update

src/mrapps/early_exit.go

@@ -0,0 +1,40 @@
+package main
+
+//
+// a word-count application "plugin" for MapReduce.
+//
+// go build -buildmode=plugin wc_long.go
+//
+
+import (
+	"strconv"
+	"strings"
+	"time"
+
+	"6.824/mr"
+)
+
+//
+// The map function is called once for each file of input.
+// This map function just returns 1 for each file
+//
+func Map(filename string, contents string) []mr.KeyValue {
+	kva := []mr.KeyValue{}
+	kva = append(kva, mr.KeyValue{filename, "1"})
+	return kva
+}
+
+//
+// The reduce function is called once for each key generated by the
+// map tasks, with a list of all the values created for that key by
+// any map task.
+//
+func Reduce(key string, values []string) string {
+	// some reduce tasks sleep for a long time; potentially seeing if
+	// a worker will accidentally exit early
+	if strings.Contains(key, "sherlock") || strings.Contains(key, "tom") {
+		time.Sleep(time.Duration(3 * time.Second))
+	}
+	// return the number of occurrences of this file.
+	return strconv.Itoa(len(values))
+}