Pre populating an Ethereum contract with digital assets

Question

I would like some advice on what approach with be best to take to achieve the following.

I want to release the contract with around 50,000 digital assets, think of it like pre filling a database with around x number of users. I want to then release a new asset every x amount of minutes, similar to CryptoKitties. Users can then purchase these newly released assets.

The asset may be structured as follows:

ID, Field 1, Field 2, Field 3

Now Im not to worried about the second part, my issue is how I go about pre loading the 50,000 digital assets. Im thinking in terms of gas costs etc as that many records might be expensive.

Answer 1

It's all possible, but the transaction costs are most likely going to blow up. You can find a rough estimate here.

Also, generating things randomly is not that easy in Ethereum, as the EVM is deterministic. You could use Oraclize.it though, as a source for a randomnes seed and use it to generate multiple items in one transaction.

Answer 2

If is it possible to calculate attributes of prepopulated assets based on their IDs, then you may generate pre-populated assets in a lazy way like this:

struct Asset {
  uint id;
  // Field 1, field 2, field 3 ...
}

// Maps asset ID to asset
mapping (uint => Asset) assets;

function getAssetByID (uint id) internal returns (Asset storage asset) {
  require (id > 0);
  asset = assets.get (id);
  if (asset.id == 0) {
    require (id <= 50000);
    prepopulateAsset (id, asset);
  }
}

function prepopulateAsset (uint id, Asset storage asset) internal {
  asset.id = id;
  // Prepopulate other asset fields based on asset ID
}