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:
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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
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20  * INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
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23  * ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
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25  * SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
26  */
27 
28 #include "upb/mini_table/extension_registry.h"
29 
30 #include "upb/hash/str_table.h"
31 #include "upb/mini_table/extension_internal.h"
32 
33 // Must be last.
34 #include "upb/port/def.inc"
35 
36 #define EXTREG_KEY_SIZE (sizeof(upb_MiniTable*) + sizeof(uint32_t))
37 
38 struct upb_ExtensionRegistry {
39   upb_Arena* arena;
40   upb_strtable exts;  // Key is upb_MiniTable* concatenated with fieldnum.
41 };
42 
extreg_key(char * buf,const upb_MiniTable * l,uint32_t fieldnum)43 static void extreg_key(char* buf, const upb_MiniTable* l, uint32_t fieldnum) {
44   memcpy(buf, &l, sizeof(l));
45   memcpy(buf + sizeof(l), &fieldnum, sizeof(fieldnum));
46 }
47 
upb_ExtensionRegistry_New(upb_Arena * arena)48 upb_ExtensionRegistry* upb_ExtensionRegistry_New(upb_Arena* arena) {
49   upb_ExtensionRegistry* r = upb_Arena_Malloc(arena, sizeof(*r));
50   if (!r) return NULL;
51   r->arena = arena;
52   if (!upb_strtable_init(&r->exts, 8, arena)) return NULL;
53   return r;
54 }
55 
upb_ExtensionRegistry_Add(upb_ExtensionRegistry * r,const upb_MiniTableExtension * e)56 UPB_API bool upb_ExtensionRegistry_Add(upb_ExtensionRegistry* r,
57                                        const upb_MiniTableExtension* e) {
58   char buf[EXTREG_KEY_SIZE];
59   extreg_key(buf, e->extendee, e->field.number);
60   if (upb_strtable_lookup2(&r->exts, buf, EXTREG_KEY_SIZE, NULL)) return false;
61   return upb_strtable_insert(&r->exts, buf, EXTREG_KEY_SIZE,
62                              upb_value_constptr(e), r->arena);
63 }
64 
upb_ExtensionRegistry_AddArray(upb_ExtensionRegistry * r,const upb_MiniTableExtension ** e,size_t count)65 bool upb_ExtensionRegistry_AddArray(upb_ExtensionRegistry* r,
66                                     const upb_MiniTableExtension** e,
67                                     size_t count) {
68   const upb_MiniTableExtension** start = e;
69   const upb_MiniTableExtension** end = UPB_PTRADD(e, count);
70   for (; e < end; e++) {
71     if (!upb_ExtensionRegistry_Add(r, *e)) goto failure;
72   }
73   return true;
74 
75 failure:
76   // Back out the entries previously added.
77   for (end = e, e = start; e < end; e++) {
78     const upb_MiniTableExtension* ext = *e;
79     char buf[EXTREG_KEY_SIZE];
80     extreg_key(buf, ext->extendee, ext->field.number);
81     upb_strtable_remove2(&r->exts, buf, EXTREG_KEY_SIZE, NULL);
82   }
83   return false;
84 }
85 
upb_ExtensionRegistry_Lookup(const upb_ExtensionRegistry * r,const upb_MiniTable * t,uint32_t num)86 const upb_MiniTableExtension* upb_ExtensionRegistry_Lookup(
87     const upb_ExtensionRegistry* r, const upb_MiniTable* t, uint32_t num) {
88   char buf[EXTREG_KEY_SIZE];
89   upb_value v;
90   extreg_key(buf, t, num);
91   if (upb_strtable_lookup2(&r->exts, buf, EXTREG_KEY_SIZE, &v)) {
92     return upb_value_getconstptr(v);
93   } else {
94     return NULL;
95   }
96 }
97