diff options
Diffstat (limited to 'swarm/storage/mru/query.go')
-rw-r--r-- | swarm/storage/mru/query.go | 78 |
1 files changed, 78 insertions, 0 deletions
diff --git a/swarm/storage/mru/query.go b/swarm/storage/mru/query.go new file mode 100644 index 000000000..9a0f261c4 --- /dev/null +++ b/swarm/storage/mru/query.go @@ -0,0 +1,78 @@ +// 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 ( + "fmt" + "strconv" + + "github.com/ethereum/go-ethereum/common" + "github.com/ethereum/go-ethereum/swarm/storage/mru/lookup" +) + +// Query is used to specify constraints when performing an update lookup +// TimeLimit indicates an upper bound for the search. Set to 0 for "now" +type Query struct { + View + Hint lookup.Epoch + TimeLimit uint64 +} + +// FromValues deserializes this instance from a string key-value store +// useful to parse query strings +func (q *Query) FromValues(values Values) error { + time, _ := strconv.ParseUint(values.Get("time"), 10, 64) + q.TimeLimit = uint64(time) + + level, _ := strconv.ParseUint(values.Get("hint.level"), 10, 32) + q.Hint.Level = uint8(level) + q.Hint.Time, _ = strconv.ParseUint(values.Get("hint.time"), 10, 64) + if q.View.User == (common.Address{}) { + return q.View.FromValues(values) + } + return nil +} + +// AppendValues serializes this structure into the provided string key-value store +// useful to build query strings +func (q *Query) AppendValues(values Values) { + if q.TimeLimit != 0 { + values.Set("time", fmt.Sprintf("%d", q.TimeLimit)) + } + if q.Hint.Level != 0 { + values.Set("hint.level", fmt.Sprintf("%d", q.Hint.Level)) + } + if q.Hint.Time != 0 { + values.Set("hint.time", fmt.Sprintf("%d", q.Hint.Time)) + } + q.View.AppendValues(values) +} + +// NewQuery constructs an Query structure to find updates on or before `time` +// if time == 0, the latest update will be looked up +func NewQuery(view *View, time uint64, hint lookup.Epoch) *Query { + return &Query{ + TimeLimit: time, + View: *view, + Hint: hint, + } +} + +// NewQueryLatest generates lookup parameters that look for the latest version of a resource +func NewQueryLatest(view *View, hint lookup.Epoch) *Query { + return NewQuery(view, 0, hint) +} |