diff options
Diffstat (limited to 'include/ruby/memory_view.h')
| -rw-r--r-- | include/ruby/memory_view.h | 325 |
1 files changed, 325 insertions, 0 deletions
diff --git a/include/ruby/memory_view.h b/include/ruby/memory_view.h new file mode 100644 index 0000000000..42309d5afc --- /dev/null +++ b/include/ruby/memory_view.h @@ -0,0 +1,325 @@ +#ifndef RUBY_MEMORY_VIEW_H /*-*-C++-*-vi:se ft=cpp:*/ +#define RUBY_MEMORY_VIEW_H 1 +/** + * @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. + * @brief Memory View. + */ + +#include "ruby/internal/config.h" + +#ifdef STDC_HEADERS +# include <stddef.h> /* size_t */ +#endif + +#ifdef HAVE_SYS_TYPES_H +# include <sys/types.h> /* ssize_t */ +#endif + +#include "ruby/internal/attr/pure.h" /* RBIMPL_ATTR_PURE */ +#include "ruby/internal/core/rtypeddata.h" /* rb_data_type_t */ +#include "ruby/internal/dllexport.h" /* RUBY_EXTERN */ +#include "ruby/internal/stdbool.h" /* bool */ +#include "ruby/internal/value.h" /* VALUE */ + +/** + * Flags passed to rb_memory_view_get(), then to ::rb_memory_view_get_func_t. + */ +enum ruby_memory_view_flags { + RUBY_MEMORY_VIEW_SIMPLE = 0, + RUBY_MEMORY_VIEW_WRITABLE = (1<<0), + RUBY_MEMORY_VIEW_FORMAT = (1<<1), + RUBY_MEMORY_VIEW_MULTI_DIMENSIONAL = (1<<2), + RUBY_MEMORY_VIEW_STRIDES = (1<<3) | RUBY_MEMORY_VIEW_MULTI_DIMENSIONAL, + RUBY_MEMORY_VIEW_ROW_MAJOR = (1<<4) | RUBY_MEMORY_VIEW_STRIDES, + RUBY_MEMORY_VIEW_COLUMN_MAJOR = (1<<5) | RUBY_MEMORY_VIEW_STRIDES, + RUBY_MEMORY_VIEW_ANY_CONTIGUOUS = RUBY_MEMORY_VIEW_ROW_MAJOR | RUBY_MEMORY_VIEW_COLUMN_MAJOR, + RUBY_MEMORY_VIEW_INDIRECT = (1<<6) | RUBY_MEMORY_VIEW_STRIDES, +}; + +/** Memory view component metadata. */ +typedef struct { + /** @see ::rb_memory_view_t::format */ + char format; + + /** :FIXME: what is a "native" size is unclear. */ + bool native_size_p; + + /** Endian of the component */ + bool little_endian_p; + + /** The component's offset. */ + size_t offset; + + /** The component's size. */ + size_t size; + + /** + * How many numbers of components are there. For instance "CCC"'s repeat is + * 3. + */ + size_t repeat; +} rb_memory_view_item_component_t; + +/** + * A MemoryView structure, `rb_memory_view_t`, is used for exporting objects' + * MemoryView. + * + * This structure contains the reference of the object, which is the owner of + * the MemoryView, the pointer to the head of exported memory, and the metadata + * that describes the structure of the memory. The metadata can describe + * multidimensional arrays with strides. + */ +typedef struct { + /** + * The original object that has the memory exported via this memory view. + */ + VALUE obj; + + /** The pointer to the exported memory. */ + void *data; + + /** The number of bytes in data. */ + ssize_t byte_size; + + /** true for readonly memory, false for writable memory. */ + bool readonly; + + /** + * A string to describe the format of an element, or NULL for unsigned bytes. + * The format string is a sequence of the following pack-template specifiers: + * + * c, C, s, s!, S, S!, n, v, i, i!, I, I!, l, l!, L, L!, + * N, V, f, e, g, q, q!, Q, Q!, d, E, G, j, J, x + * + * For example, "dd" for an element that consists of two double values, + * and "CCC" for an element that consists of three bytes, such as + * an RGB color triplet. + * + * Also, the value endianness can be explicitly specified by '<' or '>' + * following a value type specifier. + * + * The items are packed contiguously. When you emulate the alignment of + * structure members, put '|' at the beginning of the format string, + * like "|iqc". On x86_64 Linux ABI, the size of the item by this format + * is 24 bytes instead of 13 bytes. + */ + const char *format; + + /** + * The number of bytes in each element. + * item_size should equal to rb_memory_view_item_size_from_format(format). */ + ssize_t item_size; + + /** Description of each components. */ + struct { + /** + * The array of rb_memory_view_item_component_t that describes the + * item structure. rb_memory_view_prepare_item_desc and + * rb_memory_view_get_item allocate this memory if needed, + * and rb_memory_view_release frees it. */ + const rb_memory_view_item_component_t *components; + + /** The number of components in an item. */ + size_t length; + } item_desc; + + /** The number of dimension. */ + ssize_t ndim; + + /** + * ndim size array indicating the number of elements in each dimension. + * This can be NULL when ndim == 1. */ + const ssize_t *shape; + + /** + * ndim size array indicating the number of bytes to skip to go to the + * next element in each dimension. */ + const ssize_t *strides; + + /** + * The offset in each dimension when this memory view exposes a nested array. + * Or, NULL when this memory view exposes a flat array. */ + const ssize_t *sub_offsets; + + /** The private data for managing this exported memory */ + void *private_data; + + /** DO NOT TOUCH THIS: The memory view entry for the internal use */ + const struct rb_memory_view_entry *_memory_view_entry; +} rb_memory_view_t; + +/** Type of function of ::rb_memory_view_entry_t::get_func. */ +typedef bool (* rb_memory_view_get_func_t)(VALUE obj, rb_memory_view_t *view, int flags); + +/** Type of function of ::rb_memory_view_entry_t::release_func. */ +typedef bool (* rb_memory_view_release_func_t)(VALUE obj, rb_memory_view_t *view); + +/** Type of function of ::rb_memory_view_entry_t::available_p_func. */ +typedef bool (* rb_memory_view_available_p_func_t)(VALUE obj); + +/** Operations applied to a specific kind of a memory view. */ +typedef struct rb_memory_view_entry { + /** + * Exports a memory view from a Ruby object. + */ + rb_memory_view_get_func_t get_func; + + /** + * Releases a memory view that was previously generated using + * ::rb_memory_view_entry_t::get_func. + */ + rb_memory_view_release_func_t release_func; + + /** + * Queries if an object understands memory view protocol. + */ + rb_memory_view_available_p_func_t available_p_func; +} rb_memory_view_entry_t; + +RBIMPL_SYMBOL_EXPORT_BEGIN() + +/* memory_view.c */ + +/** + * Associates the passed class with the passed memory view entry. This has to + * be called before actually creating a memory view from an instance. + */ +bool rb_memory_view_register(VALUE klass, const rb_memory_view_entry_t *entry); + +RBIMPL_ATTR_PURE() +/** + * Return `true` if the data in the MemoryView `view` is row-major contiguous. + * + * Return `false` otherwise. + */ +bool rb_memory_view_is_row_major_contiguous(const rb_memory_view_t *view); + +RBIMPL_ATTR_PURE() +/** + * Return `true` if the data in the MemoryView `view` is column-major + * contiguous. + * + * Return `false` otherwise. + */ +bool rb_memory_view_is_column_major_contiguous(const rb_memory_view_t *view); + +RBIMPL_ATTR_NOALIAS() +/** + * Fill the `strides` array with byte-Strides of a contiguous array of the + * given shape with the given element size. + */ +void rb_memory_view_fill_contiguous_strides(const ssize_t ndim, const ssize_t item_size, const ssize_t *const shape, const bool row_major_p, ssize_t *const strides); + +RBIMPL_ATTR_NOALIAS() +/** + * Fill the members of `view` as an 1-dimensional byte array. + */ +bool rb_memory_view_init_as_byte_array(rb_memory_view_t *view, VALUE obj, void *data, const ssize_t len, const bool readonly); + +/** + * Deconstructs the passed format string, as describe in + * ::rb_memory_view_t::format. + */ +ssize_t rb_memory_view_parse_item_format(const char *format, + rb_memory_view_item_component_t **members, + size_t *n_members, const char **err); + +/** + * Calculate the number of bytes occupied by an element. + * + * When the calculation fails, the failed location in `format` is stored into + * `err`, and returns `-1`. + */ +ssize_t rb_memory_view_item_size_from_format(const char *format, const char **err); + +/** + * Calculate the location of the item indicated by the given `indices`. + * + * The length of `indices` must equal to `view->ndim`. + * + * This function initializes `view->item_desc` if needed. + */ +void *rb_memory_view_get_item_pointer(rb_memory_view_t *view, const ssize_t *indices); + +/** + * Return a value that consists of item members. + * + * When an item is a single member, the return value is a single value. + * + * When an item consists of multiple members, an array will be returned. + */ +VALUE rb_memory_view_extract_item_members(const void *ptr, const rb_memory_view_item_component_t *members, const size_t n_members); + +/** Fill the `item_desc` member of `view`. */ +void rb_memory_view_prepare_item_desc(rb_memory_view_t *view); + +/** * Return a value that consists of item members in the given memory view. */ +VALUE rb_memory_view_get_item(rb_memory_view_t *view, const ssize_t *indices); + +/** + * Return `true` if `obj` supports to export a MemoryView. Return `false` + * otherwise. + * + * If this function returns `true`, it doesn't mean the function + * `rb_memory_view_get` will succeed. + */ +bool rb_memory_view_available_p(VALUE obj); + +/** + * If the given `obj` supports to export a MemoryView that conforms the given + * `flags`, this function fills `view` by the information of the MemoryView and + * returns `true`. In this case, the reference count of `obj` is increased. + * + * If the given combination of `obj` and `flags` cannot export a MemoryView, + * this function returns `false`. The content of `view` is not touched in this + * case. + * + * The exported MemoryView must be released by `rb_memory_view_release` when + * the MemoryView is no longer needed. + */ +bool rb_memory_view_get(VALUE obj, rb_memory_view_t* memory_view, int flags); + +/** + * Release the given MemoryView `view` and decrement the reference count of + * `memory_view->obj`. + * + * Consumers must call this function when the MemoryView is no longer needed. + * Missing to call this function leads memory leak. + */ +bool rb_memory_view_release(rb_memory_view_t* memory_view); + +/* for testing */ +/** @cond INTERNAL_MACRO */ +RUBY_EXTERN VALUE rb_memory_view_exported_object_registry; +RUBY_EXTERN const rb_data_type_t rb_memory_view_exported_object_registry_data_type; +/** @endcond */ + +RBIMPL_SYMBOL_EXPORT_END() + +RBIMPL_ATTR_PURE() +/** + * Return `true` if the data in the MemoryView `view` is row-major or + * column-major contiguous. + * + * Return `false` otherwise. + */ +static inline bool +rb_memory_view_is_contiguous(const rb_memory_view_t *view) +{ + if (rb_memory_view_is_row_major_contiguous(view)) { + return true; + } + else if (rb_memory_view_is_column_major_contiguous(view)) { + return true; + } + else { + return false; + } +} + +#endif /* RUBY_BUFFER_H */ |