WFO-Advanced Overview

Table of Contents

1. Introduction

2. Design Drivers and Philosophy

2.1 Hierarchy of systems
2.2 Objective
2.3 History
2.4 Development Process
2.5 Design Driver
2.6 Implementation
2.7 Summary

3.1 Design Methods
3.2 Design Patterns
3.3 Programming Languages
3.3.1 C++
3.3.2 FORTRAN
3.3.3 Tcl/Tk
3.3.4 Other Scripting Languages
3.4 Incremental Development Methodology
3.5 Daily Builds
3.6 Configuration Management
3.7 Unit Testing
3.8 Integration Testing

4.1 Introduction
4.2 Data Acquisition and Communication
4.2.1 Local Area Network
4.2.1.1 Function
4.2.1.2 Description
4.2.1.3 Backup
4.2.2 Satellite Broadcast Network (SBN)
4.2.2.1 Function
4.2.2.2 Description
4.2.2.3 Backup
4.2.3 WSR-88D Radar
4.2.3.1 Function
4.2.3.2 Description
4.2.3.3 Backup
4.2.4 Other Processors
4.2.4.1 Function
4.2.4.2 Description
4.2.4.3 Backup
4.3 Database and Application Computers
4.3.1 Function
4.3.2 Description
4.3.3 Backup
4.4 Workstation
4.4.1 Function
4.4.2 Description
4.4.3 Backup
4.5 Concluding Remarks

5.1 WFO-Advanced Subsystems
5.2 Interprocess Communications
5.3 Foundation Classes
5.3.1 Container Classes
5.3.2 Common Data Classes
5.3.3 Event Logging
5.4 Off-the-shelf Software Packages
5.4.1 OI
5.4.2 Tcl/Tk
5.4.3 DMQ
5.4.4 Informix
5.4.5 NetCDF

5a.1 IPC Requirements
5a.1.1 Asynchronous Sends (Fire & Forget)
5a.1.2 Synchronous Sends
5a.1.3 Message Priority
5a.1.4 Message Selection
5a.1.5 Friendly to Event Multiplexors
5a.1.6 Unlimited Message Size
5a.1.7 Reliable and Maintainable
5a.1.8 Performance
5a.2 History of the IPC Library
5a.2.1 DEC Message Queue (DMQ)
5a.2.1.1 Design Overview
5a.2.1.2 Strengths
5a.2.1.3 Weaknesses
5a.2.2 Server Based Socket IPC
5a.2.2.1 Design Overview
5a.2.2.2 Strengths
5a.2.2.3 Weaknesses
5a.2.3 Thread Based Socket IPC
5a.2.3.1 Design Overview
5a.2.3.2 Strengths
5a.2.3.3 Weaknesses
5a.2.4 Requirement Comparisons
5a.2.5 Performance Comparisons
5a.3 Thread Based Socket IPC Design
5a.3.1 Consider This
5a.3.2 Object Interaction
5a.3.2.1 SocketConnection
5a.3.2.2 AcceptSocket
5a.3.2.3 DataSocket
5a.4 Thread Based Socket IPC Implementation
5a.4.1 Addressing
5a.4.1.1 Anonymous Addresses
5a.4.1.2 Named Addresses
5a.4.1.3 Assigning an Address to a Process
5a.4.2 Waiting for Events
5a.4.2.1 UNIX Select
5a.4.2.2 Waiting for IPC from any Source
5a.4.2.3 Waiting for IPC from a Particular Source
5a.4.2.4 Continually Waiting for All Events
5a.4.2.5 Using Tcl/Tk's Notifier for Event Waiting
5a.4.3 Client Interface for Sending a Message
5a.4.3.1 Packaging the Data
5a.4.3.2 Packaging the Metadata
5a.4.3.3 Initiating the Send
5a.4.3.4 Preparing for the Send
5a.4.4 Data Transmission
5a.4.4.1 Selecting a Socket
5a.4.4.2 Writing to a Socket
5a.4.4.3 Detecting Message Arrival
5a.4.4.4 Reading the Socket
5a.4.5 Client Interface for Receiving a Message
5a.4.5.1 Logical Modules and Message Types
5a.4.5.2 Use of Receiver Objects
5a.4.5.3 Delivering the Message to the Receiver
5a.4.5.4 Interpreting the Message
5a.4.6 Establishing and Breaking Connections Between Processes
5a.4.6.1 Making Room for a New Connection
5a.4.6.2 Initiating a New Connection Request
5a.4.6.3 Receiving a New Connection Request
5a.4.6.4 Breaking a Connection
5a.4.7 Waiting to Write to a Full Socket Buffer
5a.4.7.1 Detecting a Full Buffer
5a.4.7.2 Mutual Exclusion
5a.4.7.3 Synchronous Waiting
5a.4.7.4 Asynchronous Waiting
5a.4.7.5 Thread Management
5a.4.8 Signal Handling
5a.4.8.1 Registering for Signals
5a.4.8.2 Controlling Signal Delivery
5a.4.8.3 Synchronous and Asynchronous Signals and Re-entrancy
5a.4.8.4 Single Thread Implementation
5a.4.8.5 Multiple Thread Implementation
5a.5 Conclusions and Future Direction

6.1 Introduction
6.2 SBN
6.2.1 Design
6.2.2 Data Flow
6.2.3 Process Decomposition
6.2.4 Tables and Files Accessed
6.3 Radar Ingest
6.3.1 Class I interface
6.3.1.1 Design
6.3.1.2 Data Flow
6.3.1.3 Process Decomposition
6.3.1.4 Tables and Files Accessed
6.3.2 Dial-out Interface
6.3.2.1 Design
6.3.2.2 Data Flow
6.3.2.3 Process Decomposition
6.3.2.4 Tables and Files Accessed
6.4 LDAD Ingest
6.4.1 Introduction
6.4.2 Concept
6.4.3 CDoT
6.4.3.1 Design
6.4.3.2 Data Flow
6.4.3.3 Process Decomposition
6.4.3.4 Tables and Files Accessed
6.4.4 ALERT Decoder
6.4.4.1 Design
6.4.4.2 Data Flow
6.4.4.3 Process Decomposition
6.4.4.4 Tables and Files Accessed

7.1 Overview
7.1.1 System Design
7.1.1.1 Data Processing and Storage
7.1.2 Data Retrieval
7.2 Data Routing
7.2.1 Router Processes
7.2.1.1 Description
7.2.1.2 Main objects
7.3 Data Controller Processes
7.3.1 Description
7.3.2 Interactions With Decoders
7.3.3 Main Objects
7.4 Decoding
7.4.1 METAR
7.4.2 Satellite
7.4.3 Models
7.4.3.1 GRIB
7.4.3.2 Grids
7.4.4 RAOB
7.4.5 Text
7.4.5.1 Communications Control Block (CCB)
7.4.5.2 WMO Header
7.4.5.3 Product Data
7.4.5.4 AFOS Identifier
7.4.5.5 TextDB Class
7.4.5.6 Collective Text Decoder
7.4.5.7 Standard Text Decoder
7.4.5.8 Data Tables
7.4.6 BUFR
7.4.7 Redbook Graphics
7.5 Storage/Formats
7.5.1 Radar
7.5.2 Satellite
7.5.3 Grid
7.5.4 Point Data
7.5.4.1 RAOB
7.5.4.2 METAR
7.5.4.3 Lightning
7.5.4.4 LDAD
7.5.5 Redbook Graphics
7.6 Notification
7.6.1 Notification Server Classes
7.6.1.1 class NotificationServer
7.6.1.2 The Notification List (class NotificationListEntry)
7.6.1.3 The Client List (class ClientList)
7.6.1.4 The New Data List (Dict<DataAccessKey, SeqOf<DataTime> >)
7.6.2 Key Notification Server Algorithms
7.6.2.1 Message Receipt and Dispatching
7.6.2.2 Data Notification Arrival
7.6.2.3 Depictable Registration and Cancellation
7.6.2.4 Timer Expiration and Low-Priority Processing
7.7 Inventory
7.7.1 Concepts of time in WFO-Advanced
7.7.2 Inventory Types
7.8 Retrieval
7.8.1 Data retrieval in depictables
7.8.2 Data retrieval in applications
7.9 Purging
7.9.1 Scour
7.9.2 Fxa-data.purge
7.9.2.1 Description
7.9.2.2 Purging criteria
7.9.3 Future Plans

8.1 WFO-Advanced UI Philosophy
8.1.1 Layout
8.2 User Interface Library
8.2.1 Overview
8.2.2 Client Classes and Callbacks
8.2.3 Caveats - Tcl/Tk
8.3 Software Design
8.3.1 FXA Process Design
8.3.2 Classes/Objects
8.3.2.1 Tiled Display Window
8.3.2.2 UI Workspace Manager
8.3.2.3 Product Button Client
8.3.2.4 Product Button
8.3.2.5 Scale Menu Manager
8.3.2.6 Load Mode Manager
8.3.2.7 Control Classes
8.3.2.8 Clock Classes
8.3.2.9 Map Menu Manager
8.3.2.10 Announcement Classes
8.3.2.11 Procedure/Bundle Classes
8.3.2.12 UI_KeypadClient
8.3.3 Interprocess Communication
8.3.4 Starting FXA and the Main Function

9.1 IGC Design Drivers
9.2 Process Environment
9.2.1 Child Process
9.2.1.1 Invocation Arguments
9.2.1.2 User Interface
9.2.2 Stand-Alone Process
9.2.2.1 Invocation Arguments
9.2.2.2 User Interface
9.2.3 Thread of Execution
9.2.3.1 Initialization
9.2.3.2 Event Processing
9.2.3.3 Termination
9.3 Overview of the Main Objects
9.3.1 EventDispatcher
9.3.1.1 Process Context
9.3.1.2 Responsibilities
9.3.2 IGC_Impl
9.3.2.1 Process Context
9.3.2.2 Inheritance
9.3.2.3 Responsibilities
9.3.3 UI_WorkspaceManager
9.3.3.1 Process Context
9.3.3.2 Responsibilities
9.3.4 LoopingMgr
9.3.4.1 Process Context
9.3.4.2 Inheritance
9.3.4.3 Responsibilities
9.3.5 DisplayMgr
9.3.5.1 Process Context
9.3.5.2 Modes
9.3.5.3 Responsibilities
9.3.6 DisplayPanel
9.3.6.1 Process Context
9.3.6.2 Inheritance
9.3.6.3 Modes:
9.3.6.4 Responsibilities
9.3.7 ViewMgr
9.3.7.1 Process Context
9.3.7.2 Responsibilities
9.3.8 FrameSeq
9.3.8.1 Process Context
9.3.8.2 Inheritance
9.3.8.3 Responsibilities
9.3.9 Frame
9.3.9.1 Process Context
9.3.9.2 Responsibilities
9.3.10 GraphicDepictTuple
9.3.10.1 Process Context
9.3.10.2 Inheritance
9.3.10.3 Responsibilities
9.3.11 ImageDepictTuple
9.3.11.1 Process Context
9.3.11.2 Inheritance
9.3.11.3 Responsibilities
9.3.12 GraphicDepictSeq
9.3.12.1 Process Context
9.3.12.2 Inheritance
9.3.12.3 Responsibilities
9.3.13 ImageDepictSeq
9.3.13.1 Process Context
9.3.13.2 Inheritance
9.3.13.3 Responsibilities
9.4 Walk-through of Loading a Product
9.4.1 Load of a product to an empty display
9.4.2 Load of a product to a non-empty display
9.4.3 Image combo load
9.4.4 Multi-load
9.4.5 Product update (auto-update)
9.5 Walk-through of Displaying a Product
9.5.1 Displaying the current frame
9.5.2 Preparing frames in the background
9.5.3 Rendering a graphic tuple
9.5.4 Rendering an image tuple
9.5.4.1 Rendering a single 8-bit image
9.5.4.2 Rendering a single 24-bit image
9.5.4.3 Rendering an 8-bit image combo
9.5.4.4 Rendering a combo 24-bit image
9.5.5 Dimming and fading images
9.5.5.1 Calculating a combined color table
9.6 Walk-throughs of Other IGC Operations
9.6.1 Zooming and roaming
9.6.1.1 Zooming user interface
9.6.1.2 Roaming user interface
9.6.1.3 Zooming and roaming implementation
9.6.2 Toggling an overlay's visibility
9.6.3 Sampling
9.6.4 Stepping and looping
9.6.4.1 Stepping walk-through
9.6.4.2 Looping walk-throughs
9.6.5 Swapping

10.1 What is a depictable?
10.2 The depictable class hierarchy
10.3 Support software
10.3.1 The Painter class
10.3.2 The Depictor class
10.3.3 The Xform class
10.3.4 The XformFunctions module
10.3.5 Remapping tables
10.3.6 Fortran Graphics module
10.3.7 Current usage of Fortran in depictables
10.4 How depictables work
10.4.1 How depictables create viewable displays
10.4.2 A specific example
10.5 Managing depictables
10.5.1 Context of depictables
10.5.2 Adding new depictables
10.5.2.1 Accessor for a new data type
10.5.2.2 Formally define a new depictable type
10.5.2.3 Code for the new depictable type
10.5.2.4 Enable instantiation of the new depictable type
10.5.2.5 Enable inventories for the new depictable type
10.5.2.6 New data key entries
10.5.2.7 New depictable key entries
10.5.2.8 New product buttons
10.5.2.9 Place new product buttons on the menu

11.1 Applications
11.1.1 What is the Application Interface?
11.1.1.1 Interaction with D2D
11.1.1.2 Launching Applications
11.1.1.3 Application Characteristics
11.1.2 Implementation of the Application Interface
11.1.3 Application Requests
11.1.3.1 The Load Request
11.1.3.2 The Export Request
11.1.3.3 Miscellaneous Requests
11.1.3.4 Supporting New Requests
11.1.4 Application Notifications
11.2 Extensions
11.2.1 Extension Framework Classes
11.2.1.1 Interactive Depictables
11.2.1.2 Editable Elements
11.2.1.3 The Extension
11.2.2 Using the Extension Class
11.2.2.1 The Active State
11.2.2.2 Editable Element Notifications
11.2.2.3 Depictable Sequence Notifications
11.2.3 A Sample Extension

12.1 Overview
12.2 Data Monitor
12.3 Ingest Process Monitor
12.4 System Performance Monitor
12.5 Prototype AWIPS Monitors
12.6 Concluding Remarks

13.1 Overview
13.2 Text Display User Interface
13.2.1 Small processes
13.2.2 Use of Tcl/Tk
13.2.3 Software Interface to the Text Database
13.2.4 Text Display Processes
13.2.5 Key Text Script Files
13.2.6 The textWish Tcl/Tk Interpreter
13.3 Informix Database
13.4 Text Server
13.4.1 Text Read Server
13.4.2 Text Write Server

This document is maintained by Joe Wakefield. Last modified: Thu Oct 2 17:32:18 GMT 1997 .