ManageIQ/memory_buffer

/*
 * Ruby module to block device operations on Linux platforms.
 */

#include <stdio.h>
#include <errno.h>
#include <string.h>
#include <stdlib.h>

#ifdef HAVE_MALLOC_H
    #include <malloc.h>
#endif

#include "ruby.h"

static const char *module_name = "MemoryBuffer";

static VALUE
mb_create_aligned(VALUE self, VALUE ralign, VALUE rlen) {
    size_t    align    = (size_t)NUM2INT(ralign);
    size_t    len        = (size_t)NUM2INT(rlen);
    char    *abuf;
    VALUE    asb;

#ifdef HAVE_MEMALIGN
    abuf = memalign(align, len);
#else
    int rc;
    rc = posix_memalign((void **)&abuf, align, len);
    if (0 != rc) {
        abuf = NULL;
    }
#endif

    if (NULL == abuf) {
        rb_raise(rb_eNoMemError, "Could not allocate %d bytes of aligned memory\n", (int)len);
    }

    asb = rb_str_new(NULL, 0);
    RBASIC(asb)->flags |= RSTRING_NOEMBED;
    RSTRING(asb)->as.heap.ptr = abuf;
    RSTRING(asb)->as.heap.aux.capa = len;

    return(asb);
}

VALUE    mMemoryBuffer;

/*
 * Initialize the class.
 */
void Init_memory_buffer()    {
    /*
     * Define the module.
     */
    mMemoryBuffer = rb_define_module(module_name);

    rb_define_singleton_method(mMemoryBuffer, "create_aligned", mb_create_aligned, 2);
}