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An action representing an update to the LoE fragment, that determines which blocks can be selected in the ChainDB. With Ouroboros Genesis, this is implemented via the GDD governor, see updateLoEFragGenesis.

The callback is applied to the current chain and the current ledger state, and yields the new LoE fragment, which should be anchored in the immutable tip.

densityDisconnect genWin k states candidateSuffixes loeFrag yields the list of peers which are known to lose the density comparison with any other peer, when looking at the genesis window after loeFrag.

The peers are taken from the keys of candidateSuffixes.

candidateSuffixes tells for every peer what is the fragment that the peer proposes to use after loeFrag.

states contains further information for every peer, such as the last ChainSync instruction the peer sent, and whether the peer is idling (i.e. it sent MsgAwaitReply).

loeFrag is the fragment from the immutable tip to the first intersection with a candidate fragment.

A never ending computation that runs the GDD governor whenever the STM action getTrigger changes, writing the LoE fragment computed by loEUpdater to varLoEFrag, and then triggering ChainSel to reprocess all blocks that had previously been postponed by the LoE.

Compute the fragment loeFrag between the immutable tip and the earliest intersection between curChain and any of the candidates.

The immutable tip is the anchor of curChain.

The function also yields the suffixes of the intersection of loeFrag with every candidate fragment.

Update the LoE fragment.

See UpdateLoEFrag for the definition of LoE fragment.

Additionally, disconnect the peers that lose density comparisons.

Disconnecting peers causes chain fragments to be removed, which causes the LoE fragment to be updated over and over until no more peers are disconnected.

getCandidates is the callback to obtain the candidate fragments

getHandles is the callback to get the handles that allow to disconnect from peers.

This version of the LoE implements part of the intended Genesis approach. The fragment is set to the prefix of all candidates, ranging from the immutable tip to the earliest intersection of all peers.

Using this will cause ChainSel to stall indefinitely, or until a peer disconnects for unrelated reasons. In the future, the Genesis Density Disconnect Governor variant will extend this with an analysis that will always result in disconnections from peers to ensure the selection can advance.

A dummy version of the LoE that sets the LoE fragment to the current selection. This can be seen as emulating Praos behavior.