79 lines
2.5 KiB
Go
79 lines
2.5 KiB
Go
// Copyright 2018 The go-ethereum Authors
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// This file is part of the go-ethereum library.
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//
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// The go-ethereum library is free software: you can redistribute it and/or modify
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// it under the terms of the GNU Lesser General Public License as published by
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// the Free Software Foundation, either version 3 of the License, or
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// (at your option) any later version.
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//
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// The go-ethereum library is distributed in the hope that it will be useful,
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// but WITHOUT ANY WARRANTY; without even the implied warranty of
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// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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// GNU Lesser General Public License for more details.
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//
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// You should have received a copy of the GNU Lesser General Public License
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// along with the go-ethereum library. If not, see <http://www.gnu.org/licenses/>.
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package feeds
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import (
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"fmt"
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"strconv"
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"github.com/ethereum/go-ethereum/common"
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"github.com/ethereum/go-ethereum/swarm/storage/feeds/lookup"
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)
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// Query is used to specify constraints when performing an update lookup
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// TimeLimit indicates an upper bound for the search. Set to 0 for "now"
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type Query struct {
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Feed
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Hint lookup.Epoch
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TimeLimit uint64
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}
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// FromValues deserializes this instance from a string key-value store
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// useful to parse query strings
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func (q *Query) FromValues(values Values) error {
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time, _ := strconv.ParseUint(values.Get("time"), 10, 64)
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q.TimeLimit = time
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level, _ := strconv.ParseUint(values.Get("hint.level"), 10, 32)
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q.Hint.Level = uint8(level)
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q.Hint.Time, _ = strconv.ParseUint(values.Get("hint.time"), 10, 64)
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if q.Feed.User == (common.Address{}) {
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return q.Feed.FromValues(values)
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}
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return nil
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}
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// AppendValues serializes this structure into the provided string key-value store
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// useful to build query strings
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func (q *Query) AppendValues(values Values) {
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if q.TimeLimit != 0 {
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values.Set("time", fmt.Sprintf("%d", q.TimeLimit))
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}
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if q.Hint.Level != 0 {
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values.Set("hint.level", fmt.Sprintf("%d", q.Hint.Level))
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}
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if q.Hint.Time != 0 {
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values.Set("hint.time", fmt.Sprintf("%d", q.Hint.Time))
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}
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q.Feed.AppendValues(values)
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}
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// NewQuery constructs an Query structure to find updates on or before `time`
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// if time == 0, the latest update will be looked up
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func NewQuery(feed *Feed, time uint64, hint lookup.Epoch) *Query {
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return &Query{
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TimeLimit: time,
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Feed: *feed,
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Hint: hint,
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}
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}
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// NewQueryLatest generates lookup parameters that look for the latest update to a feed
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func NewQueryLatest(feed *Feed, hint lookup.Epoch) *Query {
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return NewQuery(feed, 0, hint)
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}
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