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, 99 insertions, 0 deletions

diff --git a/swarm/storage/database.go b/swarm/storage/database.go
new file mode 100644
index 000000000..2532490cc
--- /dev/null
+++ b/swarm/storage/database.go
@@ -0,0 +1,99 @@
+// 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
+
+// this is a clone of an earlier state of the ethereum ethdb/database
+// no need for queueing/caching
+
+import (
+	"fmt"
+
+	"github.com/ethereum/go-ethereum/compression/rle"
+	"github.com/syndtr/goleveldb/leveldb"
+	"github.com/syndtr/goleveldb/leveldb/iterator"
+	"github.com/syndtr/goleveldb/leveldb/opt"
+)
+
+const openFileLimit = 128
+
+type LDBDatabase struct {
+	db   *leveldb.DB
+	comp bool
+}
+
+func NewLDBDatabase(file string) (*LDBDatabase, error) {
+	// Open the db
+	db, err := leveldb.OpenFile(file, &opt.Options{OpenFilesCacheCapacity: openFileLimit})
+	if err != nil {
+		return nil, err
+	}
+
+	database := &LDBDatabase{db: db, comp: false}
+
+	return database, nil
+}
+
+func (self *LDBDatabase) Put(key []byte, value []byte) {
+	if self.comp {
+		value = rle.Compress(value)
+	}
+
+	err := self.db.Put(key, value, nil)
+	if err != nil {
+		fmt.Println("Error put", err)
+	}
+}
+
+func (self *LDBDatabase) Get(key []byte) ([]byte, error) {
+	dat, err := self.db.Get(key, nil)
+	if err != nil {
+		return nil, err
+	}
+
+	if self.comp {
+		return rle.Decompress(dat)
+	}
+
+	return dat, nil
+}
+
+func (self *LDBDatabase) Delete(key []byte) error {
+	return self.db.Delete(key, nil)
+}
+
+func (self *LDBDatabase) LastKnownTD() []byte {
+	data, _ := self.Get([]byte("LTD"))
+
+	if len(data) == 0 {
+		data = []byte{0x0}
+	}
+
+	return data
+}
+
+func (self *LDBDatabase) NewIterator() iterator.Iterator {
+	return self.db.NewIterator(nil, nil)
+}
+
+func (self *LDBDatabase) Write(batch *leveldb.Batch) error {
+	return self.db.Write(batch, nil)
+}
+
+func (self *LDBDatabase) Close() {
+	// Close the leveldb database
+	self.db.Close()
+}