Struct PreImageCycle

Combines two PreImageCache, allowing for faster lookup

struct PreImageCycle ;

Nodes generate a large amount of pre-images on startup, then will seek to a certain position in their pre-image chain and use the values sequentially. In order to reduce the space usage of nodes, while ensuring they don't get random delays while seeking pre-images, this struct holds two caches. The seeds are sparse values spawing the whole pre-image chain, while the preimages are consecutive values for the current cycle.

Constructors

NameDescription
this () Make sure we get initialized by disabling the default ctor
this (secret, cycle_length, preimage_count, initial_seek) Construct an instance based on a secret
this (from, at, cycle_length, initial_seek) Construct an instance based on a pre-image at a given height

Fields

NameTypeDescription
cycles ulongThe number of cycles for a bulk of pre-images
index uintThe index of the enrollment within the current cycle
PreImageCount immutable(ulong)The total number of pre-images
preimages PreImageCacheCurrently active list of pre-images
seeds PreImageCacheSeed for all enrollments for the current cycle

Methods

NameDescription
opIndex (height) Get a pre-image at the specified height.

Example

const cycle_length = 2;
const number_of_cycles = 10;
testPreImageCycle(cycle_length, number_of_cycles);

Example

const cycle_length = 3;
const number_of_cycles = 12;
testPreImageCycle(cycle_length, number_of_cycles);

Example

Test for the getCycleSeed function 

import agora.utils.WellKnownKeys;
import std.exception;

Hash seed;
Height seed_height;
getCycleSeed(NODE5, 20, seed, seed_height);
assert(seed != Hash.init);
assert(seed_height != Height(0));

getCycleSeed(NODE5, 1008, seed, seed_height);
assert(seed != Hash.init);
assert(seed_height != Height(0));