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, 117 insertions, 0 deletions

diff --git a/swarm/storage/common_test.go b/swarm/storage/common_test.go
new file mode 100644
index 000000000..e81a82b7b
--- /dev/null
+++ b/swarm/storage/common_test.go
@@ -0,0 +1,117 @@
+// 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"
+	"crypto/rand"
+	"io"
+	"sync"
+	"testing"
+
+	"github.com/ethereum/go-ethereum/logger"
+	"github.com/ethereum/go-ethereum/logger/glog"
+)
+
+type limitedReader struct {
+	r    io.Reader
+	off  int64
+	size int64
+}
+
+func limitReader(r io.Reader, size int) *limitedReader {
+	return &limitedReader{r, 0, int64(size)}
+}
+
+func (self *limitedReader) Read(buf []byte) (int, error) {
+	limit := int64(len(buf))
+	left := self.size - self.off
+	if limit >= left {
+		limit = left
+	}
+	n, err := self.r.Read(buf[:limit])
+	if err == nil && limit == left {
+		err = io.EOF
+	}
+	self.off += int64(n)
+	return n, err
+}
+
+func testDataReader(l int) (r io.Reader) {
+	return limitReader(rand.Reader, l)
+}
+
+func testDataReaderAndSlice(l int) (r io.Reader, slice []byte) {
+	slice = make([]byte, l)
+	if _, err := rand.Read(slice); err != nil {
+		panic("rand error")
+	}
+	r = limitReader(bytes.NewReader(slice), l)
+	return
+}
+
+func testStore(m ChunkStore, l int64, branches int64, t *testing.T) {
+
+	chunkC := make(chan *Chunk)
+	go func() {
+		for chunk := range chunkC {
+			m.Put(chunk)
+			if chunk.wg != nil {
+				chunk.wg.Done()
+			}
+		}
+	}()
+	chunker := NewTreeChunker(&ChunkerParams{
+		Branches: branches,
+		Hash:     defaultHash,
+	})
+	swg := &sync.WaitGroup{}
+	key, err := chunker.Split(rand.Reader, l, chunkC, swg, nil)
+	swg.Wait()
+	close(chunkC)
+	chunkC = make(chan *Chunk)
+
+	quit := make(chan bool)
+
+	go func() {
+		for ch := range chunkC {
+			go func(chunk *Chunk) {
+				storedChunk, err := m.Get(chunk.Key)
+				if err == notFound {
+					glog.V(logger.Detail).Infof("chunk '%v' not found", chunk.Key.Log())
+				} else if err != nil {
+					glog.V(logger.Detail).Infof("error retrieving chunk %v: %v", chunk.Key.Log(), err)
+				} else {
+					chunk.SData = storedChunk.SData
+					chunk.Size = storedChunk.Size
+				}
+				glog.V(logger.Detail).Infof("chunk '%v' not found", chunk.Key.Log())
+				close(chunk.C)
+			}(ch)
+		}
+		close(quit)
+	}()
+	r := chunker.Join(key, chunkC)
+
+	b := make([]byte, l)
+	n, err := r.ReadAt(b, 0)
+	if err != io.EOF {
+		t.Fatalf("read error (%v/%v) %v", n, l, err)
+	}
+	close(chunkC)
+	<-quit
+}