BIaaS

Big Integer as a Service

Server implementation for BigOperation (aka BigInteger - https://github.com/DoHITB/BigInteger.c).

How it works

1. There's an Apache Custom Module (mainh.c), that gets each ".calc" request
2. For this, just add AddHandler calc-handler .calc on your Apache .htaccess file
3. This calc-handler will get the request and write a file on ./f (folder must exist befor execution).
4. There are two kind of operations to make: 1. makeOperation, in order to enter an operation 2. getResult, in order to get the result of makeOperation.
5. The BigInteger service (plist) will take the file, calculate, and write the result on /r folder (appended with r_).

makeOperation

You have to follow this rules:

1. File name (fileName parameter) may not exceed 126 characters long.
2. File name (fileName parameter) may be set.
3. File name (fileName parameter) may be unique and non-existing. It will be searched among /f and /r folders.
4. Operation data (operation, op1 and op2 parameters) may be informed.
5. Operation data (op1 and op2 parameters) may not exceed 1024 length (during beta; on release, will stand up to 4096).
6. Operation data (operation parameter) may be only 1 character long and be either +, -, /, *, ^, s for adding, subtracting, dividing, multiplying, power, and get root of, respectively.

getResult

You have to follow this rules

1. File name (fileName parameter) may not exceed 126 character long.
2. File name (fileName parameter) may be set.
3. File name (fileName parameter) may be unique and existing. It will be searched among /f and /r folders.

Getting a result will erase the /r file.

Starting all the stuff

1. First, you may need to download all source code, including BigInteger (https://github.com/DoHITB/BigInteger.c).
2. Edit your .htaccess file to get the handler
3. Compile mainh.c by using makemain.sh. You will need apsx compiler from Apache developer package. Apache service will restart.
4. Compile plist by using makeplist.sh. You will need to have all BigInteger source in the same folder.
5. Compile plistStarter with gcc. No special needs.
6. Move plist and plistStarter objects to /var/www/c.
7. Create folders /var/www/c/f and /var/www/c/r.
8. Copy plistClean.sh (to keep /r folder clean), plistStarter.sh (script to run only one instance of plist) and watchplist.sh (scheduler for plistStarter) to /var/www/c folder.
9. Grant privileges to executable files.
10. Run ./watchplist.sh and ./plistClean.sh from /var/www/c folder.
11. Your server is ready.

You can also do most of this steps by executing install_BIaaS.sh (only need to edit .htaccess)

plist

This service just opens /var/www/c/f folder, iterate over it (storing up to 1024 files), and then treat them, storing results on /var/www/c/r folder, appending a r_ to original file name.

It delegates to BOperation.c main launcher to make all calculations.

mainh

This handler just gets GET data, and writes a file that plist can understand.

Overview

                               +---------------------------------------------+
                               |                                             |
+-------+                 +----+-----------+          +----------------+     |
|       |  makeOperation  |                |          |                |     |
|  Web  +---------------->|  calc-handler  +--------->|  /var/www/c/f  |     |
|       |<----------------+                |          |                |     |
+---+---+     response    +------------+---+          +----------------+     |
  ^ |                          ^       |                  ^                  |
  | +--------------------------+       |                  |                  |
  |          getResult                 |                  |                  |
  +------------------------------------+                  |                  |
              response                                    |                  |
                          +--------+                      | read             |
                          |        +----------------------+                  |
                          | plist  |                                         |
                          |        +----------------------+                  |
                          +--------+                      | write            |
                                                          |                  |
                                                          v                  |
                                                      +----------------+     |
                                                      |                |     |
                                                      |  /var/www/c/r  |<----+
                                                      |                |
                                                      +----------------+