protected override Provider VisitPaging(PagingProvider provider)
{
State.IsSkipTakeChain = true;
var visitedSource = VisitCompilable(provider.Source);
State.AddSkip(provider.Skip);
State.AddTake(provider.Take);
return(visitedSource);
}
protected override Provider Visit(CompilableProvider cp)
{
var isPagingProvider = cp.Type.In(ProviderType.Take, ProviderType.Skip, ProviderType.Paging);
if (isPagingProvider && !State.IsSkipTakeChain)
{
var visitedProvider = (CompilableProvider)base.Visit(cp);
var requiresRowNumber = (State.Take != null && !takeSupported) || (State.Skip != null && !skipSupported);
// add rownumber column (if needed)
if (requiresRowNumber)
{
// Arrray to avoid access to modified closure
string[] columnName = { String.Format(Strings.RowNumberX, rowNumberCount++) };
while (visitedProvider.Header.Columns.Any(column => column.Name == columnName[0]))
{
columnName[0] = String.Format(Strings.RowNumberX, rowNumberCount++);
}
visitedProvider = new RowNumberProvider(visitedProvider, columnName[0]);
}
if (State.Take != null && State.Skip != null)
{
visitedProvider = new PagingProvider(visitedProvider, State.Skip, State.Take);
}
else if (State.Take != null)
{
visitedProvider = new TakeProvider(visitedProvider, State.Take);
}
else
{
visitedProvider = new SkipProvider(visitedProvider, State.Skip);
}
// add select removing RowNumber column
if (requiresRowNumber)
{
visitedProvider = new SelectProvider(
visitedProvider,
Enumerable.Range(0, visitedProvider.Header.Length - 1).ToArray());
}
return(visitedProvider);
}
if (!isPagingProvider && State.IsSkipTakeChain)
{
using (State.CreateScope())
return(base.Visit(cp));
}
return(base.Visit(cp));
}
/// <inheritdoc/>
protected override SqlProvider VisitPaging(PagingProvider provider)
{
if (providerInfo.Supports(ProviderFeatures.NativePaging))
{
return(VisitPagingNative(provider, provider.Take, provider.Skip));
}
if (providerInfo.Supports(ProviderFeatures.RowNumber))
{
return(VisitPagingRowNumber(provider));
}
throw new NotSupportedException(string.Format(Strings.ExXIsNotSupported, "Take/Skip"));
}
private SqlProvider VisitPagingRowNumber(PagingProvider provider)
{
var fromParameterBinding = CreateLimitOffsetParameterBinding(provider.From);
var toParameterBinding = CreateLimitOffsetParameterBinding(provider.To);
var bindings = new List <QueryParameterBinding> {
fromParameterBinding, toParameterBinding
};
var compiledSource = Compile(provider.Source);
var source = compiledSource.Request.Statement;
var queryRef = SqlDml.QueryRef(source);
var query = SqlDml.Select(queryRef);
var rowNumberColumn = queryRef.Columns.Last();
query.Columns.AddRange(queryRef.Columns.Cast <SqlColumn>());
query.Where = SqlDml.Between(rowNumberColumn,
fromParameterBinding.ParameterReference,
toParameterBinding.ParameterReference);
return(CreateProvider(query, bindings, provider, compiledSource));
}
public async override Task <QueryResponse <string> > Query(PostQueryRequest query, CancellationToken cancellationToken = default)
{
query.Pagination ??= new Pagination();
var paging = PagingProvider;
if (query.Type != null)
{
switch (query.Type)
{
case PostType.Article:
paging = new PagingProvider <string>(Path.Join(RootPath, "articles"), FileProvider);
break;
case PostType.Slides:
paging = new PagingProvider <string>(Path.Join(RootPath, "slides"), FileProvider);
break;
case PostType.Note:
paging = new PagingProvider <string>(Path.Join(RootPath, "notes"), FileProvider);
break;
}
}
else if (query.Category != null && query.Category.Items.Any())
{
var catRoot = Path.Join(RootPath, "categories");
catRoot = Path.Join(catRoot, Path.Combine(query.Category.Items.Select(NameUtility.Encode).ToArray()));
paging = new PagingProvider <string>(catRoot, FileProvider);
}
else if (query.Keywords != null && query.Keywords.Items.Any())
{
var catRoot = Path.Join(RootPath, "keywords");
paging = new PagingProvider <string>(Path.Join(catRoot, query.Keywords.Items.Select(NameUtility.Encode).First()), FileProvider);
}
await paging.FillPagination(query.Pagination);
var res = new QueryResponse <string>(
await paging.GetPaging(query.Pagination),
query.Pagination);
return(res);
}
/// <summary> /// Compiles <see cref="PagingProvider"/>. /// </summary> /// <param name="provider">Paging provider.</param> protected abstract TResult VisitPaging(PagingProvider provider);
protected RecordFSReaderBase(string rootPath, IFileProvider fileProvider) : base(rootPath, fileProvider)
{
PagingProvider = new PagingProvider <TId>(Path.Join(RootPath, "pages"), FileProvider);
}