TREXImplementationAuthority

TREXImplementationAuthority holds the beacons that every shared suite of a network points at, and the archive of the versions published for them. Moving the beacons to a new version upgrades every shared suite at once. The concept is in Upgradeability: beacons and versions and the operation in 27 Upgrade a suite.

At a glance

Source	contracts/proxy/beacon/TREXImplementationAuthority.sol
Interface	ITREXImplementationAuthority
Deployed as	One contract per network, not upgradeable. Its constructor publishes a first version and deploys the five beacons, whose addresses never change
Role	The platform role VERSION_MANAGER

Versions

A Version is a uint24 that packs a major, a minor and a patch number of 8 bits each (VersionLib.pack(major, minor, patch)), so versions compare as numbers.

Function	Access	Reverts with
publish(version, impls)	VERSION_MANAGER	EmptyImplementations when an implementation address is zero, VersionAlreadyPublished. Archives the version without moving the beacons. Emits VersionPublished
upgrade(version)	VERSION_MANAGER	UnknownVersion, VersionNotNewer unless the version is above the current one. Points the five beacons at the implementations of the version. Emits SuiteUpgraded
publishAndUpgrade(version, impls)	VERSION_MANAGER	The errors of both. Does both in one transaction
currentVersion()	Anyone, read	The version the beacons point at
implementations()	Anyone, read	The implementations of the current version
implementationsFor(version)	Anyone, read	The implementations of a published version. Reverts with UnknownVersion
beacons()	Anyone, read	The five beacons

A published version cannot be replaced, and the beacons only move forward: there is no downgrade function.

The two structs

SuiteImplementations and SuiteBeacons each hold five addresses, in this order.

SuiteImplementations	SuiteBeacons	Contract
tokenImplementation	tokenBeacon	Token
trexRegistryImplementation	trexRegistryBeacon	TREXRegistry
irsImplementation	irsBeacon	IdentityRegistryStorage
mcImplementation	mcBeacon	ModularCompliance
accessManagerImplementation	accessManagerBeacon	TREXAccessManager

What an upgrade reaches

Suite	Effect of upgrade
Deployed with deployTREXSuite	Its five proxies read the shared beacons: it runs the new implementations from that transaction on
Deployed with deployTREXSuiteIsolated	None. Its beacons are its own, owned by its access manager, and the Issuer moves them

Trust statement. The holder of VERSION_MANAGER can change the code of every shared suite of the network in one transaction. An Issuer that does not accept this deploys an isolated suite and governs its own beacons.

Events

Event	Emitted when
VersionPublished(Version version, ITREXImplementationAuthority.SuiteImplementations implementations)	A version is archived
SuiteUpgraded(Version version, ITREXImplementationAuthority.SuiteImplementations implementations)	The shared beacons move to a version
BeaconsDeployed(ITREXImplementationAuthority.SuiteBeacons beacons)	Once, at construction