$2\mathrm{.}3.$ Read and Write Methods. There are two types of read and write methods that have to be implemented:

Methods with absolute addressing $($e$.$g$.,$ readBlock$)$ and methods that address relative to the current page of a file

$($e$.$g$.,$ readNextBlock$).$

readBlock

The method reads the block at position pageNum from a file and stores its content in the memory pointed

to by the memPage page handle.

If the file has less than pageNum pages, the method should return RC$\_$READ$\_$NON$\_$EXISTING$\_$PAGE.

getBlockPos

Return the current page position in a file

readFirstBlock, readLastBlock

Read the first respective last page in a file

readPreviousBlock, readCurrentBlock, readNextBlock

Read the current, previous, or next page relative to the curPagePos of the file.

The curPagePos should be moved to the page that was read.

If the user tries to read a block before the first page or after the last page of the file, the method should

return RC$\_$READ$\_$NON$\_$EXISTING$\_$PAGE.

writeBlock, writeCurrentBlock

Write a page to disk using either the current position or an absolute position.

appendEmptyBlock

Increase the number of pages in the file by one. The new last page should be filled with zero bytes.

ensureCapacity

If the file has less than number$0$fPages pages then increase the size to number$0$fPages.

$2\mathrm{.}4.$ Return codes. The header file dberror.h defines several error codes as macros. As you may have noticed,

the storage manager functions all return an RC value. This value should indicate whether an operation was successful

and if not what type of error occurred. If a method call is successful, the function should return RC$\_$OK$.$ The

printError function can be used to output an error message based on a return code and the message stored in

global variable RC$\_$message $($implemented in dberror.c $).$

Source Cone Structure

You source code directories should be structured as follows:

Put all source files in a folder assign$1$ in your git repository

This folder should contain at least

the provided header and $C$ files

a make file for building your code Makefile. This makefile should create a binary from test$\_$assign$1$

from test$\_$assign$1\_1.$c which requires dberror.c and all your C files implementing the storage$\_$mgr$.$h

interface

a bunch of $*.$c and $*.$h files implementing the storage manager

README.txt : A text file that shortly describes your solution

Example, the structure may look like that:

git

assign $1$

README. txt

dberror.c

dberror. h

storage$\_$mgr a c

storage$\_$mgr $.$ h

test$\_$assign$1\_1.$c

test$\_$helper.h

Makefile