/// <summary>
/// When overriden, return the header fields for the log file with a given <paramref name="context"/>,
/// or 'null' if none is found
/// </summary>
protected virtual async Task <string[]> TryGetHeaderFields(DelimitedTextLogContext context, CancellationToken stopToken)
{
var position = 0;
long lineNumber = 0;
using (var stream = new FileStream(context.FilePath, FileMode.Open, FileAccess.Read, FileShare.ReadWrite))
using (var reader = new LineReader(stream, _encoding, _bufferSize))
{
while (position < context.Position)
{
stopToken.ThrowIfCancellationRequested();
var(line, consumed) = await reader.ReadAsync(stopToken);
if (line is null)
{
break;
}
lineNumber++;
position += consumed;
if (IsHeaders(line, lineNumber))
{
return(ParseHeadersLine(line));
}
}
}
return(null);
}
public async Task ParseRecordsAsync(LogContext context, IList <IEnvelope <JObject> > output,
int recordCount, CancellationToken stopToken = default)
{
using (var stream = new FileStream(context.FilePath, FileMode.Open, FileAccess.Read, FileShare.ReadWrite))
{
stream.Position = context.Position;
using (var reader = new LineReader(stream, _encoding))
{
var linesCount = 0;
while (linesCount < recordCount)
{
stopToken.ThrowIfCancellationRequested();
var(line, consumed) = await reader.ReadAsync(stopToken);
_logger.LogTrace("File: '{0}', line: '{1}', bytes: {2}", context.FilePath, line, consumed);
context.Position += consumed;
if (line is null)
{
break;
}
try
{
var jObject = JObject.Parse(line);
var timestamp = _timestampExtrator is null
? DateTime.Now
: _timestampExtrator.GetTimestamp(jObject);
var envelope = new LogEnvelope <JObject>(jObject,
timestamp,
line,
context.FilePath,
context.Position,
context.LineNumber);
output.Add(envelope);
linesCount++;
}
catch (Exception ex)
{
_logger.LogError(ex, "Error processing record '{0}'", line);
continue;
}
}
}
}
}
private async Task ParseRfc3164Log(LineReader reader, LogContext context, IList <IEnvelope <SyslogData> > output,
int recordCount, CancellationToken stopToken)
{
var packet = new Rfc3164Packet();
var parser = new Rfc3164Parser(new Rfc3164ParserOptions
{
RequirePri = false,
DefaultYear = DateTime.Now.Year
});
var linesCount = 0;
while (linesCount < recordCount)
{
stopToken.ThrowIfCancellationRequested();
var(line, consumed) = await reader.ReadAsync(stopToken);
_logger.LogTrace("File: '{0}', line: '{1}', bytes: {2}", context.FilePath, line, consumed);
context.Position += consumed;
if (line is null)
{
break;
}
context.LineNumber++;
var valid = parser.ParseString(line, ref packet);
if (!valid)
{
_logger.LogWarning($"Unable to parse record at line {context.LineNumber} in file {context.FilePath}. Record may be in invalid format");
}
var record = new SyslogData(
packet.TimeStamp ?? DateTimeOffset.Now,
packet.HostName,
packet.Tag,
packet.Content);
var envelope = new LogEnvelope <SyslogData>(
record,
record.Timestamp.UtcDateTime,
line,
context.FilePath,
context.Position,
context.LineNumber);
output.Add(envelope);
linesCount++;
}
}
/// <inheritdoc/>
public async Task ParseRecordsAsync(LogContext context, IList <IEnvelope <string> > output,
int recordCount, CancellationToken stopToken)
{
using (var stream = new FileStream(context.FilePath, FileMode.Open, FileAccess.Read, FileShare.ReadWrite))
{
stream.Position = context.Position;
using (var reader = new LineReader(stream, _encoding, _bufferSize))
{
string line;
int consumed;
var linesCount = 0;
while (linesCount < recordCount)
{
stopToken.ThrowIfCancellationRequested();
(line, consumed) = await reader.ReadAsync(stopToken);
_logger.LogTrace("File: '{0}', line: '{1}', bytes: {2}", context.FilePath, line, consumed);
context.Position += consumed;
if (line is null)
{
break;
}
if (context.LineNumber++ < _skipLines)
{
continue;
}
var envelope = new LogEnvelope <string>(line,
DateTime.UtcNow,
line,
context.FilePath,
context.Position,
context.LineNumber);
output.Add(envelope);
linesCount++;
}
}
}
}
public async Task ParseRecordsAsync(RegexLogContext context, IList <IEnvelope <IDictionary <string, string> > > output,
int recordCount, CancellationToken stopToken = default)
{
var count = 0;
using (var stream = new FileStream(context.FilePath, FileMode.Open, FileAccess.Read, FileShare.ReadWrite))
{
stream.Position = context.Position;
using (var reader = new LineReader(stream, _encoding, _bufferSize))
{
while (count < recordCount)
{
stopToken.ThrowIfCancellationRequested();
var(line, consumed) = await reader.ReadAsync(stopToken);
_logger.LogTrace("File: '{0}', line: '{1}', bytes: {2}", context.FilePath, line, consumed);
if (line is null)
{
// end-of-file
var record = CreateRecord(context);
if (record is not null)
{
output.Add(record);
}
context.RecordBuilder.Clear();
context.MatchedLineNumber = -1;
context.MatchedLineTimestamp = null;
break;
}
context.LineNumber++;
context.Position += consumed;
var match = _patternRegex.Match(line);
if (match.Success)
{
_logger.LogDebug("Regex matched.");
// this is start of a new record, get the last record
var record = CreateRecord(context);
if (record is not null)
{
output.Add(record);
count++;
}
// remember the new record's first line
context.RecordBuilder.Clear();
context.RecordBuilder.Append(line);
context.MatchedLineNumber = context.LineNumber;
// if the matched line has a 'Timestamp' match group, use it as the record's timestamp
context.MatchedLineTimestamp = GetTimeStamp(match);
}
else
{
_logger.LogDebug("Regex NOT matched.");
// line is not the beginning of a new record
if (context.RecordBuilder.Length != 0)
{
// some lines have been added to the new record
context.RecordBuilder.AppendLine();
context.RecordBuilder.Append(line);
}
else if (_removeUnmatchedRecord)
{
_logger.LogWarning("Line discarded: {0}", line);
}
else
{
// start a new record
// TODO figure out what's the use case scenario for this
context.RecordBuilder.Append(line);
context.MatchedLineNumber = context.LineNumber;
}
}
}
}
}
}
/// <inheritdoc/>
public async Task ParseRecordsAsync(DelimitedTextLogContext context, IList <IEnvelope <TData> > output,
int recordCount, CancellationToken stopToken = default)
{
if (context.Fields is null)
{
context.Fields = await TryGetHeaderFields(context, stopToken);
}
var count = 0;
using (var stream = new FileStream(context.FilePath, FileMode.Open, FileAccess.Read, FileShare.ReadWrite))
{
stream.Position = context.Position;
using (var reader = new LineReader(stream, _encoding, _bufferSize))
{
while (count < recordCount)
{
stopToken.ThrowIfCancellationRequested();
var(line, consumed) = await reader.ReadAsync(stopToken);
_logger.LogTrace("File: '{0}', line: '{1}', bytes: {2}", context.FilePath, line, consumed);
context.Position += consumed;
if (line is null)
{
break;
}
if (ShouldStopAndRollback(line, context))
{
context.Position -= consumed;
return;
}
context.LineNumber++;
if (IsHeaders(line, context.LineNumber))
{
context.Fields = ParseHeadersLine(line);
continue;
}
else if (IsComment(line))
{
continue;
}
try
{
// 'ParseDataFragments' and 'CreateRecord' might throw error, so we need to catch it and skip the record
var fragments = ParseDataFragments(line);
if (context.Fields is null)
{
_logger.LogWarning("Unknown field mapping, skipping line {0}", context.LineNumber);
continue;
}
var dict = new Dictionary <string, string>();
for (var i = 0; i < context.Fields.Length; i++)
{
if (i >= fragments.Length)
{
break;
}
var(key, val) = KeyValueSelector(context.Fields[i], fragments[i]);
dict[key] = val;
}
var record = CreateRecord(context, dict);
var envelope = new LogEnvelope <TData>(record, record.Timestamp, line, context.FilePath, context.Position, context.LineNumber);
output.Add(envelope);
count++;
}
catch (Exception ex)
{
_logger.LogError(ex, "Error processing record '{0}'", line);
continue;
}
}
}
}
}