1 /*
2 * Copyright (c) 2009-2021, Google LLC
3 * All rights reserved.
4 *
5 * Redistribution and use in source and binary forms, with or without
6 * modification, are permitted provided that the following conditions are met:
7 * * Redistributions of source code must retain the above copyright
8 * notice, this list of conditions and the following disclaimer.
9 * * Redistributions in binary form must reproduce the above copyright
10 * notice, this list of conditions and the following disclaimer in the
11 * documentation and/or other materials provided with the distribution.
12 * * Neither the name of Google LLC nor the
13 * names of its contributors may be used to endorse or promote products
14 * derived from this software without specific prior written permission.
15 *
16 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
17 * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
18 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
19 * ARE DISCLAIMED. IN NO EVENT SHALL Google LLC BE LIABLE FOR ANY DIRECT,
20 * INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
21 * (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
22 * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND
23 * ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
24 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
25 * SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
26 */
27
28 #ifndef UPB_MINI_TABLE_ENUM_INTERNAL_H_
29 #define UPB_MINI_TABLE_ENUM_INTERNAL_H_
30
31 #include "upb/mini_table/types.h"
32
33 // Must be last.
34 #include "upb/port/def.inc"
35
36 struct upb_MiniTableEnum {
37 uint32_t mask_limit; // Limit enum value that can be tested with mask.
38 uint32_t value_count; // Number of values after the bitfield.
39 uint32_t data[]; // Bitmask + enumerated values follow.
40 };
41
42 typedef enum {
43 _kUpb_FastEnumCheck_ValueIsInEnum = 0,
44 _kUpb_FastEnumCheck_ValueIsNotInEnum = 1,
45 _kUpb_FastEnumCheck_CannotCheckFast = 2,
46 } _kUpb_FastEnumCheck_Status;
47
48 #ifdef __cplusplus
49 extern "C" {
50 #endif
51
52 UPB_INLINE _kUpb_FastEnumCheck_Status
_upb_MiniTable_CheckEnumValueFast(const upb_MiniTableEnum * e,uint32_t val)53 _upb_MiniTable_CheckEnumValueFast(const upb_MiniTableEnum* e, uint32_t val) {
54 if (UPB_UNLIKELY(val >= 64)) return _kUpb_FastEnumCheck_CannotCheckFast;
55 uint64_t mask = e->data[0] | ((uint64_t)e->data[1] << 32);
56 return (mask & (1ULL << val)) ? _kUpb_FastEnumCheck_ValueIsInEnum
57 : _kUpb_FastEnumCheck_ValueIsNotInEnum;
58 }
59
_upb_MiniTable_CheckEnumValueSlow(const upb_MiniTableEnum * e,uint32_t val)60 UPB_INLINE bool _upb_MiniTable_CheckEnumValueSlow(const upb_MiniTableEnum* e,
61 uint32_t val) {
62 if (val < e->mask_limit) return e->data[val / 32] & (1ULL << (val % 32));
63 // OPT: binary search long lists?
64 const uint32_t* start = &e->data[e->mask_limit / 32];
65 const uint32_t* limit = &e->data[(e->mask_limit / 32) + e->value_count];
66 for (const uint32_t* p = start; p < limit; p++) {
67 if (*p == val) return true;
68 }
69 return false;
70 }
71
72 // Validates enum value against range defined by enum mini table.
upb_MiniTableEnum_CheckValue(const upb_MiniTableEnum * e,uint32_t val)73 UPB_INLINE bool upb_MiniTableEnum_CheckValue(const upb_MiniTableEnum* e,
74 uint32_t val) {
75 _kUpb_FastEnumCheck_Status status = _upb_MiniTable_CheckEnumValueFast(e, val);
76 if (UPB_UNLIKELY(status == _kUpb_FastEnumCheck_CannotCheckFast)) {
77 return _upb_MiniTable_CheckEnumValueSlow(e, val);
78 }
79 return status == _kUpb_FastEnumCheck_ValueIsInEnum ? true : false;
80 }
81
82 #ifdef __cplusplus
83 } /* extern "C" */
84 #endif
85
86 #include "upb/port/undef.inc"
87
88 #endif /* UPB_MINI_TABLE_ENUM_INTERNAL_H_ */
89