Improve logs (#89)

http/api.go

@@ -1,7 +1,11 @@
 package http
 
 import (
+	"bytes"
+	"io"
+	"math"
 	"net/http"
+	"os"
 	"sort"
 
 	"github.com/anacrolix/missinggo/v2/filecache"
@@ -61,3 +65,48 @@ var apiDelTorrentHandler = func(s *torrent.Service) gin.HandlerFunc {
 		ctx.JSON(http.StatusOK, nil)
 	}
 }
+
+var apiLogHandler = func(path string) gin.HandlerFunc {
+	return func(ctx *gin.Context) {
+		f, err := os.Open(path)
+		if err != nil {
+			ctx.JSON(http.StatusBadRequest, gin.H{"error": err.Error()})
+			return
+		}
+
+		fi, err := f.Stat()
+		if err != nil {
+			ctx.JSON(http.StatusBadRequest, gin.H{"error": err.Error()})
+			return
+		}
+
+		max := math.Max(float64(-fi.Size()), -1024*8*8)
+		_, err = f.Seek(int64(max), os.SEEK_END)
+		if err != nil {
+			ctx.JSON(http.StatusBadRequest, gin.H{"error": err.Error()})
+			return
+		}
+
+		var b bytes.Buffer
+		ctx.Stream(func(w io.Writer) bool {
+			_, err := b.ReadFrom(f)
+			if err != nil {
+				ctx.JSON(http.StatusBadRequest, gin.H{"error": err.Error()})
+				return false
+			}
+
+			_, err = b.WriteTo(w)
+			if err != nil {
+				ctx.JSON(http.StatusBadRequest, gin.H{"error": err.Error()})
+				return false
+			}
+
+			return true
+		})
+
+		if err := f.Close(); err != nil {
+			ctx.JSON(http.StatusBadRequest, gin.H{"error": err.Error()})
+			return
+		}
+	}
+}

http/http.go

@@ -13,7 +13,7 @@ import (
 	"github.com/shurcooL/httpfs/html/vfstemplate"
 )
 
-func New(fc *filecache.Cache, ss *torrent.Stats, s *torrent.Service, ch *config.Handler, port int) error {
+func New(fc *filecache.Cache, ss *torrent.Stats, s *torrent.Service, ch *config.Handler, port int, logPath string) error {
 	gin.SetMode(gin.ReleaseMode)
 	r := gin.New()
 	r.Use(gin.Recovery())
@@ -30,9 +30,11 @@ func New(fc *filecache.Cache, ss *torrent.Stats, s *torrent.Service, ch *config.
 
 	r.GET("/", indexHandler)
 	r.GET("/routes", routesHandler(ss))
+	r.GET("/logs", logsHandler)
 
 	api := r.Group("/api")
 	{
+		api.GET("/log", apiLogHandler(logPath))
 		api.GET("/status", apiStatusHandler(fc, ss))
 		api.GET("/routes", apiRoutesHandler(ss))
 		api.POST("/routes/:route/torrent", apiAddTorrentHandler(s))

http/web.go

@@ -16,3 +16,7 @@ var routesHandler = func(ss *torrent.Stats) gin.HandlerFunc {
 		c.HTML(http.StatusOK, "routes.html", ss.RoutesStats())
 	}
 }
+
+var logsHandler = func(c *gin.Context) {
+	c.HTML(http.StatusOK, "logs.html", nil)
+}