1 /*
2 * Copyright (c) 2016-2020, Facebook, Inc.
3 * All rights reserved.
4 *
5 * This source code is licensed under both the BSD-style license (found in the
6 * LICENSE file in the root directory of this source tree) and the GPLv2 (found
7 * in the COPYING file in the root directory of this source tree).
8 * You may select, at your option, one of the above-listed licenses.
9 */
10
11 #ifndef RESULT_H
12 #define RESULT_H
13
14 #include <stddef.h>
15
16 /**
17 * The error type enum.
18 */
19 typedef enum {
20 result_error_ok, /**< No error. */
21 result_error_skip, /**< This method was skipped. */
22 result_error_system_error, /**< Some internal error happened. */
23 result_error_compression_error, /**< Compression failed. */
24 result_error_decompression_error, /**< Decompression failed. */
25 result_error_round_trip_error, /**< Data failed to round trip. */
26 } result_error_t;
27
28 /**
29 * The success type.
30 */
31 typedef struct {
32 size_t total_size; /**< The total compressed size. */
33 } result_data_t;
34
35 /**
36 * The result type.
37 * Do not access the member variables directory, use the helper functions.
38 */
39 typedef struct {
40 result_error_t internal_error;
41 result_data_t internal_data;
42 } result_t;
43
44 /**
45 * Create a result of the error type.
46 */
47 static result_t result_error(result_error_t error);
48 /**
49 * Create a result of the success type.
50 */
51 static result_t result_data(result_data_t data);
52
53 /**
54 * Check if the result is an error or skip.
55 */
56 static int result_is_error(result_t result);
57 /**
58 * Check if the result error is skip.
59 */
60 static int result_is_skip(result_t result);
61 /**
62 * Get the result error or okay.
63 */
64 static result_error_t result_get_error(result_t result);
65 /**
66 * Get the result data. The result MUST be checked with result_is_error() first.
67 */
68 static result_data_t result_get_data(result_t result);
69
result_error(result_error_t error)70 static result_t result_error(result_error_t error) {
71 result_t result = {
72 .internal_error = error,
73 };
74 return result;
75 }
76
result_data(result_data_t data)77 static result_t result_data(result_data_t data) {
78 result_t result = {
79 .internal_error = result_error_ok,
80 .internal_data = data,
81 };
82 return result;
83 }
84
result_is_error(result_t result)85 static int result_is_error(result_t result) {
86 return result_get_error(result) != result_error_ok;
87 }
88
result_is_skip(result_t result)89 static int result_is_skip(result_t result) {
90 return result_get_error(result) == result_error_skip;
91 }
92
result_get_error(result_t result)93 static result_error_t result_get_error(result_t result) {
94 return result.internal_error;
95 }
96
97 char const* result_get_error_string(result_t result);
98
result_get_data(result_t result)99 static result_data_t result_get_data(result_t result) {
100 return result.internal_data;
101 }
102
103 #endif
104