market,dex: SuspendMarket methods for OrderRouter and DEX mgr

Add (*OrderRouter).SuspendMarket, called from the DEX manager in the new
server/dex.(*DEX) SuspendMarket method.

server/admin: suspend and market info routes

server/admin/api.go

@@ -8,6 +8,7 @@ import (
 	"fmt"
 	"net/http"
 	"strconv"
+	"strings"
 	"time"
 
 	"decred.org/dcrdex/dex/encode"
@@ -42,22 +43,75 @@ func (s *Server) apiConfig(w http.ResponseWriter, _ *http.Request) {
 	writeJSON(w, s.core.ConfigMsg())
 }
 
-func (s *Server) apiSuspend(w http.ResponseWriter, r *http.Request) {
-	suspTimeStr := chi.URLParam(r, timePathKey)
-	suspTimeMs, err := strconv.ParseInt(suspTimeStr, 10, 64)
-	if err != nil {
-		http.Error(w, fmt.Sprintf("invalid time %q: %v", suspTimeStr, err), http.StatusBadRequest)
+// apiMarketInfo is the handler for the '/market/{marketName}' API request.
+func (s *Server) apiMarketInfo(w http.ResponseWriter, r *http.Request) {
+	mkt := strings.ToLower(chi.URLParam(r, marketNameKey))
+	found, running := s.core.MarketRunning(mkt)
+	if !found {
+		http.Error(w, fmt.Sprintf("unknown market %q", mkt), http.StatusBadRequest)
 		return
 	}
 
-	suspTime := encode.UnixTimeMilli(suspTimeMs)
-	if time.Until(suspTime) < 0 {
-		http.Error(w, fmt.Sprintf("specified trade suspension time is in the past: %v", suspTime),
-			http.StatusBadRequest)
+	writeJSON(w, &MarketStatus{
+		Name:    mkt,
+		Running: running,
+	})
+}
+
+// hander for route '/market/{marketName}/suspend?t=13241234&persist=false'
+func (s *Server) apiSuspend(w http.ResponseWriter, r *http.Request) {
+	// Ensure the market exists and is running.
+	mkt := strings.ToLower(chi.URLParam(r, marketNameKey))
+	found, running := s.core.MarketRunning(mkt)
+	if !found {
+		http.Error(w, fmt.Sprintf("unknown market %q", mkt), http.StatusBadRequest)
 		return
 	}
+	if !running {
+		http.Error(w, fmt.Sprintf("market %q not running", mkt), http.StatusBadRequest)
+		return
+	}
+
+	// Validate the suspend time provided in the "t" query. If not specified,
+	// the zero time.Time is used to indicate ASAP.
+	var suspTime time.Time
+	if tSuspendStr := r.URL.Query().Get("t"); tSuspendStr != "" {
+		suspTimeMs, err := strconv.ParseInt(tSuspendStr, 10, 64)
+		if err != nil {
+			http.Error(w, fmt.Sprintf("invalid suspend time %q: %v", tSuspendStr, err), http.StatusBadRequest)
+			return
+		}
 
-	marketSuspEpochs := s.core.Suspend(suspTime)
+		suspTime = encode.UnixTimeMilli(suspTimeMs)
+		if time.Until(suspTime) < 0 {
+			http.Error(w, fmt.Sprintf("specified market suspend time is in the past: %v", suspTime),
+				http.StatusBadRequest)
+			return
+		}
+	}
+
+	// Validate the persist book flag provided in the "persist" query. If not
+	// specified, persist the books, do not purge.
+	persistBook := true
+	if persistBookStr := r.URL.Query().Get("persist"); persistBookStr != "" {
+		var err error
+		persistBook, err = strconv.ParseBool(persistBookStr)
+		if err != nil {
+			http.Error(w, fmt.Sprintf("invalid persist book boolean %q: %v", persistBookStr, err), http.StatusBadRequest)
+			return
+		}
+	}
+
+	suspEpoch := s.core.SuspendMarket(mkt, suspTime, persistBook)
+	if suspEpoch == nil {
+		// Should not happen.
+		http.Error(w, "failed to suspend market "+mkt, http.StatusInternalServerError)
+		return
+	}
 
-	writeJSON(w, marketSuspEpochs)
+	writeJSON(w, &SuspendResult{
+		Market:      mkt,
+		FinalEpoch:  suspEpoch.Idx,
+		SuspendTime: APITime{suspEpoch.End},
+	})
 }

server/admin/server.go

@@ -29,7 +29,7 @@ const (
 	// is closed.
 	rpcTimeoutSeconds = 10
 
-	timePathKey = "epochMs"
+	marketNameKey = "market"
 )
 
 var (
@@ -39,7 +39,9 @@ var (
 // SvrCore is satisfied by core.Core.
 type SvrCore interface {
 	ConfigMsg() json.RawMessage
-	Suspend(time.Time, ...time.Time) map[string]*market.SuspendEpoch
+	MarketRunning(mktName string) (found, running bool)
+	Suspend(tSusp time.Time, persistBooks bool) map[string]*market.SuspendEpoch
+	SuspendMarket(name string, tSusp time.Time, persistBooks bool) *market.SuspendEpoch
 }
 
 // Server is a multi-client https server.
@@ -115,7 +117,11 @@ func NewServer(cfg *SrvConfig) (*Server, error) {
 		r.Use(middleware.AllowContentType("application/json"))
 		r.Get("/ping", s.apiPing)
 		r.Get("/config", s.apiConfig)
-		r.Get("/suspend/{"+timePathKey+"}", s.apiSuspend)
+
+		r.Route("/market/{"+marketNameKey+"}", func(rm chi.Router) {
+			rm.Get("/", s.apiMarketInfo)
+			rm.Get("/suspend", s.apiSuspend)
+		})
 	})
 
 	return s, nil