/*----------------------------------------------------------------------------------
 *
 * mxct.c
 *		Postgres-XC memory context management code for applications.
 *
 * This module is for Postgres-XC application/utility programs.  Sometimes,
 * applications/utilities may need Postgres-XC internal functions which
 * depends upon mcxt.c of gtm or Postgres.
 *
 * This module "virtualize" such module-dependent memory management.
 *
 * This code is for general use, which depends only upon confentional
 * memory management functions.
 *
 * Copyright (c) 2012, Postgres-XC Development Group
 *
 *-------------------------------------------------------------------------------------
 */

#include <stdlib.h>
#include <string.h>
#include "gen_alloc.h"

static void* current_cxt;

static void* memCxtAlloc(void*, size_t);
static void* memCxtRealloc(void*, size_t);
static void* memCxtAlloc0(void*, size_t);
static void memCxtFree(void*);
static void* memCxtAllocTop(size_t);
static void* memCxtCurrentContext(void);

static void* memCxtAlloc(void* current, size_t needed)
{
    return (malloc(needed));
}

static void* memCxtRealloc(void* addr, size_t needed)
{
    return (realloc(addr, needed));
}

static void* memCxtAlloc0(void* current, size_t needed)
{
    void* allocated = NULL;

    allocated = malloc(needed);
    if (allocated == NULL)
        return (NULL);
    memset(allocated, 0, needed);
    return (allocated);
}

static void memCxtFree(void* addr)
{
    free(addr);
    return;
}

static void* memCxtCurrentContext()
{
    return ((void*)&current_cxt);
}

static void* memCxtAllocTop(size_t needed)
{
    return (malloc(needed));
}

Gen_Alloc genAlloc_class = {(void* (*)(void*, size_t))memCxtAlloc,
    (void* (*)(void*, size_t))memCxtAlloc0,
    (void* (*)(void*, size_t))memCxtRealloc,
    (void (*)(void*))memCxtFree,
    (void* (*)())memCxtCurrentContext,
    (void* (*)(size_t))memCxtAllocTop};