/* This file is part of GDBM, the GNU data base manager.

   Copyright (C) 2018-2023 Free Software Foundation, Inc.

   GDBM is free software; you can redistribute it and/or modify

   it under the terms of the GNU General Public License as published by

   the Free Software Foundation; either version 3, or (at your option)

   any later version.

   GDBM is distributed in the hope that it will be useful,

   but WITHOUT ANY WARRANTY; without even the implied warranty of

   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the

   GNU General Public License for more details.

   You should have received a copy of the GNU General Public License

   along with GDBM. If not, see <http://www.gnu.org/licenses/>.    */

#include "gdbmtool.h"

struct instream_file

{

  struct instream base;   /* Base structure */

  FILE *fp;               /* Opened file */

  dev_t dev;              /* Device number */

  ino_t ino;              /* Inode number */

};

static ssize_t

instream_file_read (instream_t istr, char *buf, size_t size)

{

  struct instream_file *file = (struct instream_file *)istr;

  return fread (buf, 1, size, file->fp);

}

static void

instream_file_close (instream_t istr)

{

  struct instream_file *file = (struct instream_file *)istr;

  fclose (file->fp);

  free (file->base.in_name);

  free (file);

}

static int

instream_file_eq (instream_t a, instream_t b)

{

  struct instream_file *file_a = (struct instream_file *)a;

  struct instream_file *file_b = (struct instream_file *)b;

  return file_a->dev == file_b->dev && file_a->ino == file_b->ino;

}

instream_t

instream_file_create (char const *name)

{

  struct instream_file *istr;

  struct stat st;

  FILE *fp;

  if (stat (name, &st))

    {

      terror (_("cannot open `%s': %s"), name, strerror (errno));

      return NULL;

    }

  else if (!S_ISREG (st.st_mode))

    {

      terror (_("%s is not a regular file"), name);

      return NULL;

    }

  fp = fopen (name, "r");

  if (!fp)

    {

      terror (_("cannot open %s for reading: %s"), name,

        strerror (errno));

      return NULL;

    }

  istr = emalloc (sizeof *istr);

  istr->base.in_name = estrdup (name);

  istr->base.in_inter = 0;

  istr->base.in_read = instream_file_read;

  istr->base.in_close = instream_file_close;

  istr->base.in_eq = instream_file_eq;

  istr->base.in_history_size = NULL;

  istr->base.in_history_get = NULL;  

  istr->fp = fp;

  istr->dev = st.st_dev;

  istr->ino = st.st_ino;

  return (instream_t) istr;

}