+++ /dev/null
-// Package reqid creates request IDs and stores them in Contexts.
-package reqid
-
-import (
- "context"
- "crypto/rand"
- "encoding/hex"
- "net/http"
-
- log "github.com/sirupsen/logrus"
-)
-
-// key is an unexported type for keys defined in this package.
-// This prevents collisions with keys defined in other packages.
-type key int
-
-const (
- // reqIDKey is the key for request IDs in Contexts. It is
- // unexported; clients use NewContext and FromContext
- // instead of using this key directly.
- reqIDKey key = iota
- // subReqIDKey is the key for sub-request IDs in Contexts. It is
- // unexported; clients use NewSubContext and FromSubContext
- // instead of using this key directly.
- subReqIDKey
- // coreIDKey is the key for Chain-Core-ID request header field values.
- // It is only for statistics; don't use it for authorization.
- coreIDKey
- // pathKey is the key for the request path being handled.
- pathKey
-)
-
-// New generates a random request ID.
-func New() string {
- // Given n IDs of length b bits, the probability that there will be a collision is bounded by
- // the number of pairs of IDs multiplied by the probability that any pair might collide:
- // p ≤ n(n - 1)/2 * 1/(2^b)
- //
- // We assume an upper bound of 1000 req/sec, which means that in a week there will be
- // n = 1000 * 604800 requests. If l = 10, b = 8*10, then p ≤ 1.512e-7, which is a suitably
- // low probability.
- l := 10
- b := make([]byte, l)
- _, err := rand.Read(b)
- if err != nil {
- log.WithField("error", err).Info("error making reqID")
- }
- return hex.EncodeToString(b)
-}
-
-// NewContext returns a new Context that carries reqid.
-// It also adds a log prefix to print the request ID using
-// package bytom/log.
-func NewContext(ctx context.Context, reqid string) context.Context {
- ctx = context.WithValue(ctx, reqIDKey, reqid)
- return ctx
-}
-
-// FromContext returns the request ID stored in ctx,
-// if any.
-func FromContext(ctx context.Context) string {
- reqID, _ := ctx.Value(reqIDKey).(string)
- return reqID
-}
-
-// CoreIDFromContext returns the Chain-Core-ID stored in ctx,
-// or the empty string.
-func CoreIDFromContext(ctx context.Context) string {
- id, _ := ctx.Value(coreIDKey).(string)
- return id
-}
-
-// PathFromContext returns the HTTP path stored in ctx,
-// or the empty string.
-func PathFromContext(ctx context.Context) string {
- path, _ := ctx.Value(pathKey).(string)
- return path
-}
-
-func NewSubContext(ctx context.Context, reqid string) context.Context {
- ctx = context.WithValue(ctx, subReqIDKey, reqid)
- return ctx
-}
-
-// FromSubContext returns the sub-request ID stored in ctx,
-// if any.
-func FromSubContext(ctx context.Context) string {
- subReqID, _ := ctx.Value(subReqIDKey).(string)
- return subReqID
-}
-
-func Handler(handler http.Handler) http.Handler {
- return http.HandlerFunc(func(w http.ResponseWriter, req *http.Request) {
- })
-}