supply_chain

Description:

supply chain

Supply Chain - Data Flow & State Management #
Supply Chain (SC) is a data flow and state management architecture.
Table of Content #

Idea
Goals
Getting Started
Features

Effective Asynchronous Workflow
Priorization
Animations
No Unneccessary Updates
Build-In Test Methods
Timeout Protection
Visualize the Node Graph


Features and bugs

Idea #

A node receives components from one or more suppliers.
It produces a product and delivers it to customers.
Doing so complex data flow graphs can be created.
A supply chain manager SCM coordinates the process.


Goals #

✅ Efficiently manage application state
✅ Visualize application data flow & dependencies
✅ Smoothly animate state transitions
✅ Data caching
✅ Prioritze updates

Getting Started #

Checkout the example
Checkout node_test.dart
Checkout scm_test.dart

Features #
Effective Asynchronous Workflow #

Our workflow consists of three stages: Nomination, Preparation and Production.
In the first stage nodes are nominated for production
The SCM collects nominated nodes for a short time, e.g. a frame or a event loop cycle.
In the second stage, the SCM prepares a dependency graph. Nodes are staged for production.
In the final step nodes are instructed to produce depending on dependencies and priorities.

Priorization #

Node can have a priority.
Nodes with higher priorities are processed first.
If a node has a high priority, its suppliers will a high priority too.
Currently a realtime and a frame priority is offered.
Nodes with realtime priority will produce in the same run loop cycle.
Nodes with frame priority will produce at the next frame / tick.

Animations #

Scm offers a tick() method.
Tick will nominate all nodes with frame priority
These node are instructed to provide a new product on every frame

No Unneccessary Updates #

All products produced by suppliers have a hash
SCM uses suppliers to estimate if a node needs to produce or not
No hash changes, no production.
Additionally SCM builds a dependency graph

Build-In Test Methods #

We break the paradigm not to mix production and test code
Scm can be set to test mode using the isTest constructor param
Use methods like testRunNormalTasks, testRunFastTasks etc. to control the test flow

Timeout Protection #

I a node does not produce in a given time window, it will be skipped
Thus nodes cannot block the production process

Visualize the Node Graph #

Use SupplyChain.graph to get a Graphviz graph that can be turned into an svg file

Features and bugs #
Please file feature requests and bugs at GitHub.