fe_memutils.c

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/*-------------------------------------------------------------------------
 *
 * fe_memutils.c
 *    memory management support for frontend code
 *
 * Portions Copyright (c) 1996-2020, PostgreSQL Global Development Group
 * Portions Copyright (c) 1994, Regents of the University of California
 *
 *
 * IDENTIFICATION
 *    src/common/fe_memutils.c
 *
 *-------------------------------------------------------------------------
 */

#ifndef FRONTEND
#error "This file is not expected to be compiled for backend code"
#endif

#include "postgres_fe.h"

static inline void *
pg_malloc_internal(size_t size, int flags)
{
    void       *tmp;

    /* Avoid unportable behavior of malloc(0) */
    if (size == 0)
        size = 1;
    tmp = malloc(size);
    if (tmp == NULL)
    {
        if ((flags & MCXT_ALLOC_NO_OOM) == 0)
        {
            fprintf(stderr, _("out of memory\n"));
            exit(EXIT_FAILURE);
        }
        return NULL;
    }

    if ((flags & MCXT_ALLOC_ZERO) != 0)
        MemSet(tmp, 0, size);
    return tmp;
}

void *
pg_malloc(size_t size)
{
    return pg_malloc_internal(size, 0);
}

void *
pg_malloc0(size_t size)
{
    return pg_malloc_internal(size, MCXT_ALLOC_ZERO);
}

void *
pg_malloc_extended(size_t size, int flags)
{
    return pg_malloc_internal(size, flags);
}

void *
pg_realloc(void *ptr, size_t size)
{
    void       *tmp;

    /* Avoid unportable behavior of realloc(NULL, 0) */
    if (ptr == NULL && size == 0)
        size = 1;
    tmp = realloc(ptr, size);
    if (!tmp)
    {
        fprintf(stderr, _("out of memory\n"));
        exit(EXIT_FAILURE);
    }
    return tmp;
}

/*
 * "Safe" wrapper around strdup().
 */
char *
pg_strdup(const char *in)
{
    char       *tmp;

    if (!in)
    {
        fprintf(stderr,
                _("cannot duplicate null pointer (internal error)\n"));
        exit(EXIT_FAILURE);
    }
    tmp = strdup(in);
    if (!tmp)
    {
        fprintf(stderr, _("out of memory\n"));
        exit(EXIT_FAILURE);
    }
    return tmp;
}

void
pg_free(void *ptr)
{
    if (ptr != NULL)
        free(ptr);
}

/*
 * Frontend emulation of backend memory management functions.  Useful for
 * programs that compile backend files.
 */
void *
palloc(Size size)
{
    return pg_malloc_internal(size, 0);
}

void *
palloc0(Size size)
{
    return pg_malloc_internal(size, MCXT_ALLOC_ZERO);
}

void *
palloc_extended(Size size, int flags)
{
    return pg_malloc_internal(size, flags);
}

void
pfree(void *pointer)
{
    pg_free(pointer);
}

char *
pstrdup(const char *in)
{
    return pg_strdup(in);
}

char *
pnstrdup(const char *in, Size size)
{
    char       *tmp;
    int         len;

    if (!in)
    {
        fprintf(stderr,
                _("cannot duplicate null pointer (internal error)\n"));
        exit(EXIT_FAILURE);
    }

    len = strnlen(in, size);
    tmp = malloc(len + 1);
    if (tmp == NULL)
    {
        fprintf(stderr, _("out of memory\n"));
        exit(EXIT_FAILURE);
    }

    memcpy(tmp, in, len);
    tmp[len] = '\0';

    return tmp;
}

void *
repalloc(void *pointer, Size size)
{
    return pg_realloc(pointer, size);
}