Documentation
¶
Overview ¶
Package callctx provides helpers for storing and retrieving values out of context.Context. These values are used by our client libraries in various ways across the stack.
Index ¶
- Constants
- func HeadersFromContext(ctx context.Context) map[string][]string
- func LoggerFromContext(ctx context.Context) (*slog.Logger, bool)
- func SetHeaders(ctx context.Context, keyvals ...string) context.Context
- func TelemetryFromContext(ctx context.Context, key string) (string, bool)
- func WithLoggerContext(ctx context.Context, logger *slog.Logger) context.Context
- func WithTelemetryContext(ctx context.Context, keyvals ...string) context.Context
Examples ¶
Constants ¶
const ( // XGoogFieldMaskHeader is the canonical header key for the [System Parameter] // that specifies the response read mask. The value(s) for this header // must adhere to format described in [fieldmaskpb]. // // [System Parameter]: https://cloud.google.com/apis/docs/system-parameters // [fieldmaskpb]: https://google.golang.org/protobuf/types/known/fieldmaskpb XGoogFieldMaskHeader = "x-goog-fieldmask" )
Variables ¶
This section is empty.
Functions ¶
func HeadersFromContext ¶
HeadersFromContext retrieves headers set from SetHeaders. These headers can then be cast to http.Header or metadata.MD to send along on requests.
func LoggerFromContext ¶ added in v2.19.0
LoggerFromContext extracts a slog.Logger from the context. The returned bool indicates whether a logger was found.
func SetHeaders ¶
SetHeaders stores key value pairs in the returned context that can later be retrieved by HeadersFromContext. Values stored in this manner will automatically be retrieved by client libraries and sent as outgoing headers on all requests. keyvals should have a corresponding value for every key provided. If there is an odd number of keyvals this method will panic.
Example ¶
package main
import (
"context"
"fmt"
"github.com/googleapis/gax-go/v2/callctx"
)
func main() {
ctx := context.Background()
ctx = callctx.SetHeaders(ctx, "key", "value")
// Send the returned context to the request you are making. Later on these
// values will be retrieved and set on outgoing requests.
headers := callctx.HeadersFromContext(ctx)
fmt.Println(headers["key"][0])
}
Output: value
func TelemetryFromContext ¶ added in v2.18.0
TelemetryFromContext extracts a telemetry attribute value from the context. The returned bool indicates a successful typecast of the value to a string.
func WithLoggerContext ¶ added in v2.19.0
WithLoggerContext injects a slog.Logger into the context. This logger will be extracted by the client library or transport wrappers to emit logs.
func WithTelemetryContext ¶ added in v2.18.0
WithTelemetryContext injects telemetry attribute values (like resource name or client version) into the context. In accordance with standard Go context guidelines, this should only be used for data that transits processes and APIs, and not for passing optional parameters to functions. keyvals should have a corresponding value for every key provided. If there is an odd number of keyvals this method will panic.
Types ¶
This section is empty.
Source Files