text: /* Copyright  (C) 2010-2020 The RetroArch team
   *
   * ---------------------------------------------------------------------------------------
   * The following license statement only applies to this file (file_stream.c).
   * ---------------------------------------------------------------------------------------
   *
   * Permission is hereby granted, free of charge,
   * to any person obtaining a copy of this software and associated documentation files (the "Software"),
   * to deal in the Software without restriction, including without limitation the rights to
   * use, copy, modify, merge, publish, distribute, sublicense, and/or sell copies of the Software,
   * and to permit persons to whom the Software is furnished to do so, subject to the following conditions:
   *
   * The above copyright notice and this permission notice shall be included in all copies or substantial portions of the Software.
   *
   * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR IMPLIED,
   * INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
   * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.
   * IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY,
   * WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
   * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
   */
  
  #include <stdio.h>
  #include <stdlib.h>
  #include <string.h>
  #include <stdarg.h>
  #include <ctype.h>
  #include <errno.h>
  
  #ifdef HAVE_CONFIG_H
  #include "config.h"
  #endif
  
  #ifdef _MSC_VER
  #include <compat/msvc.h>
  #endif
  
  #include <string/stdstring.h>
  #include <streams/file_stream.h>
  #define VFS_FRONTEND
  #include <vfs/vfs_implementation.h>
  
  #define VFS_ERROR_RETURN_VALUE -1
  
  struct RFILE
  {
     struct retro_vfs_file_handle *hfile;
  	bool error_flag;
  	bool eof_flag;
  };
  
  static retro_vfs_get_path_t filestream_get_path_cb = NULL;
  static retro_vfs_open_t filestream_open_cb         = NULL;
  static retro_vfs_close_t filestream_close_cb       = NULL;
  static retro_vfs_size_t filestream_size_cb         = NULL;
  static retro_vfs_truncate_t filestream_truncate_cb = NULL;
  static retro_vfs_tell_t filestream_tell_cb         = NULL;
  static retro_vfs_seek_t filestream_seek_cb         = NULL;
  static retro_vfs_read_t filestream_read_cb         = NULL;
  static retro_vfs_write_t filestream_write_cb       = NULL;
  static retro_vfs_flush_t filestream_flush_cb       = NULL;
  static retro_vfs_remove_t filestream_remove_cb     = NULL;
  static retro_vfs_rename_t filestream_rename_cb     = NULL;
  
  /* VFS Initialization */
  
  void filestream_vfs_init(const struct retro_vfs_interface_info* vfs_info)
  {
     const struct retro_vfs_interface *
        vfs_iface           = vfs_info->iface;
  
     filestream_get_path_cb = NULL;
     filestream_open_cb     = NULL;
     filestream_close_cb    = NULL;
     filestream_tell_cb     = NULL;
     filestream_size_cb     = NULL;
     filestream_truncate_cb = NULL;
     filestream_seek_cb     = NULL;
     filestream_read_cb     = NULL;
     filestream_write_cb    = NULL;
     filestream_flush_cb    = NULL;
     filestream_remove_cb   = NULL;
     filestream_rename_cb   = NULL;
  
     if (
               (vfs_info->required_interface_version < 
               FILESTREAM_REQUIRED_VFS_VERSION)
           || !vfs_iface)
        return;
  
     filestream_get_path_cb = vfs_iface->get_path;
     filestream_open_cb     = vfs_iface->open;
     filestream_close_cb    = vfs_iface->close;
     filestream_size_cb     = vfs_iface->size;
     filestream_truncate_cb = vfs_iface->truncate;
     filestream_tell_cb     = vfs_iface->tell;
     filestream_seek_cb     = vfs_iface->seek;
     filestream_read_cb     = vfs_iface->read;
     filestream_write_cb    = vfs_iface->write;
     filestream_flush_cb    = vfs_iface->flush;
     filestream_remove_cb   = vfs_iface->remove;
     filestream_rename_cb   = vfs_iface->rename;
  }
  
  /* Callback wrappers */
  bool filestream_exists(const char *path)
  {
     RFILE *dummy           = NULL;
  
     if (!path || !*path)
        return false;
  
     dummy                  = filestream_open(
           path,
           RETRO_VFS_FILE_ACCESS_READ,
           RETRO_VFS_FILE_ACCESS_HINT_NONE);
  
     if (!dummy)
        return false;
  
     if (filestream_close(dummy) != 0)
        if (dummy)
           free(dummy);
  
     dummy = NULL;
     return true;
  }
  
  int64_t filestream_get_size(RFILE *stream)
  {
     int64_t output;
  
     if (filestream_size_cb)
        output = filestream_size_cb(stream->hfile);
     else
        output = retro_vfs_file_size_impl(
              (libretro_vfs_implementation_file*)stream->hfile);
  
     if (output == VFS_ERROR_RETURN_VALUE)
        stream->error_flag = true;
  
     return output;
  }
  
  int64_t filestream_truncate(RFILE *stream, int64_t length)
  {
     int64_t output;
  
     if (filestream_truncate_cb)
        output = filestream_truncate_cb(stream->hfile, length);
     else
        output = retro_vfs_file_truncate_impl(
              (libretro_vfs_implementation_file*)stream->hfile, length);
  
     if (output == VFS_ERROR_RETURN_VALUE)
        stream->error_flag = true;
  
     return output;
  }
  
  /**
   * filestream_open:
   * @path               : path to file
   * @mode               : file mode to use when opening (read/write)
   * @hints              :
   *
   * Opens a file for reading or writing, depending on the requested mode.
   * Returns a pointer to an RFILE if opened successfully, otherwise NULL.
   **/
  RFILE* filestream_open(const char *path, unsigned mode, unsigned hints)
  {
     struct retro_vfs_file_handle  *fp = NULL;
     RFILE* output                     = NULL;
  
     if (filestream_open_cb)
        fp = (struct retro_vfs_file_handle*)
           filestream_open_cb(path, mode, hints);
     else
        fp = (struct retro_vfs_file_handle*)
           retro_vfs_file_open_impl(path, mode, hints);
  
     if (!fp)
        return NULL;
  
     output             = (RFILE*)malloc(sizeof(RFILE));
     output->error_flag = false;
     output->eof_flag   = false;
     output->hfile      = fp;
     return output;
  }
  
  char* filestream_gets(RFILE *stream, char *s, size_t len)
  {
     int c   = 0;
     char *p = s;
     if (!stream)
        return NULL;
  
     /* get max bytes or up to a newline */
  
     for (len--; len > 0; len--)
     {
        if ((c = filestream_getc(stream)) == EOF)
           break;
        *p++ = c;
        if (c == '\n')
           break;
     }
     *p = 0;
  
     if (p == s && c == EOF)
        return NULL;
     return (s);
  }
  
  int filestream_getc(RFILE *stream)
  {
     char c = 0;
     if (stream && filestream_read(stream, &c, 1) == 1)
        return (int)(unsigned char)c;
     return EOF;
  }
  
  int filestream_vscanf(RFILE *stream, const char* format, va_list *args)
  {
     char buf[4096];
     char subfmt[64];
     va_list args_copy;
     const char * bufiter = buf;
     int        ret       = 0;
     int64_t startpos     = filestream_tell(stream);
     int64_t maxlen       = filestream_read(stream, buf, sizeof(buf)-1);
  
     if (maxlen <= 0)
        return EOF;
  
     buf[maxlen] = '\0';
  
     /* Have to copy the input va_list here
      * > Calling va_arg() on 'args' directly would
      *   cause the va_list to have an indeterminate value
      *   in the function calling filestream_vscanf(),
      *   leading to unexpected behaviour */
     va_copy(args_copy, *args);
  
     while (*format)
     {
        if (*format == '%')
        {
           int sublen;
           char* subfmtiter = subfmt;
           bool asterisk    = false;
  
           *subfmtiter++    = *format++; /* '%' */
  
           /* %[*][width][length]specifier */
  
           if (*format == '*')
           {
              asterisk      = true;
              *subfmtiter++ = *format++;
           }
  
           while (ISDIGIT((unsigned char)*format))
              *subfmtiter++ = *format++; /* width */
  
           /* length */
           if (*format == 'h' || *format == 'l')
           {
              if (format[1] == format[0])
                 *subfmtiter++ = *format++;
              *subfmtiter++    = *format++;
           }
           else if (
                 *format == 'j' || 
                 *format == 'z' || 
                 *format == 't' || 
                 *format == 'L')
           {
              *subfmtiter++ = *format++;
           }
  
           /* specifier - always a single character (except ]) */
           if (*format == '[')
           {
              while (*format != ']')
                 *subfmtiter++ = *format++;
              *subfmtiter++    = *format++;
           }
           else
              *subfmtiter++    = *format++;
  
           *subfmtiter++       = '%';
           *subfmtiter++       = 'n';
           *subfmtiter++       = '\0';
  
           if (sizeof(void*) != sizeof(long*))
              abort(); /* all pointers must have the same size */
  
           if (asterisk)
           {
              int v = sscanf(bufiter, subfmt, &sublen);
              if (v == EOF)
                 return EOF;
              if (v != 0)
                 break;
           }
           else
           {
              int v = sscanf(bufiter, subfmt, va_arg(args_copy, void*), &sublen);
              if (v == EOF)
                 return EOF;
              if (v != 1)
                 break;
           }
  
           ret++;
           bufiter += sublen;
        }
        else if (isspace((unsigned char)*format))
        {
           while (isspace((unsigned char)*bufiter))
              bufiter++;
           format++;
        }
        else
        {
           if (*bufiter != *format)
              break;
           bufiter++;
           format++;
        }
     }
  
     va_end(args_copy);
     filestream_seek(stream, startpos+(bufiter-buf),
           RETRO_VFS_SEEK_POSITION_START);
  
     return ret;
  }
  
  int filestream_scanf(RFILE *stream, const char* format, ...)
  {
     int result;
     va_list vl;
     va_start(vl, format);
     result = filestream_vscanf(stream, format, &vl);
     va_end(vl);
     return result;
  }
  
  int64_t filestream_seek(RFILE *stream, int64_t offset, int seek_position)
  {
     int64_t output;
  
     if (filestream_seek_cb)
        output = filestream_seek_cb(stream->hfile, offset, seek_position);
     else
        output = retro_vfs_file_seek_impl(
              (libretro_vfs_implementation_file*)stream->hfile,
              offset, seek_position);
  
     if (output == VFS_ERROR_RETURN_VALUE)
        stream->error_flag = true;
  
     stream->eof_flag      = false;
  
     return output;
  }
  
  int filestream_eof(RFILE *stream)
  {
     return stream->eof_flag;
  }
  
  int64_t filestream_tell(RFILE *stream)
  {
     int64_t output;
  
     if (filestream_size_cb)
        output = filestream_tell_cb(stream->hfile);
     else
        output = retro_vfs_file_tell_impl(
              (libretro_vfs_implementation_file*)stream->hfile);
  
     if (output == VFS_ERROR_RETURN_VALUE)
        stream->error_flag = true;
  
     return output;
  }
  
  void filestream_rewind(RFILE *stream)
  {
     if (!stream)
        return;
     filestream_seek(stream, 0L, RETRO_VFS_SEEK_POSITION_START);
     stream->error_flag = false;
     stream->eof_flag   = false;
  }
  
  int64_t filestream_read(RFILE *stream, void *s, int64_t len)
  {
     int64_t output;
  
     if (filestream_read_cb)
        output = filestream_read_cb(stream->hfile, s, len);
     else
        output = retro_vfs_file_read_impl(
              (libretro_vfs_implementation_file*)stream->hfile, s, len);
  
     if (output == VFS_ERROR_RETURN_VALUE)
        stream->error_flag = true;
     if (output < len)
        stream->eof_flag   = true;
  
     return output;
  }
  
  int filestream_flush(RFILE *stream)
  {
     int output;
  
     if (filestream_flush_cb)
        output = filestream_flush_cb(stream->hfile);
     else
        output = retro_vfs_file_flush_impl(
              (libretro_vfs_implementation_file*)stream->hfile);
  
     if (output == VFS_ERROR_RETURN_VALUE)
        stream->error_flag = true;
  
     return output;
  }
  
  int filestream_delete(const char *path)
  {
     if (filestream_remove_cb)
        return filestream_remove_cb(path);
  
     return retro_vfs_file_remove_impl(path);
  }
  
  int filestream_rename(const char *old_path, const char *new_path)
  {
     if (filestream_rename_cb)
        return filestream_rename_cb(old_path, new_path);
  
     return retro_vfs_file_rename_impl(old_path, new_path);
  }
  
  const char* filestream_get_path(RFILE *stream)
  {
     if (filestream_get_path_cb)
        return filestream_get_path_cb(stream->hfile);
  
     return retro_vfs_file_get_path_impl(
           (libretro_vfs_implementation_file*)stream->hfile);
  }
  
  int64_t filestream_write(RFILE *stream, const void *s, int64_t len)
  {
     int64_t output;
  
     if (filestream_write_cb)
        output = filestream_write_cb(stream->hfile, s, len);
     else
        output = retro_vfs_file_write_impl(
              (libretro_vfs_implementation_file*)stream->hfile, s, len);
  
     if (output == VFS_ERROR_RETURN_VALUE)
        stream->error_flag = true;
  
     return output;
  }
  
  int filestream_putc(RFILE *stream, int c)
  {
     char c_char = (char)c;
     if (!stream)
        return EOF;
     return filestream_write(stream, &c_char, 1) == 1 
        ? (int)(unsigned char)c 
        : EOF;
  }
  
  int filestream_vprintf(RFILE *stream, const char* format, va_list args)
  {
     static char buffer[8 * 1024];
     int64_t num_chars = vsnprintf(buffer, sizeof(buffer),
           format, args);
  
     if (num_chars < 0)
        return -1;
     else if (num_chars == 0)
        return 0;
  
     return (int)filestream_write(stream, buffer, num_chars);
  }
  
  int filestream_printf(RFILE *stream, const char* format, ...)
  {
     va_list vl;
     int result;
     va_start(vl, format);
     result = filestream_vprintf(stream, format, vl);
     va_end(vl);
     return result;
  }
  
  int filestream_error(RFILE *stream)
  {
     if (stream && stream->error_flag)
        return 1;
     return 0;
  }
  
  int filestream_close(RFILE *stream)
  {
     int output;
     struct retro_vfs_file_handle* fp = stream->hfile;
  
     if (filestream_close_cb)
        output = filestream_close_cb(fp);
     else
        output = retro_vfs_file_close_impl(
              (libretro_vfs_implementation_file*)fp);
  
     if (output == 0)
        free(stream);
  
     return output;
  }
  
  /**
   * filestream_read_file:
   * @path             : path to file.
   * @buf              : buffer to allocate and read the contents of the
   *                     file into. Needs to be freed manually.
   * @len              : optional output integer containing bytes read.
   *
   * Read the contents of a file into @buf.
   *
   * Returns: non zero on success.
   */
  int64_t filestream_read_file(const char *path, void **buf, int64_t *len)
  {
     int64_t ret              = 0;
     int64_t content_buf_size = 0;
     void *content_buf        = NULL;
     RFILE *file              = filestream_open(path,
           RETRO_VFS_FILE_ACCESS_READ,
           RETRO_VFS_FILE_ACCESS_HINT_NONE);
  
     if (!file)
     {
        *buf = NULL;
        return 0;
     }
  
     content_buf_size = filestream_get_size(file);
  
     if (content_buf_size < 0)
        goto error;
  
     content_buf      = malloc((size_t)(content_buf_size + 1));
  
     if (!content_buf)
        goto error;
     if ((int64_t)(uint64_t)(content_buf_size + 1) != (content_buf_size + 1))
        goto error;
  
     ret = filestream_read(file, content_buf, (int64_t)content_buf_size);
     if (ret < 0)
        goto error;
  
     if (filestream_close(file) != 0)
        if (file)
           free(file);
  
     *buf    = content_buf;
  
     /* Allow for easy reading of strings to be safe.
      * Will only work with sane character formatting (Unix). */
     ((char*)content_buf)[ret] = '\0';
  
     if (len)
        *len = ret;
  
     return 1;
  
  error:
     if (file)
        if (filestream_close(file) != 0)
           free(file);
     if (content_buf)
        free(content_buf);
     if (len)
        *len = -1;
     *buf = NULL;
     return 0;
  }
  
  /**
   * filestream_write_file:
   * @path             : path to file.
   * @data             : contents to write to the file.
   * @size             : size of the contents.
   *
   * Writes data to a file.
   *
   * Returns: true (1) on success, false (0) otherwise.
   */
  bool filestream_write_file(const char *path, const void *data, int64_t size)
  {
     int64_t ret   = 0;
     RFILE *file   = filestream_open(path,
           RETRO_VFS_FILE_ACCESS_WRITE,
           RETRO_VFS_FILE_ACCESS_HINT_NONE);
     if (!file)
        return false;
  
     ret = filestream_write(file, data, size);
     if (filestream_close(file) != 0)
        if (file)
           free(file);
  
     if (ret != size)
        return false;
  
     return true;
  }
  
  /* Returned pointer must be freed by the caller. */
  char* filestream_getline(RFILE *stream)
  {
     char *newline_tmp  = NULL;
     size_t cur_size    = 8;
     size_t idx         = 0;
     int in             = 0;
     char *newline      = (char*)malloc(9);
  
     if (!stream || !newline)
     {
        if (newline)
           free(newline);
        return NULL;
     }
  
     in                 = filestream_getc(stream);
  
     while (in != EOF && in != '\n')
     {
        if (idx == cur_size)
        {
           cur_size    *= 2;
           newline_tmp  = (char*)realloc(newline, cur_size + 1);
  
           if (!newline_tmp)
           {
              free(newline);
              return NULL;
           }
  
           newline     = newline_tmp;
        }
  
        newline[idx++] = in;
        in             = filestream_getc(stream);
     }
  
     newline[idx]      = '\0';
     return newline;
  }
  
  libretro_vfs_implementation_file* filestream_get_vfs_handle(RFILE *stream)
  {
     return (libretro_vfs_implementation_file*)stream->hfile;
  }
  