updatesync

Documentation

Overview

Package updatesync is deprecated and should not be used.

Index

• func UpdateSync(mctx manipulate.Context, m manipulate.Manipulator, obj elemental.Identifiable, ...) error

Functions

func UpdateSync

func UpdateSync(
	mctx manipulate.Context,
	m manipulate.Manipulator,
	obj elemental.Identifiable,
	updateFunc func(elemental.Identifiable),
) error

UpdateSync is an advanced function that allows to retry an failed update operation due to an updateTime mismatch (basically an update occurred between the time you got a copy of an object and the time you try to update it.

It gets a manipulator and context to perform the updatea dnd also a function that returns an identifiable. This function must be used to apply the desired update. IT MUST NOT ALLOCATE A NEW OBJECT. For perf reasons, UpdateSync does not enforce that the return of your function must be a pointer.

UpdateSync gets the Identifiable you want to update using your function and tries to update it. If it fails because of a desync, it will retrieve the latest copy of your object (modifying it) then will apply your function again (so you can reaply your desired changes) and try again until it succeeds or until the max number of tries is reached.

Example:

// If we have this object unit in memory
o := &Object{
    Name: "Hello World",
    Description: "This is the original description"
}

// Then if we want to change the description, even if an update happened, we do:
err := UpdateSync(ctx.Background(), m, nil, func(obj elemental.Identifiable) {
    obj.(*Object).Description = "This is the description I want!"
}

Please keep in mind you have to be very careful with this function. You may still put the target object in a very weird state, if you override attributes that can be managed by a different source of truth.