// Copyright (c) AlphaSierraPapa for the SharpDevelop Team (for details please see \doc\copyright.txt)
// This code is distributed under the GNU LGPL (for details please see \doc\license.txt)
using System;
using System.Collections.Generic;
using System.Globalization;
using System.Linq;
using ICSharpCode.AvalonEdit.Document;
namespace ICSharpCode.AvalonEdit.Xml
{
/// <summary>
/// Holds all objects that need to keep offsets up to date.
/// </summary>
class TrackedSegmentCollection
{
/// <summary>
/// Holds all types of objects in one collection.
/// </summary>
TextSegmentCollection<TextSegment> segments = new TextSegmentCollection<TextSegment>();
/// <summary>
/// Is used to identify what memory range was touched by object
/// The default is (StartOffset, EndOffset + 1) which is not stored
/// </summary>
class TouchedRange: TextSegment
{
public AXmlObject TouchedByObject { get; set; }
}
public void UpdateOffsetsAndInvalidate(IEnumerable<DocumentChangeEventArgs> changes)
{
foreach(DocumentChangeEventArgs change in changes) {
// Update offsets of all items
segments.UpdateOffsets(change);
// Remove any items affected by the change
AXmlParser.Log("Changed {0}-{1}", change.Offset, change.Offset + change.InsertionLength);
// Removing will cause one of the ends to be set to change.Offset
// FindSegmentsContaining includes any segments touching
// so that conviniently takes care of the +1 byte
var segmentsContainingOffset = segments.FindOverlappingSegments(change.Offset, change.InsertionLength);
foreach(AXmlObject obj in segmentsContainingOffset.OfType<AXmlObject>().Where(o => o.IsCached)) {
InvalidateCache(obj, false);
}
foreach(TouchedRange range in segmentsContainingOffset.OfType<TouchedRange>()) {
AXmlParser.Log("Found that {0} dependeds on ({1}-{2})", range.TouchedByObject, range.StartOffset, range.EndOffset);
InvalidateCache(range.TouchedByObject, true);
segments.Remove(range);
}
}
}
/// <summary>
/// Invlidates all objects. That is, the whole document has changed.
/// </summary>
/// <remarks> We still have to keep the items becuase they might be in the document </remarks>
public void InvalidateAll()
{
AXmlParser.Log("Invalidating all objects");
foreach(AXmlObject obj in segments.OfType<AXmlObject>()) {
obj.IsCached = false;
}
}
/// <summary> Add object to cache, optionally adding extra memory tracking </summary>
public void AddParsedObject(AXmlObject obj, int? maxTouchedLocation)
{
if (!(obj.Length > 0 || obj is AXmlDocument))
AXmlParser.Assert(false, string.Format(CultureInfo.InvariantCulture, "Invalid object {0}. It has zero length.", obj));
// // Expensive check
// if (obj is AXmlContainer) {
// int objStartOffset = obj.StartOffset;
// int objEndOffset = obj.EndOffset;
// foreach(AXmlObject child in ((AXmlContainer)obj).Children) {
// AXmlParser.Assert(objStartOffset <= child.StartOffset && child.EndOffset <= objEndOffset, "Wrong nesting");
// }
// }
segments.Add(obj);
AddSyntaxErrorsOf(obj);
obj.IsCached = true;
if (maxTouchedLocation != null) {
// location is assumed to be read so the range ends at (location + 1)
// For example eg for "a_" it is (0-2)
TouchedRange range = new TouchedRange() {
StartOffset = obj.StartOffset,
EndOffset = maxTouchedLocation.Value + 1,
TouchedByObject = obj
};
segments.Add(range);
AXmlParser.Log("{0} touched range ({1}-{2})", obj, range.StartOffset, range.EndOffset);
}
}
/// <summary> Removes object with all of its non-cached children </summary>
public void RemoveParsedObject(AXmlObject obj)
{
// Cached objects may be used in the future - do not remove them
if (obj.IsCached) return;
segments.Remove(obj);
RemoveSyntaxErrorsOf(obj);
AXmlParser.Log("Stopped tracking {0}", obj);
AXmlContainer container = obj as AXmlContainer;
if (container != null) {
foreach (AXmlObject child in container.Children) {
RemoveParsedObject(child);
}
}
}
public void AddSyntaxErrorsOf(AXmlObject obj)
{
foreach(SyntaxError syntaxError in obj.MySyntaxErrors) {
segments.Add(syntaxError);
}
}
public void RemoveSyntaxErrorsOf(AXmlObject obj)
{
foreach(SyntaxError syntaxError in obj.MySyntaxErrors) {
segments.Remove(syntaxError);
}
}
IEnumerable<AXmlObject> FindParents(AXmlObject child)
{
int childStartOffset = child.StartOffset;
int childEndOffset = child.EndOffset;
foreach(AXmlObject parent in segments.FindSegmentsContaining(child.StartOffset).OfType<AXmlObject>()) {
// Parent is anyone wholy containg the child
if (parent.StartOffset <= childStartOffset && childEndOffset <= parent.EndOffset && parent != child) {
yield return parent;
}
}
}
/// <summary> Invalidates items, but keeps tracking them </summary>
/// <remarks> Can be called redundantly (from range tacking) </remarks>
void InvalidateCache(AXmlObject obj, bool includeParents)
{
if (includeParents) {
foreach(AXmlObject parent in FindParents(obj)) {
parent.IsCached = false;
AXmlParser.Log("Invalidating cached item {0} (it is parent)", parent);
}
}
obj.IsCached = false;
AXmlParser.Log("Invalidating cached item {0}", obj);
}
public T GetCachedObject<T>(int offset, int lookaheadCount, Predicate<T> conditon) where T: AXmlObject, new()
{
TextSegment obj = segments.FindFirstSegmentWithStartAfter(offset);
while(obj != null && offset <= obj.StartOffset && obj.StartOffset <= offset + lookaheadCount) {
if (obj is T && ((AXmlObject)obj).IsCached && conditon((T)obj)) {
return (T)obj;
}
obj = segments.GetNextSegment(obj);
}
return null;
}
}
}