private IEnumerable <IPathNode> GetNodeChildrenInternal(IProviderContext context)
{
//find the current parent node
var item = this.ContainerNode;
if (item == null || item.IsLeaf)
{
// WriteChildItem()/P2F can call us while 'dir -recurse' even if the node is set to leaflet.
yield break;
}
// Set the ProviderContext as the DynamicParameters and Filter objects will be used in the
// PowerShell module's GetChildItem().
// If dynamic parameters are used, then SHiPS is not using cache.
// ProviderContext has to be set right now because context.NeedRefresh uses it.
item.SHiPSProviderContext.Set(context);
// The item is the parent node from where we can find its child node list.
// We will find child nodes from the cache if GetChildItem() has been called already and NeedRefresh is false.
// Otherwise, we will execute the scriptblock and then add the returned nodes to item's child list
if (item.UseCache && item.ItemNavigated && !context.NeedRefresh(item, _drive))
{
var list = item.Children.Values.SelectMany(each => each);
foreach (var node in list)
{
// Making sure to obey the StopProcessing.
if (context.Stopping)
{
yield break;
}
yield return(node);
}
}
else
{
var script = Constants.ScriptBlockWithParam1.StringFormat(Constants.GetChildItem);
var nodes = PSScriptRunner.InvokeScriptBlockAndBuildTree(context, item, _drive, script, PSScriptRunner.ReportErrors)?.ToList();
// Save the info of the node just visisted
SHiPSProvider.LastVisisted.Set(context.Path, this, nodes);
if (nodes == null || nodes.Count == 0)
{
yield break;
}
foreach (var node in nodes)
{
// Making sure to obey the StopProcessing.
if (context.Stopping)
{
yield break;
}
yield return(node);
}
}
}
private IPathNode GetNodeObjectFromPath(IProviderContext context, ContainerNodeService parent, string pathName, bool force)
{
var parentNode = parent?.ContainerNode;
if (parentNode == null)
{
return(null);
}
// Check if the node has been dir'ed
// Here we do not need to add NeedRefresh check because:
// For cd (set-location), there is no -force, i.e., NeedRefresh is always false. This means for cached cases,
// a user needs to do 'dir -force' to get fresh data.
// For dir case, path in ResolvePath() is pointing to the parent path, e.g., dir c:\foo\bar\baz.txt,
// the path is poing to c:\foo\bar even if baz.txt just gets created. Thus ResolvePath() only needs to resolve
// the parent path and the GetChildItem() will check NeedRefresh to get fresh data.
if (!force && parentNode.UseCache && parentNode.ItemNavigated)
{
var nodes = parentNode.Children.Where(each => pathName.EqualsIgnoreCase(each.Key)).Select(item => item.Value)
.FirstOrDefault();
if (nodes != null && nodes.Any())
{
return(nodes.FirstOrDefault());
}
else
{
// If a childitem exists and cached, but none of them matches what specified in the 'pathName',
// we will return null, because
//
// dir --- Assuming displays a long list of child items. So user does
// dir a[tab] --- a user wants to see any child items start with 'a'. This may be no child item starts with a.
// so we do not need to go out fetching again if cache misses.
//
// caveat:
// dir foobar --- if a user expects foobar child item exists, and cache misses, SHiPS is not going out fetch
// automatically, unless -force
// By removing the else block, SHiPS will go out fetching for data if cache misses. But dir a[tab] will be slow.
return(null);
}
}
var script = Constants.ScriptBlockWithParam1.StringFormat(Constants.GetChildItem);
var children = PSScriptRunner.InvokeScriptBlockAndBuildTree(context, parentNode, _drive, script, PSScriptRunner.ReportErrors)?.ToList();
if (children == null)
{
return(null);
}
foreach (var node in children)
{
// Making sure to obey the StopProcessing.
if (context.Stopping)
{
return(null);
}
//add it to its child list
if (node != null)
{
if (pathName.EqualsIgnoreCase(node.Name))
{
return(node);
}
}
}
return(null);
}
