private String MakeFragment(WeightedFragInfo fragInfo, String src, int s)
{
StringBuilder fragment = new StringBuilder();
int srcIndex = 0;
var items = from subInfo in fragInfo.subInfos
from to in subInfo.termsOffsets
orderby to.startOffset
select new
{
to,
subInfo
};
foreach (var item in items)
{
var headerIndex = item.to.startOffset - s;
fragment.Append(src.Substring(srcIndex, headerIndex - srcIndex))
.Append(GetPreTag(item.subInfo.seqnum))
.Append(src.Substring(headerIndex, item.to.endOffset - item.to.startOffset))
.Append(GetPostTag(item.subInfo.seqnum));
srcIndex = item.to.endOffset - s;
}
fragment.Append(src.Substring(srcIndex));
return(fragment.ToString());
}
public virtual string[] CreateFragments(IndexReader reader, int docId, string fieldName, FieldFragList fieldFragList, int maxNumFragments, int fragCharSize, IState state)
{
if (maxNumFragments < 0)
{
throw new ArgumentException("maxNumFragments(" + maxNumFragments + ") must be positive number.");
}
List <WeightedFragInfo> fragInfos = GetWeightedFragInfoList(fieldFragList.fragInfos);
List <String> fragments = new List <String>(maxNumFragments);
Field[] values = GetFields(reader, docId, fieldName, state);
if (values.Length == 0)
{
return(null);
}
StringBuilder buffer = new StringBuilder();
int[] nextValueIndex = { 0 };
for (int n = 0; n < maxNumFragments && n < fragInfos.Count; n++)
{
WeightedFragInfo fragInfo = fragInfos[n];
fragments.Add(MakeFragment(buffer, nextValueIndex, values, fragInfo, fragCharSize, state));
}
return(fragments.ToArray());
}
private String MakeFragment(WeightedFragInfo fragInfo, String src, int adjustedStart, int fragCharSize)
{
StringBuilder fragment = new StringBuilder();
int srcIndex = 0;
var items = from subInfo in fragInfo.subInfos
from to in subInfo.termsOffsets
orderby to.startOffset
select new
{
to,
subInfo
};
foreach (var item in items)
{
var headerIndex = item.to.startOffset - adjustedStart;
var matchLen = item.to.endOffset - item.to.startOffset;
var startLen = Math.Max(0, Math.Min(headerIndex - srcIndex, (fragCharSize - matchLen) / 2));
fragCharSize -= matchLen + startLen;
fragment.Append(src.Substring(headerIndex - startLen, startLen))
.Append(GetPreTag(item.subInfo.seqnum))
.Append(src.Substring(headerIndex, matchLen))
.Append(GetPostTag(item.subInfo.seqnum));
srcIndex = item.to.endOffset - adjustedStart;
}
fragment.Append(src.Substring(srcIndex, Math.Min(Math.Max(0, fragCharSize), src.Length - srcIndex)));
return(fragment.ToString());
}
private String MakeFragment(WeightedFragInfo fragInfo, String src, int s)
{
StringBuilder fragment = new StringBuilder();
int srcIndex = 0;
foreach (SubInfo subInfo in fragInfo.subInfos)
{
foreach (Toffs to in subInfo.termsOffsets)
{
fragment.Append(src.Substring(srcIndex, to.startOffset - s - srcIndex)).Append(GetPreTag(subInfo.seqnum))
.Append(src.Substring(to.startOffset - s, to.endOffset - s - (to.startOffset - s))).Append(GetPostTag(subInfo.seqnum));
srcIndex = to.endOffset - s;
}
}
fragment.Append(src.Substring(srcIndex));
return(fragment.ToString());
}
private string GetFragmentSource(StringBuilder buffer, int[] index, Field[] values, WeightedFragInfo weightedFragInfo, out int startOffset)
{
while (buffer.Length < weightedFragInfo.endOffset && index[0] < values.Length)
{
buffer.Append(values[index[0]].StringValue);
if (values[index[0]].IsTokenized && values[index[0]].StringValue.Length > 0 && index[0] + 1 < values.Length)
buffer.Append(' ');
index[0]++;
}
var endOffset = 0;
startOffset = buffer.Length - 1;
foreach (var subInfo in weightedFragInfo.subInfos)
{
foreach (var termsOffset in subInfo.termsOffsets)
{
if (termsOffset.startOffset < startOffset)
startOffset = termsOffset.startOffset;
if (termsOffset.endOffset > endOffset)
endOffset = termsOffset.endOffset;
}
}
int maxStart = startOffset;
int minEnd = endOffset;
var maxLength = weightedFragInfo.endOffset - weightedFragInfo.startOffset;
var bufferLength = buffer.Length;
var stopChars = new[] {',', '.', ';','!','?'};
while (endOffset - startOffset < maxLength - 2) // limit the size of the returned string
{
if (endOffset >= bufferLength) // out of range
{
endOffset = bufferLength;
startOffset = Math.Max(0, startOffset - maxLength - endOffset);
break;
}
if (startOffset == 0) // out of range
{
endOffset = Math.Min(bufferLength, startOffset + maxLength);
break;
}
var localStartOffset = startOffset;
if (stopChars.Any(c => c == buffer[localStartOffset]) && buffer[startOffset + 1] == ' ')
{
startOffset += 2; //remove the char and the white space
endOffset = Math.Min(bufferLength, startOffset + maxLength);
break;
}
endOffset++;
startOffset--;
}
int retStartOffset;
var retVal = TrimEdges(buffer, startOffset, endOffset, out retStartOffset, maxStart, minEnd); // cuts part words
startOffset = retStartOffset;
return retVal;
}
private String MakeFragment(WeightedFragInfo fragInfo, String src, int s)
{
StringBuilder fragment = new StringBuilder();
int srcIndex = 0;
foreach (SubInfo subInfo in fragInfo.subInfos)
{
foreach (Toffs to in subInfo.termsOffsets)
{
var headerIndex = to.startOffset - s;
fragment.Append(src.Substring(srcIndex, headerIndex - srcIndex))
.Append(GetPreTag(subInfo.seqnum))
.Append(src.Substring(headerIndex, to.endOffset - to.startOffset))
.Append(GetPostTag(subInfo.seqnum));
srcIndex = to.endOffset - s;
}
}
fragment.Append(src.Substring(srcIndex));
return fragment.ToString();
}
protected virtual String MakeFragment(StringBuilder buffer, int[] index, Field[] values, WeightedFragInfo fragInfo)
{
int adjustedStartPos;
var fragmentSource = GetFragmentSource(buffer, index, values, fragInfo, out adjustedStartPos);
return MakeFragment(fragInfo, fragmentSource, adjustedStartPos);
}
protected virtual String MakeFragment(StringBuilder buffer, int[] index, String[] values, WeightedFragInfo fragInfo)
{
int s = fragInfo.startOffset;
return MakeFragment(fragInfo, GetFragmentSource(buffer, index, values, s, fragInfo.endOffset), s);
}
private string GetFragmentSource(StringBuilder buffer, int[] index, Field[] values, WeightedFragInfo weightedFragInfo, out int startOffset, IState state)
{
while (buffer.Length < weightedFragInfo.endOffset && index[0] < values.Length)
{
buffer.Append(values[index[0]].StringValue(state));
if (values[index[0]].IsTokenized && values[index[0]].StringValue(state).Length > 0 && index[0] + 1 < values.Length)
{
buffer.Append(' ');
}
index[0]++;
}
var endOffset = 0;
startOffset = buffer.Length - 1;
foreach (var subInfo in weightedFragInfo.subInfos)
{
foreach (var termsOffset in subInfo.termsOffsets)
{
if (termsOffset.startOffset < startOffset)
{
startOffset = termsOffset.startOffset;
}
if (termsOffset.endOffset > endOffset)
{
endOffset = termsOffset.endOffset;
}
}
}
int maxStart = startOffset;
int minEnd = endOffset;
var maxLength = weightedFragInfo.endOffset - weightedFragInfo.startOffset;
var bufferLength = buffer.Length;
var stopChars = new[] { ',', '.', ';', '!', '?' };
while (endOffset - startOffset < maxLength - 2) // limit the size of the returned string
{
if (endOffset >= bufferLength) // out of range
{
endOffset = bufferLength;
startOffset = Math.Max(0, startOffset - maxLength - endOffset);
break;
}
if (startOffset == 0) // out of range
{
endOffset = Math.Min(bufferLength, startOffset + maxLength);
break;
}
var localStartOffset = startOffset;
if (stopChars.Any(c => c == buffer[localStartOffset]) && buffer[startOffset + 1] == ' ')
{
startOffset += 2; //remove the char and the white space
endOffset = Math.Min(bufferLength, startOffset + maxLength);
break;
}
endOffset++;
startOffset--;
}
int retStartOffset;
var retVal = TrimEdges(buffer, startOffset, endOffset, out retStartOffset, maxStart, minEnd); // cuts part words
startOffset = retStartOffset;
return(retVal);
}
protected virtual string MakeFragment(StringBuilder buffer, int[] index, Field[] values, WeightedFragInfo fragInfo, int fragCharSize, IState state)
{
int adjustedStartPos;
var fragmentSource = GetFragmentSource(buffer, index, values, fragInfo, out adjustedStartPos, state);
return(MakeFragment(fragInfo, fragmentSource, adjustedStartPos, fragCharSize));
}
protected virtual String MakeFragment(StringBuilder buffer, int[] index, String[] values, WeightedFragInfo fragInfo)
{
int s = fragInfo.startOffset;
return(MakeFragment(fragInfo, GetFragmentSource(buffer, index, values, s, fragInfo.endOffset), s));
}
private String MakeFragment(WeightedFragInfo fragInfo, String src, int adjustedStart, int fragCharSize)
{
StringBuilder fragment = new StringBuilder();
int srcIndex = 0;
var items = from subInfo in fragInfo.subInfos
from to in subInfo.termsOffsets
orderby to.startOffset
select new
{
to,
subInfo
};
foreach (var item in items)
{
var headerIndex = item.to.startOffset - adjustedStart;
var matchLen = item.to.endOffset - item.to.startOffset;
var startLen = Math.Max(0, Math.Min(headerIndex - srcIndex, (fragCharSize - matchLen)/2));
fragCharSize -= matchLen + startLen;
fragment.Append(src.Substring(headerIndex-startLen, startLen))
.Append(GetPreTag(item.subInfo.seqnum))
.Append(src.Substring(headerIndex, matchLen))
.Append(GetPostTag(item.subInfo.seqnum));
srcIndex = item.to.endOffset - adjustedStart;
}
fragment.Append(src.Substring(srcIndex, Math.Min(Math.Max(0, fragCharSize), src.Length - srcIndex)));
return fragment.ToString();
}
private String MakeFragment(WeightedFragInfo fragInfo, String src, int s)
{
StringBuilder fragment = new StringBuilder();
int srcIndex = 0;
var items = from subInfo in fragInfo.subInfos
from to in subInfo.termsOffsets
orderby to.startOffset
select new
{
to,
subInfo
};
foreach (var item in items)
{
var headerIndex = item.to.startOffset - s;
fragment.Append(src.Substring(srcIndex, headerIndex - srcIndex))
.Append(GetPreTag(item.subInfo.seqnum))
.Append(src.Substring(headerIndex, item.to.endOffset - item.to.startOffset))
.Append(GetPostTag(item.subInfo.seqnum));
srcIndex = item.to.endOffset - s;
}
fragment.Append(src.Substring(srcIndex));
return fragment.ToString();
}
