44 lines
1.8 KiB
C
44 lines
1.8 KiB
C
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// Copyright (c) 2011-present, Facebook, Inc. All rights reserved.
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// This source code is licensed under both the GPLv2 (found in the
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// COPYING file in the root directory) and Apache 2.0 License
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// (found in the LICENSE.Apache file in the root directory).
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#pragma once
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#include <memory>
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#include <string>
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#include "rocksdb/slice.h"
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namespace rocksdb {
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namespace blob_db {
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// TTLExtractor allow applications to extract TTL from key-value pairs.
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// This useful for applications using Put or WriteBatch to write keys and
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// don't intend to migrate to PutWithTTL or PutUntil.
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//
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// Applications can implement either ExtractTTL or ExtractExpiration. If both
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// are implemented, ExtractExpiration will take precedence.
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class TTLExtractor {
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public:
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// Extract TTL from key-value pair.
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// Return true if the key has TTL, false otherwise. If key has TTL,
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// TTL is pass back through ttl. The method can optionally modify the value,
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// pass the result back through new_value, and also set value_changed to true.
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virtual bool ExtractTTL(const Slice& key, const Slice& value, uint64_t* ttl,
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std::string* new_value, bool* value_changed);
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// Extract expiration time from key-value pair.
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// Return true if the key has expiration time, false otherwise. If key has
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// expiration time, it is pass back through expiration. The method can
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// optionally modify the value, pass the result back through new_value,
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// and also set value_changed to true.
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virtual bool ExtractExpiration(const Slice& key, const Slice& value,
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uint64_t now, uint64_t* expiration,
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std::string* new_value, bool* value_changed);
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virtual ~TTLExtractor() = default;
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};
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} // namespace blob_db
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} // namespace rocksdb
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