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      1 /******************************************************************************
      2  *
      3  *  Copyright (C) 2014 Google, Inc.
      4  *
      5  *  Licensed under the Apache License, Version 2.0 (the "License");
      6  *  you may not use this file except in compliance with the License.
      7  *  You may obtain a copy of the License at:
      8  *
      9  *  http://www.apache.org/licenses/LICENSE-2.0
     10  *
     11  *  Unless required by applicable law or agreed to in writing, software
     12  *  distributed under the License is distributed on an "AS IS" BASIS,
     13  *  WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
     14  *  See the License for the specific language governing permissions and
     15  *  limitations under the License.
     16  *
     17  ******************************************************************************/
     18 
     19 #define LOG_TAG "bt_osi_array"
     20 
     21 #include "osi/include/array.h"
     22 
     23 #include <base/logging.h>
     24 #include <stdlib.h>
     25 #include <string.h>
     26 
     27 #include "osi/include/allocator.h"
     28 #include "osi/include/log.h"
     29 
     30 struct array_t {
     31   size_t element_size;
     32   size_t length;
     33   size_t capacity;
     34   uint8_t* data;
     35   uint8_t internal_storage[];
     36 };
     37 
     38 static bool grow(array_t* array);
     39 
     40 static const size_t INTERNAL_ELEMENTS = 16;
     41 
     42 array_t* array_new(size_t element_size) {
     43   CHECK(element_size > 0);
     44 
     45   array_t* array = static_cast<array_t*>(
     46       osi_calloc(sizeof(array_t) + element_size * INTERNAL_ELEMENTS));
     47 
     48   array->element_size = element_size;
     49   array->capacity = INTERNAL_ELEMENTS;
     50   array->data = array->internal_storage;
     51   return array;
     52 }
     53 
     54 void array_free(array_t* array) {
     55   if (!array) return;
     56 
     57   if (array->data != array->internal_storage) free(array->data);
     58 
     59   osi_free(array);
     60 }
     61 
     62 void* array_ptr(const array_t* array) { return array_at(array, 0); }
     63 
     64 void* array_at(const array_t* array, size_t index) {
     65   CHECK(array != NULL);
     66   CHECK(index < array->length);
     67   return array->data + (index * array->element_size);
     68 }
     69 
     70 size_t array_length(const array_t* array) {
     71   CHECK(array != NULL);
     72   return array->length;
     73 }
     74 
     75 bool array_append_value(array_t* array, uint32_t value) {
     76   return array_append_ptr(array, &value);
     77 }
     78 
     79 bool array_append_ptr(array_t* array, void* data) {
     80   CHECK(array != NULL);
     81   CHECK(data != NULL);
     82 
     83   if (array->length == array->capacity && !grow(array)) {
     84     LOG_ERROR(LOG_TAG,
     85               "%s unable to grow array past current capacity of %zu elements "
     86               "of size %zu.",
     87               __func__, array->capacity, array->element_size);
     88     return false;
     89   }
     90 
     91   ++array->length;
     92   memcpy(array_at(array, array->length - 1), data, array->element_size);
     93   return true;
     94 }
     95 
     96 static bool grow(array_t* array) {
     97   const size_t new_capacity = array->capacity + (array->capacity / 2);
     98   const bool is_moving = (array->data == array->internal_storage);
     99 
    100   void* new_data = realloc(is_moving ? NULL : array->data,
    101                            new_capacity * array->element_size);
    102   if (!new_data) return false;
    103 
    104   if (is_moving)
    105     memcpy(new_data, array->internal_storage,
    106            array->length * array->element_size);
    107 
    108   array->data = static_cast<uint8_t*>(new_data);
    109   array->capacity = new_capacity;
    110   return true;
    111 }
    112