstring ns> <oid>
DBRef: a database reference: basically a collection name plus an Object ID
BinData: <int len> <byte subtype> <byte[len] data>
Code: a function (not a closure): same format as String.
Symbol: a language symbol (say a python symbol). same format as String.
Code With Scope: <total size><String><Object>
\endcode
*/
class BSONObj {
public:
/** Construct a BSONObj from data in the proper format.
@param ifree true if the BSONObj should free() the msgdata when
it destructs.
*/
explicit BSONObj(const char *msgdata, bool ifree = false) {
init(msgdata, ifree);
}
BSONObj(const Record *r);
/** Construct an empty BSONObj -- that is, {}. */
BSONObj();
// defensive
~BSONObj() { _objdata = 0; }
void appendSelfToBufBuilder(BufBuilder& b) const {
assert( objsize() );
b.appendBuf(reinterpret_cast<const void *>( objdata() ), objsize());
}
/** Readable representation of a BSON object in an extended JSON-style notation.
This is an abbreviated representation which might be used for logging.
*/
string toString( bool isArray = false, bool full=false ) const;
void toString(StringBuilder& s, bool isArray = false, bool full=false ) const;
/** Properly formatted JSON string.
@param pretty if true we try to add some lf's and indentation
*/
string jsonString( JsonStringFormat format = Strict, int pretty = 0 ) const;
/** note: addFields always adds _id even if not specified */
int addFields(BSONObj& from, set<string>& fields); /* returns n added */
/** returns # of top level fields in the object
note: iterates to count the fields
*/
int nFields() const;
/** adds the field names to the fields set. does NOT clear it (appends). */
int getFieldNames(set<string>& fields) const;
/** return has eoo() true if no match
supports "." notation to reach into embedded objects
*/
BSONElement getFieldDotted(const char *name) const;
/** return has eoo() true if no match
supports "." notation to reach into embedded objects
*/
BSONElement getFieldDotted(const string& name) const {
return getFieldDotted( name.c_str() );
}
/** Like getFieldDotted(), but expands multikey arrays and returns all matching objects
*/
void getFieldsDotted(const StringData& name, BSONElementSet &ret ) const;
/** Like getFieldDotted(), but returns first array encountered while traversing the
dotted fields of name. The name variable is updated to represent field
names with respect to the returned element. */
BSONElement getFieldDottedOrArray(const char *&name) const;
/** Get the field of the specified name. eoo() is true on the returned
element if not found.
*/
BSONElement getField(const StringData& name) const;
/** Get the field of the specified name. eoo() is true on the returned
element if not found.
*/
BSONElement operator[] (const char *field) const {
return getField(field);
}
BSONElement operator[] (const string& field) const {
return getField(field);
}
BSONElement operator[] (int field) const {
StringBuilder ss;
ss << field;
string s = ss.str();
return getField(s.c_str());
}
/** @return true if field exists */
bool hasField( const char * name )const {
return ! getField( name ).eoo();
}
/** @return "" if DNE or wrong type */
const char * getStringField(const char *name) const;
/** @return subobject of the given name */
BSONObj getObjectField(const char *name) const;
/** @return INT_MIN if not present - does some type conversions */
int getIntField(const char *name) const;
/** @return false if not present */
bool getBoolField(const char *name) const;
/**
sets element field names to empty string
If a field in pattern is missing, it is omitted from the returned
object.
*/
BSONObj extractFieldsUnDotted(BSONObj pattern) const;
/** extract items from object which match a pattern object.
e.g., if pattern is { x : 1, y : 1 }, builds an object with
x and y elements of this object, if they are present.
returns elements with original field names
*/
BSONObj extractFields(const BSONObj &pattern , bool fillWithNull=false) const;
BSONObj filterFieldsUndotted(const BSONObj &filter, bool inFilter) const;
BSONElement getFieldUsingIndexNames(const char *fieldName, const BSONObj &indexKey) const;
/** @return the raw data of the object */
const char *objdata() const {
return _objdata;
}
/** @return total size of the BSON object in bytes */
int objsize() const {
return *(reinterpret_cast<const int*>(objdata()));
}
/** performs a cursory check on the object's size only. */
bool isValid();
/** @return if the user is a valid user doc
criter: isValid() no . or $ field names
*/
bool okForStorage() const;
/** @return true if object is empty -- i.e., {} */
bool isEmpty() const {
return objsize() <= 5;
}
void dump() const;
/** Alternative output format */
string hexDump() const;
/**wo='well ordered'. fields must be in same order in each object.
Ordering is with respect to the signs of the elements
and allows ascending / descending key mixing.
@return <0 if l<r. 0 if l==r. >0 if l>r
*/
int woCompare(const BSONObj& r, const Ordering &o,
bool considerFieldName=true) const;
/**wo='well ordered'. fields must be in same order in each object.
Ordering is with respect to the signs of the elements
and allows ascending / descending key mixing.
@return <0 if l<r. 0 if l==r. >0 if l>r
*/
int woCompare(const BSONObj& r, const BSONObj &ordering = BSONObj(),
bool considerFieldName=true) const;
bool operator<( const BSONObj& other ) const { return woCompare( other ) < 0; }
bool operator<=( const BSONObj& other ) const { return woCompare( other ) <= 0; }
bool operator>( const BSONObj& other ) const { return woCompare( other ) > 0; }
bool operator>=( const BSONObj& other ) const { return woCompare( other ) >= 0; }
/**
* @param useDotted whether to treat sort key fields as possibly dotted and expand into them
*/
int woSortOrder( const BSONObj& r , const BSONObj& sortKey , bool useDotted=false ) const;
/** This is "shallow equality" -- ints and doubles won't match. for a
deep equality test use woCompare (which is slower).
*/
bool woEqual(const BSONObj& r) const {
int os = objsize();
if ( os == r.objsize() ) {
return (os == 0 || memcmp(objdata(),r.objdata(),os)==0);
}
return false;
}
/** @return first field of the object */
BSONElement firstElement() const {
return BSONElement(objdata() + 4);
}
/** @return true if field exists in the object */
bool hasElement(const char *name) const;
/** Get the _id field from the object. For good performance drivers should
assure that _id is the first element of the object; however, correct operation
is assured regardless.
@return true if found
*/
bool getObjectID(BSONElement& e) const;
/** makes a copy of the object. */
BSONObj copy() const;
/* make sure the data buffer is under the control of this BSONObj and not a remote buffer */
BSONObj getOwned() const{
if ( !isOwned() )
return copy();
return *this;
}
bool isOwned() const { return _holder.get() != 0; }
/** @return A hash code for the object */
int hash() const {
unsigned x = 0;
const char *p = objdata();
for ( int i = 0; i < objsize(); i++ )
x = x * 131 + p[i];
return (x & 0x7fffffff) | 0x8000000; // must be > 0
}
// Return a version of this object where top level elements of types
// that are not part of the bson wire protocol are replaced with
// string identifier equivalents.
// TODO Support conversion of element types other than min and max.
BSONObj clientReadable() const;
/** Return new object with the field names replaced by those in the
passed object. */
BSONObj replaceFieldNames( const BSONObj &obj ) const;
/** true unless corrupt */
bool valid() const;
/** @return an md5 value for this object. */
string md5() const;
bool operator==( const BSONObj& other ) const{
return woCompare( other ) == 0;
}
enum MatchType {
Equality = 0,
LT = 0x1,
LTE = 0x3,
GTE = 0x6,
GT = 0x4,
opIN = 0x8, // { x : { $in : [1,2,3] } }
NE = 0x9,
opSIZE = 0x0A,
opALL = 0x0B,
NIN = 0x0C,
opEXISTS = 0x0D,
opMOD = 0x0E,
opTYPE = 0x0F,
opREGEX = 0x10,
opOPTIONS = 0x11,
opELEM_MATCH = 0x12,
opNEAR = 0x13,
opWITHIN = 0x14,
opMAX_DISTANCE=0x15
};
/** add all elements of the object to the specified vector */
void elems(vector<BSONElement> &) const;
/** add all elements of the object to the specified list */
void elems(list<BSONElement> &) const;
/** add all values of the object to the specified vector. If type mismatches, exception. */
template <class T>
void Vals(vector<T> &) const;
/** add all values of the object to the specified list. If type mismatches, exception. */
template <class T>
void Vals(list<T> &) const;
/** add all values of the object to the specified vector. If type mismatches, skip. */
template <class T>
void vals(vector<T> &) const;
/** add all values of the object to the specified list. If type mismatches, skip. */
template <class T>
void vals(list<T> &) const;
friend class BSONObjIterator;
typedef BSONObjIterator iterator;
BSONObjIterator begin();
private:
class Holder {
public:
Holder( const char *objdata ) :
_objdata( objdata ) {
}
~Holder() {
free((void *)_objdata);
_objdata = 0;
}
private:
const char *_objdata;
};
const char *_objdata;
boost::shared_ptr< Holder > _holder;
void init(const char *data, bool ifree) {
if ( ifree )
_holder.reset( new Holder( data ) );
_objdata = data;
if ( ! isValid() ){
StringBuilder ss;
int os = objsize();
ss << "Invalid BSONObj spec size: " << os << " (" << toHex( &os, 4 ) << ")";
try {
BSONElement e = firstElement();
ss << " first element:" << e.toString() << " ";
}
catch ( ... ){}
string s = ss.str();
massert( 10334 , s , 0 );
}
}
};
ostream& operator<<( ostream &s, const BSONObj &o );
ostream& operator<<( ostream &s, const BSONElement &e );
struct BSONArray : BSONObj {
// Don't add anything other than forwarding constructors!!!
BSONArray(): BSONObj() {}
explicit BSONArray(const BSONObj& obj): BSONObj(obj) {}
};
}
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