| 1 | //===----------------------------------------------------------------------===// | 
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| 2 | //                         DuckDB | 
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| 3 | // | 
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| 4 | // duckdb/execution/index/art/swizzleable_pointer.hpp | 
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| 5 | // | 
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| 6 | // | 
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| 7 | //===----------------------------------------------------------------------===// | 
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| 8 | #pragma once | 
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| 9 |  | 
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| 10 | #include "duckdb/common/constants.hpp" | 
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| 11 |  | 
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| 12 | namespace duckdb { | 
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| 13 |  | 
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| 14 | // classes | 
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| 15 | class MetaBlockReader; | 
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| 16 |  | 
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| 17 | // structs | 
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| 18 | struct BlockPointer; | 
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| 19 |  | 
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| 20 | //! SwizzleablePointer provides functions on a (possibly) swizzled pointer. If the swizzle flag is set, then the | 
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| 21 | //! pointer points to a storage address (and has no type), otherwise the pointer has a type and stores | 
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| 22 | //! other information (e.g., a buffer location) | 
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| 23 | class SwizzleablePointer { | 
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| 24 | public: | 
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| 25 | //! Constructs an empty SwizzleablePointer | 
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| 26 | SwizzleablePointer() : swizzle_flag(0), type(0), offset(0), buffer_id(0) {}; | 
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| 27 | //! Constructs a swizzled pointer from a buffer ID and an offset | 
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| 28 | explicit SwizzleablePointer(MetaBlockReader &reader); | 
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| 29 | //! Constructs a non-swizzled pointer from a buffer ID and an offset | 
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| 30 | SwizzleablePointer(uint32_t offset, uint32_t buffer_id) | 
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| 31 | : swizzle_flag(0), type(0), offset(offset), buffer_id(buffer_id) {}; | 
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| 32 |  | 
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| 33 | //! The swizzle flag, set if swizzled, not set otherwise | 
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| 34 | uint8_t swizzle_flag : 1; | 
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| 35 | //! The type of the pointer, zero if not set | 
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| 36 | uint8_t type : 7; | 
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| 37 | //! The offset of a memory location | 
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| 38 | uint32_t offset : 24; | 
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| 39 | //! The buffer ID of a memory location | 
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| 40 | uint32_t buffer_id : 32; | 
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| 41 |  | 
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| 42 | public: | 
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| 43 | //! Checks if the pointer is swizzled | 
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| 44 | inline bool IsSwizzled() const { | 
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| 45 | return swizzle_flag; | 
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| 46 | } | 
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| 47 | //! Returns true, if neither the swizzle flag nor the type is set, and false otherwise | 
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| 48 | inline bool IsSet() const { | 
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| 49 | return swizzle_flag || type; | 
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| 50 | } | 
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| 51 | //! Reset the pointer | 
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| 52 | inline void Reset() { | 
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| 53 | swizzle_flag = 0; | 
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| 54 | type = 0; | 
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| 55 | } | 
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| 56 | }; | 
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| 57 |  | 
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| 58 | } // namespace duckdb | 
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| 59 |  | 
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