41 lines
812 B
Go
41 lines
812 B
Go
package store
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import (
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"bytes"
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cmn "github.com/tendermint/tmlibs/common"
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)
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// Gets the first item.
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func First(st KVStore, start, end []byte) (kv cmn.KVPair, ok bool) {
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iter := st.Iterator(start, end)
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if !iter.Valid() {
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return kv, false
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}
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defer iter.Close()
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return cmn.KVPair{iter.Key(), iter.Value()}, true
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}
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// Gets the last item. `end` is exclusive.
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func Last(st KVStore, start, end []byte) (kv cmn.KVPair, ok bool) {
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iter := st.ReverseIterator(end, start)
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if !iter.Valid() {
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if v := st.Get(start); v != nil {
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return cmn.KVPair{cp(start), cp(v)}, true
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}
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return kv, false
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}
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defer iter.Close()
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if bytes.Equal(iter.Key(), end) {
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// Skip this one, end is exclusive.
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iter.Next()
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if !iter.Valid() {
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return kv, false
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}
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}
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return cmn.KVPair{iter.Key(), iter.Value()}, true
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}
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