text: /**
   * \file input.c
   * \brief Generic stdio-like input interface
   * \author Abramo Bagnara <abramo@alsa-project.org>
   * \date 2000
   *
   * Generic stdio-like input interface
   */
  /*
   *  Input object
   *  Copyright (c) 2000 by Abramo Bagnara <abramo@alsa-project.org>
   *
   *
   *   This library is free software; you can redistribute it and/or modify
   *   it under the terms of the GNU Lesser General Public License as
   *   published by the Free Software Foundation; either version 2.1 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 Lesser General Public License for more details.
   *
   *   You should have received a copy of the GNU Lesser General Public
   *   License along with this library; if not, write to the Free Software
   *   Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301  USA
   *
   */
  
  #include <stdarg.h>
  #include <stdio.h>
  #include <stdlib.h>
  #include <unistd.h>
  #include "local.h"
  
  #ifndef DOC_HIDDEN
  
  typedef struct _snd_input_ops {
  	int (*close)(snd_input_t *input);
  	int (*scan)(snd_input_t *input, const char *format, va_list args);
  	char *(*(gets))(snd_input_t *input, char *str, size_t size);
  	int (*getch)(snd_input_t *input);
  	int (*ungetch)(snd_input_t *input, int c);
  } snd_input_ops_t;
  
  struct _snd_input {
  	snd_input_type_t type;
  	const snd_input_ops_t *ops;
  	void *private_data;
  };
  #endif
  
  /**
   * \brief Closes an input handle.
   * \param input The input handle to be closed.
   * \return Zero if successful, otherwise a negative error code.
   */
  int snd_input_close(snd_input_t *input)
  {
  	int err = input->ops->close(input);
  	free(input);
  	return err;
  }
  
  /**
   * \brief Reads formatted input (like \c fscanf(3)) from an input handle.
   * \param input The input handle.
   * \param format Format string in \c fscanf format.
   * \param ... Other \c fscanf arguments.
   * \return The number of input items assigned, or \c EOF.
   *
   * \bug Reading from a memory buffer doesn't work.
   */
  int snd_input_scanf(snd_input_t *input, const char *format, ...)
  {
  	int result;
  	va_list args;
  	va_start(args, format);
  	result = input->ops->scan(input, format, args);
  	va_end(args);
  	return result;
  }
  
  /**
   * \brief Reads a line from an input handle (like \c fgets(3)).
   * \param input The input handle.
   * \param str Address of the destination buffer.
   * \param size The size of the destination buffer.
   * \return Pointer to the buffer if successful, otherwise \c NULL.
   *
   * Like \c fgets, the returned string is zero-terminated, and contains
   * the new-line character \c '\\n' if the line fits into the buffer.
   */
  char *snd_input_gets(snd_input_t *input, char *str, size_t size)
  {
  	return (input->ops->gets)(input, str, size);
  }
  			
  /**
   * \brief Reads a character from an input handle (like \c fgetc(3)).
   * \param input The input handle.
   * \return The character read, or \c EOF on end of file or error.
   */
  int snd_input_getc(snd_input_t *input)
  {
  	return input->ops->getch(input);
  }
  
  /**
   * \brief Puts the last character read back to an input handle (like \c ungetc(3)).
   * \param input The input handle.
   * \param c The character to push back.
   * \return The character pushed back, or \c EOF on error.
   */
  int snd_input_ungetc(snd_input_t *input, int c)
  {
  	return input->ops->ungetch(input, c);
  }
  
  #ifndef DOC_HIDDEN
  typedef struct _snd_input_stdio {
  	int close;
  	FILE *fp;
  } snd_input_stdio_t;
  
  static int snd_input_stdio_close(snd_input_t *input ATTRIBUTE_UNUSED)
  {
  	snd_input_stdio_t *stdio = input->private_data;
  	if (stdio->close)
  		fclose(stdio->fp);
  	free(stdio);
  	return 0;
  }
  
  static int snd_input_stdio_scan(snd_input_t *input, const char *format, va_list args)
  {
  	snd_input_stdio_t *stdio = input->private_data;
  	extern int vfscanf(FILE *, const char *, va_list);
  	return vfscanf(stdio->fp, format, args);
  }
  
  static char *snd_input_stdio_gets(snd_input_t *input, char *str, size_t size)
  {
  	snd_input_stdio_t *stdio = input->private_data;
  	return fgets(str, (int) size, stdio->fp);
  }
  			
  static int snd_input_stdio_getc(snd_input_t *input)
  {
  	snd_input_stdio_t *stdio = input->private_data;
  	return getc(stdio->fp);
  }
  
  static int snd_input_stdio_ungetc(snd_input_t *input, int c)
  {
  	snd_input_stdio_t *stdio = input->private_data;
  	return ungetc(c, stdio->fp);
  }
  
  static const snd_input_ops_t snd_input_stdio_ops = {
  	.close		= snd_input_stdio_close,
  	.scan		= snd_input_stdio_scan,
  	.gets		= snd_input_stdio_gets,
  	.getch		= snd_input_stdio_getc,
  	.ungetch	= snd_input_stdio_ungetc,
  };
  #endif
  
  /**
   * \brief Creates a new input object using an existing stdio \c FILE pointer.
   * \param inputp The function puts the pointer to the new input object
   *               at the address specified by \p inputp.
   * \param fp The \c FILE pointer to read from.
   *           Reading begins at the current file position.
   * \param _close Close flag. Set this to 1 if #snd_input_close should close
   *              \p fp by calling \c fclose.
   * \return Zero if successful, otherwise a negative error code.
   */
  int snd_input_stdio_attach(snd_input_t **inputp, FILE *fp, int _close)
  {
  	snd_input_t *input;
  	snd_input_stdio_t *stdio;
  	assert(inputp && fp);
  	stdio = calloc(1, sizeof(*stdio));
  	if (!stdio)
  		return -ENOMEM;
  	input = calloc(1, sizeof(*input));
  	if (!input) {
  		free(stdio);
  		return -ENOMEM;
  	}
  	stdio->fp = fp;
  	stdio->close = _close;
  	input->type = SND_INPUT_STDIO;
  	input->ops = &snd_input_stdio_ops;
  	input->private_data = stdio;
  	*inputp = input;
  	return 0;
  }
  	
  /**
   * \brief Creates a new input object reading from a file.
   * \param inputp The functions puts the pointer to the new input object
   *               at the address specified by \p inputp.
   * \param file The name of the file to read from.
   * \param mode The open mode, like \c fopen(3).
   * \return Zero if successful, otherwise a negative error code.
   */
  int snd_input_stdio_open(snd_input_t **inputp, const char *file, const char *mode)
  {
  	int err;
  	FILE *fp = fopen(file, mode);
  	if (!fp) {
  		//SYSERR("fopen");
  		return -errno;
  	}
  	err = snd_input_stdio_attach(inputp, fp, 1);
  	if (err < 0)
  		fclose(fp);
  	return err;
  }
  
  #ifndef DOC_HIDDEN
  
  typedef struct _snd_input_buffer {
  	unsigned char *buf;
  	unsigned char *ptr;
  	size_t size;
  } snd_input_buffer_t;
  
  static int snd_input_buffer_close(snd_input_t *input)
  {
  	snd_input_buffer_t *buffer = input->private_data;
  	free(buffer->buf);
  	free(buffer);
  	return 0;
  }
  
  static int snd_input_buffer_scan(snd_input_t *input, const char *format, va_list args)
  {
  	snd_input_buffer_t *buffer = input->private_data;
  	extern int vsscanf(const char *, const char *, va_list);
  	/* FIXME: how can I obtain consumed chars count? */
  	assert(0);
  	return vsscanf((char *)buffer->ptr, format, args);
  }
  
  static char *snd_input_buffer_gets(snd_input_t *input, char *str, size_t size)
  {
  	snd_input_buffer_t *buffer = input->private_data;
  	size_t bsize = buffer->size;
  	while (--size > 0 && bsize > 0) {
  		unsigned char c = *buffer->ptr++;
  		bsize--;
  		*str++ = c;
  		if (c == '\n')
  			break;
  	}
  	if (bsize == buffer->size)
  		return NULL;
  	buffer->size = bsize;
  	*str = '\0';
  	return str;
  }
  			
  static int snd_input_buffer_getc(snd_input_t *input)
  {
  	snd_input_buffer_t *buffer = input->private_data;
  	if (buffer->size == 0)
  		return EOF;
  	buffer->size--;
  	return *buffer->ptr++;
  }
  
  static int snd_input_buffer_ungetc(snd_input_t *input, int c)
  {
  	snd_input_buffer_t *buffer = input->private_data;
  	if (buffer->ptr == buffer->buf)
  		return EOF;
  	buffer->ptr--;
  	assert(*buffer->ptr == (unsigned char) c);
  	buffer->size++;
  	return c;
  }
  
  static const snd_input_ops_t snd_input_buffer_ops = {
  	.close		= snd_input_buffer_close,
  	.scan		= snd_input_buffer_scan,
  	.gets		= snd_input_buffer_gets,
  	.getch		= snd_input_buffer_getc,
  	.ungetch	= snd_input_buffer_ungetc,
  };
  #endif
  
  /**
   * \brief Creates a new input object from a memory buffer.
   * \param inputp The function puts the pointer to the new input object
   *               at the address specified by \p inputp.
   * \param buf Address of the input buffer.
   * \param size Size of the input buffer.
   * \return Zero if successful, otherwise a negative error code.
   *
   * This functions creates a copy of the input buffer, so the application is
   * not required to preserve the buffer after this function has been called.
   */
  int snd_input_buffer_open(snd_input_t **inputp, const char *buf, ssize_t size)
  {
  	snd_input_t *input;
  	snd_input_buffer_t *buffer;
  	assert(inputp);
  	buffer = calloc(1, sizeof(*buffer));
  	if (!buffer)
  		return -ENOMEM;
  	input = calloc(1, sizeof(*input));
  	if (!input) {
  		free(buffer);
  		return -ENOMEM;
  	}
  	if (size < 0)
  		size = strlen(buf);
  	buffer->buf = malloc((size_t)size + 1);
  	if (!buffer->buf) {
  		free(input);
  		free(buffer);
  		return -ENOMEM;
  	}
  	memcpy(buffer->buf, buf, (size_t) size);
  	buffer->buf[size] = 0;
  	buffer->ptr = buffer->buf;
  	buffer->size = size;
  	input->type = SND_INPUT_BUFFER;
  	input->ops = &snd_input_buffer_ops;
  	input->private_data = buffer;
  	*inputp = input;
  	return 0;
  }
  	
  