DMAC/notes

time to plan

terms

RLC - reactor level coordinator (Beagleboard)
RH - Reactor Handler (goroutine)
SH - sensor handler (gourtine)
Reactor Side:

needs
    - way to discover active sensors
    - spin up goroutine for each sensor responsible for keeping status and logs
    - way to read back and truncate logs for safe data delivery to servr
    - routing requests from reactor level coordinator to relevant sensor
    - internal memory sharing and channels for reactor level coordination
    
thoughts
    - maybe the RLC can be responsible for packaging data for coordinator response
        adv:
        - clears up the network
        - simplifies pinging
        - keeps the data aributrary
        cons:
        - unknown data size
        - how to coordinate data structure

Server Side:

needs 
    - way to look into a config file for active reactors
    - should then spin up a goroutine for each reactor
        - responsible for recovery and consistent communication
        - individual database entries
        - API?
        - use gRPC for comms between server and BB
    - each reactor handler needs mechanism for pinging, recovery, and database correctness
    - 

message PingRequest {
    // do we even need anything in a ping request?
}

message PingResponse {
    repeated Sensor sensor = 1;
}

message Sensor {
    string type = 1;
    bool status = 2;
    byte data = 3;
}

sensors := [string]q
    
6/23 TODO:

X- BBB mem fix
    - 32 gig for the main but where to put the OS?
        - obv in EMMC but how to init sd card? (probably dev tree :( )
Y- Server side impl
   Y - Need a struct for the RC
       X - Should we store and load configs based on IDs? (efficiency of this vs performance increases i.e. bandwidth vs storage)
   Y/X - Who should kill the RC and how do we know its dead? (Garbage collection to the rescue hopefully)
    
X- UPDATE PRES
    - Add bottle necks for each part in that section
        - I2C: 128 addrs and ~90 bytes/s per device at 128 devs optimally
        - BB: Hardware is upgradeable even customizable ;) 
        - Server: Its overkill as is, can benchmark with a rudementary go overload once its completed
- Sensor configs
    - how to store sensor info efficiently and searchably lol
        - who needs to know what the sensor is? (Just the SM? Even the SM?)
X- TUI
    - pls this would be so sick
TODO: 6-24

Y - Pres stuff from yesterday + python gRPC abstraction
Y - RPI flash
- Add resiliance to coordinator process (aka error handley blech)


TODO 6/27
- Time to tackle sensor managers officially
    - to hell with port generation
    - going to use channels but not like a jackass
        - going to try generating channels interface side but via implicit types to avoid the interface stff
    - should set up a structure where I can use arbiturary types on the backend and fulfill methods to get/infer information on the frontend
- rewrite I2C interface to employ same method, should allow for this 
    1) generate type
    2) send it to worker
    3) receive back (original? copy?) 
    4) use interface methods to get required values 
- should simplify all internal communication and potentially suggests api for implementation

TODO 6/28
- It works... kind of
    - I learned a lot about
        "the smaller the interface, the more useful it is"
-Y time to tackle the server side error handleing aka reconnect
    - custom backoff? Max TO? Sleep Period?
       5ms -> 10ms -> 25ms -> 50ms -> 100ms -> 250ms -> 500ms -> 1s -> 1s
-Y Actual logic?
    1) Create listener
    2) create reactor managers for each reactor
        a) whose job is it to kill on disconnect? Should we kill?
        b) the RM will have the actual ping mechanism with coordinator aggregating in eventual TUI
    3) reactivated reactors should connect to the same RM to resume connections with less downtime. Memory use be damned (ALLOCATED?? ID VS IP)
    4) need a way to purge manually disconnected reactors
        a) also should check ids which are deterministic and map actual hardware
    5) continue forever (for select??)
-Y RM Logic?
    1) on spawn ping reactor to get initial sensor status
    2) enter ping loop to get status and keep heartbeat alive
    3) no action on sensor going down (unless method but duh)
    4) on reactor going down
        1) save to config?
        2) "sleep mode"
            i.e. stop pinging and wasting resources doing stuff
        3) wait for coordinator to reactivated
    5) reactivation: call start and resume pinging
- RM Struct?
    - needs to know
        - ip:port of reactor
        - id of reactor
        - mapping of sensors to status
        - last seen for reactor (and sensor?)
    - needs to be able to 
        - ping reactor for status
        - get status
        - store and update status reliabily
        - stop pinging on down detection
        - detection outages
        - respond to coordinator requests? (rpc or method most likely?)
    - relies on
        - SM for sensor status
    - implements
        - start/restart mechanism for coordinator
        - ping response for coordinator
- Coordinator Struct?
    - needs to know
        - mapping of ids of connected reactors to RM
        - its own ip:port to serve listener on
        - internal mapping of system? (any efficiency benifiets here vs mem usage?)
    - needs to be able to 
        - setup new RMs on incoming connections
        - call existing RMs on incoming connections
        - ping for reactor status from RMs
        - store status for TUI?
    - relies on
        - RM for reactor status
    - implements
        - application logic

That went surprisingly well... Same method for tui

process outline:
TUI
    1) display TUI outline and connect to coordinator
    2) let coordinator know where to send reactor/sensor changes
    3) enter loop of checking for changes and drawing
    4) on quit should gracefully exit

Coordinator
    1) on TUI connection start routine
    2) collect? sensor/reactor info and send init to TUI
    3) upon changes? send to TUI
    4) exit when TUI connection closes


- TUI struct
    - needs to know
        - all the tui stuff (duh)
        - reactor/sensor status
    - needs to be able to
        - create (several instances of) a TUI
        - receive and display up to date system info
        - delete reactors/sensors
        - be efficient
            - i know this is broad but bear with me
    - relies on
        - coordinator struct for system info
        - coordinator struct to fulfil delete request
    - implements
        - tui
        - user interface or management
- Coordinator Struct
    - needs to know
        - all the sensor and reactor states
    - needs to be able to 
        - know what the TUI knows/doesnt know
        - efficiently notify tui of change in system
        - notify sensors or reactors of removal
    - relies on
        - rm/sm to implement reactor/sensor removal
        - rm for reactor/sensor status
    - implements
        - sender of system status for TUI
       
TODO 6/29
- refactoring
    - creating general listener and then a coordinator for reactor/tui that uses listener to field incoming requests
    - change update loops for status to only send new data or empty messages for pings
- tui
    - creating coordinator/manager for TUI clients
    - create update loop for tui clients 
        - grpc to tui client with updates and hb
        - drawfunc loops over change buffer
        - on disconnect should display static terminal with offline warning

- Listener Struct
    - needs to know
        - IP
        - Port
    - needs to be able to
        - respond to incoming gRPC
        - create corrisponding manager // taken care of in the actual handler
    - relies on 
        - grpc for the endpoint stuff
        - manager impl
    - implements
        - listener for main func
        - manager generator essentially

coordinator should be seperate ***
- new coordinator struct
    - listener sends new connections to coordinator who appends to internal registery and reacts
    - needs to know
        - incoming:
            - ip
            - port
            - client type?
    - needs to be able to 
        - wait for incoming connections
        - create a new manager for the client
        - update internal directory
        - remove entries ?? (tui -> reactor)
    - implements
        - manager creation
        - connection handling
        - client hb
    - relies on
        - manager impl
        - listener call?


alright complete redesign
server acts as singular listener
routes all requests to a central coordiantor
this calls cooresponding client coordinator which then initiates managers etc

now redesinging sensor info

new fmt
1) have a seperate long running coordinator routine responsible for a "changed" list of sensors
2) on reactor status request:
    a) send the changed list
    b) if the send was acknowledged purge the change list
    * both must be atomic

new rlc struct

- needs to know
    - sensors connected
    - changes in sensors
    - how to establish connection to central server
- needs to be able to
    - track changes in its system layout
    - atomically relay these to the cc
- depends on
    - I2C sensor info
- implements
    - reactor sensor change tracking

new general coord

What does it need to do?
- Needs to respond to incoming clients from listener
    - what does this mean?
    - needs to link a client to a manager
        - this is the whole high level idea
        - can everything else be abstracted away? Why not?
    - how to link? Channel? Shared Memory?
    - channel is probably the best choice here
    - structure:
    managers 
        [uint32] : chan<- bool
        10292133 : chan<- bool
    - how to use?
        - when a client connects we search to see if a channel exits
            - if it does we just send "true" down the channel to signal that the client connected
            - if we dont we create a channel and a manager and start the manager
            - we then send true down the newly created channel
        -Do we ever close the channel?
            - shouldn't that would mean the program is done accepting connections (could be a useful behavior in the future)
         - do we ever send false?
            - no, not sure what that would signal.
            - coordinator is specifically only designed to create/notify managers of a client connection

formally, New Coordinator:
- needs to know
    - client type
- needs to be able to
    - either notify or create and notify a manager on client connection
    - handle concurrency
- relies on
    - listener to send incoming clients
    - manager to implement actual manager
- implements
    - manager activation and memory