func purgeCache() {
sleepTime := 1 * time.Second
for {
expireTime := time.Now().UTC().Add(-5 * time.Second)
// remove old entries
for _, span := range spanCache {
var timeStr = span.ClientStart
if timeStr == "" {
timeStr = span.RemoteStart
}
t, err := time.Parse(time.RFC3339Nano, timeStr)
if err != nil {
fmt.Fprintf(os.Stderr, "Error parsing cached span's start time: %s\n", err.Error())
} else {
if t.Before(expireTime) {
spanMutex.Lock()
delete(spanCache, span.Id)
spanMutex.Unlock()
data.InsertSpan(span)
}
}
}
time.Sleep(sleepTime)
}
}
func spanHandler(w http.ResponseWriter, r *http.Request) {
// decode log message
var span types.Span
err := json.NewDecoder(r.Body).Decode(&span)
if err != nil {
w.WriteHeader(400)
w.Write([]byte(err.Error()))
return
}
if span.TraceId == span.Id {
// Initiating span
data.InsertSpan(span)
} else {
mergeSpan(span)
}
}
func mergeSpan(span types.Span) {
spanMutex.Lock()
sp, exists := spanCache[span.Id]
if !exists {
// either client or remote half of this span is missing -
// cache it until we get all the details
spanCache[span.Id] = span
spanMutex.Unlock()
return
}
spanMutex.Unlock()
// remove span from cache
delete(spanCache, span.Id)
// copy across missing values
if sp.TraceId == "" {
sp.TraceId = span.TraceId
} else if sp.TraceId != span.TraceId {
writeMismatch("TraceId", sp.TraceId, span.TraceId)
}
if sp.ParentId == "" {
sp.ParentId = span.ParentId
} else if span.ParentId != "" && sp.ParentId != span.ParentId {
writeMismatch("ParentId", sp.ParentId, span.ParentId)
}
if sp.ClientStart == "" {
sp.ClientStart = span.ClientStart
}
if sp.ClientEnd == "" {
sp.ClientEnd = span.ClientEnd
}
if sp.RemoteStart == "" {
sp.RemoteStart = span.RemoteStart
}
if sp.RemoteEnd == "" {
sp.RemoteEnd = span.RemoteEnd
}
if sp.Host == "" {
sp.Host = span.Host
} else if span.Host != "" && sp.Host != span.Host {
writeMismatch("Host", sp.Host, span.Host)
}
if sp.Method == "" {
sp.Method = span.Method
} else if span.Method != "" && sp.Method != span.Method {
writeMismatch("Method", sp.Method, span.Method)
}
if sp.Url == "" {
sp.Url = span.Url
} else if span.Url != "" && sp.Url != span.Url {
writeMismatch("Url", sp.Url, span.Url)
}
if sp.Headers == nil || len(sp.Headers) == 0 {
sp.Headers = span.Headers
}
if sp.Parameters == nil || len(sp.Parameters) == 0 {
sp.Parameters = span.Parameters
}
if sp.Body == "" {
sp.Body = span.Body
} else if span.Body != "" && sp.Body != span.Body {
writeMismatch("Body", sp.Body, span.Body)
}
if sp.ResponseCode == 0 {
sp.ResponseCode = span.ResponseCode
} else if span.ResponseCode != 0 && sp.ResponseCode != span.ResponseCode {
writeMismatch("ResponseCode", string(sp.ResponseCode), string(span.ResponseCode))
}
data.InsertSpan(sp)
}