BlockBuffer (Bada Bhai)

Generic Class for representing a disk block of any type (Record, Internal Index, Leaf Index). RecBuffer and IndBuffer are child classes of BlockBuffer with Static Buffer being a friend.

BlockBuffer::BlockBuffer() Constructor 1

If the Block has been already set, then the subsequent access to the block is done using RecBuffer Constructor 2

Arguments -> R, I, L -> blockType

===If block could not be allocated in the disk, then the blockNum field of this class will contain the appropriate error code. All other sub classes have to check its validity.===

NITCbase requires two conditions to be true before invoking RecBuffer::constructor1 -> 1. A record is added into a relation (or when a new relation is created, resulting in an insertion into the catalogs). 2. None of its already allocated blocks have a free slot to store the inserted record, implying that insertion cannot take place without allocating a new block.