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Diffstat (limited to 'include/ruby/internal/intern/hash.h')
| -rw-r--r-- | include/ruby/internal/intern/hash.h | 306 |
1 files changed, 306 insertions, 0 deletions
diff --git a/include/ruby/internal/intern/hash.h b/include/ruby/internal/intern/hash.h new file mode 100644 index 0000000000..504770fa5f --- /dev/null +++ b/include/ruby/internal/intern/hash.h @@ -0,0 +1,306 @@ +#ifndef RBIMPL_INTERN_HASH_H /*-*-C++-*-vi:se ft=cpp:*/ +#define RBIMPL_INTERN_HASH_H +/** + * @file + * @author Ruby developers <ruby-core@ruby-lang.org> + * @copyright This file is a part of the programming language Ruby. + * Permission is hereby granted, to either redistribute and/or + * modify this file, provided that the conditions mentioned in the + * file COPYING are met. Consult the file for details. + * @warning Symbols prefixed with either `RBIMPL` or `rbimpl` are + * implementation details. Don't take them as canon. They could + * rapidly appear then vanish. The name (path) of this header file + * is also an implementation detail. Do not expect it to persist + * at the place it is now. Developers are free to move it anywhere + * anytime at will. + * @note To ruby-core: remember that this header can be possibly + * recursively included from extension libraries written in C++. + * Do not expect for instance `__VA_ARGS__` is always available. + * We assume C99 for ruby itself but we don't assume languages of + * extension libraries. They could be written in C++98. + * @brief Public APIs related to ::rb_cHash. + */ +#include "ruby/internal/attr/nonnull.h" +#include "ruby/internal/dllexport.h" +#include "ruby/internal/value.h" +#include "ruby/st.h" + +RBIMPL_SYMBOL_EXPORT_BEGIN() + +/* hash.c */ + +RBIMPL_ATTR_NONNULL(()) +/** + * Identical to rb_st_foreach(), except it raises exceptions when the callback + * function tampers the table during iterating over it. + * + * @param[in] st Table to iterate over. + * @param[in] func Callback function to apply. + * @param[in] arg Passed as-is to `func`. + * @exception rb_eRuntimeError `st` was tampered during iterating. + * + * @internal + * + * This is declared here because exceptions are Ruby level concept. + * + * This is in fact a very thin wrapper of rb_st_foreach_check(). + */ +void rb_st_foreach_safe(struct st_table *st, st_foreach_callback_func *func, st_data_t arg); + +/** @alias{rb_st_foreach_safe} */ +#define st_foreach_safe rb_st_foreach_safe + +/** + * Try converting an object to its hash representation using its `to_hash` + * method, if any. If there is no such thing, returns ::RUBY_Qnil. + * + * @param[in] obj Arbitrary ruby object to convert. + * @exception rb_eTypeError `obj.to_hash` returned something non-Hash. + * @retval RUBY_Qnil No conversion from `obj` to hash defined. + * @retval otherwise Converted hash representation of `obj`. + * @see rb_io_check_io + * @see rb_check_array_type + * @see rb_check_string_type + * + * @internal + * + * There is no rb_hash_to_hash() that analogous to rb_str_to_str(). + * Intentional or ...? + */ +VALUE rb_check_hash_type(VALUE obj); + +RBIMPL_ATTR_NONNULL(()) +/** + * Iterates over a hash. This basically does the same thing as + * rb_st_foreach(). But because the passed hash is a Ruby object, its keys and + * values are both Ruby objects. + * + * @param[in] hash An instance of ::rb_cHash to iterate over. + * @param[in] func Callback function to yield. + * @param[in] arg Passed as-is to `func`. + * @exception rb_eRuntimeError `hash` was tampered during iterating. + */ +void rb_hash_foreach(VALUE hash, int (*func)(VALUE key, VALUE val, VALUE arg), VALUE arg); + +/** + * Calculates a message authentication code of the passed object. The return + * value is a very small integer used as an index of a key of a table. In + * order to calculate the value this function calls `#hash` method of the + * passed object. Ruby provides you a default implementation. But if you + * implement your class in C, that default implementation cannot know the + * underlying data structure. You must implement your own `#hash` method then, + * which must return an integer of uniform distribution in a sufficiently + * instant manner. + * + * @param[in] obj Arbitrary Ruby object. + * @exception rb_eTypeError `obj.hash` returned something non-Integer. + * @return A small integer. + * @note `#hash` can return very big integers, but they get truncated. + */ +VALUE rb_hash(VALUE obj); + +/** + * Creates a new, empty hash object. + * + * @return An allocated new instance of ::rb_cHash. + */ +VALUE rb_hash_new(void); + +/** + * Identical to rb_hash_new(), except it additionally specifies how many keys + * it is expected to contain. This way you can create a hash that is large enough + * for your need. For large hashes it means it won't need to be reallocated and + * rehashed as much, improving performance. + * + * @param[in] capa Designed capacity of the hash. + * @return An empty Hash, whose capacity is `capa`. + */ +VALUE rb_hash_new_capa(long capa); + +/** + * Duplicates a hash. + * + * @param[in] hash An instance of ::rb_cHash. + * @return An allocated new instance of ::rb_cHash, whose contents are + * a verbatim copy of from `hash`. + */ +VALUE rb_hash_dup(VALUE hash); + +/** @alias{rb_obj_freeze} */ +VALUE rb_hash_freeze(VALUE obj); + +/** + * Queries the given key in the given hash table. If there is the key in the + * hash, returns the value associated with the key. Otherwise it returns the + * "default" value (defined per hash table). + * + * @param[in] hash Hash table to look into. + * @param[in] key Hash key to look for. + * @return Either the value associated with the key, or the default one if + * absent. + */ +VALUE rb_hash_aref(VALUE hash, VALUE key); + +/** + * Identical to rb_hash_aref(), except it always returns ::RUBY_Qnil for + * misshits. + * + * @param[in] hash Hash table to look into. + * @param[in] key Hash key to look for. + * @return Either the value associated with the key, or ::RUBY_Qnil if + * absent. + * @note A hash can store ::RUBY_Qnil as an ordinary value. You cannot + * distinguish whether the key is missing, or just its associated + * value happens to be ::RUBY_Qnil, as far as you use this API. + */ +VALUE rb_hash_lookup(VALUE hash, VALUE key); + +/** + * Identical to rb_hash_lookup(), except you can specify what to return on + * misshits. This is much like 2-arguments version of `Hash#fetch`. + * + * ```CXX + * VALUE hash; + * VALUE key; + * VALUE tmp = rb_obj_alloc(rb_cObject); + * VALUE val = rb_hash_lookup2(hash, key, tmp); + * if (val == tmp) { + * printf("misshit"); + * } + * else { + * printf("hit"); + * } + * ``` + * + * @param[in] hash Hash table to look into. + * @param[in] key Hash key to look for. + * @param[in] def Default value. + * @retval def `hash` does not have `key`. + * @retval otherwise The value associated with `key`. + */ +VALUE rb_hash_lookup2(VALUE hash, VALUE key, VALUE def); + +/** + * Identical to rb_hash_lookup(), except it yields the (implicitly) passed + * block instead of returning ::RUBY_Qnil. + * + * @param[in] hash Hash table to look into. + * @param[in] key Hash key to look for. + * @exception rb_eKeyError No block given. + * @return Either the value associated with the key, or what the block + * evaluates to if absent. + */ +VALUE rb_hash_fetch(VALUE hash, VALUE key); + +/** + * Inserts or replaces ("upsert"s) the objects into the given hash table. This + * basically associates the given value with the given key. On duplicate key + * this function updates its associated value with the given one. Otherwise it + * inserts the association at the end of the table. + * + * @param[out] hash Target hash table to modify. + * @param[in] key Arbitrary Ruby object. + * @param[in] val A value to be associated with `key`. + * @exception rb_eFrozenError `hash` is frozen. + * @return The passed `val` + * @post `val` is associated with `key` in `hash`. + */ +VALUE rb_hash_aset(VALUE hash, VALUE key, VALUE val); + +/** + * Swipes everything out of the passed hash table. + * + * @param[out] hash Target to clear. + * @exception rb_eFrozenError `hash`is frozen. + * @return The passed `hash` + * @post `hash` has no contents. + */ +VALUE rb_hash_clear(VALUE hash); + +/** + * Deletes each entry for which the block returns a truthy value. If there is + * no block given, it returns an enumerator that does the thing. + * + * @param[out] hash Target hash to modify. + * @exception rb_eFrozenError `hash` is frozen. + * @retval hash The hash is modified. + * @retval otherwise An instance of ::rb_cEnumerator that does it. + */ +VALUE rb_hash_delete_if(VALUE hash); + +/** + * Deletes the passed key from the passed hash table, if any. + * + * @param[out] hash Target hash to modify. + * @param[in] key Key to delete. + * @retval RUBY_Qnil `hash` has no such key as `key`. + * @retval otherwise What was associated with `key`. + * @post `hash` has no such key as `key`. + */ +VALUE rb_hash_delete(VALUE hash, VALUE key); + +/** + * Inserts a list of key-value pairs into a hash table at once. It is + * semantically identical to repeatedly calling rb_hash_aset(), but can be + * faster than that. + * + * @param[in] argc Length of `argv`, must be even. + * @param[in] argv A list of key, value, key, value, ... + * @param[out] hash Target hash table to modify. + * @post `hash` has contents from `argv`. + * @note `argv` is allowed to be NULL as long as `argc` is zero. + * + * @internal + * + * What happens for duplicated keys? Well it silently discards older ones to + * accept the newest (rightmost) one. This behaviour also mimics repeated call + * of rb_hash_aset(). + */ +void rb_hash_bulk_insert(long argc, const VALUE *argv, VALUE hash); + +/** + * Type of callback functions to pass to rb_hash_update_by(). + * + * @param[in] newkey A key of the table. + * @param[in] oldkey Value associated with `key` in hash1. + * @param[in] value Value associated with `key` in hash2. + * @return Either one of the passed values to take. + */ +typedef VALUE rb_hash_update_func(VALUE newkey, VALUE oldkey, VALUE value); + +/** + * Destructively merges two hash tables into one. It resolves key conflicts by + * calling the passed function and take its return value. + * + * @param[out] hash1 Target hash to be modified. + * @param[in] hash2 A hash to merge into `hash1`. + * @param[in] func Conflict reconciler. + * @exception rb_eFrozenError `hash1` is frozen. + * @exception rb_eRuntimeError `hash2` is updated instead. + * @return The passed `hash1`. + * @post Contents of `hash2` is merged into `hash1`. + * @note You can pass zero to `func`. This means values from `hash2` + * are always taken. + */ +VALUE rb_hash_update_by(VALUE hash1, VALUE hash2, rb_hash_update_func *func); + +/** + * Destructively removes every environment variables of the running process. + * + * @return The `ENV` object. + * @post The process has no environment variables. + */ +VALUE rb_env_clear(void); + +/** + * Identical to #RHASH_SIZE(), except it returns the size in Ruby's integer + * instead of C's. + * + * @param[in] hash A hash object. + * @return The size of the hash. + */ +VALUE rb_hash_size(VALUE hash); + +RBIMPL_SYMBOL_EXPORT_END() + +#endif /* RBIMPL_INTERN_HASH_H */ |