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
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
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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 #include "upb/wire/reader.h"
29 
30 #include "upb/wire/eps_copy_input_stream.h"
31 #include "upb/wire/types.h"
32 
33 // Must be last.
34 #include "upb/port/def.inc"
35 
36 UPB_NOINLINE _upb_WireReader_ReadLongVarintRet
_upb_WireReader_ReadLongVarint(const char * ptr,uint64_t val)37 _upb_WireReader_ReadLongVarint(const char* ptr, uint64_t val) {
38   _upb_WireReader_ReadLongVarintRet ret = {NULL, 0};
39   uint64_t byte;
40   int i;
41   for (i = 1; i < 10; i++) {
42     byte = (uint8_t)ptr[i];
43     val += (byte - 1) << (i * 7);
44     if (!(byte & 0x80)) {
45       ret.ptr = ptr + i + 1;
46       ret.val = val;
47       return ret;
48     }
49   }
50   return ret;
51 }
52 
_upb_WireReader_SkipGroup(const char * ptr,uint32_t tag,int depth_limit,upb_EpsCopyInputStream * stream)53 const char* _upb_WireReader_SkipGroup(const char* ptr, uint32_t tag,
54                                       int depth_limit,
55                                       upb_EpsCopyInputStream* stream) {
56   if (--depth_limit == 0) return NULL;
57   uint32_t end_group_tag = (tag & ~7ULL) | kUpb_WireType_EndGroup;
58   while (!upb_EpsCopyInputStream_IsDone(stream, &ptr)) {
59     uint32_t tag;
60     ptr = upb_WireReader_ReadTag(ptr, &tag);
61     if (!ptr) return NULL;
62     if (tag == end_group_tag) return ptr;
63     ptr = _upb_WireReader_SkipValue(ptr, tag, depth_limit, stream);
64     if (!ptr) return NULL;
65   }
66   return ptr;
67 }
68