public PagingIterator(FdbRangeQuery <T> query, IFdbReadOnlyTransaction transaction)
{
Contract.Requires(query != null);
this.Query = query;
this.Transaction = transaction ?? query.Transaction;
}
public ResultIterator([NotNull] FdbRangeQuery <T> query, IFdbReadOnlyTransaction transaction, [NotNull] Func <KeyValuePair <Slice, Slice>, T> transform)
{
Contract.Requires(query != null && transform != null);
m_query = query;
m_transaction = transaction ?? query.Transaction;
m_resultTransform = transform;
}
public static FdbRangeQuery <TValue> Values <TKey, TValue>([NotNull] this FdbRangeQuery <KeyValuePair <TKey, TValue> > query)
{
Contract.NotNull(query, nameof(query));
var f = query.Transform;
//note: we only keep a reference on 'f' to allow the previous query instance to be collected.
Contract.Assert(f != null);
return(query.Map <TValue>((x) => f(x).Value));
}
/// <summary>Copy constructor</summary>
private FdbRangeQuery([NotNull] FdbRangeQuery <T> query, [NotNull] FdbRangeOptions options)
{
Contract.Requires(query != null && options != null);
this.Transaction = query.Transaction;
this.Begin = query.Begin;
this.End = query.End;
this.Transform = query.Transform;
this.Snapshot = query.Snapshot;
this.Options = options;
this.OriginalRange = query.OriginalRange;
}
public static FdbRangeQuery <TResult> Keys <TKey, TValue, TResult>([NotNull] this FdbRangeQuery <KeyValuePair <TKey, TValue> > query, [NotNull] Func <TKey, TResult> transform)
{
Contract.NotNull(query, nameof(query));
Contract.NotNull(transform, nameof(transform));
var f = query.Transform;
//note: we only keep a reference on 'f' to allow the previous query instance to be collected.
Contract.Assert(f != null);
return(query.Map <TResult>((x) => transform(f(x).Key)));
}
public override AsyncIterator <TResult> Select <TResult>(Func <T, TResult> selector)
{
var query = new FdbRangeQuery <TResult>(
m_transaction,
m_query.Begin,
m_query.End,
(x) => selector(m_resultTransform(x)),
m_query.Snapshot,
m_query.Options
);
return(new FdbRangeQuery <TResult> .ResultIterator(query, m_transaction, query.Transform));
}
public static FdbRangeQuery <V> Values <K, V>(this FdbRangeQuery <KeyValuePair <K, V> > query)
{
if (query == null)
{
throw new ArgumentNullException("query");
}
var f = query.Transform;
//note: we only keep a reference on 'f' to allow the previous query instance to be collected.
Contract.Assert(f != null);
return(query.Map <V>((x) => f(x).Value));
}
public static FdbRangeQuery <R> Keys <K, V, R>(this FdbRangeQuery <KeyValuePair <K, V> > query, [NotNull] Func <K, R> transform)
{
if (query == null)
{
throw new ArgumentNullException("query");
}
if (transform == null)
{
throw new ArgumentNullException("transform");
}
var f = query.Transform;
//note: we only keep a reference on 'f' to allow the previous query instance to be collected.
Contract.Assert(f != null);
return(query.Map <R>((x) => transform(f(x).Key)));
}
