text: /*
   * Copyright © 2008 Kristian Høgsberg
   *
   * Permission is hereby granted, free of charge, to any person obtaining
   * a copy of this software and associated documentation files (the
   * "Software"), to deal in the Software without restriction, including
   * without limitation the rights to use, copy, modify, merge, publish,
   * distribute, sublicense, and/or sell copies of the Software, and to
   * permit persons to whom the Software is furnished to do so, subject to
   * the following conditions:
   *
   * The above copyright notice and this permission notice (including the
   * next paragraph) shall be included in all copies or substantial
   * portions of the Software.
   *
   * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
   * EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
   * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
   * NONINFRINGEMENT.  IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS
   * BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN
   * ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN
   * CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
   * SOFTWARE.
   */
  
  /** \file wayland-util.h
   *
   * \brief Utility classes, functions, and macros.
   */
  
  #ifndef WAYLAND_UTIL_H
  #define WAYLAND_UTIL_H
  
  #ifdef  __cplusplus
  extern "C" {
  #endif
  
  #include <math.h>
  #include <stddef.h>
  #include <inttypes.h>
  #include <stdarg.h>
  
  /* GCC visibility */
  #if defined(__GNUC__) && __GNUC__ >= 4
  #define WL_EXPORT __attribute__ ((visibility("default")))
  #else
  #define WL_EXPORT
  #endif
  
  /* Deprecated attribute */
  #if defined(__GNUC__) && __GNUC__ >= 4
  #define WL_DEPRECATED __attribute__ ((deprecated))
  #else
  #define WL_DEPRECATED
  #endif
  
  /* Printf annotation */
  #if defined(__GNUC__) && __GNUC__ >= 4
  #define WL_PRINTF(x, y) __attribute__((__format__(__printf__, x, y)))
  #else
  #define WL_PRINTF(x, y)
  #endif
  
  struct wl_message {
  	const char *name;
  	const char *signature;
  	const struct wl_interface **types;
  };
  
  struct wl_interface {
  	const char *name;
  	int version;
  	int method_count;
  	const struct wl_message *methods;
  	int event_count;
  	const struct wl_message *events;
  };
  
  /** \class wl_list
   *
   * \brief doubly-linked list
   *
   * The list head is of "struct wl_list" type, and must be initialized
   * using wl_list_init().  All entries in the list must be of the same
   * type.  The item type must have a "struct wl_list" member. This
   * member will be initialized by wl_list_insert(). There is no need to
   * call wl_list_init() on the individual item. To query if the list is
   * empty in O(1), use wl_list_empty().
   *
   * Let's call the list reference "struct wl_list foo_list", the item type as
   * "item_t", and the item member as "struct wl_list link".
   *
   * The following code will initialize a list:
   * \code
   * struct wl_list foo_list;
   *
   * struct item_t {
   * 	int foo;
   * 	struct wl_list link;
   * };
   * struct item_t item1, item2, item3;
   *
   * wl_list_init(&foo_list);
   * wl_list_insert(&foo_list, &item1.link);	// Pushes item1 at the head
   * wl_list_insert(&foo_list, &item2.link);	// Pushes item2 at the head
   * wl_list_insert(&item2.link, &item3.link);	// Pushes item3 after item2
   * \endcode
   *
   * The list now looks like [item2, item3, item1]
   *
   * Iterate the list in ascending order:
   * \code
   * item_t *item;
   * wl_list_for_each(item, foo_list, link) {
   * 	Do_something_with_item(item);
   * }
   * \endcode
   */
  struct wl_list {
  	struct wl_list *prev;
  	struct wl_list *next;
  };
  
  void
  wl_list_init(struct wl_list *list);
  
  void
  wl_list_insert(struct wl_list *list, struct wl_list *elm);
  
  void
  wl_list_remove(struct wl_list *elm);
  
  int
  wl_list_length(const struct wl_list *list);
  
  int
  wl_list_empty(const struct wl_list *list);
  
  void
  wl_list_insert_list(struct wl_list *list, struct wl_list *other);
  
  /**
   * Retrieves a pointer to the containing struct of a given member item.
   *
   * This macro allows conversion from a pointer to a item to its containing
   * struct. This is useful if you have a contained item like a wl_list,
   * wl_listener, or wl_signal, provided via a callback or other means and would
   * like to retrieve the struct that contains it.
   *
   * To demonstrate, the following example retrieves a pointer to
   * `example_container` given only its `destroy_listener` member:
   *
   * \code
   * struct example_container {
   *     struct wl_listener destroy_listener;
   *     // other members...
   * };
   *
   * void example_container_destroy(struct wl_listener *listener, void *data)
   * {
   *     struct example_container *ctr;
   *
   *     ctr = wl_container_of(listener, ctr, destroy_listener);
   *     // destroy ctr...
   * }
   * \endcode
   *
   * \param ptr A valid pointer to the contained item.
   *
   * \param sample A pointer to the type of content that the list item
   * stores. Sample does not need be a valid pointer; a null or
   * an uninitialised pointer will suffice.
   *
   * \param member The named location of ptr within the sample type.
   *
   * \return The container for the specified pointer.
   */
  #define wl_container_of(ptr, sample, member)				\
  	(__typeof__(sample))((char *)(ptr) -				\
  			     offsetof(__typeof__(*sample), member))
  /* If the above macro causes problems on your compiler you might be
   * able to find an alternative name for the non-standard __typeof__
   * operator and add a special case here */
  
  #define wl_list_for_each(pos, head, member)				\
  	for (pos = wl_container_of((head)->next, pos, member);	\
  	     &pos->member != (head);					\
  	     pos = wl_container_of(pos->member.next, pos, member))
  
  #define wl_list_for_each_safe(pos, tmp, head, member)			\
  	for (pos = wl_container_of((head)->next, pos, member),		\
  	     tmp = wl_container_of((pos)->member.next, tmp, member);	\
  	     &pos->member != (head);					\
  	     pos = tmp,							\
  	     tmp = wl_container_of(pos->member.next, tmp, member))
  
  #define wl_list_for_each_reverse(pos, head, member)			\
  	for (pos = wl_container_of((head)->prev, pos, member);	\
  	     &pos->member != (head);					\
  	     pos = wl_container_of(pos->member.prev, pos, member))
  
  #define wl_list_for_each_reverse_safe(pos, tmp, head, member)		\
  	for (pos = wl_container_of((head)->prev, pos, member),	\
  	     tmp = wl_container_of((pos)->member.prev, tmp, member);	\
  	     &pos->member != (head);					\
  	     pos = tmp,							\
  	     tmp = wl_container_of(pos->member.prev, tmp, member))
  
  struct wl_array {
  	size_t size;
  	size_t alloc;
  	void *data;
  };
  
  #define wl_array_for_each(pos, array)					\
  	for (pos = (array)->data;					\
  	     (const char *) pos < ((const char *) (array)->data + (array)->size); \
  	     (pos)++)
  
  void
  wl_array_init(struct wl_array *array);
  
  void
  wl_array_release(struct wl_array *array);
  
  void *
  wl_array_add(struct wl_array *array, size_t size);
  
  int
  wl_array_copy(struct wl_array *array, struct wl_array *source);
  
  typedef int32_t wl_fixed_t;
  
  static inline double
  wl_fixed_to_double (wl_fixed_t f)
  {
  	union {
  		double d;
  		int64_t i;
  	} u;
  
  	u.i = ((1023LL + 44LL) << 52) + (1LL << 51) + f;
  
  	return u.d - (3LL << 43);
  }
  
  static inline wl_fixed_t
  wl_fixed_from_double(double d)
  {
  	union {
  		double d;
  		int64_t i;
  	} u;
  
  	u.d = d + (3LL << (51 - 8));
  
  	return u.i;
  }
  
  static inline int
  wl_fixed_to_int(wl_fixed_t f)
  {
  	return f / 256;
  }
  
  static inline wl_fixed_t
  wl_fixed_from_int(int i)
  {
  	return i * 256;
  }
  
  /**
   * \brief A union representing all of the basic data types that can be passed
   * along the wayland wire format.
   *
   * This union represents all of the basic data types that can be passed in the
   * wayland wire format.  It is used by dispatchers and runtime-friendly
   * versions of the event and request marshaling functions.
   */
  union wl_argument {
  	int32_t i; /**< signed integer */
  	uint32_t u; /**< unsigned integer */
  	wl_fixed_t f; /**< fixed point */
  	const char *s; /**< string */
  	struct wl_object *o; /**< object */
  	uint32_t n; /**< new_id */
  	struct wl_array *a; /**< array */
  	int32_t h; /**< file descriptor */
  };
  
  /**
   * \brief A function pointer type for a dispatcher.
   *
   * A dispatcher is a function that handles the emitting of callbacks in client
   * code.  For programs directly using the C library, this is done by using
   * libffi to call function pointers.  When binding to languages other than C,
   * dispatchers provide a way to abstract the function calling process to be
   * friendlier to other function calling systems.
   *
   * A dispatcher takes five arguments:  The first is the dispatcher-specific
   * implementation data associated with the target object.  The second is the
   * object on which the callback is being invoked (either wl_proxy or
   * wl_resource).  The third and fourth arguments are the opcode the wl_messsage
   * structure corresponding to the callback being emitted.  The final argument
   * is an array of arguments received from the other process via the wire
   * protocol.
   */
  typedef int (*wl_dispatcher_func_t)(const void *, void *, uint32_t,
  				    const struct wl_message *,
  				    union wl_argument *);
  
  typedef void (*wl_log_func_t)(const char *, va_list) WL_PRINTF(1, 0);
  
  #ifdef  __cplusplus
  }
  #endif
  
  #endif
  