text: /*
   * Copyright © 2015 Intel Corporation
   *
   * 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.
   */
  
  /* 
   * u_vector is a vector based queue for storing arbitrary
   * sized arrays of objects without using a linked list.
   */
  
  #ifndef U_VECTOR_H
  #define U_VECTOR_H
  
  #include <stdint.h>
  #include <stdlib.h>
  #include "util/macros.h"
  
  /* TODO - move to u_math.h - name it better etc */
  static inline uint32_t
  u_align_u32(uint32_t v, uint32_t a)
  {
     assert(a != 0 && a == (a & -((int32_t) a)));
     return (v + a - 1) & ~(a - 1);
  }
  
  struct u_vector {
     uint32_t head;
     uint32_t tail;
     uint32_t element_size;
     uint32_t size;
     void *data;
  };
  
  int u_vector_init(struct u_vector *queue, uint32_t element_size, uint32_t size);
  void *u_vector_add(struct u_vector *queue);
  void *u_vector_remove(struct u_vector *queue);
  
  static inline int
  u_vector_length(struct u_vector *queue)
  {
     return (queue->head - queue->tail) / queue->element_size;
  }
  
  static inline void *
  u_vector_head(struct u_vector *vector)
  {
     assert(vector->tail < vector->head);
     return (void *)((char *)vector->data +
                     ((vector->head - vector->element_size) &
                      (vector->size - 1)));
  }
  
  static inline void *
  u_vector_tail(struct u_vector *vector)
  {
     return (void *)((char *)vector->data + (vector->tail & (vector->size - 1)));
  }
  
  static inline void
  u_vector_finish(struct u_vector *queue)
  {
     free(queue->data);
  }
  
  #define u_vector_foreach(elem, queue)                                  \
     STATIC_ASSERT(__builtin_types_compatible_p(__typeof__(queue), struct u_vector *)); \
     for (uint32_t __u_vector_offset = (queue)->tail;                                \
          elem = (void *)((char *)(queue)->data + (__u_vector_offset & ((queue)->size - 1))), __u_vector_offset < (queue)->head; \
          __u_vector_offset += (queue)->element_size)
  
  
  #endif
  
  