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1 /*
2  * Copyright (C) 2015 The Android Open Source Project
3  *
4  * Licensed under the Apache License, Version 2.0 (the "License");
5  * you may not use this file except in compliance with the License.
6  * You may obtain a copy of the License at
7  *
8  *      http://www.apache.org/licenses/LICENSE-2.0
9  *
10  * Unless required by applicable law or agreed to in writing, software
11  * distributed under the License is distributed on an "AS IS" BASIS,
12  * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
13  * See the License for the specific language governing permissions and
14  * limitations under the License.
15  */
16 
17 #ifndef __FEC_H__
18 #define __FEC_H__
19 
20 #include <utils/Compat.h>
21 #include <string>
22 #include <vector>
23 #include <fec/io.h>
24 #include <fec/ecc.h>
25 
26 #define IMAGE_MIN_THREADS     1
27 #define IMAGE_MAX_THREADS     128
28 
29 #define INFO(x...) \
30     fprintf(stderr, x);
31 #define FATAL(x...) { \
32     fprintf(stderr, x); \
33     exit(1); \
34 }
35 
36 #define unlikely(x)    __builtin_expect(!!(x), 0)
37 
38 struct image {
39     /* if true, decode file in place instead of creating a new output file */
40     bool inplace;
41     /* if true, use memory mapping instead of copying all input into memory */
42     bool mmap;
43     /* if true, assume input is a sparse file */
44     bool sparse;
45     /* if true, print more verbose information to stderr */
46     bool verbose;
47     const char *fec_filename;
48     int fec_fd;
49     int inp_fd;
50     /* the number of Reed-Solomon generator polynomial roots, also the number
51        of parity bytes generated for each N bytes in RS(M, N) */
52     int roots;
53     /* for RS(M, N), N = M - roots */
54     int rs_n;
55     int threads;
56     uint32_t fec_size;
57     uint64_t blocks;
58     uint64_t inp_size;
59     uint64_t pos;
60     uint64_t rounds;
61     uint64_t rv;
62     uint8_t *fec;
63     uint8_t *fec_mmap_addr;
64     uint8_t *input;
65     uint8_t *output;
66 };
67 
68 struct image_proc_ctx;
69 typedef void (*image_proc_func)(image_proc_ctx *);
70 
71 struct image_proc_ctx {
72     image_proc_func func;
73     int id;
74     image *ctx;
75     uint64_t rv;
76     uint64_t fec_pos;
77     uint64_t start;
78     uint64_t end;
79     void *rs;
80 };
81 
82 extern bool image_load(const std::vector<std::string>& filename, image *ctx,
83         bool output_needed);
84 extern bool image_save(const std::string& filename, image *ctx);
85 
86 extern bool image_ecc_new(const std::string& filename, image *ctx);
87 extern bool image_ecc_load(const std::string& filename, image *ctx);
88 extern bool image_ecc_save(image *ctx);
89 
90 extern bool image_process(image_proc_func f, image *ctx);
91 
92 extern void image_init(image *ctx);
93 extern void image_free(image *ctx);
94 
image_get_interleaved_byte(uint64_t i,image * ctx)95 inline uint8_t image_get_interleaved_byte(uint64_t i, image *ctx)
96 {
97     uint64_t offset = fec_ecc_interleave(i, ctx->rs_n, ctx->rounds);
98 
99     if (unlikely(offset >= ctx->inp_size)) {
100         return 0;
101     }
102 
103     return ctx->input[offset];
104 }
105 
image_set_interleaved_byte(uint64_t i,image * ctx,uint8_t value)106 inline void image_set_interleaved_byte(uint64_t i, image *ctx,
107         uint8_t value)
108 {
109     uint64_t offset = fec_ecc_interleave(i, ctx->rs_n, ctx->rounds);
110 
111     if (unlikely(offset >= ctx->inp_size)) {
112         assert(value == 0);
113     } else if (ctx->output && ctx->output[offset] != value) {
114         ctx->output[offset] = value;
115     }
116 }
117 
118 #endif // __FEC_H__
119