1// Copyright The OpenTelemetry Authors
 2// SPDX-License-Identifier: Apache-2.0
 3
 4package otelhttp // import "go.opentelemetry.io/contrib/instrumentation/net/http/otelhttp"
 5
 6import (
 7	"net/http"
 8
 9	"go.opentelemetry.io/otel/attribute"
10	"go.opentelemetry.io/otel/trace"
11)
12
13// Attribute keys that can be added to a span.
14const (
15	ReadBytesKey  = attribute.Key("http.read_bytes")  // if anything was read from the request body, the total number of bytes read
16	ReadErrorKey  = attribute.Key("http.read_error")  // If an error occurred while reading a request, the string of the error (io.EOF is not recorded)
17	WroteBytesKey = attribute.Key("http.wrote_bytes") // if anything was written to the response writer, the total number of bytes written
18	WriteErrorKey = attribute.Key("http.write_error") // if an error occurred while writing a reply, the string of the error (io.EOF is not recorded)
19)
20
21// Client HTTP metrics.
22const (
23	clientRequestSize  = "http.client.request.size"  // Outgoing request bytes total
24	clientResponseSize = "http.client.response.size" // Outgoing response bytes total
25	clientDuration     = "http.client.duration"      // Outgoing end to end duration, milliseconds
26)
27
28// Filter is a predicate used to determine whether a given http.request should
29// be traced. A Filter must return true if the request should be traced.
30type Filter func(*http.Request) bool
31
32func newTracer(tp trace.TracerProvider) trace.Tracer {
33	return tp.Tracer(ScopeName, trace.WithInstrumentationVersion(Version()))
34}