bson getfields method

getfirstelementfieldname method - faster than firstElement().fieldName()
bson cleaning tweaking and comments

3 files changed, 60 insertions, 21 deletions

diff --git a/bson/bson-inl.h b/bson/bson-inl.h
index ee7010dc06f..8d2e34a5b74 100644
--- a/bson/bson-inl.h
+++ b/bson/bson-inl.h
@@ -89,16 +89,18 @@ namespace mongo {
         return b.obj();
     }
 
-    inline bool BSONObj::hasElement(const char *name) const {
-        if ( !isEmpty() ) {
-            BSONObjIterator it(*this);
-            while ( it.moreWithEOO() ) {
-                BSONElement e = it.next();
-                if ( strcmp(name, e.fieldName()) == 0 )
-                    return true;
+    inline void BSONObj::getFields(unsigned n, const char **fieldNames, BSONElement *fields) const { 
+        BSONObjIterator i(*this);
+        while ( i.more() ) {
+            BSONElement e = i.next();
+            const char *p = e.fieldName();
+            for( unsigned i = 0; i < n; i++ ) {
+                if( strcmp(p, fieldNames[i]) == 0 ) {
+                    fields[i] = e;
+                    break;
+                }
             }
         }
-        return false;
     }
 
     inline BSONElement BSONObj::getField(const StringData& name) const {
@@ -111,6 +113,21 @@ namespace mongo {
         return BSONElement();
     }
 
+    inline int BSONObj::getIntField(const char *name) const {
+        BSONElement e = getField(name);
+        return e.isNumber() ? (int) e.number() : INT_MIN;
+    }
+
+    inline bool BSONObj::getBoolField(const char *name) const {
+        BSONElement e = getField(name);
+        return e.type() == Bool ? e.boolean() : false;
+    }
+
+    inline const char * BSONObj::getStringField(const char *name) const {
+        BSONElement e = getField(name);
+        return e.type() == String ? e.valuestr() : "";
+    }
+
     /* add all the fields from the object specified to this object */
     inline BSONObjBuilder& BSONObjBuilder::appendElements(BSONObj x) {
         BSONObjIterator it(x);
diff --git a/bson/bsonelement.h b/bson/bsonelement.h
index 2b63a869c21..a6bf23e825b 100644
--- a/bson/bsonelement.h
+++ b/bson/bsonelement.h
@@ -153,9 +153,11 @@ namespace mongo {
             You must assure element is a boolean before
             calling. */
         bool boolean() const {
-            return *value() ? true : false;
+            return *value(); // ? true : false;
         }
 
+        bool booleanSafe() const { return isBoolean() && boolean(); }
+
         /** Retrieve a java style date value from the element.
             Ensure element is of type Date before calling.
             @see Bool(), trueValue()
@@ -495,7 +497,7 @@ namespace mongo {
         return true;
     }
 
-    /** True if element is of a numeric type. */
+    /** @return true if element is of a numeric type. */
     inline bool BSONElement::isNumber() const {
         switch( type() ) {
         case NumberLong:
diff --git a/bson/bsonobj.h b/bson/bsonobj.h
index cf402bdbb33..548d7f07bbe 100644
--- a/bson/bsonobj.h
+++ b/bson/bsonobj.h
@@ -124,7 +124,9 @@ namespace mongo {
         */
         bool isOwned() const { return _holder.get() != 0; }
 
-        /* make sure the data buffer is under the control of this BSONObj and not a remote buffer */
+        /** assure the data buffer is under the control of this BSONObj and not a remote buffer 
+            @see isOwned()
+        */
         BSONObj getOwned() const;
 
         /** @return a new full (and owned) copy of the object. */
@@ -152,18 +154,20 @@ namespace mongo {
         /** 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
+        /** @return the specified element.  element.eoo() will be true if not found.
+            @param name field to find. supports dot (".") notation to reach into embedded objects.
+             for example "x.y" means "in the nested object in field x, retrieve field y"
         */
         BSONElement getFieldDotted(const char *name) const;
-        /** return has eoo() true if no match
-           supports "." notation to reach into embedded objects
+        /** @return the specified element.  element.eoo() will be true if not found.
+            @param name field to find. supports dot (".") notation to reach into embedded objects.
+             for example "x.y" means "in the nested object in field x, retrieve field y"
         */
         BSONElement getFieldDotted(const string& name) const {
             return getFieldDotted( name.c_str() );
         }
 
-        /** Like getFieldDotted(), but expands multikey arrays and returns all matching objects.
+        /** Like getFieldDotted(), but expands arrays and returns all matching objects.
          *  Turning off expandLastArray allows you to retrieve nested array objects instead of
          *  their contents.
          */
@@ -180,6 +184,14 @@ namespace mongo {
         */
         BSONElement getField(const StringData& name) const;
 
+        /** Get several fields at once. This is faster than separate getField() calls as the size of 
+            elements iterated can then be calculated only once each.
+            @param n number of fieldNames, and number of elements in the fields array
+            @param fields if a field is found its element is stored in its corresponding position in this array.
+                   if not found the array element is unchanged.
+         */
+        void getFields(unsigned n, const char **fieldNames, BSONElement *fields) const;
+
         /** Get the field of the specified name. eoo() is true on the returned
             element if not found.
         */
@@ -199,7 +211,9 @@ namespace mongo {
         }
 
         /** @return true if field exists */
-        bool hasField( const char * name ) const { return ! getField( name ).eoo(); }
+        bool hasField( const char * name ) const { return !getField(name).eoo(); }
+        /** @return true if field exists */
+        bool hasElement(const char *name) const { return hasField(name); }
 
         /** @return "" if DNE or wrong type */
         const char * getStringField(const char *name) const;
@@ -210,7 +224,9 @@ namespace mongo {
         /** @return INT_MIN if not present - does some type conversions */
         int getIntField(const char *name) const;
 
-        /** @return false if not present */
+        /** @return false if not present 
+            @see BSONElement::trueValue()
+         */
         bool getBoolField(const char *name) const;
 
         /**
@@ -270,7 +286,6 @@ namespace mongo {
         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; }
@@ -295,8 +310,13 @@ namespace mongo {
         /** @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;
+        /** faster than firstElement().fieldName() - for the first element we can easily find the fieldname without 
+            computing the element size.
+        */
+        const char * firstElementFieldName() const { 
+            const char *p = objdata() + 4;
+            return *p == EOO ? "" : p+1;
+        }
 
         /** 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