/*

 * Test directory reading operations, exploring concurrency issues.

 *

 * Copyright (C) 2020, 2021, 2022 Paul Boddie <paul@boddie.org.uk>

 *

 * This program 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 2 of

 * the License, or (at your option) any later version.

 *

 * This program 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 this program; if not, write to the Free Software

 * Foundation, Inc., 51 Franklin Street, Fifth Floor,

 * Boston, MA  02110-1301, USA

 */

#include <l4/re/env.h>

#include <l4/sys/err.h>

#include <stdio.h>

#include <string.h>

#include <stdlib.h>

#include <fsclient/client.h>

#include <systypes/fcntl.h>

static int count_files(const char *filename, int *found)

{

  file_t *reader = client_opendir(filename);

  struct dirent *dirent;

  if (reader == NULL)

    return 1;

  *found = 0;

  while ((dirent = client_readdir(reader)) != NULL)

  {

    free(dirent);

    (*found)++;

  }

  client_close(reader);

  return 0;

}

int main(int argc, char *argv[])

{

  if (argc < 2)

  {

    printf("Need a directory name.\n");

    return 1;

  }

  char *filename = argv[1];

  int original;

  if (count_files(filename, &original))

  {

    printf("Could not read from directory.\n");

    return 1;

  }

  printf("Files found: %d\n", original);

  struct dirent *dirent;

  int filenum_base = 1000, filenum = filenum_base;

  int to_create = 100, remaining = to_create;

  char buffer[strlen(filename) + strlen("/file-XXXX.txt") + 10];

  char data[256];

  int found = 0;

  file_t *files[to_create];

  printf("Opening %s...\n", filename);

  file_t *reader = client_opendir(filename);

  if (reader == NULL)

  {

    printf("Could not read from directory.\n");

    return 1;

  }

  printf("Reading...\n");

  while ((dirent = client_readdir(reader)) != NULL)

  {

    free(dirent);

    found++;

    /* Create files while getting the listing. */

    if (remaining)

    {

      sprintf(buffer, "%s/file-%d.txt", filename, filenum);

      file_t *file = client_open(buffer, O_RDWR | O_CREAT);

      if (file == NULL)

      {

        printf("Could not open file: %s\n", buffer);

        return 1;

      }

      /* Write something to each file. */

      sprintf(data, "Data in file-%d.txt", filenum);

      client_write(file, data, strlen(data));

      /* Remember the file for later. */

      files[filenum - filenum_base] = file;

      remaining--;

      filenum++;

    }

  }

  printf("Files found: %d\n", found);

  /* Re-read, counting files. */

  if (count_files(filename, &found))

  {

    printf("Could not read from directory.\n");

    return 1;

  }

  printf("Files found: %d\n", found);

  /* Remove some files. */

  for (filenum = 1000, remaining = to_create; remaining > 0; remaining--, filenum++)

  {

    sprintf(buffer, "%s/file-%d.txt", filename, filenum);

    long err = client_remove(buffer);

    if (err)

    {

      printf("Could not remove file: %s\n", buffer);

      return 1;

    }

  }

  /* Re-read, counting files. */

  if (count_files(filename, &found))

  {

    printf("Could not read from directory.\n");

    return 1;

  }

  printf("Files found: %d\n", found);

  /* Read from the still-open but now removed files. */

  found = 0;

  for (filenum = 1000, remaining = 0; remaining < to_create; remaining++, filenum++)

  {

    file_t *file = files[filenum - filenum_base];

    char read_data[256];

    client_seek(file, SEEK_SET, 0);

    offset_t nread = client_read(file, read_data, 256);

    if (nread)

    {

      read_data[nread] = '\0';

      sprintf(data, "Data in file-%d.txt", filenum);

      if (!strcmp(data, read_data))

        found++;

    }

  }

  printf("Files still open: %d (%d)\n", found, to_create);

  /* Close the files. */

  for (remaining = 0; remaining < to_create; remaining++)

    client_close(files[remaining]);

  printf("Closed files.\n");

  /* Re-read, counting files. */

  if (count_files(filename, &found))

  {

    printf("Could not read from directory.\n");

    return 1;

  }

  printf("Files found: %d (%d)\n", found, original);

  return 0;

}

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