/// <summary>
/// Convert a Segment to an instance of <see cref="TraceHeader"/>.
/// </summary>
/// <param name="entity">A instance of <see cref="Entity"/> that will be used to convert to <see cref="TraceHeader"/>.</param>
/// <param name="header">When the method returns, contains the <see cref="TraceHeader"/> object converted from <paramref name="entity"/>,
/// if the conversion succeeded, or null if the conversion failed. The conversion fails if the <paramref name="entity"/> is null, or
/// is not of the correct format. This parameter is passed uninitialized; any value originally supplied will be overwritten.</param>
/// <returns>true if <paramref name="entity"/> converted successfully; otherwise, false.</returns>
public static bool TryParse(Entity entity, out TraceHeader header)
{
header = null;
if (entity == null)
{
_logger.DebugFormat("Failed to parse TraceHeader because segment is null.");
return(false);
}
if (string.IsNullOrEmpty(entity.Id))
{
_logger.DebugFormat("Failed to parse TraceHeader because segment id is null or empty.");
return(false);
}
if (string.IsNullOrEmpty(entity.RootSegment.TraceId))
{
_logger.DebugFormat("Failed to parse TraceHeader because trace id is null or empty.");
return(false);
}
var newHeader = new TraceHeader();
// Trace id doesn't exist in subsegment, so get it from rootsegment
newHeader.RootTraceId = entity.RootSegment.TraceId;
newHeader.ParentId = entity.Id;
newHeader.Sampled = entity.Sampled;
header = newHeader;
return(true);
}
/// <summary>
/// Convert the string representation of a trace header to an instance of <see cref="TraceHeader"/>.
/// </summary>
/// <param name="rawHeader">A string from HTTP request containing a trace header</param>
/// <param name="traceHeader">When the method returns, contains the <see cref="TraceHeader"/> object converted from <paramref name="rawHeader"/>,
/// if the conversion succeeded, or null if the conversion failed. The conversion fails if the <paramref name="rawHeader"/> is null or empty,
/// is not of the correct format. This parameter is passed uninitialized; any value originally supplied will be overwritten. RootId, ParentId
/// and Sampling decision are all required in valid form</param>
/// <returns>true if <paramref name="rawHeader"/> converted successfully; otherwise, false.</returns>
public static bool TryParseAll(string rawHeader, out TraceHeader traceHeader)
{
traceHeader = FromString(rawHeader);
if (string.IsNullOrEmpty(rawHeader) || string.IsNullOrEmpty(traceHeader.RootTraceId) || string.IsNullOrEmpty(traceHeader.ParentId) || traceHeader.Sampled == SampleDecision.Unknown)
{
return(false);
}
return(true);
}
/// <summary>
/// Converts the string representation of a trace header to an instance of <see cref="TraceHeader"/>.
/// </summary>
/// <param name="rawHeader">A string from HTTP request containing a trace header.</param>
/// <param name="header">When the method returns, contains the <see cref="TraceHeader"/> object converted from <paramref name="rawHeader"/>,
/// It only extracts non-null and valid values.</param>
/// <returns>true if <paramref name="rawHeader"/> converted successfully; otherwise, false.</returns>
public static TraceHeader FromString(string rawHeader)
{
TraceHeader result = new TraceHeader();
try
{
if (string.IsNullOrEmpty(rawHeader))
{
return(result);
}
Dictionary <string, string> keyValuePairs = rawHeader.Split(_validSeparators, StringSplitOptions.RemoveEmptyEntries)
.Select(value => value.Trim().Split('='))
.ToDictionary(pair => pair[0], pair => pair[1]);
string tmpValue;
if (keyValuePairs.TryGetValue(RootKey, out tmpValue) && TraceId.IsIdValid(tmpValue))
{
result.RootTraceId = tmpValue;
}
if (keyValuePairs.TryGetValue(ParentKey, out tmpValue) && Entity.IsIdValid(tmpValue))
{
result.ParentId = tmpValue;
}
char tmpChar;
if (keyValuePairs.TryGetValue(SampledKey, out tmpValue) && char.TryParse(tmpValue, out tmpChar))
{
if (Enum.IsDefined(typeof(SampleDecision), (int)tmpChar))
{
result.Sampled = (SampleDecision)tmpChar;
}
}
return(result);
}
catch (IndexOutOfRangeException e)
{
_logger.Error(e, "Invalid trace header from string: {0}", rawHeader);
return(result);
}
}
/// <summary>
/// Convert the string representation of a trace header to an instance of <see cref="TraceHeader"/>.
/// </summary>
/// <param name="rawHeader">A string from HTTP request containing a trace header</param>
/// <param name="header">When the method returns, contains the <see cref="TraceHeader"/> object converted from <paramref name="rawHeader"/>,
/// if the conversion succeeded, or null if the conversion failed. The conversion fails if the <paramref name="rawHeader"/> is null or empty,
/// is not of the correct format. This parameter is passed uninitialized; any value originally supplied will be overwritten.</param>
/// <returns>true if <paramref name="rawHeader"/> converted successfully; otherwise, false. Root trace id
/// required while parent id and sample decision is optional.</returns>
public static bool TryParse(string rawHeader, out TraceHeader header)
{
header = null;
try
{
if (string.IsNullOrEmpty(rawHeader))
{
return(false);
}
var result = new TraceHeader();
Dictionary <string, string> keyValuePairs = rawHeader.Split(_validSeparators, StringSplitOptions.RemoveEmptyEntries)
.Select(value => value.Trim().Split('='))
.ToDictionary(pair => pair[0], pair => pair[1]);
string tmpValue;
// Root trace id is required
if (!keyValuePairs.TryGetValue(RootKey, out tmpValue))
{
return(false);
}
if (!TraceId.IsIdValid(tmpValue))
{
return(false);
}
result.RootTraceId = tmpValue;
// Parent id is optional
if (keyValuePairs.TryGetValue(ParentKey, out tmpValue))
{
if (!Entity.IsIdValid(tmpValue))
{
return(false);
}
result.ParentId = tmpValue;
}
// Sample decision is optional
char tmpChar;
if (keyValuePairs.TryGetValue(SampledKey, out tmpValue) && char.TryParse(tmpValue, out tmpChar))
{
if (Enum.IsDefined(typeof(SampleDecision), (int)tmpChar))
{
result.Sampled = (SampleDecision)tmpChar;
}
}
header = result;
return(true);
}
catch (IndexOutOfRangeException e)
{
_logger.Error(e, "Invalid trace header from string: {0}", rawHeader);
return(false);
}
}
