technology requirements.txt

a. install the requirements.txt file
b. run pilot file like: python pilot.py. you can open openapi docs with     
   http://127.0.0.1:8000/docs.
c. user authentication hasn't implementend here.
d. when I tried running lockfile_testing.py file and tried upload, share API, 
   I am getting locked, 423 status code.
e. E-tag can be implemented to avoid uploading same files again and again.
   Here, in this case, I am not able to manage using E-tag and If-Match
f. I considered, updating file as file modification, threfore whenever a file
   is updating, no other can update it..
g. the previous downloads will get, pre-condition failed status.

h. when the file is locked, if the owner wants to download it, owner can download
   as the lock will breakdown.

i. if in case, owner wants to update, when the user, uploading it, there is a
   row-level lock, which given be access only once the current user done with it.

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DOcker:
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j. Created DockerFile for the backend appliation.
k. pulled the postgres imge from docker hub and tried to interact both the cotnainers
   using docker compose.
l. communication has not been able to establish between them due to port TCP/IP issue.




Tech stack:
1. FastAPI
2. psycopg2
3. PostgreSQL (it canbe replaces with SQLite)


****All the static variables are being imported from CONSTANTS.py************

features:
Applied thread lock too.
In our case, it is irrelevant as per my assumption and
moved to row level locking. We can remove it at any point of time.


row level locking will be locking the the row of a given file
while updating the document.
Though updating the document api is uploading the document, logically
it is nothing but editing till the file is uploaded and all the 
modifications in the File and Collaborator tables are updated.

Implemented file locking too..


I added a sleep time to check if the download works, during update with
the above scenario, user not able to downlaod during the process
of update api. The other user keeps on waiting for the resource till
update api complete its functionality.(It is commented now)


Will be adding file lock too...
that means till the user is updating the file properties will be changed.
In row level lokcing, user can do anything with physical file, but can't modify
it through API. In this case, user neither modify it through API not physically.
In this case, user don't need to wait till the resource is free. User will get
instant response like, the resource is locked etc.,