1 /*
2  * Copyright (C) 2020 Linux Studio Plugins Project <https://lsp-plug.in/>
3  *           (C) 2020 Vladimir Sadovnikov <sadko4u@gmail.com>
4  *
5  * This file is part of lsp-plugins
6  * Created on: 14 янв. 2018 г.
7  *
8  * lsp-plugins is free software: you can redistribute it and/or modify
9  * it under the terms of the GNU Lesser General Public License as published by
10  * the Free Software Foundation, either version 3 of the License, or
11  * any later version.
12  *
13  * lsp-plugins is distributed in the hope that it will be useful,
14  * but WITHOUT ANY WARRANTY; without even the implied warranty of
15  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
16  * GNU Lesser General Public License for more details.
17  *
18  * You should have received a copy of the GNU Lesser General Public License
19  * along with lsp-plugins. If not, see <https://www.gnu.org/licenses/>.
20  */
21 
22 #ifndef CORE_FILES_LSPC_LSPCCHUNKREADER_H_
23 #define CORE_FILES_LSPC_LSPCCHUNKREADER_H_
24 
25 #include <core/files/lspc/LSPCChunkAccessor.h>
26 
27 namespace lsp
28 {
29 
30     class LSPCChunkReader: public LSPCChunkAccessor
31     {
32         private:
33             LSPCChunkReader & operator = (const LSPCChunkReader &);
34 
35         protected:
36             friend class LSPCFile;
37 
38         protected:
39             uint32_t            nUnread;            // Number of bytes still not read from chunk
40             size_t              nBufTail;           // Buffer tail
41             wsize_t             nFileOff;           // File read offset
42             bool                bLast;
43 
44         protected:
45             explicit LSPCChunkReader(LSPCResource *fd, uint32_t magic, uint32_t uid);
46 
47         public:
48             virtual ~LSPCChunkReader();
49 
50         public:
51             /**
52              * Read chunk data header from LSPC chunk. Header should contain lspc_header_t at
53              * the beginning.
54              * @param hdr the header data to store
55              * @param size the size of header, should be at least sizeof(lspc_header_t)
56              * @return status of operation or error code (negative)
57              */
58             virtual ssize_t     read_header(void *hdr, size_t size);
59 
60             /**
61              * Read regular data from LSPC chunk.
62              * @param buf the pointer to store data
63              * @param count number of bytes to read
64              * @return status of operation or error code (negative)
65              */
66             virtual ssize_t     read(void *buf, size_t count);
67 
68             /**
69              * Skip some amount of data
70              * @param count amount of bytes to skip
71              * @return number of skipped bytes or error code (negative)
72              */
73             virtual ssize_t     skip(size_t count);
74     };
75 
76 } /* namespace lsp */
77 
78 #endif /* CORE_FILES_LSPC_LSPCCHUNKREADER_H_ */
79