cairo-output-stream-private.h

按照官方的说法：Cairo is a vector graphics library with cross-device output support. 翻译过来

/* cairo - a vector graphics library with display and print output
 *
 * Copyright © 2006 Red Hat, Inc
 *
 * This library is free software; you can redistribute it and/or
 * modify it either under the terms of the GNU Lesser General Public
 * License version 2.1 as published by the Free Software Foundation
 * (the "LGPL") or, at your option, under the terms of the Mozilla
 * Public License Version 1.1 (the "MPL"). If you do not alter this
 * notice, a recipient may use your version of this file under either
 * the MPL or the LGPL.
 *
 * You should have received a copy of the LGPL along with this library
 * in the file COPYING-LGPL-2.1; if not, write to the Free Software
 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
 * You should have received a copy of the MPL along with this library
 * in the file COPYING-MPL-1.1
 *
 * The contents of this file are subject to the Mozilla Public License
 * Version 1.1 (the "License"); you may not use this file except in
 * compliance with the License. You may obtain a copy of the License at
 * http://www.mozilla.org/MPL/
 *
 * This software is distributed on an "AS IS" basis, WITHOUT WARRANTY
 * OF ANY KIND, either express or implied. See the LGPL or the MPL for
 * the specific language governing rights and limitations.
 *
 * The Original Code is cairo_output_stream.c as distributed with the
 *   cairo graphics library.
 *
 * The Initial Developer of the Original Code is Red Hat, Inc.
 *
 * Author(s):
 *	Kristian Høgsberg <[e-mail]>
 */

#ifndef CAIRO_OUTPUT_STREAM_PRIVATE_H
#define CAIRO_OUTPUT_STREAM_PRIVATE_H

typedef struct _cairo_output_stream cairo_output_stream_t;

typedef cairo_status_t (*cairo_output_stream_write_func_t) (cairo_output_stream_t *output_stream,
							    const unsigned char   *data,
							    unsigned int           length);

typedef cairo_status_t (*cairo_output_stream_close_func_t) (cairo_output_stream_t *output_stream);

struct _cairo_output_stream {
    cairo_output_stream_write_func_t write_func;
    cairo_output_stream_close_func_t close_func;
    unsigned long		     position;
    cairo_status_t		     status;
    cairo_bool_t		     closed;
};

extern const cairo_private cairo_output_stream_t cairo_output_stream_nil;

cairo_private void
_cairo_output_stream_init (cairo_output_stream_t            *stream,
			   cairo_output_stream_write_func_t  write_func,
			   cairo_output_stream_close_func_t  close_func);

cairo_private void
_cairo_output_stream_fini (cairo_output_stream_t *stream);


/* We already have the following declared in cairo.h:

typedef cairo_status_t (*cairo_write_func_t) (void		  *closure,
					      const unsigned char *data,
					      unsigned int	   length);
*/
typedef cairo_status_t (*cairo_close_func_t) (void *closure);


/* This function never returns NULL. If an error occurs (NO_MEMORY)
 * while trying to create the output stream this function returns a
 * valid pointer to a nil output stream.
 *
 * Note that even with a nil surface, the close_func callback will be
 * called by a call to _cairo_output_stream_close or
 * _cairo_output_stream_destroy.
 */
cairo_private cairo_output_stream_t *
_cairo_output_stream_create (cairo_write_func_t		write_func,
			     cairo_close_func_t		close_func,
			     void			*closure);

cairo_private void
_cairo_output_stream_close (cairo_output_stream_t *stream);

cairo_private void
_cairo_output_stream_destroy (cairo_output_stream_t *stream);

cairo_private void
_cairo_output_stream_write (cairo_output_stream_t *stream,
			    const void *data, size_t length);

cairo_private void
_cairo_output_stream_write_hex_string (cairo_output_stream_t *stream,
				       const char *data,
				       size_t length);

cairo_private int
_cairo_dtostr (char *buffer, size_t size, double d);

cairo_private void
_cairo_output_stream_vprintf (cairo_output_stream_t *stream,
			      const char *fmt, va_list ap);

cairo_private void
_cairo_output_stream_printf (cairo_output_stream_t *stream,
			     const char *fmt, ...);

cairo_private long
_cairo_output_stream_get_position (cairo_output_stream_t *stream);

cairo_private cairo_status_t
_cairo_output_stream_get_status (cairo_output_stream_t *stream);

/* This function never returns NULL. If an error occurs (NO_MEMORY or
 * WRITE_ERROR) while trying to create the output stream this function
 * returns a valid pointer to a nil output stream.
 *
 * NOTE: Even if a nil surface is returned, the caller should still
 * call _cairo_output_stream_destroy (or _cairo_output_stream_close at
 * least) in order to ensure that everything is properly cleaned up.
 */
cairo_private cairo_output_stream_t *
_cairo_output_stream_create_for_filename (const char *filename);

/* This function never returns NULL. If an error occurs (NO_MEMORY or
 * WRITE_ERROR) while trying to create the output stream this function
 * returns a valid pointer to a nil output stream.
 *
 * The caller still "owns" file and is responsible for calling fclose
 * on it when finished. The stream will not do this itself.
 */
cairo_private cairo_output_stream_t *
_cairo_output_stream_create_for_file (FILE *file);

cairo_private cairo_output_stream_t *
_cairo_memory_stream_create (void);

cairo_private void
_cairo_memory_stream_copy (cairo_output_stream_t *base,
			   cairo_output_stream_t *dest);

cairo_private int
_cairo_memory_stream_length (cairo_output_stream_t *stream);

/* cairo_base85_stream.c */
cairo_private cairo_output_stream_t *
_cairo_base85_stream_create (cairo_output_stream_t *output);

#endif /* CAIRO_OUTPUT_STREAM_PRIVATE_H */