Jeremy Tregunna
6fc3be617d
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Adds a complete LSM-based storage engine with these features: - Single-writer based architecture for the storage engine - WAL for durability, and hey it's configurable - MemTable with skip list implementation for fast read/writes - SSTable with block-based structure for on-disk level-based storage - Background compaction with tiered strategy - ACID transactions - Good documentation (I hope)
74 lines
2.0 KiB
Go
74 lines
2.0 KiB
Go
package iterator
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// This file documents the recommended adapter pattern for iterator implementations.
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//
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// Guidelines for Iterator Adapters:
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//
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// 1. Naming Convention:
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// - Use the suffix "IteratorAdapter" for adapter types
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// - Use "New[SourceType]IteratorAdapter" for constructor functions
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//
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// 2. Implementation Pattern:
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// - Store the source iterator as a field
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// - Implement the Iterator interface by delegating to the source
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// - Add any necessary conversion or transformation logic
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// - For nil/error handling, be defensive and check validity
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//
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// 3. Performance Considerations:
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// - Avoid unnecessary copying of keys/values when possible
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// - Consider buffer reuse for frequently allocated memory
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// - Use read-write locks instead of full mutexes where appropriate
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//
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// 4. Adapter Location:
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// - Implement adapters within the package that owns the source type
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// - For example, memtable adapters should be in the memtable package
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//
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// Example:
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//
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// // ExampleAdapter adapts a SourceIterator to the common Iterator interface
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// type ExampleAdapter struct {
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// source SourceIterator
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// }
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//
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// func NewExampleAdapter(source SourceIterator) *ExampleAdapter {
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// return &ExampleAdapter{source: source}
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// }
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//
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// func (a *ExampleAdapter) SeekToFirst() {
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// a.source.SeekToFirst()
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// }
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//
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// func (a *ExampleAdapter) SeekToLast() {
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// a.source.SeekToLast()
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// }
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//
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// func (a *ExampleAdapter) Seek(target []byte) bool {
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// return a.source.Seek(target)
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// }
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//
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// func (a *ExampleAdapter) Next() bool {
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// return a.source.Next()
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// }
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//
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// func (a *ExampleAdapter) Key() []byte {
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// if !a.Valid() {
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// return nil
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// }
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// return a.source.Key()
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// }
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//
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// func (a *ExampleAdapter) Value() []byte {
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// if !a.Valid() {
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// return nil
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// }
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// return a.source.Value()
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// }
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//
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// func (a *ExampleAdapter) Valid() bool {
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// return a.source != nil && a.source.Valid()
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// }
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//
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// func (a *ExampleAdapter) IsTombstone() bool {
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// return a.Valid() && a.source.IsTombstone()
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// }
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