cstorage

cstorage is a pastebin clone.

Build & Run

You will need make and clang-12 to build it. You will also need python3, netcat-traditional,uuid-runtime to run tests.

The easiest way to run tests is to run them via docker:

make test-docker

Examples

Start server

$ ./cstorage 8080 servdir
[INFO] serving on port 8080 with folder servdir
[INFO] [connection 1] new connection
[INFO] [connection 1] called set
[INFO] [connection 1] save data to disk
[INFO] saved data to file ./servdir/6oh9sa1obn6z90oqg06r3ohlfnxstwhzkyos
[INFO] [connection 1] saved
[INFO] [connection 1] response is sent, closing

Paste file using client

$ ./cstorage-client 127.0.0.1 8080 set example.txt
d8f7dxhqjq3gqu3ct43v6djw3qm6b264alcn

Download file using client

$ ./cstorage-client 127.0.0.1 8080 get d8f7dxhqjq3gqu3ct43v6djw3qm6b264alcn
#include <stdio.h>

int main() {
  printf("Hello World!\n");
}

Protocol

cstorage uses a simple protocol over TCP.

SET

Request

• First line contains SET header;
• Second line contains 8 characters with hexadecimal content-length;
• Then the file content.

Response

• Single line -- 36 characters of paste id.

Example using netcat as a client

$ cat set-request-example.txt
SET
0000000D
Hello, World!
$ cat set-request-example.txt | nc localhost 8080
oph0d3f233tj4fqn47ozb1rkxpjy3nqssns5

GET

Request

• First line contains GET header;
• Second line contains 36 characters of paste id;

Response

• File content.

Example using netcat as a client

$ cat get-request-example.txt
GET
oph0d3f233tj4fqn47ozb1rkxpjy3nqssns5
$ cat get-request-example.txt | nc localhost 8080
Hello, World!

Details

cstorage

• is single-threaded;
• uses epoll(7) for network communication;
• uses blocking disk i/o;
• borrows some code from this blog.

The entrypoints are:

• main.c for server
• client.c for client