swarm: plan bee for content storage and distribution on web3

This change imports the Swarm protocol codebase. Compared to the 'swarm'
branch, a few mostly cosmetic changes had to be made:

* The various redundant log message prefixes are gone.
* All files now have LGPLv3 license headers.
* Minor code changes were needed to please go vet and make the tests
  pass on Windows.
* Further changes were required to adapt to the go-ethereum develop
  branch and its new Go APIs.

Some code has not (yet) been brought over:

* swarm/cmd/bzzhash: will reappear as cmd/bzzhash later
* swarm/cmd/bzzup.sh: will be reimplemented in cmd/bzzup
* swarm/cmd/makegenesis: will reappear somehow
* swarm/examples/album: will move to a separate repository
* swarm/examples/filemanager: ditto
* swarm/examples/files: will not be merged
* swarm/test/*: will not be merged
* swarm/services/swear: will reappear as contracts/swear when needed

1 files changed, 144 insertions, 0 deletions

diff --git a/swarm/storage/dpa_test.go b/swarm/storage/dpa_test.go
new file mode 100644
index 000000000..1cde1c00e
--- /dev/null
+++ b/swarm/storage/dpa_test.go
@@ -0,0 +1,144 @@
+// Copyright 2016 The go-ethereum Authors
+// This file is part of the go-ethereum library.
+//
+// The go-ethereum library is free software: you can redistribute it and/or modify
+// it under the terms of the GNU Lesser General Public License as published by
+// the Free Software Foundation, either version 3 of the License, or
+// (at your option) any later version.
+//
+// The go-ethereum library is distributed in the hope that it will be useful,
+// but WITHOUT ANY WARRANTY; without even the implied warranty of
+// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+// GNU Lesser General Public License for more details.
+//
+// You should have received a copy of the GNU Lesser General Public License
+// along with the go-ethereum library. If not, see <http://www.gnu.org/licenses/>.
+
+package storage
+
+import (
+	"bytes"
+	"io"
+	"io/ioutil"
+	"os"
+	"sync"
+	"testing"
+)
+
+const testDataSize = 0x1000000
+
+func TestDPArandom(t *testing.T) {
+	dbStore := initDbStore(t)
+	dbStore.setCapacity(50000)
+	memStore := NewMemStore(dbStore, defaultCacheCapacity)
+	localStore := &LocalStore{
+		memStore,
+		dbStore,
+	}
+	chunker := NewTreeChunker(NewChunkerParams())
+	dpa := &DPA{
+		Chunker:    chunker,
+		ChunkStore: localStore,
+	}
+	dpa.Start()
+	defer dpa.Stop()
+	defer os.RemoveAll("/tmp/bzz")
+
+	reader, slice := testDataReaderAndSlice(testDataSize)
+	wg := &sync.WaitGroup{}
+	key, err := dpa.Store(reader, testDataSize, wg, nil)
+	if err != nil {
+		t.Errorf("Store error: %v", err)
+	}
+	wg.Wait()
+	resultReader := dpa.Retrieve(key)
+	resultSlice := make([]byte, len(slice))
+	n, err := resultReader.ReadAt(resultSlice, 0)
+	if err != io.EOF {
+		t.Errorf("Retrieve error: %v", err)
+	}
+	if n != len(slice) {
+		t.Errorf("Slice size error got %d, expected %d.", n, len(slice))
+	}
+	if !bytes.Equal(slice, resultSlice) {
+		t.Errorf("Comparison error.")
+	}
+	ioutil.WriteFile("/tmp/slice.bzz.16M", slice, 0666)
+	ioutil.WriteFile("/tmp/result.bzz.16M", resultSlice, 0666)
+	localStore.memStore = NewMemStore(dbStore, defaultCacheCapacity)
+	resultReader = dpa.Retrieve(key)
+	for i, _ := range resultSlice {
+		resultSlice[i] = 0
+	}
+	n, err = resultReader.ReadAt(resultSlice, 0)
+	if err != io.EOF {
+		t.Errorf("Retrieve error after removing memStore: %v", err)
+	}
+	if n != len(slice) {
+		t.Errorf("Slice size error after removing memStore got %d, expected %d.", n, len(slice))
+	}
+	if !bytes.Equal(slice, resultSlice) {
+		t.Errorf("Comparison error after removing memStore.")
+	}
+}
+
+func TestDPA_capacity(t *testing.T) {
+	dbStore := initDbStore(t)
+	memStore := NewMemStore(dbStore, defaultCacheCapacity)
+	localStore := &LocalStore{
+		memStore,
+		dbStore,
+	}
+	memStore.setCapacity(0)
+	chunker := NewTreeChunker(NewChunkerParams())
+	dpa := &DPA{
+		Chunker:    chunker,
+		ChunkStore: localStore,
+	}
+	dpa.Start()
+	reader, slice := testDataReaderAndSlice(testDataSize)
+	wg := &sync.WaitGroup{}
+	key, err := dpa.Store(reader, testDataSize, wg, nil)
+	if err != nil {
+		t.Errorf("Store error: %v", err)
+	}
+	wg.Wait()
+	resultReader := dpa.Retrieve(key)
+	resultSlice := make([]byte, len(slice))
+	n, err := resultReader.ReadAt(resultSlice, 0)
+	if err != io.EOF {
+		t.Errorf("Retrieve error: %v", err)
+	}
+	if n != len(slice) {
+		t.Errorf("Slice size error got %d, expected %d.", n, len(slice))
+	}
+	if !bytes.Equal(slice, resultSlice) {
+		t.Errorf("Comparison error.")
+	}
+	// Clear memStore
+	memStore.setCapacity(0)
+	// check whether it is, indeed, empty
+	dpa.ChunkStore = memStore
+	resultReader = dpa.Retrieve(key)
+	n, err = resultReader.ReadAt(resultSlice, 0)
+	if err == nil {
+		t.Errorf("Was able to read %d bytes from an empty memStore.", len(slice))
+	}
+	// check how it works with localStore
+	dpa.ChunkStore = localStore
+	//	localStore.dbStore.setCapacity(0)
+	resultReader = dpa.Retrieve(key)
+	for i, _ := range resultSlice {
+		resultSlice[i] = 0
+	}
+	n, err = resultReader.ReadAt(resultSlice, 0)
+	if err != io.EOF {
+		t.Errorf("Retrieve error after clearing memStore: %v", err)
+	}
+	if n != len(slice) {
+		t.Errorf("Slice size error after clearing memStore got %d, expected %d.", n, len(slice))
+	}
+	if !bytes.Equal(slice, resultSlice) {
+		t.Errorf("Comparison error after clearing memStore.")
+	}
+}