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42 lines
1.7 KiB
Go
42 lines
1.7 KiB
Go
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// Copyright 2013 Prometheus Team
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// Licensed under the Apache License, Version 2.0 (the "License");
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// you may not use this file except in compliance with the License.
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// You may obtain a copy of the License at
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//
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// http://www.apache.org/licenses/LICENSE-2.0
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//
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// Unless required by applicable law or agreed to in writing, software
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// distributed under the License is distributed on an "AS IS" BASIS,
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// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
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// See the License for the specific language governing permissions and
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// limitations under the License.
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package leveldb
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// TODO: Evaluate whether to use coding.Encoder for the key and values instead
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// raw bytes for consistency reasons.
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// Iterator wraps Levigo and LevelDB's iterator behaviors in a manner that is
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// conducive to IO-free testing.
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//
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// It borrows some of the operational assumptions from goskiplist, which
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// functions very similarly, in that it uses no separate Valid method to
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// determine health. All methods that have a return signature of (ok bool)
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// assume in the real LevelDB case that if ok == false that the iterator
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// must be disposed of at this given instance and recreated if future
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// work is desired. This is a quirk of LevelDB itself!
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type Iterator interface {
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// GetError reports low-level errors, if available. This should not indicate
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// that the iterator is necessarily unhealthy but maybe that the underlying
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// table is corrupted itself. See the notes above for (ok bool) return
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// signatures to determine iterator health.
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GetError() error
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Key() []byte
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Next() (ok bool)
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Previous() (ok bool)
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Seek(key []byte) (ok bool)
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SeekToFirst() (ok bool)
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SeekToLast() (ok bool)
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Value() []byte
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}
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