Swarm MRUs: Adaptive frequency / Predictable lookups / API simplification (#17559)

* swarm/storage/mru: Adaptive Frequency

swarm/storage/mru/lookup: fixed getBaseTime
Added NewEpoch constructor

swarm/api/client: better error handling in GetResource()


swarm/storage/mru: Renamed structures.
Renamed ResourceMetadata to ResourceID. 
Renamed ResourceID.Name to ResourceID.Topic

swarm/storage/mru: Added binarySerializer interface and test tools

swarm/storage/mru/lookup: Changed base time to time and + marshallers

swarm/storage/mru:  Added ResourceID (former resourceMetadata)

swarm/storage/mru: Added ResourceViewId and serialization tests

swarm/storage/mru/lookup: fixed epoch unmarshaller. Added Epoch Equals

swarm/storage/mru: Fixes as per review comments

cmd/swarm: reworded resource create/update help text regarding topic

swarm/storage/mru: Added UpdateLookup and serializer tests

swarm/storage/mru: Added UpdateHeader, serializers and tests

swarm/storage/mru: changed UpdateAddr / epoch to Base()

swarm/storage/mru: Added resourceUpdate serializer and tests

swarm/storage/mru: Added SignedResourceUpdate tests and serializers

swarm/storage/mru/lookup: fixed GetFirstEpoch bug

swarm/storage/mru: refactor, comments, cleanup

Also added tests for Topic
swarm/storage/mru: handler tests pass

swarm/storage/mru: all resource package tests pass

swarm/storage/mru: resource test pass after adding
timestamp checking support

swarm/storage/mru: Added JSON serializers to ResourceIDView structures

swarm/storage/mru: Sever, client, API test pass

swarm/storage/mru: server test pass

swarm/storage/mru: Added topic length check

swarm/storage/mru: removed some literals,
improved "previous lookup" test case

swarm/storage/mru: some fixes and comments as per review

swarm/storage/mru: first working version without metadata chunk

swarm/storage/mru: Various fixes as per review

swarm/storage/mru: client test pass

swarm/storage/mru: resource query strings and manifest-less queries


swarm/storage/mru: simplify naming

swarm/storage/mru: first autofreq working version



swarm/storage/mru: renamed ToValues to AppendValues

swarm/resource/mru: Added ToValues / FromValues for URL query strings

swarm/storage/mru: Changed POST resource to work with query strings.
No more JSON.

swarm/storage/mru: removed resourceid

swarm/storage/mru: Opened up structures

swarm/storage/mru: Merged Request and SignedResourceUpdate

swarm/storage/mru: removed initial data from CLI resource create

swarm/storage/mru: Refactor Topic as a direct fixed-length array

swarm/storage/mru/lookup: Comprehensive GetNextLevel tests

swarm/storage/mru: Added comments

Added length checks in Topic
swarm/storage/mru: fixes in tests and some code comments

swarm/storage/mru/lookup: new optimized lookup algorithm

swarm/api: moved getResourceView to api out of server

swarm/storage/mru: Lookup algorithm working

swarm/storage/mru: comments and renamed NewLookupParams

Deleted commented code


swarm/storage/mru/lookup: renamed Epoch.LaterThan to After

swarm/storage/mru/lookup: Comments and tidying naming



swarm/storage/mru: fix lookup algorithm

swarm/storage/mru: exposed lookup hint
removed updateheader

swarm/storage/mru/lookup: changed GetNextEpoch for initial values

swarm/storage/mru: resource tests pass

swarm/storage/mru: valueSerializer interface and tests



swarm/storage/mru/lookup: Comments, improvements, fixes, more tests

swarm/storage/mru: renamed UpdateLookup to ID, LookupParams to Query

swarm/storage/mru: renamed query receiver var



swarm/cmd: MRU CLI tests

* cmd/swarm: remove rogue fmt

* swarm/storage/mru: Add version / header for future use

* swarm/storage/mru: Fixes/comments as per review

cmd/swarm: remove rogue fmt

swarm/storage/mru: Add version / header for future use-

* swarm/storage/mru: fix linter errors

* cmd/swarm: Speeded up TestCLIResourceUpdate

1 files changed, 125 insertions, 0 deletions

diff --git a/swarm/storage/mru/view.go b/swarm/storage/mru/view.go
new file mode 100644
index 000000000..2e4ce4a0b
--- /dev/null
+++ b/swarm/storage/mru/view.go
@@ -0,0 +1,125 @@
+// Copyright 2018 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 mru
+
+import (
+	"hash"
+	"unsafe"
+
+	"github.com/ethereum/go-ethereum/common"
+	"github.com/ethereum/go-ethereum/common/hexutil"
+	"github.com/ethereum/go-ethereum/swarm/storage"
+)
+
+// View represents a particular user's view of a resource
+type View struct {
+	Topic Topic          `json:"topic"`
+	User  common.Address `json:"user"`
+}
+
+// View layout:
+// TopicLength bytes
+// userAddr common.AddressLength bytes
+const viewLength = TopicLength + common.AddressLength
+
+// mapKey calculates a unique id for this view for the cache map in `Handler`
+func (u *View) mapKey() uint64 {
+	serializedData := make([]byte, viewLength)
+	u.binaryPut(serializedData)
+	hasher := hashPool.Get().(hash.Hash)
+	defer hashPool.Put(hasher)
+	hasher.Reset()
+	hasher.Write(serializedData)
+	hash := hasher.Sum(nil)
+	return *(*uint64)(unsafe.Pointer(&hash[0]))
+}
+
+// binaryPut serializes this View instance into the provided slice
+func (u *View) binaryPut(serializedData []byte) error {
+	if len(serializedData) != viewLength {
+		return NewErrorf(ErrInvalidValue, "Incorrect slice size to serialize View. Expected %d, got %d", viewLength, len(serializedData))
+	}
+	var cursor int
+	copy(serializedData[cursor:cursor+TopicLength], u.Topic[:TopicLength])
+	cursor += TopicLength
+
+	copy(serializedData[cursor:cursor+common.AddressLength], u.User[:])
+	cursor += common.AddressLength
+
+	return nil
+}
+
+// binaryLength returns the expected size of this structure when serialized
+func (u *View) binaryLength() int {
+	return viewLength
+}
+
+// binaryGet restores the current instance from the information contained in the passed slice
+func (u *View) binaryGet(serializedData []byte) error {
+	if len(serializedData) != viewLength {
+		return NewErrorf(ErrInvalidValue, "Incorrect slice size to read View. Expected %d, got %d", viewLength, len(serializedData))
+	}
+
+	var cursor int
+	copy(u.Topic[:], serializedData[cursor:cursor+TopicLength])
+	cursor += TopicLength
+
+	copy(u.User[:], serializedData[cursor:cursor+common.AddressLength])
+	cursor += common.AddressLength
+
+	return nil
+}
+
+// Hex serializes the View to a hex string
+func (u *View) Hex() string {
+	serializedData := make([]byte, viewLength)
+	u.binaryPut(serializedData)
+	return hexutil.Encode(serializedData)
+}
+
+// FromValues deserializes this instance from a string key-value store
+// useful to parse query strings
+func (u *View) FromValues(values Values) (err error) {
+	topic := values.Get("topic")
+	if topic != "" {
+		if err := u.Topic.FromHex(values.Get("topic")); err != nil {
+			return err
+		}
+	} else { // see if the user set name and relatedcontent
+		name := values.Get("name")
+		relatedContent, _ := hexutil.Decode(values.Get("relatedcontent"))
+		if len(relatedContent) > 0 {
+			if len(relatedContent) < storage.AddressLength {
+				return NewErrorf(ErrInvalidValue, "relatedcontent field must be a hex-encoded byte array exactly %d bytes long", storage.AddressLength)
+			}
+			relatedContent = relatedContent[:storage.AddressLength]
+		}
+		u.Topic, err = NewTopic(name, relatedContent)
+		if err != nil {
+			return err
+		}
+	}
+	u.User = common.HexToAddress(values.Get("user"))
+	return nil
+}
+
+// AppendValues serializes this structure into the provided string key-value store
+// useful to build query strings
+func (u *View) AppendValues(values Values) {
+	values.Set("topic", u.Topic.Hex())
+	values.Set("user", u.User.Hex())
+}