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1 /*! \file exif-loader.h
2  * \brief Defines the ExifLoader type
3  */
4 /*
5  * Copyright (c) 2003 Lutz Mueller <lutz@users.sourceforge.net>
6  *
7  * This library is free software; you can redistribute it and/or
8  * modify it under the terms of the GNU Lesser General Public
9  * License as published by the Free Software Foundation; either
10  * version 2 of the License, or (at your option) any later version.
11  *
12  * This library is distributed in the hope that it will be useful,
13  * but WITHOUT ANY WARRANTY; without even the implied warranty of
14  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
15  * Lesser General Public License for more details.
16  *
17  * You should have received a copy of the GNU Lesser General Public
18  * License along with this library; if not, write to the
19  * Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor,
20  * Boston, MA  02110-1301  USA.
21  */
22 
23 #ifndef __EXIF_LOADER_H__
24 #define __EXIF_LOADER_H__
25 
26 #include <libexif/exif-data.h>
27 #include <libexif/exif-log.h>
28 #include <libexif/exif-mem.h>
29 
30 #ifdef __cplusplus
31 extern "C" {
32 #endif /* __cplusplus */
33 
34 /*! Data used by the loader interface */
35 typedef struct _ExifLoader ExifLoader;
36 
37 /*! Allocate a new #ExifLoader.
38  *
39  *  \return allocated ExifLoader
40  */
41 ExifLoader *exif_loader_new     (void);
42 
43 /*! Allocate a new #ExifLoader using the specified memory allocator.
44  *
45  *  \param[in] mem the ExifMem
46  *  \return allocated ExifLoader
47  */
48 ExifLoader *exif_loader_new_mem (ExifMem *mem);
49 
50 /*! Increase the refcount of the #ExifLoader.
51  *
52  *  \param[in] loader the ExifLoader to increase the refcount of.
53  */
54 void        exif_loader_ref     (ExifLoader *loader);
55 
56 /*! Decrease the refcount of the #ExifLoader.
57  * If the refcount reaches 0, the loader is freed.
58  *
59  * \param[in] loader ExifLoader for which to decrease the refcount
60  */
61 void        exif_loader_unref   (ExifLoader *loader);
62 
63 /*! Load a file into the given #ExifLoader from the filesystem.
64  * The relevant data is copied in raw form into the #ExifLoader.
65  *
66  * \param[in] loader loader to write to
67  * \param[in] fname path to the file to read
68  */
69 void        exif_loader_write_file (ExifLoader *loader, const char *fname);
70 
71 /*! Load a buffer into the #ExifLoader from a memory buffer.
72  * The relevant data is copied in raw form into the #ExifLoader.
73  *
74  * \param[in] loader loader to write to
75  * \param[in] buf buffer to read from
76  * \param[in] sz size of the buffer
77  * \return 1 while EXIF data is read (or while there is still hope that
78  *   there will be EXIF data later on), 0 otherwise.
79  */
80 unsigned char exif_loader_write (ExifLoader *loader, unsigned char *buf, unsigned int sz);
81 
82 /*! Free any data previously loaded and reset the #ExifLoader to its
83  * newly-initialized state.
84  *
85  * \param[in] loader the loader
86  */
87 void          exif_loader_reset (ExifLoader *loader);
88 
89 /*! Create an #ExifData from the data in the loader. The loader must
90  * already contain data from a previous call to #exif_loader_write_file
91  * or #exif_loader_write.
92  *
93  * \note The #ExifData returned is created using its default options, which
94  * may take effect before the data is returned. If other options are desired,
95  * an #ExifData must be created explicitly and data extracted from the loader
96  * using #exif_loader_get_buf instead.
97  *
98  * \param[in] loader the loader
99  * \return allocated ExifData
100  *
101  * \see exif_loader_get_buf
102  */
103 ExifData     *exif_loader_get_data (ExifLoader *loader);
104 
105 /*! Return the raw data read by the loader.  The returned pointer is only
106  * guaranteed to be valid until the next call to a function modifying
107  * this #ExifLoader.  Either or both of buf and buf_size may be NULL on
108  * entry, in which case that value is not returned.
109  *
110  * \param[in] loader the loader
111  * \param[out] buf read-only pointer to the data read by the loader, or NULL
112  *                 in case of error
113  * \param[out] buf_size size of the data at buf, or 0 in case of error
114  */
115 void exif_loader_get_buf (ExifLoader *loader, const unsigned char **buf,
116 						  unsigned int *buf_size);
117 
118 /*! Set the log message object used by this #ExifLoader.
119  * \param[in] loader the loader
120  * \param[in] log #ExifLog
121  */
122 void exif_loader_log (ExifLoader *loader, ExifLog *log);
123 
124 #ifdef __cplusplus
125 }
126 #endif /* __cplusplus */
127 
128 #endif /* __EXIF_LOADER_H__ */
129