implement set on client/server

chord/httpnode/client.go

@@ -2,11 +2,13 @@ package httpnode
 
 import (
 	"context"
+	"encoding/base64"
 	"errors"
 	"fmt"
 	"net/http"
 	"net/url"
 	"path"
+	"strings"
 
 	"git.sunturtle.xyz/zephyr/chord/chord"
 )
@@ -44,6 +46,29 @@ func (cl *Client) Find(ctx context.Context, s chord.Peer, id chord.ID) (chord.Pe
 	return chord.Address(p.Peer), p.Value, nil
 }
 
+func (cl *Client) Set(ctx context.Context, s chord.Peer, id chord.ID, v string) error {
+	_, addr := s.Values()
+	url := url.URL{
+		Scheme: "http",
+		Host:   addr.String(),
+		Path:   path.Join("/", cl.APIBase, "key", id.String()),
+	}
+	body := strings.NewReader(base64.StdEncoding.EncodeToString([]byte(v)))
+	req, err := http.NewRequestWithContext(ctx, "POST", url.String(), body)
+	if err != nil {
+		return err
+	}
+	resp, err := cl.HTTP.Do(req)
+	if err != nil {
+		return err
+	}
+	if resp.StatusCode >= 400 {
+		_, err := readResponse[struct{}](resp)
+		return err
+	}
+	return nil
+}
+
 // Notify tells s we believe n to be its predecessor.
 func (cl *Client) Notify(ctx context.Context, n *chord.Node, s chord.Peer) error {
 	_, addr := s.Values()

chord/httpnode/server.go

@@ -2,8 +2,10 @@ package httpnode
 
 import (
 	"context"
+	"encoding/base64"
 	"errors"
 	"fmt"
+	"io"
 	"net"
 	"net/http"
 	"net/netip"
@@ -46,6 +48,7 @@ func New(l net.Listener, cl chord.Client) (*Node, error) {
 func (n *Node) Router() http.Handler {
 	m := http.NewServeMux()
 	m.HandleFunc("GET /key/{id}", n.key)
+	m.HandleFunc("POST /key/{id}", n.set)
 	m.HandleFunc("POST /pred", n.notify)
 	m.HandleFunc("GET /neighbors", n.neighbors)
 	return m
@@ -82,6 +85,25 @@ func (n *Node) key(w http.ResponseWriter, r *http.Request) {
 	writeOk(w, pv)
 }
 
+func (n *Node) set(w http.ResponseWriter, r *http.Request) {
+	s := r.PathValue("id")
+	id, err := chord.ParseID(s)
+	if err != nil {
+		writeError(w, http.StatusBadRequest, err.Error())
+		return
+	}
+	val, err := io.ReadAll(base64.NewDecoder(base64.StdEncoding, r.Body))
+	if err != nil {
+		writeError(w, http.StatusInternalServerError, err.Error())
+		return
+	}
+	if !n.self.SetLocal(id, string(val)) {
+		writeError(w, http.StatusNotFound, "id does not belong to this peer")
+		return
+	}
+	w.WriteHeader(http.StatusNoContent)
+}
+
 func (n *Node) notify(w http.ResponseWriter, r *http.Request) {
 	s := r.FormValue("p")
 	addr, err := netip.ParseAddrPort(s)