File format documentation for the database------------------------------------------* GENERAL INFORMATION.The data in the indexes represents an ordered lists of offsets into the database.  The order is defined by functions subclassed by the application that owns the records in the database file.The data in the header represents the end of the db file, along with theattributes the database, and the free lists.  There are 4 free lists, in size order of 32, 64, 128 and 256 bytes.  The size of a free list indicates thelargest element contained within that free list.  For instance a gap of 54 bytes would be inserted into the free list with size 64.  The structure isa singly linked list.  Each element contains a 32 bit unsigned int indicatingthe offset o the next element in the free list.Both the index file and the header file can be generated from reading the entire database file.The database file represents primarily two types of data, records and free listelements.  Each type of data is identfied by a type, followed by a size (see above).  Data integrity is ensured by first writing and flushing thetype of the data (changing data is marked invalid if the size for that data has not yet been written, unknown otherwise), then writing and flushing the data, then again writing and flushing the new type (record or free if successful).As a size of a block is never changed once written, if a record in the middleof the file fails to write it will still be possible to determine how toskip that element.  Hence a failed write will not prevent accessing existingdata.  The invalid type is only used when adding a new block (size not writtenyet).  This is why any data base a block starting with the invalid type isindeterminate.The trade-off for keeping data integrity is that it is there is no guarunteethat space usage will be optimal.  It is expected however that when theuser syncs their portable device, that the desktop machine (with more resourcescan then optimize the space usage of the database file.* INDEX FILEbytes	type			represents4 	32 bit unsigned int	0x0, if the index is ok, 0xffffffff if the index is dirty				and should be regenerated from the database4	32 bit unsigned int.	number of elements n in the indexn*4	32 bit unsigned ints.	Each uint represents an offset into				the database file.  The uints are				in sorted order of this index.* HEADER FILEbytes	type			represents0..3	32 bit unsigned int.	The dirt count.  See 0..3 of database file.4..5	32 bit unsigned int.	The total size of known data in the database				file.  Data beyond this offset is indeterminate.6..9	32 bit unsigned int.	Number of attributes.* Attribute * num attributes.0       8 bit unsigned char	Attribute index.1..n	utf8 encoded string	Attribute name.* Free List * 40..3	32 bit unsigned int	Offset into dbfile to the first element of the				Free list.4..5	32 bit unsigned int	Number of element in the free list.* DATABASE FILEbytes	type			represents4	32 bit unsigned int	The dirt count.  incremented every time the				database is changed.  Can be used by				external classes to determine quickly if they				are up to date with the database file.* Record * number of records.1	type byte.		Indicates the status of the proceeding data.				0xFF indicates invalid.  The remaining data				is inderteminate.				0xFE indicates unknown.  This record is				inderterminate, but the size of it isn't (see				below).  Hence it is possible to read data				beyound this record.				0x02 indicates a free list element.				0x01 indicates a record.4	32 bit unsigned int	If record is not of type invalid, then this				represents the remaining size of the record,				in bytes (8bit)....	...			Data of the record. See below for details* Record details16	16 byte Uid		Unique id to identify the record4	32 bit unsigned int	Number of categories this record belongs to (nc)4	32 bit unsigned int	Number of fields this record contains (nf)4*nc	32 bit unsigned ints	List of categories the record belongs to8*nf	FieldList		List of Fields in the record...	additional data		additional data referenced by the fields. Currently only				string data* FieldList details2	16 bit unsigned int	Id of the field2 	16 bit unsigned int	Type of field4	32 bit unsigned int	offsetOrData. Contains the data in case the type fits				into 4 bytes, otherwise a offset into the additional				data, pointing to the actual data.The field id is application specific and can be assigned at will bythe application.  The type id specifies the type of the data stored,allowing other applications to easily read out the data without evenknowing what the Ids mean. It also provides an additional consistencycheck for the data in the file.Currently the following data types are supported:UndefinedType		non defined typeBoolType 		represents a boolIntType 		an IntegerDateType		a Date, stored in seconds since 1.1.1970 UTCDateTimeType		a Date and time stored in seconds since 1.1.1970 UTCStringType		a String. The offsetOrData variable gives an offset into the			data region to where the string is stored. The string itself			is stored by having 4 bytes for the length of the string, 			then the string in UCS2.