n_stack.c

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/*
 * Nilorea Library
 * Copyright (C) 2005-2026 Castagnier Mickael
 *
 * 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.
 *
 * SPDX-License-Identifier: Apache-2.0
 */
 
#include "nilorea/n_stack.h"
 
STACK* new_stack(size_t size) {
    STACK* stack = NULL;
 
    if (size == 0) {
        n_log(LOG_ERR, "stack size cannot be 0");
        return NULL;
    }
 
    Malloc(stack, STACK, 1);
    __n_assert(stack, return NULL);
    Malloc(stack->stack_array, STACK_ITEM, size);
    __n_assert(stack->stack_array, Free(stack); return NULL;);
 
    stack->size = size;
    stack->head = stack->tail = 0;
    stack->nb_items = 0;
    return stack;
}
 
bool delete_stack(STACK** stack) {
    __n_assert(stack, return FALSE);
    __n_assert((*stack), return FALSE);
    Free((*stack)->stack_array);
    Free((*stack));
    return TRUE;
}
 
bool stack_is_full(const STACK* stack) {
    if (!stack) return false;
    return ((stack->head + 1) % stack->size == stack->tail);
}
 
bool stack_is_empty(const STACK* stack) {
    if (!stack) return false;
    return (stack->nb_items == 0);
}
 
STACK_ITEM* stack_peek(STACK* stack, size_t position) {
    STACK_ITEM* item = NULL;
    __n_assert(stack, return NULL);
 
    if (stack_is_empty(stack)) {
        return NULL;
    }
 
    if (stack->tail < stack->head) {
        if (position >= stack->tail && position < stack->head && position < stack->size && stack->stack_array[position].is_set) {
            item = &stack->stack_array[position];
        }
    } else if (stack->tail > stack->head) {
        if ((position >= stack->tail || position < stack->head) && position < stack->size && stack->stack_array[position].is_set) {
            item = &stack->stack_array[position];
        }
    }
    return item;
}
 
size_t __stack_push(STACK* stack, uint8_t* status) {
    (*status) = STACK_IS_UNDEFINED;
    __n_assert(stack, return 0);
 
    (*status) = STACK_IS_FULL;
    if (stack_is_full(stack))
        return 0;
 
    size_t next_pos = (stack->head + 1) % stack->size;
 
    // if next_pos == tail, the stack is full
    if (next_pos == stack->tail) {
        // status already set to (*status) = STACK_IS_FULL ;
        return 0;
    }
 
    // set data, move, set item status, inc counter
    (*status) = STACK_ITEM_OK;
    stack->stack_array[stack->head].is_set = 1;
    stack->stack_array[stack->head].is_empty = 0;
    // inc
    stack->nb_items++;
    return next_pos;
}
 
size_t __stack_pop(STACK* stack, uint8_t* status) {
    (*status) = STACK_IS_UNDEFINED;
    __n_assert(stack, return FALSE);
 
    size_t next_pos = 0;
    size_t prev_pos = 0;
 
    // if the head == tail, the stack is empty
    if (stack->head == stack->tail) {
        (*status) = STACK_IS_EMPTY;
        return 0;
    }
 
    // item is here and read
    (*status) = STACK_ITEM_OK;
 
    // next is where tail will point to after this read
    next_pos = (stack->tail + 1) % stack->size;
 
    // set item status, dec counter, move, return value
    stack->stack_array[stack->tail].is_set = 0;
    stack->stack_array[stack->tail].is_empty = 1;
    prev_pos = stack->tail;
    // tail to next offset.
    stack->tail = next_pos;
    // dec
    stack->nb_items--;
    return prev_pos;
}
 
bool stack_push_b(STACK* stack, bool b) {
    uint8_t status = STACK_ITEM_OK;
    size_t next_pos = __stack_push(stack, &status);
    if (status != STACK_ITEM_OK)
        return FALSE;
    stack->stack_array[stack->head].data.b = b;
    stack->stack_array[stack->head].v_type = STACK_ITEM_BOOL;
    stack->head = next_pos;
 
    return TRUE;
}
 
bool stack_pop_b(STACK* stack, uint8_t* status) {
    (*status) = STACK_IS_UNDEFINED;
    __n_assert(stack, return FALSE);
 
    if (stack->head == stack->tail) {
        (*status) = STACK_IS_EMPTY;
        return 0;
    }
 
    if (stack->stack_array[stack->tail].v_type != STACK_ITEM_BOOL) {
        (*status) = STACK_ITEM_WRONG_TYPE;
        return 0;
    }
 
    uint8_t pop_status = STACK_IS_UNDEFINED;
    size_t prev_pos = __stack_pop(stack, &pop_status);
    if (pop_status != STACK_ITEM_OK) {
        (*status) = pop_status;
        return 0;
    }
    return stack->stack_array[prev_pos].data.b;
}
 
bool stack_push_c(STACK* stack, char c) {
    uint8_t status = STACK_ITEM_OK;
 
    size_t next_pos = __stack_push(stack, &status);
    if (status != STACK_ITEM_OK)
        return FALSE;
 
    stack->stack_array[stack->head].data.c = c;
    stack->stack_array[stack->head].v_type = STACK_ITEM_CHAR;
    stack->head = next_pos;
 
    return TRUE;
}
 
char stack_pop_c(STACK* stack, uint8_t* status) {
    (*status) = STACK_IS_UNDEFINED;
    __n_assert(stack, return FALSE);
 
    if (stack->head == stack->tail) {
        (*status) = STACK_IS_EMPTY;
        return 0;
    }
 
    if (stack->stack_array[stack->tail].v_type != STACK_ITEM_CHAR) {
        (*status) = STACK_ITEM_WRONG_TYPE;
        return 0;
    }
 
    uint8_t pop_status = STACK_IS_UNDEFINED;
    size_t prev_pos = __stack_pop(stack, &pop_status);
    if (pop_status != STACK_ITEM_OK) {
        (*status) = pop_status;
        return 0;
    }
    return stack->stack_array[prev_pos].data.c;
}
 
bool stack_push_ui8(STACK* stack, uint8_t ui8) {
    uint8_t status = STACK_ITEM_OK;
 
    size_t next_pos = __stack_push(stack, &status);
    if (status != STACK_ITEM_OK)
        return FALSE;
 
    stack->stack_array[stack->head].data.ui8 = ui8;
    stack->stack_array[stack->head].v_type = STACK_ITEM_UINT8;
    stack->head = next_pos;
 
    return TRUE;
}
 
uint8_t stack_pop_ui8(STACK* stack, uint8_t* status) {
    (*status) = STACK_IS_UNDEFINED;
    __n_assert(stack, return FALSE);
 
    if (stack->head == stack->tail) {
        (*status) = STACK_IS_EMPTY;
        return 0;
    }
 
    if (stack->stack_array[stack->tail].v_type != STACK_ITEM_UINT8) {
        (*status) = STACK_ITEM_WRONG_TYPE;
        return 0;
    }
 
    uint8_t pop_status = STACK_IS_UNDEFINED;
    size_t prev_pos = __stack_pop(stack, &pop_status);
    if (pop_status != STACK_ITEM_OK) {
        (*status) = pop_status;
        return 0;
    }
    return stack->stack_array[prev_pos].data.ui8;
}
 
bool stack_push_i8(STACK* stack, int8_t i8) {
    uint8_t status = STACK_ITEM_OK;
 
    size_t next_pos = __stack_push(stack, &status);
    if (status != STACK_ITEM_OK)
        return FALSE;
 
    stack->stack_array[stack->head].data.i8 = i8;
    stack->stack_array[stack->head].v_type = STACK_ITEM_INT8;
    stack->head = next_pos;
 
    return TRUE;
}
 
int8_t stack_pop_i8(STACK* stack, uint8_t* status) {
    (*status) = STACK_IS_UNDEFINED;
    __n_assert(stack, return FALSE);
 
    if (stack->head == stack->tail) {
        (*status) = STACK_IS_EMPTY;
        return 0;
    }
 
    if (stack->stack_array[stack->tail].v_type != STACK_ITEM_INT8) {
        (*status) = STACK_ITEM_WRONG_TYPE;
        return 0;
    }
 
    uint8_t pop_status = STACK_IS_UNDEFINED;
    size_t prev_pos = __stack_pop(stack, &pop_status);
    if (pop_status != STACK_ITEM_OK) {
        (*status) = pop_status;
        return 0;
    }
    return stack->stack_array[prev_pos].data.i8;
}
 
bool stack_push_ui32(STACK* stack, uint32_t ui32) {
    uint8_t status = STACK_ITEM_OK;
 
    size_t next_pos = __stack_push(stack, &status);
    if (status != STACK_ITEM_OK)
        return FALSE;
 
    stack->stack_array[stack->head].data.ui32 = ui32;
    stack->stack_array[stack->head].v_type = STACK_ITEM_UINT32;
    stack->head = next_pos;
 
    return TRUE;
}
 
uint32_t stack_pop_ui32(STACK* stack, uint8_t* status) {
    (*status) = STACK_IS_UNDEFINED;
    __n_assert(stack, return FALSE);
 
    if (stack->head == stack->tail) {
        (*status) = STACK_IS_EMPTY;
        return 0;
    }
 
    if (stack->stack_array[stack->tail].v_type != STACK_ITEM_UINT32) {
        (*status) = STACK_ITEM_WRONG_TYPE;
        return 0;
    }
 
    uint8_t pop_status = STACK_IS_UNDEFINED;
    size_t prev_pos = __stack_pop(stack, &pop_status);
    if (pop_status != STACK_ITEM_OK) {
        (*status) = pop_status;
        return 0;
    }
    return stack->stack_array[prev_pos].data.ui32;
}
 
bool stack_push_i32(STACK* stack, int32_t i32) {
    uint8_t status = STACK_ITEM_OK;
 
    size_t next_pos = __stack_push(stack, &status);
    if (status != STACK_ITEM_OK)
        return FALSE;
 
    stack->stack_array[stack->head].data.i32 = i32;
    stack->stack_array[stack->head].v_type = STACK_ITEM_INT32;
    stack->head = next_pos;
 
    return TRUE;
}
 
int32_t stack_pop_i32(STACK* stack, uint8_t* status) {
    (*status) = STACK_IS_UNDEFINED;
    __n_assert(stack, return FALSE);
 
    if (stack->head == stack->tail) {
        (*status) = STACK_IS_EMPTY;
        return 0;
    }
 
    if (stack->stack_array[stack->tail].v_type != STACK_ITEM_INT32) {
        (*status) = STACK_ITEM_WRONG_TYPE;
        return 0;
    }
 
    uint8_t pop_status = STACK_IS_UNDEFINED;
    size_t prev_pos = __stack_pop(stack, &pop_status);
    if (pop_status != STACK_ITEM_OK) {
        (*status) = pop_status;
        return 0;
    }
    return stack->stack_array[prev_pos].data.i32;
}
 
bool stack_push_f(STACK* stack, float f) {
    uint8_t status = STACK_ITEM_OK;
 
    size_t next_pos = __stack_push(stack, &status);
    if (status != STACK_ITEM_OK)
        return FALSE;
 
    stack->stack_array[stack->head].data.f = f;
    stack->stack_array[stack->head].v_type = STACK_ITEM_FLOAT;
    stack->head = next_pos;
 
    return TRUE;
}
 
float stack_pop_f(STACK* stack, uint8_t* status) {
    (*status) = STACK_IS_UNDEFINED;
    __n_assert(stack, return FALSE);
 
    if (stack->head == stack->tail) {
        (*status) = STACK_IS_EMPTY;
        return 0;
    }
 
    if (stack->stack_array[stack->tail].v_type != STACK_ITEM_FLOAT) {
        (*status) = STACK_ITEM_WRONG_TYPE;
        return 0;
    }
 
    uint8_t pop_status = STACK_IS_UNDEFINED;
    size_t prev_pos = __stack_pop(stack, &pop_status);
    if (pop_status != STACK_ITEM_OK) {
        (*status) = pop_status;
        return 0;
    }
    return stack->stack_array[prev_pos].data.f;
}
 
bool stack_push_d(STACK* stack, double d) {
    uint8_t status = STACK_ITEM_OK;
 
    size_t next_pos = __stack_push(stack, &status);
    if (status != STACK_ITEM_OK)
        return FALSE;
 
    stack->stack_array[stack->head].data.d = d;
    stack->stack_array[stack->head].v_type = STACK_ITEM_DOUBLE;
    stack->head = next_pos;
 
    return TRUE;
}
 
double stack_pop_d(STACK* stack, uint8_t* status) {
    (*status) = STACK_IS_UNDEFINED;
    __n_assert(stack, return FALSE);
 
    if (stack->head == stack->tail) {
        (*status) = STACK_IS_EMPTY;
        return 0;
    }
 
    if (stack->stack_array[stack->tail].v_type != STACK_ITEM_DOUBLE) {
        (*status) = STACK_ITEM_WRONG_TYPE;
        return 0;
    }
 
    uint8_t pop_status = STACK_IS_UNDEFINED;
    size_t prev_pos = __stack_pop(stack, &pop_status);
    if (pop_status != STACK_ITEM_OK) {
        (*status) = pop_status;
        return 0;
    }
    return stack->stack_array[prev_pos].data.d;
}
 
bool stack_push_p(STACK* stack, void* p, uint16_t p_type) {
    uint8_t status = STACK_ITEM_OK;
 
    size_t next_pos = __stack_push(stack, &status);
    if (status != STACK_ITEM_OK)
        return FALSE;
 
    stack->stack_array[stack->head].data.p = p;
    stack->stack_array[stack->head].v_type = STACK_ITEM_PTR;
    stack->stack_array[stack->head].p_type = p_type;
    stack->head = next_pos;
 
    return TRUE;
}
 
void* stack_pop_p(STACK* stack, uint8_t* status) {
    (*status) = STACK_IS_UNDEFINED;
    __n_assert(stack, return NULL);
 
    if (stack->head == stack->tail) {
        (*status) = STACK_IS_EMPTY;
        return 0;
    }
 
    if (stack->stack_array[stack->tail].v_type != STACK_ITEM_PTR) {
        (*status) = STACK_ITEM_WRONG_TYPE;
        return 0;
    }
 
    uint8_t pop_status = STACK_IS_UNDEFINED;
    size_t prev_pos = __stack_pop(stack, &pop_status);
    if (pop_status != STACK_ITEM_OK) {
        (*status) = pop_status;
        return 0;
    }
    return stack->stack_array[prev_pos].data.p;
}
 
bool stack_push_p_default(STACK* stack, void* p) {
    return stack_push_p(stack, p, 0);
}
 
#ifdef ENV_64BITS
bool stack_push_ui64(STACK* stack, uint64_t ui64) {
    uint8_t status = STACK_ITEM_OK;
 
    size_t next_pos = __stack_push(stack, &status);
    if (status != STACK_ITEM_OK)
        return FALSE;
 
    stack->stack_array[stack->head].data.ui64 = ui64;
    stack->stack_array[stack->head].v_type = STACK_ITEM_UINT64;
    stack->head = next_pos;
 
    return TRUE;
}
 
uint64_t stack_pop_ui64(STACK* stack, uint8_t* status) {
    (*status) = STACK_IS_UNDEFINED;
    __n_assert(stack, return FALSE);
 
    if (stack->head == stack->tail) {
        (*status) = STACK_IS_EMPTY;
        return 0;
    }
 
    if (stack->stack_array[stack->tail].v_type != STACK_ITEM_UINT64) {
        (*status) = STACK_ITEM_WRONG_TYPE;
        return 0;
    }
 
    uint8_t pop_status = STACK_IS_UNDEFINED;
    size_t prev_pos = __stack_pop(stack, &pop_status);
    if (pop_status != STACK_ITEM_OK) {
        (*status) = pop_status;
        return 0;
    }
    return stack->stack_array[prev_pos].data.ui64;
}
 
bool stack_push_i64(STACK* stack, int64_t i64) {
    uint8_t status = STACK_ITEM_OK;
 
    size_t next_pos = __stack_push(stack, &status);
    if (status != STACK_ITEM_OK)
        return FALSE;
 
    stack->stack_array[stack->head].data.i64 = i64;
    stack->stack_array[stack->head].v_type = STACK_ITEM_INT64;
    stack->head = next_pos;
 
    return TRUE;
}
 
int64_t stack_pop_i64(STACK* stack, uint8_t* status) {
    (*status) = STACK_IS_UNDEFINED;
    __n_assert(stack, return FALSE);
 
    if (stack->head == stack->tail) {
        (*status) = STACK_IS_EMPTY;
        return 0;
    }
 
    if (stack->stack_array[stack->tail].v_type != STACK_ITEM_INT64) {
        (*status) = STACK_ITEM_WRONG_TYPE;
        return 0;
    }
 
    uint8_t pop_status = STACK_IS_UNDEFINED;
    size_t prev_pos = __stack_pop(stack, &pop_status);
    if (pop_status != STACK_ITEM_OK) {
        (*status) = pop_status;
        return 0;
    }
    return stack->stack_array[prev_pos].data.i64;
}
#endif