transactions.txt

command_id // strcat("%d", "%s")
1 ss join ns
"%s"
"[path]"

TREE LOCK
2 create file
"%s %d %d"
"path perms type"

3 delete
"%d %s"
"ssid path"

4 copy
"%d %d %s"
"ssid1 ssid2 path"

TREE NOT LOCK
5 read
"%s"
"path"

6 write
"%d %s"
"ssid path"

7 getinfo
"%d %s"
"ssid path"


transaction requests to NM from CLIENT:

  "LIST <path>;"
* "CREATE <path> <type>;"              type=0 for file, type=1 for folder
* "DELETE <path>;"
* "COPY <path> <path>;"
  "READ <path>;"
* "WRITE <path> <opt> <localfile>/<text>;"     if opt=0, open localfile; if opt=1, send <text>
  "GETINFO <path>;"

*are operations that communicate with SS


transaction requests to SS:

"REQ <jobid> <jobdata>;"
"TREE <jobid>;"
"TRANSFER <serverdata> <jobid>;"
"RECEIVE <serverdata> <jobid>;"

updates from SS to NM:

"HEARTBEAT;"
"REQ <jobid> <data>;"
"REQ <jobid> STOP;"
"DISCONNECT;"
"ERROR <jobid> <code> <message>;"        // job terminates if error

TRANSACTION FLOW:
    type of transaction determined
    storage server informed of the job
    storage server locked
    if needed, Client/another storage server connects to storage server for the job
    transfer of data
    storage server unlocked
    acknowledgement sent to naming server by storage server and/or client
    Client request array and server requests count updated
    naming server tree locked
    tree changes
    naming server tree unlocked
    acknowledgement sent to client

    *if acknowledgement not recieved or error recieved, tree not changed and effort to rever change\
    in the storage server using one of the backup servers

After creating a file, storage server sends its details like normal (most importantly size)

REQUEST PROCESSING FLOW:
    Client sends request to NM
    NM updates client requests array
    NM updates server requests count
    Job request sent to server
    Request added to job queue
    data is sent to NM occasionally and once job is done, STOP is sent
    Request array and job count handled on client

A wait array on Storage server is maintained and its count is maintained on NM
If the count is full, job is rejected with an error message.

FORMAT OF <path>: (either of these)
    <id>:dir/dir/.../file
    dir/dir/.../file
    file