libvips/libvips/include/vips/sbuf.h

145 lines
3.6 KiB
C

/* Buffered inputput from a VipsSource
*
* J.Cupitt, 18/11/19
*/
/*
This file is part of VIPS.
VIPS 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 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 program; if not, write to the Free Software
Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA
02110-1301 USA
*/
/*
These files are distributed with VIPS - http://www.vips.ecs.soton.ac.uk
*/
#ifndef VIPS_SBUF_H
#define VIPS_SBUF_H
#include <glib.h>
#include <glib-object.h>
#include <vips/object.h>
#ifdef __cplusplus
extern "C" {
#endif /*__cplusplus*/
#define VIPS_TYPE_SBUF (vips_sbuf_get_type())
#define VIPS_SBUF( obj ) \
(G_TYPE_CHECK_INSTANCE_CAST( (obj), \
VIPS_TYPE_SBUF, VipsSbuf ))
#define VIPS_SBUF_CLASS( klass ) \
(G_TYPE_CHECK_CLASS_CAST( (klass), \
VIPS_TYPE_SBUF, VipsSbufClass))
#define VIPS_IS_SBUF( obj ) \
(G_TYPE_CHECK_INSTANCE_TYPE( (obj), VIPS_TYPE_SBUF ))
#define VIPS_IS_SBUF_CLASS( klass ) \
(G_TYPE_CHECK_CLASS_TYPE( (klass), VIPS_TYPE_SBUF ))
#define VIPS_SBUF_GET_CLASS( obj ) \
(G_TYPE_INSTANCE_GET_CLASS( (obj), \
VIPS_TYPE_SBUF, VipsSbufClass ))
#define VIPS_SBUF_BUFFER_SIZE (4096)
/* Layer over source: read with an input buffer.
*
* Libraries like libjpeg do their own input buffering and need raw IO, but
* others, like radiance, need to parse the input into lines. A buffered read
* class is very convenient.
*/
typedef struct _VipsSbuf {
VipsObject parent_object;
/*< private >*/
/* The VipsSource we wrap.
*/
VipsSource *source;
/* The +1 means there's always a \0 byte at the end.
*
* Unsigned char, since we don't want >127 to be -ve.
*
* chars_in_buffer is how many chars we have in input_buffer,
* read_point is the current read position in that buffer.
*/
unsigned char input_buffer[VIPS_SBUF_BUFFER_SIZE + 1];
int chars_in_buffer;
int read_point;
/* Build lines of text here.
*/
unsigned char line[VIPS_SBUF_BUFFER_SIZE + 1];
} VipsSbuf;
typedef struct _VipsSbufClass {
VipsObjectClass parent_class;
} VipsSbufClass;
VIPS_API
GType vips_sbuf_get_type( void );
VIPS_API
VipsSbuf *vips_sbuf_new_from_source( VipsSource *source );
VIPS_API
void vips_sbuf_unbuffer( VipsSbuf *sbuf );
VIPS_API
int vips_sbuf_getc( VipsSbuf *sbuf );
#define VIPS_SBUF_GETC( S ) ( \
(S)->read_point < (S)->chars_in_buffer ? \
(S)->input_buffer[(S)->read_point++] : \
vips_sbuf_getc( S ) \
)
VIPS_API
void vips_sbuf_ungetc( VipsSbuf *sbuf );
#define VIPS_SBUF_UNGETC( S ) { \
if( (S)->read_point > 0 ) \
(S)->read_point -= 1; \
}
VIPS_API
int vips_sbuf_require( VipsSbuf *sbuf, int require );
#define VIPS_SBUF_REQUIRE( S, R ) ( \
(S)->read_point + (R) <= (S)->chars_in_buffer ? \
0 : \
vips_sbuf_require( (S), (R) ) \
)
#define VIPS_SBUF_PEEK( S ) ((S)->input_buffer + (S)->read_point)
#define VIPS_SBUF_FETCH( S ) ((S)->input_buffer[(S)->read_point++])
VIPS_API
const char *vips_sbuf_get_line( VipsSbuf *sbuf );
VIPS_API
char *vips_sbuf_get_line_copy( VipsSbuf *sbuf );
VIPS_API
const char *vips_sbuf_get_non_whitespace( VipsSbuf *sbuf );
VIPS_API
int vips_sbuf_skip_whitespace( VipsSbuf *sbuf );
#ifdef __cplusplus
}
#endif /*__cplusplus*/
#endif /*VIPS_SBUF_H*/