public FindInFileResult FindByLine(int startLine, string criteria)
{
const int queueBufferSize = 100;
var result = new FindInFileResult{Criteria = criteria};
var lines = new StringBuilder();
var lineBuffer = new Queue<string>(queueBufferSize);
int lineNumber = 1;
using (var reader = new StreamReader(FilePath))
{
string line;
while (lineNumber < startLine)
{
if ((line = reader.ReadLine()) == null)
return result;
if (lineBuffer.Count == queueBufferSize)
lineBuffer.Dequeue();
lineBuffer.Enqueue(line);
lineNumber++;
}
while ((line = reader.ReadLine()) != null)
{
lineNumber++;
if (lineBuffer.Count == queueBufferSize)
lineBuffer.Dequeue();
lineBuffer.Enqueue(line);
var charIndex = line.IndexOf(criteria, StringComparison.OrdinalIgnoreCase);
if (charIndex > -1)
{
// we've found the criteria so return a string buffer
// surrounding the result
result.FoundAtLine = lineNumber;
result.FoundAtCharIndex = charIndex;
result.SurroundingTextStartLine = lineNumber;
// take the last 5 lines from the buffer
foreach (var l in lineBuffer.ToArray()
.Skip(Math.Max(0, lineBuffer.Count - 5))
.Take(5))
{
lines.AppendLine(l);
result.SurroundingTextStartLine--;
}
lineNumber = 1;
while ((line = reader.ReadLine()) != null &&
lineNumber < (queueBufferSize - 5))
{
lines.AppendLine(line);
lineNumber++;
}
break;
}
}
}
result.SurroundingText = lines.ToString();
return result;
}
public FindInFileResult FindByPos(int startpos, string criteria)
{
var buffer = new byte[32768];
int filePos = 0;
var result = new FindInFileResult {Criteria = criteria};
using (var file = File.OpenRead(FilePath))
{
while (filePos < file.Length)
{
var bytesRead = file.Read(buffer, 0, buffer.Length);
var content = Encoding.UTF8.GetString(buffer, 0, bytesRead);
var criteriaIndex =
content.IndexOf(criteria, StringComparison.OrdinalIgnoreCase);
if (criteriaIndex > -1)
{
result.FoundAtBytePosition = filePos + criteriaIndex;
file.Seek(-1024, SeekOrigin.Current);
bytesRead = file.Read(buffer, 0, buffer.Length);
result.SurroundingText = Encoding.UTF8.GetString(buffer, 0, bytesRead);
break;
}
file.Seek(criteria.Length * -1, SeekOrigin.Current);
filePos += (buffer.Length - criteria.Length);
}
}
return result;
}
