From 638bc6d36403fcc4534bd37ed79ee25ea2b6f50f Mon Sep 17 00:00:00 2001
From: zelig <viktor.tron@gmail.com>
Date: Wed, 13 May 2015 20:10:16 +0200
Subject: [PATCH] memStore chunk protection added, no chunk removed without
 being written to disk

---
 bzz/dbstore.go    |  3 +++
 bzz/dpa.go        | 13 +++++++------
 bzz/localstore.go |  1 +
 bzz/memstore.go   | 10 ++++++++--
 4 files changed, 19 insertions(+), 8 deletions(-)

diff --git a/bzz/dbstore.go b/bzz/dbstore.go
index 680c9d6d39..78fcb6ec0b 100644
--- a/bzz/dbstore.go
+++ b/bzz/dbstore.go
@@ -287,6 +287,9 @@ func (s *dbStore) Put(chunk *Chunk) {
 	batch.Put(ikey, idata)
 
 	s.db.Write(batch)
+	if chunk.dbStored != nil {
+		close(chunk.dbStored)
+	}
 }
 
 // try to find index; if found, update access cnt and return true
diff --git a/bzz/dpa.go b/bzz/dpa.go
index 85d77ff047..b93f17c283 100644
--- a/bzz/dpa.go
+++ b/bzz/dpa.go
@@ -54,12 +54,13 @@ type DPA struct {
 // but the size of the subtree encoded in the chunk
 // 0 if request, to be supplied by the dpa
 type Chunk struct {
-	SData []byte         // nil if request, to be supplied by dpa
-	Size  int64          // size of the data covered by the subtree encoded in this chunk
-	Key   Key            // always
-	C     chan bool      // to signal data delivery by the dpa
-	req   *requestStatus //
-	wg    *sync.WaitGroup
+	SData    []byte         // nil if request, to be supplied by dpa
+	Size     int64          // size of the data covered by the subtree encoded in this chunk
+	Key      Key            // always
+	C        chan bool      // to signal data delivery by the dpa
+	req      *requestStatus //
+	wg       *sync.WaitGroup
+	dbStored chan bool
 }
 
 type ChunkStore interface {
diff --git a/bzz/localstore.go b/bzz/localstore.go
index 7cb506d89a..7f6a4eabd8 100644
--- a/bzz/localstore.go
+++ b/bzz/localstore.go
@@ -9,6 +9,7 @@ type localStore struct {
 // localStore is itself a chunk store , to stores a chunk only
 // its integrity is checked ?
 func (self *localStore) Put(chunk *Chunk) {
+	chunk.dbStored = make(chan bool)
 	self.memStore.Put(chunk)
 	if chunk.wg != nil {
 		chunk.wg.Add(1)
diff --git a/bzz/memstore.go b/bzz/memstore.go
index 0c5f17d5be..6204a067db 100644
--- a/bzz/memstore.go
+++ b/bzz/memstore.go
@@ -314,8 +314,14 @@ func (s *memStore) removeOldest() {
 
 	}
 
-	node.entry = nil
-	s.entryCnt--
+	if node.entry.dbStored != nil {
+		<-node.entry.dbStored
+	}
+	if node.entry.SData != nil {
+		node.entry = nil
+		s.entryCnt--
+	}
+
 	node.access[0] = 0
 
 	//---