private int SetPageSizeAndGetPage(int skip, int max, ArchiveQueryParameters context)
{
if (skip > ArchiveQueryParameters.MAX_PAGE_SIZE)
{
throw new NotSupportedException("Skip cannot exceed the maximum page size of " + ArchiveQueryParameters.MAX_PAGE_SIZE);
}
if (skip > 0 && max > 0 && skip % SKIP_MULTIPLE != 0)
{
throw new NotSupportedException("When specifying both Skip and Take (max) then Skip must be a multiple of " + SKIP_MULTIPLE);
}
if (skip > max && max > 0)
{
//we don't want to fetch a lot of useless results, so we use small page sizes to get to our max.
//the downsideis that we might be doing a lot of calls before we get to max
context.PageSize = SKIP_MULTIPLE;
return(skip / context.PageSize);
}
else
{
//when no max is specified or if skip <= max we just fetch everything after the skipped rows
context.PageSize = skip;
return(1);
}
}
private IList <T> InnerDoQuery(RestrictionBuilderBase restrictionBuilder, OrderByBuilder orderByBuilder, int max, int skip)
{
ArchiveExecutionContext executionContext = _archiveExecutionContextProvider.Get();
if (executionContext == null)
{
throw new InvalidOperationException(nameof(executionContext) + " not set, cannot be null");
}
ArchiveQueryParameters context = new ArchiveQueryParameters();
context.ArchiveName = executionContext.ArchiveName;
context.Entities = executionContext.Entities;
context.RequestedColumns = DynamicPropertyHelper.GetAllDbColumnsPrefixed <T>();
int page = 0;
if (skip > 0)
{
page = SetPageSizeAndGetPage(skip, max, context);
}
if (restrictionBuilder != null)
{
context.Restrictions = restrictionBuilder.GetRestrictions();
}
if (orderByBuilder != null)
{
context.OrderBy = orderByBuilder.Get();
}
return(_resultParser.Parse <T>(executionContext, _executor.GetItems(context, max, page)));
}
private ArchiveOrderByInfo[] GetOrderBy(ArchiveQueryParameters context)
{
if (context.OrderBy == null)
{
return(null);
}
return(context.OrderBy.ToArray());
}
private ArchiveRestrictionInfo[] GetRestrictions(ArchiveQueryParameters context)
{
if (context.Restrictions == null)
{
return(null);
}
return(context.Restrictions.ToArray());
}
private string[] GetColumns(ArchiveQueryParameters context)
{
if (context.RequestedColumns.Count == 0)
{
throw new Exception("No columns specified");
}
return(context.RequestedColumns.Distinct().ToArray());
}
private IList <ArchiveListItem> GetMultiPageItems(ArchiveQueryParameters parameters, int max, int page)
{
List <ArchiveListItem> items = new List <ArchiveListItem>();
if (parameters.PageSize > max && max > 0 && page == 0)
{
//if we can get the requested amount of items in one go, do so. this only works if we don't want to start from a specific page
parameters.PageSize = max;
}
using (IArchiveAgentWrapper agent = _archiveAgentWrapperCreator())
{
bool hasResult = true;
int loopPage = page;
while (hasResult) //loop while we still can get results
{
//change the context if we are nearing our max, but only if we did not specify a page
if (max > 0 && items.Count + parameters.PageSize > max && page == 0)
{
parameters.PageSize = max - items.Count;
}
IList <ArchiveListItem> itemsOnPage = GetItems(parameters, agent, loopPage);
//stop if there are no more items found
if (itemsOnPage == null)
{
hasResult = false;
}
else
{
items.AddRange(itemsOnPage);
loopPage++;
//check if the number of results matches the page-size, if not, stop
if (itemsOnPage.Count < parameters.PageSize)
{
hasResult = false;
}
//if there is a max and the item count is equal to or exceeded the max, we should stop as well
if (max > 0 && items.Count >= max)
{
hasResult = false;
}
}
}
}
//remove items if we fetched too many (possible when max and page is specified
if (max > 0 && items.Count > max)
{
items.RemoveRange(max, items.Count - max);
}
return(items);
}
private IList <ArchiveListItem> GetItems(ArchiveQueryParameters parameters, IArchiveAgentWrapper agent, int page)
{
if (parameters.PageSize > ArchiveQueryParameters.MAX_PAGE_SIZE)
{
throw new NotSupportedException("Page size cannot be larger than " + ArchiveQueryParameters.MAX_PAGE_SIZE);
}
if (parameters.Restrictions == null || parameters.Restrictions.Count == 0)
{
throw new Exception("No restriction specified. The SuperOffice ArchiveAgent needs at least one restriction.");
}
ArchiveListItem[] results = agent.GetArchiveListByColumns(parameters.ArchiveName, GetColumns(parameters), GetOrderBy(parameters), GetRestrictions(parameters), parameters.Entities, page, parameters.PageSize);
if (results == null || results.Length == 0)
{
return(null);
}
else
{
return(results);
}
}
public IList <ArchiveListItem> GetItems(ArchiveQueryParameters parameters, int maxItems, int page)
{
return(GetMultiPageItems(parameters, maxItems, page));
}
