This library is a stripped down version of some of the utilities developed for the Trustability project https:/markburgess/Trustability. These provide intentionally simple solution methods that are not provided by other projects. They can be viewed as pedagogical examples to be incorporated into other code, perhaps replacing files with embedded databases etc, where appropriate.
The purpose of this library is probably not what you think it should be. There is no library that can assess trust for you, or that can make your code more trustworthy. The methods here assist in the practical management of trust and the policies we form around it. If you'd like to understand what they have to do with trust, please refer to the project page at http://markburgess.org/trustproject.html
test_context_eval.go - evaluate some test policy expressions
test_context.go - example of using context in dynamic changes
test_promise_wrapper.go - example of using the promise locking wrapper
Two sets of functions for wrapping transactional events or critical sections parenthetically (with begin-end semantics).
- Functions that timestamp transactions at the moment of measurement according to the local system clock
PromiseContext_Begin(g Analytics, name string) PromiseContext
PromiseContext_End(g Analytics, ctx PromiseContext) PromiseHistory
- Functions with Golang time stamp supplied from outside, e.g. for offline analysis with epoch timestamps.
StampedPromiseContext_Begin(g Analytics, name string, before time.Time) PromiseContext
StampedPromiseContext_End(g Analytics, ctx PromiseContext, after time.Time) PromiseHistory
The wrappers refuse to acquire a lock unless a minmum time has elapsed. If a maximum holding time has expired, the lock will be forced. The configured values are currently fixed at 30 and sixty seconds.
ifelapsed := int64(30)
expireafter := int64(60)
The method is to assign real numbers between 0and 1 to flag/signal variables that are set as a result of conditions within a program, and to evaluate quasi-logical probabilistic expressions to describe policy conditions. An undefined variable or a variable with value 0 is effectively false and any positive value is somewhat true.
-InitializeContext() - reset all symbols in context to undefined / false
-ContextActive(string) - active the symbol, set to true
-ContextSet() - return the set of defined symbols
-SetContext(s string,c float64) - set the real value of a context variable to an explicit real confidence value
-Confidence(s string) float64 - return the real value named symbol
-ContextEval(s string) (string,float64) - return the real value of the expression evaluated according to AND/OR algebra rules
-IsDefinedContext(s string) bool - if the expression evaluates to a result greater than zero according to AND/OR algebra rules this returns true
My working environment is GNU/Linux, where everything is simple. Setting up the working environment for all the parts is a little bit of work (more steps than are desirable), but it should be smooth.
- Install git client packages on your computer.
- Go to: https://golang.org/dl/ to download a package.
- Some file management to create a working directory and link it to environment variables:
$ mkdir -p ~/go/bin
$ mkdir -p ~/go/src
$ cd ~/somedirectory
$ git clone https:/markburgess/TnT.git
$ ln -s ~/somedirectory/Trustability/pkg/TnT ~/go/src/TnT
- It's useful to put this in your ~/.bashrc file
export PATH=$PATH:/usr/local/go/binexport GOPATH=~/go
Don’t forget to restart your shell or command window after editing this or do a
$ source ~/.bashrc
- You can get fetch the drivers for using the graph database code and the
$ go get github.com/arangodb/go-driver