| /* |
| * 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. |
| */ |
| #include "util/u_vector.h" |
| |
| int |
| u_vector_init(struct u_vector *vector, uint32_t element_size, uint32_t size) |
| { |
| assert(util_is_power_of_two(size)); |
| assert(element_size < size && util_is_power_of_two(element_size)); |
| |
| vector->head = 0; |
| vector->tail = 0; |
| vector->element_size = element_size; |
| vector->size = size; |
| vector->data = malloc(size); |
| |
| return vector->data != NULL; |
| } |
| |
| void * |
| u_vector_add(struct u_vector *vector) |
| { |
| uint32_t offset, size, split, src_tail, dst_tail; |
| void *data; |
| |
| if (vector->head - vector->tail == vector->size) { |
| size = vector->size * 2; |
| data = malloc(size); |
| if (data == NULL) |
| return NULL; |
| src_tail = vector->tail & (vector->size - 1); |
| dst_tail = vector->tail & (size - 1); |
| if (src_tail == 0) { |
| /* Since we know that the vector is full, this means that it's |
| * linear from start to end so we can do one copy. |
| */ |
| memcpy((char *)data + dst_tail, vector->data, vector->size); |
| } else { |
| /* In this case, the vector is split into two pieces and we have |
| * to do two copies. We have to be careful to make sure each |
| * piece goes to the right locations. Thanks to the change in |
| * size, it may or may not still wrap around. |
| */ |
| split = u_align_u32(vector->tail, vector->size); |
| assert(vector->tail <= split && split < vector->head); |
| memcpy((char *)data + dst_tail, (char *)vector->data + src_tail, |
| split - vector->tail); |
| memcpy((char *)data + (split & (size - 1)), vector->data, |
| vector->head - split); |
| } |
| free(vector->data); |
| vector->data = data; |
| vector->size = size; |
| } |
| |
| assert(vector->head - vector->tail < vector->size); |
| |
| offset = vector->head & (vector->size - 1); |
| vector->head += vector->element_size; |
| |
| return (char *)vector->data + offset; |
| } |
| |
| void * |
| u_vector_remove(struct u_vector *vector) |
| { |
| uint32_t offset; |
| |
| if (vector->head == vector->tail) |
| return NULL; |
| |
| assert(vector->head - vector->tail <= vector->size); |
| |
| offset = vector->tail & (vector->size - 1); |
| vector->tail += vector->element_size; |
| |
| return (char *)vector->data + offset; |
| } |