1/* 2 * Copyright © 2015 Intel Corporation 3 * 4 * Permission is hereby granted, free of charge, to any person obtaining a 5 * copy of this software and associated documentation files (the "Software"), 6 * to deal in the Software without restriction, including without limitation 7 * the rights to use, copy, modify, merge, publish, distribute, sublicense, 8 * and/or sell copies of the Software, and to permit persons to whom the 9 * Software is furnished to do so, subject to the following conditions: 10 * 11 * The above copyright notice and this permission notice (including the next 12 * paragraph) shall be included in all copies or substantial portions of the 13 * Software. 14 * 15 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR 16 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, 17 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL 18 * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER 19 * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING 20 * FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS 21 * IN THE SOFTWARE. 22 */ 23#include "util/u_vector.h" 24 25int 26u_vector_init(struct u_vector *vector, uint32_t element_size, uint32_t size) 27{ 28 assert(util_is_power_of_two(size)); 29 assert(element_size < size && util_is_power_of_two(element_size)); 30 31 vector->head = 0; 32 vector->tail = 0; 33 vector->element_size = element_size; 34 vector->size = size; 35 vector->data = malloc(size); 36 37 return vector->data != NULL; 38} 39 40void * 41u_vector_add(struct u_vector *vector) 42{ 43 uint32_t offset, size, split, src_tail, dst_tail; 44 void *data; 45 46 if (vector->head - vector->tail == vector->size) { 47 size = vector->size * 2; 48 data = malloc(size); 49 if (data == NULL) 50 return NULL; 51 src_tail = vector->tail & (vector->size - 1); 52 dst_tail = vector->tail & (size - 1); 53 if (src_tail == 0) { 54 /* Since we know that the vector is full, this means that it's 55 * linear from start to end so we can do one copy. 56 */ 57 memcpy((char *)data + dst_tail, vector->data, vector->size); 58 } else { 59 /* In this case, the vector is split into two pieces and we have 60 * to do two copies. We have to be careful to make sure each 61 * piece goes to the right locations. Thanks to the change in 62 * size, it may or may not still wrap around. 63 */ 64 split = u_align_u32(vector->tail, vector->size); 65 assert(vector->tail <= split && split < vector->head); 66 memcpy((char *)data + dst_tail, (char *)vector->data + src_tail, 67 split - vector->tail); 68 memcpy((char *)data + (split & (size - 1)), vector->data, 69 vector->head - split); 70 } 71 free(vector->data); 72 vector->data = data; 73 vector->size = size; 74 } 75 76 assert(vector->head - vector->tail < vector->size); 77 78 offset = vector->head & (vector->size - 1); 79 vector->head += vector->element_size; 80 81 return (char *)vector->data + offset; 82} 83 84void * 85u_vector_remove(struct u_vector *vector) 86{ 87 uint32_t offset; 88 89 if (vector->head == vector->tail) 90 return NULL; 91 92 assert(vector->head - vector->tail <= vector->size); 93 94 offset = vector->tail & (vector->size - 1); 95 vector->tail += vector->element_size; 96 97 return (char *)vector->data + offset; 98} 99