IEnumerable <HexBufferSpan> FindAllCore(SearchState state, HexSpan span, HexFindOptions options)
{
var pos = span.Start;
if (pos + pattern.LongLength > span.End)
{
yield break;
}
var endPos = span.End - pattern.LongLength + 1;
while (pos < endPos)
{
state.CancellationToken.ThrowIfCancellationRequested();
var result = FindCore(state, pos, span.End);
if (result == null)
{
break;
}
yield return(new HexBufferSpan(state.Buffer, new HexSpan(result.Value, (ulong)pattern.LongLength)));
if ((options & HexFindOptions.NoOverlaps) != 0)
{
pos = result.Value + (ulong)pattern.LongLength;
}
else
{
// We must return all possible matches. If we search for 1111 and data is
// 11111111, we must return positions 0, 1, 2, and not 0, 2.
pos = result.Value + 1;
}
}
}
public FindAllCoreEnumerable(ByteHexSearchService owner, HexBufferSpan searchRange, HexBufferPoint startingPosition, HexFindOptions options, CancellationToken cancellationToken)
{
this.owner = owner;
this.searchRange = searchRange;
this.startingPosition = startingPosition;
this.options = options;
this.cancellationToken = cancellationToken;
}
/// <summary>
/// Finds the pattern
/// </summary>
/// <param name="startingPosition">Starting position</param>
/// <param name="options">Options</param>
/// <param name="cancellationToken">Cancellation token</param>
/// <returns></returns>
public HexBufferSpan?Find(HexBufferPoint startingPosition, HexFindOptions options, CancellationToken cancellationToken)
{
if (startingPosition.IsDefault)
{
throw new ArgumentException();
}
var buffer = startingPosition.Buffer;
return(Find(new HexBufferSpan(buffer, buffer.Span), startingPosition, options, cancellationToken));
}
IEnumerable <HexBufferSpan> FindAllCoreReverse(SearchState state, HexSpan span, HexFindOptions options)
{
if (span.Length < pattern.LongLength)
{
yield break;
}
var lowerBounds = span.Start + pattern.LongLength - 1;
var pos = span.End - 1;
while (pos >= lowerBounds)
{
state.CancellationToken.ThrowIfCancellationRequested();
var result = FindCoreReverse(state, pos, lowerBounds);
if (result == null)
{
break;
}
yield return(new HexBufferSpan(state.Buffer, new HexSpan(result.Value, (ulong)pattern.LongLength)));
if ((options & HexFindOptions.NoOverlaps) != 0)
{
if (result.Value == HexPosition.Zero)
{
break;
}
pos = result.Value - 1;
}
else
{
// We must return all possible matches. If we search for 1111 and data is
// 11111111, we must return positions 3, 2, 1, and not 3, 1
pos = result.Value + (pattern.LongLength - 1);
if (pos == HexPosition.Zero)
{
break;
}
pos = pos - 1;
}
}
}
IEnumerable <HexBufferSpan> FindAllCoreReverse(SearchState state, HexBufferSpan searchRange, HexBufferPoint startingPosition, HexFindOptions options, CancellationToken cancellationToken)
{
HexBufferSpan?firstBlockResult = null;
foreach (var span in GetValidSpansReverse(startingPosition.Buffer, startingPosition, searchRange.Start))
{
cancellationToken.ThrowIfCancellationRequested();
foreach (var span2 in FindAllCoreReverse(state, span, options))
{
if (firstBlockResult == null)
{
firstBlockResult = span2;
}
yield return(span2);
}
}
if ((options & HexFindOptions.Wrap) != 0)
{
var lowerBounds = startingPosition.Position >= pattern.LongLength - 1 ?
startingPosition.Position - (pattern.LongLength - 1) :
HexPosition.Zero;
if (lowerBounds < searchRange.Span.Start)
{
lowerBounds = searchRange.Span.Start;
}
if ((options & HexFindOptions.NoOverlaps) != 0 && firstBlockResult != null && lowerBounds < firstBlockResult.Value.End)
{
lowerBounds = firstBlockResult.Value.End;
}
foreach (var span in GetValidSpansReverse(startingPosition.Buffer, searchRange.End - 1, lowerBounds))
{
cancellationToken.ThrowIfCancellationRequested();
foreach (var span2 in FindAllCoreReverse(state, span, options))
{
yield return(span2);
}
}
}
}
public override IEnumerable <HexBufferSpan> FindAll(HexBufferSpan searchRange, HexBufferPoint startingPosition, HexFindOptions options, CancellationToken cancellationToken)
{
if (searchRange.IsDefault)
{
throw new ArgumentException();
}
if (searchRange.Buffer != startingPosition.Buffer)
{
throw new ArgumentException();
}
if (startingPosition < searchRange.Start || startingPosition > searchRange.End)
{
throw new ArgumentException();
}
if (searchRange.IsEmpty)
{
return(Array.Empty <HexBufferSpan>());
}
return(new FindAllCoreEnumerable(this, searchRange, startingPosition, options, cancellationToken));
}
IEnumerable <HexBufferSpan> FindAllCore(SearchState state, HexBufferSpan searchRange, HexBufferPoint startingPosition, HexFindOptions options, CancellationToken cancellationToken)
{
HexBufferSpan?firstBlockResult = null;
foreach (var span in GetValidSpans(startingPosition.Buffer, startingPosition, searchRange.End))
{
cancellationToken.ThrowIfCancellationRequested();
foreach (var span2 in FindAllCore(state, span, options))
{
if (firstBlockResult == null)
{
firstBlockResult = span2;
}
yield return(span2);
}
}
if ((options & HexFindOptions.Wrap) != 0)
{
var upperBounds = HexPosition.Min(searchRange.Span.End, startingPosition.Position + pattern.LongLength - 1);
if ((options & HexFindOptions.NoOverlaps) != 0 && firstBlockResult != null && upperBounds > firstBlockResult.Value.Start)
{
upperBounds = firstBlockResult.Value.Start;
}
foreach (var span in GetValidSpans(startingPosition.Buffer, searchRange.Start, upperBounds))
{
cancellationToken.ThrowIfCancellationRequested();
foreach (var span2 in FindAllCore(state, span, options))
{
yield return(span2);
}
}
}
}
/// <summary> /// Finds all matches /// </summary> /// <param name="searchRange">Search range</param> /// <param name="startingPosition">Starting position</param> /// <param name="options">Options</param> /// <param name="cancellationToken">Cancellation token</param> /// <returns></returns> public abstract IEnumerable <HexBufferSpan> FindAll(HexBufferSpan searchRange, HexBufferPoint startingPosition, HexFindOptions options, CancellationToken cancellationToken);
/// <summary> /// Finds all matches /// </summary> /// <param name="searchRange">Search range</param> /// <param name="options">Options</param> /// <param name="cancellationToken">Cancellation token</param> /// <returns></returns> public IEnumerable <HexBufferSpan> FindAll(HexBufferSpan searchRange, HexFindOptions options, CancellationToken cancellationToken) => FindAll(searchRange, searchRange.Start, options, cancellationToken);
/// <summary>
/// Finds the pattern
/// </summary>
/// <param name="searchRange">Search range</param>
/// <param name="startingPosition">Starting position</param>
/// <param name="options">Options</param>
/// <param name="cancellationToken">Cancellation token</param>
/// <returns></returns>
public HexBufferSpan?Find(HexBufferSpan searchRange, HexBufferPoint startingPosition, HexFindOptions options, CancellationToken cancellationToken)
{
foreach (var span in FindAll(searchRange, startingPosition, options, cancellationToken))
{
return(span);
}
return(null);
}
/// <summary> /// Finds all matches /// </summary> /// <param name="searchRange">Search range</param> /// <param name="startingPosition">Starting position</param> /// <param name="options">Options</param> /// <param name="cancellationToken">Cancellation token</param> /// <returns></returns> public abstract IEnumerable<HexBufferSpan> FindAll(HexBufferSpan searchRange, HexBufferPoint startingPosition, HexFindOptions options, CancellationToken cancellationToken);
/// <summary> /// Finds all matches /// </summary> /// <param name="searchRange">Search range</param> /// <param name="options">Options</param> /// <param name="cancellationToken">Cancellation token</param> /// <returns></returns> public IEnumerable<HexBufferSpan> FindAll(HexBufferSpan searchRange, HexFindOptions options, CancellationToken cancellationToken) => FindAll(searchRange, searchRange.Start, options, cancellationToken);
/// <summary>
/// Finds the pattern
/// </summary>
/// <param name="searchRange">Search range</param>
/// <param name="startingPosition">Starting position</param>
/// <param name="options">Options</param>
/// <param name="cancellationToken">Cancellation token</param>
/// <returns></returns>
public HexBufferSpan? Find(HexBufferSpan searchRange, HexBufferPoint startingPosition, HexFindOptions options, CancellationToken cancellationToken) {
foreach (var span in FindAll(searchRange, startingPosition, options, cancellationToken))
return span;
return null;
}
/// <summary>
/// Finds the pattern
/// </summary>
/// <param name="startingPosition">Starting position</param>
/// <param name="options">Options</param>
/// <param name="cancellationToken">Cancellation token</param>
/// <returns></returns>
public HexBufferSpan? Find(HexBufferPoint startingPosition, HexFindOptions options, CancellationToken cancellationToken) {
if (startingPosition.IsDefault)
throw new ArgumentException();
var buffer = startingPosition.Buffer;
return Find(new HexBufferSpan(buffer, buffer.Span), startingPosition, options, cancellationToken);
}