llvm::hashing::detail::hash_combine_recursive_helper Struct Reference

Helper class to manage the recursive combining of hash_combine arguments. More...

#include "llvm/ADT/Hashing.h"

Public Member Functions
	hash_combine_recursive_helper ()
	Construct a recursive hash combining helper.
template<typename T >
char *	combine_data (size_t &length, char *buffer_ptr, char *buffer_end, T data)
	Combine one chunk of data into the current in-flight hash.
template<typename T , typename ... Ts>
hash_code	combine (size_t length, char *buffer_ptr, char *buffer_end, const T &arg, const Ts &...args)
	Recursive, variadic combining method.
hash_code	combine (size_t length, char *buffer_ptr, char *buffer_end)
	Base case for recursive, variadic combining.

Public Attributes
char	buffer [64] = {}
hash_state	state
const uint64_t	seed

Detailed Description

Helper class to manage the recursive combining of hash_combine arguments.

This class exists to manage the state and various calls involved in the recursive combining of arguments used in hash_combine. It is particularly useful at minimizing the code in the recursive calls to ease the pain caused by a lack of variadic functions.

Definition at line 487 of file Hashing.h.

Constructor & Destructor Documentation

hash_combine_recursive_helper()

llvm::hashing::detail::hash_combine_recursive_helper::hash_combine_recursive_helper ( )

inline

Construct a recursive hash combining helper.

This sets up the state for a recursive hash combine, including getting the seed and buffer setup.

Definition at line 497 of file Hashing.h.

Member Function Documentation

combine() [1/2]

hash_code llvm::hashing::detail::hash_combine_recursive_helper::combine ( size_t  length, char *  buffer_ptr, char *  buffer_end  )

inline

Base case for recursive, variadic combining.

The base case when combining arguments recursively is reached when all arguments have been handled. It flushes the remaining buffer and constructs a hash_code.

Definition at line 559 of file Hashing.h.

References buffer, llvm::hashing::detail::hash_state::finalize(), llvm::hashing::detail::hash_short(), llvm::hashing::detail::hash_state::mix(), seed, and state.

combine() [2/2]

template<typename T , typename ... Ts>

hash_code llvm::hashing::detail::hash_combine_recursive_helper::combine ( size_t  length, char *  buffer_ptr, char *  buffer_end, const T &  arg, const Ts &...  args  )

inline

Recursive, variadic combining method.

This function recurses through each argument, combining that argument into a single hash.

Definition at line 546 of file Hashing.h.

References args, combine(), combine_data(), and llvm::hashing::detail::get_hashable_data().

Referenced by combine(), and llvm::hash_combine().

combine_data()

template<typename T >

char * llvm::hashing::detail::hash_combine_recursive_helper::combine_data ( size_t &  length, char *  buffer_ptr, char *  buffer_end, T  data  )

inline

Combine one chunk of data into the current in-flight hash.

This merges one chunk of data into the hash. First it tries to buffer the data. If the buffer is full, it hashes the buffer into its hash_state, empties it, and then merges the new chunk in. This also handles cases where the data straddles the end of the buffer.

Definition at line 507 of file Hashing.h.

References buffer, llvm::hashing::detail::hash_state::create(), llvm_unreachable, llvm::hashing::detail::hash_state::mix(), seed, state, and llvm::hashing::detail::store_and_advance().

Referenced by combine().

Member Data Documentation

buffer

char llvm::hashing::detail::hash_combine_recursive_helper::buffer[64] = {}

Definition at line 488 of file Hashing.h.

Referenced by combine(), combine_data(), and llvm::hash_combine().

seed

const uint64_t llvm::hashing::detail::hash_combine_recursive_helper::seed

Definition at line 490 of file Hashing.h.

Referenced by combine(), and combine_data().

state

hash_state llvm::hashing::detail::hash_combine_recursive_helper::state

Definition at line 489 of file Hashing.h.

Referenced by combine(), and combine_data().

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The documentation for this struct was generated from the following file:

• include/llvm/ADT/Hashing.h