[SOLVED] Cse 320 hw #2 part ii

Goal of this homework is to help you understand better how memory allocation/management works and give you better understanding of pointers. On top
of that, you will also learn how to create your own Makefile and practice using
gdb. This homework consists of two parts. We found that readings are important and crucial in succeeding in the homeworks. Thus, in the first part you are
required to read provided material that serves as a basis for doing the second
part. The second part of the homework is a programming exercise where you
need to apply gained knowledge from the readings.
In this second part you need to implement a simple interactive application
that will mimic a database of art collections. You will have a set of warehouses
where you can store those collections. In some way, warehouse represent a
memory block and an art collection represents an actual payload. To operate
that database you should implement an interactive shell where user can input
commands. Please read all the sections prior attempting writing the code as it
will give you a clearer picture of the whole program.
2 Part I
You program should be interactive. After starting the program you should
keep prompting user commands and perform various actions depending on the
command. The list of acceptable commands is as follows:
• help
• load warehouse filename
• load art filename
• printall
• print public
1
• print private
• add art name size price
• delete art name
• utilization
• exit
Now let’s go over each command.
help. This command should print a help message giving a brief description
of each command. Exact format is up to, just make it readable and actually
helpful. You can check help messages of Linux tools to get an idea of how a
help message may look like, e.g. “ls –help”.
load warehouse filename. This command should populate your linked
list (exact details on the linked list are in the later sections) of warehouses. The
filename specifies a file name that contains information about warehouses. You
should check that such file exists and you can open/read it. Each line in the file
represents information about warehouse and have the following format:
ID SIZE TYPE
where ID is a warehouse ID and should be a positive number, SIZE is a
size/capacity of the warehouse, and TYPE defines its ownership, which is either
“public” or “private”. Please note, that this command can be called multiple
times to add more warehouses.
load art filename. This command should populate your warehouses with
art collections provided in the file with the filename. You should check that such
file exists and you can open/read it. Each line in the file represents information
about art collection and have the following format:
NAME SIZE PRICE
where NAME is the name of an art collection, SIZE is a size of an art collection, and PRICE is a price of an art collection. Please note, that this command
can be called multiple times to add more art collections to the database.
printall. This command should print information about all art collection
in the database. Each art collection should be on a separate line and should
adhere to the following format:
NAME SIZE PRICE
where NAME is the name of an art collection, SIZE is a size of an art
collection, and PRICE is a price of an art collection. After all art collections
being printed you should print the total worth of art collections on a separate
line.
print public. This command should print information about all art collections in the database that are stored in public warehouses. Each art collection
should be on a separate line and should adhere to the following format:
NAME SIZE PRICE
where NAME is the name of an art collection, SIZE is a size of an art
collection, and PRICE is a price of an art collection. After all art collections
2
being printed you should print the total worth of art collections stored in public
warehouses on a separate line.
print private. This command should print information about all art collection in the database that are stored in private warehouses. Each art collection
should be on a separate line and should adhere to the following format:
NAME SIZE PRICE
where NAME is the name of an art collection, SIZE is a size of an art
collection, and PRICE is a price of an art collection. After all art collections
being printed you should print the total worth of art collections stored in private
warehouses on a separate line.
add art name size price. This command should attempt to add a new
art collection to the database with provided attributes.
delete art name. This command should attempt to delete all art collections
with matching name.
utilization. This command should print two numbers each on a separate
line. First number is the ratio of occupied warehouses versus total number of
warehouses. The second number is the ratio of total size of all art collections versus total capacity of all warehouses. Basically, you need to print two utilization
statistics.
exit. This command should exit your program. Don’t forget to perform any
necessary clean up.
NOTE: you program should never crash, get stuck, or have memory leaks.
We will deduct points for every such event.
If user happened to input a wrong command then please print that such
command is not correct and print a message saying that list of available commands is available through “help” command. Again, exact text to print is up
to you.
If at any point in time you will not be able to place a new art collection due
to the lack of warehouse capacity then you should print an appropriate message
and return to the prompt. In case of a quiet mode (see next section) there is
obviously no returning to the prompt.
NOTE: if a string in a file/user prompt consists of multiple words then
these words will be surrounded by double quotes.
NOTE: to avoid any capitalization issues just convert everything into lowercase.
REQUIREMENT: you should name you executable as art db.
3 Part II
Now let’s discuss supported flags in your program. Your program should support
two flags: quiet mode initiated by “-q” and printing sorted output initiated
by “-s”.
In the quiet mode you don’t fire up the interactive shell. But rather provide
two files names. The first file is the file with warehouses information and the
second file is the file with art collections information. To make support for quiet
3
mode easier let’s add two more flags: “-w” and “-a” that will be followed by
the file name for the file with warehouses information and the file name with
art collections information respectively. An example of running program with
enabled quiet mode is below:
$ a r t d b −q −w w fil e n am e −a a fil e n am e
NOTE: the “-q” flag takes no parameters and should print all the records
in the database.
The second, “-s” flag indicates that records should be printed in sorted order.
This flag takes a parameter that decides what should be used as a key. If the
parameter is “s” then records should be printed in sorted order using the art
collections size as a key. If the parameter is “-p” then records should be printed
in a sorted order using the art collections price as a key. This flag affects both
quiet and interactive modes.
Thus, you program should run as follows:
$ a r t d b [−q −w w fil e n am e −a a fil e n am e ] [−s s | p ]
as before square brackets mean being optional.
4 Part III
Now let’s talk about internals of your database. More specifically, how do you
need to store records. In this assignment, you need to replicate segregated fits to
some extent. We provide struct constructs that you need for this assignment
in the warehouse.h.
As you may notice, each warehouse has a size. So you need to create a linked
list to store all warehouses of the same size in the same linked list. However,
you may have warehouses of different sizes. Thus, you need to have a separate
linked list for every size you have. In order to maintain these linked lists you
need to create another linked list. Each node of that linked list should point to
the corresponding linked list of a particular size.
Every node of the linked list of a particular size should contain a pointer to
the warehouse, pointer to the next node in the list, and a meta data information. The meta data information should contain information about size of the
warehouse that this node points to, information if the warehouse is currently
occupied, and information if the warehouse is private or public. That meta data
mimics memory block header and should be 64 bits wide (one word in a 64-bit
system). Additional information can be found in the warehouse.h.
The warehouse struct contains information about its ID, size, and pointer
to the art collection unit. The art collection struct contains information about
its name, size, and price.
Please use our warehouse.h file.
4
5 Part IV
Now we will briefly go over inserting art collections into database and removing
them.
Similar to the actual memory management you need to search for the linked
list that corresponds to the size that can fit an art collection. Once you located
such linked list you need to iterate over it and find first non-occupied warehouse
to place your art collection there. Obviously, after such placement you need to
mark warehouse as being occupied.
You may face a situation when either there is no linked list of the exact size
you are looking for or there are no non-occupied warehouses in such linked list.
In that case, you simply go to the next available linked list with bigger size and
repeat that procedure.
In the unfortunate event when you cannot fit an art collection you need to
print an appropriate message. If it was a manual placement of an art collection
through interactive shell then after error message you simply return to the
interactive shell. However, if the source for the art collection was the file then
you need to print an additional error message saying that parsing file has failed
and exit the program. As usual, do not forget to clean your data structures and
memories.
6 Part V
You may remember that we spoke about coalescing in the class. So your task
will be to implement something similar. However, within current setup there is
nothing to coalesce as we never move our warehouses yet to other linked lists.
So first, when you allocate a warehouse for the art collection and if there is some
space left in it (difference between the size of the warehouse and the size of the
art collection) then you need to split this warehouse into two and move them
to the appropriate linked lists. If there is no appropriate linked list then simply
create one. As this operation will result into creating a new warehouse you also
will need a new ID for it. Our only REQUIREMENT is to make sure that
new ID you will choose for it will be unique.
Now we have an ability of splitting warehouses into two. So let’s come up
with a procedure of coalescing two warehouses. Let’s coalesce two warehouse
when both of them are not occupied and they are directly surrounded by occupied warehouses. In other words, if you face a situation when there is an
occupied warehouse followed by two non-occupied and then followed by an occupied warehouse in the linked list then you need to coalesce two non-occupied
warehouses and place them in the appropriate linked list.
7 Part VI
Finally, let’s discuss some extra credit opportunities. Both of them target only
interactive mode of your program.
5
Extra Credit 1. In the first extra credit opportunity, you need to implement a new command “print warehouse” that will print to the console a nice
layout of the warehouses with them being marked if they are occupied or not.
Be creative, we would love to see some ASCII visual magic.
Extra Credit 2. Recall that if you get the art collection from the file and
it fails you need to exit the program. In this extra credit opportunity, you need
to implement a rollback feature. It means that if you tried to load art collection
from the file then you need to return to the interactive shell but also undo all
the changes that were introduced to the database while parsing that particular
file.
8 Last Remarks
NOTE: Failing to follow any of the requirements will result into 50%
grade penalty.
As you may see, you are given a lot of freedom. Basically, we give some
information about input, functionality, and restrictions. Everything in between
is up to you. Do not hesitate to ask questions and seek out for help (from us)
if you need it. We are ready to help.
9 Code Hand-out/in
To start please click on this link so your repository will be created for you.
There were cases when GitHub will stuck trying to create a repository for you
and it should not take more than few minutes. In such case write me an email
so I can manually create a repository for you.
Please note, that this time you need to keep your source files in the folder
name “src” instead of having them in the root directory of your repository.
REQUIREMENT: you need to put linked list related code to the file
named “linked list.c” and also place it into “src” folder. Thus, you will have at
least three files in that folder. Note, that you are not allowed to include “.c”
files in other source files using #include directive and they should be compiled
using gcc.
REQUIREMENT: your Makefile should be placed in the root directory
of your repository. To compile your code we will simply type make.
To submit your code please push it to the GitHub. We will grade the latest
push within the deadline.
As before, keep pushing your code, ask us any questions, and good luck.
6