stack.c

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// SPDX-FileCopyrightText: 2007-2020 ret2libc <sirmy15@gmail.com>
// SPDX-License-Identifier: LGPL-3.0-only
 
#include <rz_util.h>
 
RZ_API RzStack *rz_stack_new(ut32 n) {
    RzStack *s = RZ_NEW0(RzStack);
    if (!s) {
        return NULL;
    }
    s->elems = RZ_NEWS0(void *, n);
    if (!s->elems) {
        free(s);
        return NULL;
    }
    s->n_elems = n;
    s->top = -1;
    return s;
}
 
RZ_API RzStack *rz_stack_newf(ut32 n, RzStackFree f) {
    RzStack *s = rz_stack_new(n);
    if (s) {
        s->free = f;
    }
    return s;
}
 
RZ_API void rz_stack_free(RzStack *s) {
    if (s) {
        if (s->free) {
            int i;
            for (i = 0; i <= s->top; i++) {
                s->free(s->elems[i]);
            }
        }
        free(s->elems);
        free(s);
    }
}
 
RZ_API bool rz_stack_push(RzStack *s, void *el) {
    if (s->top == s->n_elems - 1) {
        /* reallocate the stack */
        s->n_elems *= 2;
        void **elems = realloc(s->elems, s->n_elems * sizeof(void *));
        if (!elems) {
            return false;
        }
        s->elems = elems;
    }
 
    s->top++;
    s->elems[s->top] = el;
    return true;
}
 
// the caller should be take care of the object returned
RZ_API void *rz_stack_pop(RzStack *s) {
    if (s->top == -1) {
        return NULL;
    }
    void *res = s->elems[s->top];
    s->top--;
    return res;
}
 
RZ_API bool rz_stack_is_empty(RzStack *s) {
    return s->top == -1;
}
 
RZ_API size_t rz_stack_size(RzStack *s) {
    return (size_t)(s->top + 1);
}
 
RZ_API void *rz_stack_peek(RzStack *s) {
    return rz_stack_is_empty(s) ? NULL : s->elems[s->top];
}