Fledasty/Src/Core/Queue.c

/*
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *     http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 * 
 * -----------------------------------------------------------------------------
 * File: Queue.c
 * Description:
 *  This file contains the functions for modifying the queue. It includes functions 
 *  to Push, Pop, Peek and check if empty.
 * 
 * Author: Mineplay
 * -----------------------------------------------------------------------------
 */
#include "../../Include/Fledasty/Core/Queue.h"
#include "Fledasty/Utils/Error.h"

#include <Hallocy/Core/Allocator.h>
#include <Hallocy/Core/Memory.h>
#include <Hallocy/Utils/Error.h>

FledastyError fledasty_queue_initialize(FledastyQueue *new_queue, void *values, const size_t values_size, const size_t element_byte_size) {
    if (new_queue == NULL) {
        return FLEDASTY_ERROR_INVALID_POINTER;
    }

    new_queue->head = 0;
    new_queue->element_byte_size = element_byte_size;
    if (values == NULL || values_size == 0) {
        new_queue->size = 0;
        new_queue->capacity = 10;

        new_queue->buffer = (unsigned char*)hallocy_malloc(new_queue->capacity * element_byte_size);
        if (new_queue->buffer == NULL) {
            return FLEDASTY_ERROR_FAILED_ALLOCATION;
        }
    } else {
        new_queue->size = values_size;
        new_queue->capacity = new_queue->size + new_queue->size;
     
        new_queue->buffer = (unsigned char*)hallocy_malloc(new_queue->capacity * element_byte_size);
        if (new_queue->buffer == NULL) {
            return FLEDASTY_ERROR_FAILED_ALLOCATION;
        }

        hallocy_copy_memory(new_queue->buffer, values, values_size * element_byte_size);
    }

    new_queue->tail = new_queue->size;
    return FLEDASTY_ERROR_NONE;
}

FledastyError fledasty_queue_destroy(FledastyQueue *current_queue) {
    if (current_queue == NULL) {
        return FLEDASTY_ERROR_INVALID_POINTER;
    }

    HallocyError result = hallocy_free(current_queue->buffer);
    if (result != HALLOCY_ERROR_NONE) {
        return FLEDASTY_ERROR_FAILED_ALLOCATION;
    }

    current_queue->buffer = NULL;
    return FLEDASTY_ERROR_NONE;
}

FledastyError fledasty_queue_push(FledastyQueue *current_queue, void *value) {
    if (current_queue == NULL || value == NULL) {
        return FLEDASTY_ERROR_INVALID_POINTER;
    }

    if (current_queue->size == current_queue->capacity) {
        current_queue->capacity += current_queue->capacity;
        current_queue->buffer = (unsigned char*)hallocy_realloc(current_queue->buffer, current_queue->capacity * current_queue->element_byte_size);

        if (current_queue->buffer == NULL) {
            return FLEDASTY_ERROR_FAILED_ALLOCATION;
        }

        if (current_queue->tail < current_queue->head) {
            size_t head_size = (current_queue->size - current_queue->tail) * current_queue->element_byte_size;
    
            hallocy_move_memory(current_queue->buffer, current_queue->buffer + (current_queue->head * current_queue->element_byte_size), head_size);
            hallocy_move_memory(current_queue->buffer + head_size, current_queue->buffer, current_queue->tail * current_queue->element_byte_size);
        } else {
            hallocy_move_memory(current_queue->buffer, current_queue->buffer + (current_queue->head * current_queue->element_byte_size), current_queue->size * current_queue->element_byte_size);
        }

        current_queue->head = 0;
        current_queue->tail = current_queue->size;
    }

    hallocy_copy_memory(current_queue->buffer + (current_queue->tail * current_queue->element_byte_size), value, current_queue->element_byte_size);

    current_queue->size += 1;
    current_queue->tail += 1;
    if (current_queue->tail >= current_queue->capacity) {
        current_queue->tail = 0;
    }
    
    return FLEDASTY_ERROR_NONE;
}

void *fledasty_queue_pop(FledastyQueue *current_queue) {
    if (current_queue == NULL || current_queue->size == 0) {
        return NULL;
    }

    void *value_address = current_queue->buffer + (current_queue->head * current_queue->element_byte_size);
    
    current_queue->size -= 1;
    current_queue->head += 1;
    if (current_queue->head == current_queue->capacity) {
        current_queue->head = 0;
    }

    return value_address;
}

FledastyError fledasty_queue_clear(FledastyQueue *current_queue) {
    if (current_queue == NULL) {
        return FLEDASTY_ERROR_INVALID_POINTER;
    }

    current_queue->size = 0;
    return FLEDASTY_ERROR_NONE;
}

FledastyError fledasty_queue_shrink_to_fit(FledastyQueue *current_queue) {
    if (current_queue == NULL) {
        return FLEDASTY_ERROR_INVALID_POINTER;
    }

    size_t new_capacity = (current_queue->size == 0) ? 10 : current_queue->size;
    unsigned char *shrinked_buffer = (unsigned char*)hallocy_malloc(new_capacity);
    if (shrinked_buffer == NULL) {
        return FLEDASTY_ERROR_FAILED_ALLOCATION;
    }

    if (current_queue->tail < current_queue->head) {
        size_t head_size = (current_queue->size - current_queue->tail) * current_queue->element_byte_size;

        hallocy_copy_memory(shrinked_buffer, current_queue->buffer + (current_queue->head * current_queue->element_byte_size), head_size);
        hallocy_copy_memory(shrinked_buffer + head_size, current_queue->buffer, current_queue->tail * current_queue->element_byte_size);
    } else {
        hallocy_copy_memory(shrinked_buffer, current_queue->buffer + (current_queue->head * current_queue->element_byte_size), current_queue->size * current_queue->element_byte_size);
    } 

    if (hallocy_free(current_queue->buffer) != HALLOCY_ERROR_NONE) {
        return FLEDASTY_ERROR_FAILED_ALLOCATION;
    }

    current_queue->head = 0;
    current_queue->tail = current_queue->size;
    current_queue->capacity = new_capacity;
    current_queue->buffer = shrinked_buffer;

    return FLEDASTY_ERROR_NONE;
}