keep-exercise: limit PRNG usage to 512KiB per write. No issue #

diff --git a/tools/keep-exercise/keep-exercise.go b/tools/keep-exercise/keep-exercise.go
index 4131d752b85144d6ed95c1f5989ade92086f1c92..6d791bf9876a5b84a2b1b642025b730771f76da2 100644 (file)
--- a/tools/keep-exercise/keep-exercise.go
+++ b/tools/keep-exercise/keep-exercise.go
@@ -56,11 +56,11 @@ func main() {
 
        overrideServices(kc)
 
-       nextBuf := make(chan []byte, *WriteThreads)
        nextLocator := make(chan string, *ReadThreads+*WriteThreads)
 
        go countBeans(nextLocator)
        for i := 0; i < *WriteThreads; i++ {
+               nextBuf := make(chan []byte, 1)
                go makeBufs(nextBuf, i)
                go doWrites(kc, nextBuf, nextLocator)
        }
@@ -106,23 +106,28 @@ func countBeans(nextLocator chan string) {
        }
 }
 
-func makeBufs(nextBuf chan []byte, threadID int) {
+func makeBufs(nextBuf chan<- []byte, threadID int) {
        buf := make([]byte, *BlockSize)
        if *VaryThread {
                binary.PutVarint(buf, int64(threadID))
        }
+       randSize := 524288
+       if randSize > *BlockSize {
+               randSize = *BlockSize
+       }
        for {
                if *VaryRequest {
-                       buf = make([]byte, *BlockSize)
-                       if _, err := io.ReadFull(rand.Reader, buf); err != nil {
+                       rnd := make([]byte, randSize)
+                       if _, err := io.ReadFull(rand.Reader, rnd); err != nil {
                                log.Fatal(err)
                        }
+                       buf = append(rnd, buf[randSize:]...)
                }
                nextBuf <- buf
        }
 }
 
-func doWrites(kc *keepclient.KeepClient, nextBuf chan []byte, nextLocator chan string) {
+func doWrites(kc *keepclient.KeepClient, nextBuf <-chan []byte, nextLocator chan<- string) {
        for buf := range nextBuf {
                locator, _, err := kc.PutB(buf)
                if err != nil {
@@ -139,7 +144,7 @@ func doWrites(kc *keepclient.KeepClient, nextBuf chan []byte, nextLocator chan s
        }
 }
 
-func doReads(kc *keepclient.KeepClient, nextLocator chan string) {
+func doReads(kc *keepclient.KeepClient, nextLocator <-chan string) {
        for locator := range nextLocator {
                rdr, size, url, err := kc.Get(locator)
                if err != nil {