/// <summary>
/// Builds the basic filter for a given block.
///
/// The basic filter is designed to contain everything that a light client needs to sync a regular Bitcoin wallet.
/// A basic filter MUST contain exactly the following items for each transaction in a block:
/// * The outpoint of each input, except for the coinbase transaction
/// * The scriptPubKey of each output
/// * The txid of the transaction itself
/// </summary>
/// <param name="block">The block used for building the filter.</param>
/// <returns>The basic filter for the block.</returns>
public static GolombRiceFilter BuildBasicFilter(Block block)
{
var builder = new GolombRiceFilterBuilder()
.SetKey(block.GetHash());
foreach (var tx in block.Transactions)
{
if (!tx.IsCoinBase) // except for the coinbase transaction
{
foreach (var txin in tx.Inputs)
{
// The outpoint of each input
builder.AddOutPoint(txin.PrevOut);
}
}
foreach (var txout in tx.Outputs)
{
// The scriptPubKey of each output
builder.AddScriptPubkey(txout.ScriptPubKey);
}
}
return(builder.Build());
}
/// <summary>
/// Builds the extended filter for a given block.
///
/// The extended filter contains extra data that is meant to enable applications with more advanced smart contracts.
/// An extended filter MUST contain exactly the following items for each transaction in a block except the coinbase:
/// * Each item within the witness stack of each input (if the input has a witness)
/// * Each data push in the scriptSig of each input
/// </summary>
/// <param name="block">The block used for building the filter.</param>
/// <returns>The extended filter for the block.</returns>
public static GolombRiceFilter BuildExtendedFilter(Block block)
{
var builder = new GolombRiceFilterBuilder()
.SetKey(block.GetHash());
foreach (var tx in block.Transactions)
{
if (!tx.IsCoinBase) // except the coinbase
{
foreach (var txin in tx.Inputs)
{
if (txin.ScriptSig != Script.Empty)
{
// Each data push in the scriptSig of each input
builder.AddScriptSig(txin.ScriptSig);
}
if (txin.WitScript != WitScript.Empty)
{
// Each item within the witness stack of each input (if the input has a witness)
builder.AddWitness(txin.WitScript);
}
}
}
}
return(builder.Build());
}
