0c025fa937
We don't use reverse listing in any of our code, outside of tests, and it is only exposed through libuplink in the lib/uplink.(*Project).ListBuckets() API. We also don't know of any users who might have a need for reverse listing through ListBuckets(). Since one of our prospective pointerdb backends can not support backwards iteration, and because of the above considerations, we are going to remove the reverse listing feature. Change-Id: I8d2a1f33d01ee70b79918d584b8c671f57eef2a0
78 lines
1.7 KiB
Go
78 lines
1.7 KiB
Go
// Copyright (C) 2019 Storj Labs, Inc.
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// See LICENSE for copying information.
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package storage
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import (
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"bytes"
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"context"
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"sort"
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)
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// IteratorFunc implements basic iterator
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type IteratorFunc func(ctx context.Context, item *ListItem) bool
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// Next returns the next item
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func (next IteratorFunc) Next(ctx context.Context, item *ListItem) bool { return next(ctx, item) }
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// SelectPrefixed keeps only items that have prefix
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// items will be reused and modified
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// TODO: remove this
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func SelectPrefixed(items Items, prefix []byte) Items {
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result := items[:0]
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for _, item := range items {
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if bytes.HasPrefix(item.Key, prefix) {
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result = append(result, item)
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}
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}
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return result
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}
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// SortAndCollapse sorts items and combines elements based on Delimiter
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// items will be reused and modified
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// TODO: remove this
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func SortAndCollapse(items Items, prefix []byte) Items {
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sort.Sort(items)
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result := items[:0]
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var currentPrefix []byte
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var prefixed bool
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for _, item := range items {
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if prefixed {
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if bytes.HasPrefix(item.Key, currentPrefix) {
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continue
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}
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prefixed = false
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}
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if p := bytes.IndexByte(item.Key[len(prefix):], Delimiter); p >= 0 {
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currentPrefix = item.Key[:len(prefix)+p+1]
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prefixed = true
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result = append(result, ListItem{
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Key: currentPrefix,
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IsPrefix: true,
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})
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} else {
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result = append(result, item)
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}
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}
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return result
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}
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// StaticIterator implements an iterator over list of items
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type StaticIterator struct {
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Items Items
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Index int
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}
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// Next returns the next item from the iterator
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func (it *StaticIterator) Next(ctx context.Context, item *ListItem) bool {
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if it.Index >= len(it.Items) {
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return false
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}
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*item = it.Items[it.Index]
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it.Index++
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return true
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}
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