/// <summary>
/// Perform the action to load data from data source.
/// </summary>
/// <returns></returns>
protected async Task LoadData()
{
try
{
IsLoading = true;
await OnDataLoading.InvokeAsync(new GridViewPaginationEventArgs(CurrentPage, PageSize));
}
finally
{
IsLoading = false;
await InvokeAsync(NotifyStateChanged);
}
}
/// <summary>
/// 加载 <see cref="DataSourceProvider"/> 绑定方法的数据。
/// </summary>
public async Task LoadData()
{
ShowLoading();
var dataSource = await Task.Run(() => DataSourceProvider());
if (!(dataSource is IEnumerable data))
{
throw new InvalidOperationException($"{nameof(DataSourceProvider)} 返回的对象不是 {nameof(IEnumerable)} 的实例");
}
await OnDataLoading.InvokeAsync(null);
Data = data.Cast <object>().ToList();
await OnDataLoaded.InvokeAsync(Data);
HideLoading();
InitializeRowCss();
}
private static async Task <Element> DeserializeAsync(Stream stream, CancellationToken cancellationToken)
{
Element root = new Element();
Element parent = root;
Element node = root;
while (stream.Position < stream.Length)
{
byte controlByte = (byte)stream.ReadByte();
switch (controlByte & (byte)Directions.Mask)
{
case (byte)Directions.New:
node = AddNewNode(parent);
break;
case (byte)Directions.Down:
parent = node;
node = AddNewNode(parent);
break;
case (byte)Directions.Up:
parent = parent.Parent;
node = AddNewNode(parent);
break;
case (byte)Directions.Append:
break;
}
int chunkSize = GetChunkSize(controlByte);
if (((controlByte & (byte)Directions.Mask) == (byte)Directions.Append) && (chunkSize == 0))
{
break;
}
byte[] buffer = new byte[chunkSize];
await stream.ReadAsync(buffer, 0, chunkSize, cancellationToken).ConfigureAwait(false);
if (IsDataChunk(controlByte))
{
if (node != null && chunkSize > 0)
{
if (node.Data == null)
{
node.Data = new MemoryStream();
}
#region Fireing event
OnDataLoading?.Invoke(node, new PromptuariumLoadingEventArgs());
#endregion
await node.Data.WriteAsync(buffer, 0, chunkSize, cancellationToken).ConfigureAwait(false);
#region Fireing event
OnDataLoaded?.Invoke(node, new PromptuariumLoadedEventArgs());
#endregion
}
}
else
{
if (node != null && chunkSize > 0)
{
if (node.MetaData == null)
{
node.MetaData = new MemoryStream();
}
#region Fireing event
OnMetaDataLoading?.Invoke(node, new PromptuariumLoadingEventArgs());
#endregion
await node.MetaData.WriteAsync(buffer, 0, chunkSize, cancellationToken).ConfigureAwait(false);
#region Fireing event
OnMetaDataLoaded?.Invoke(node, new PromptuariumLoadedEventArgs());
#endregion
}
}
}
PurgeEmptyNodes(root);
if (root.children.Count > 0)
{
return(root.children[0]);
}
else
{
return(new Element());
}
}
public static async Task Load(IDictionary <string, object> dataExprsAndCookies, DateTime StartDate, DateTime EndDate,
long[] ids, string idParamName, string contextInitializationScript,
OnDataLoading onDataLoading,
Action <float> onProgress,
int maxPartSize,
System.Threading.CancellationToken ct)
{
bool timeRange = StartDate < EndDate;
bool withAggr = ids.Length > 1;
int nTotalPartsToLoad = 0;
int nPartsLoaded = 0;
AsyncFn fProgress = async(aec, args) =>
{
if (!ct.IsCancellationRequested)
{
var info = (LoadingInfo)await OPs.ConstValueOf(aec, args[0]);
var value = await OPs.ConstValueOf(aec, args[1]);
var data = value as IList;
if (data != null)
{
var aggData = await info.Aggregate(aec, data);
onDataLoading(info.dataExpr, info.cookie, (IList)aggData);
Interlocked.Increment(ref nPartsLoaded);
}
else // calc n
{
int n = Convert.ToInt32(value);
Interlocked.Add(ref nTotalPartsToLoad, n);
}
if (onProgress != null)
{
onProgress(100f * nPartsLoaded / nTotalPartsToLoad);
}
}
return(string.Empty);
};
// initialize code generator context
var defs = new Dictionary <string, object>(StringComparer.OrdinalIgnoreCase);
defs.Add(idParamName, ids);
defs.Add("PROGRESS", new FuncDef(fProgress, 2, "PROGRESS"));
if (timeRange)
{
defs.Add(nameof(ValueInfo.A_TIME__XT), StartDate.ToOADate());
defs.Add(nameof(ValueInfo.B_TIME__XT), EndDate.ToOADate());
}
else
{
defs.Add(nameof(ValueInfo.At_TIME__XT), StartDate.ToOADate());
}
var rootCtx = new Generator.Ctx(defs, CoreFuncDefs().GetFuncs);
Generator.Generate(Parser.ParseToExpr(contextInitializationScript), rootCtx);
rootCtx.UseFuncs(new FuncDefs().AddFrom(withAggr ? typeof(FuncDefs_Aggr) : typeof(FuncDefs_NoAggr)).GetFuncs);
var infos = new List <LoadingInfo>(dataExprsAndCookies.Count);
var tasks = new List <Task>();
foreach (var pair in dataExprsAndCookies)
{
infos.Add(new LoadingInfo(pair.Key, pair.Value, rootCtx));
}
var loadingExpr = Parser.ParseToExpr(@"(
PartsOfLimitedSize(" + idParamName + " ," + maxPartSize.ToString() + @")
..let(parts)
,let(n,COLUMNS(parts)) .. PROGRESS(" + sLoadingInfo + @"),
,_ParFor(
let(i,0),
i<n,
(
let(" + idParamName + @", parts[i])
,FindSolutionExpr({}, " + sUsedParamsDict + @".Keys()) . ExprToExecutable() . AtNdx(0) .. PROGRESS(" + sLoadingInfo + @")
,let(i, i+1)
)
)
)");
var rootAec = new AsyncExprRootCtx(rootCtx.name2ndx, rootCtx.values, OPs.GlobalMaxParallelismSemaphore);
foreach (var info in infos)
{
tasks.Add(Task.Factory.StartNew(() => info.LoadData(rootAec, loadingExpr, ct)).Unwrap());
}
await TaskEx.WhenAll(tasks);
}