1// Protocol Buffers - Google's data interchange format
2// Copyright 2008 Google Inc. All rights reserved.
3// https://developers.google.com/protocol-buffers/
4//
5// Redistribution and use in source and binary forms, with or without
6// modification, are permitted provided that the following conditions are
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8//
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10// notice, this list of conditions and the following disclaimer.
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13// in the documentation and/or other materials provided with the
14// distribution.
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16// contributors may be used to endorse or promote products derived from
17// this software without specific prior written permission.
18//
19// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
20// "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
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25// LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
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30
31// Author: kenton@google.com (Kenton Varda)
32// Based on original Protocol Buffers design by
33// Sanjay Ghemawat, Jeff Dean, and others.
34
35#include <algorithm>
36
37#include <google/protobuf/stubs/logging.h>
38#include <google/protobuf/stubs/common.h>
39#include <google/protobuf/implicit_weak_message.h>
40#include <google/protobuf/repeated_field.h>
41#include <google/protobuf/port.h>
42
43// Must be included last.
44#include <google/protobuf/port_def.inc>
45
46namespace google {
47namespace protobuf {
48
49namespace internal {
50
51void** RepeatedPtrFieldBase::InternalExtend(int extend_amount) {
52 int new_size = current_size_ + extend_amount;
53 if (total_size_ >= new_size) {
54 // N.B.: rep_ is non-nullptr because extend_amount is always > 0, hence
55 // total_size must be non-zero since it is lower-bounded by new_size.
56 return &rep_->elements[current_size_];
57 }
58 Rep* old_rep = rep_;
59 Arena* arena = GetOwningArena();
60 new_size = internal::CalculateReserveSize<void*, kRepHeaderSize>(total_size: total_size_,
61 new_size);
62 GOOGLE_CHECK_LE(static_cast<int64_t>(new_size),
63 static_cast<int64_t>(
64 (std::numeric_limits<size_t>::max() - kRepHeaderSize) /
65 sizeof(old_rep->elements[0])))
66 << "Requested size is too large to fit into size_t.";
67 size_t bytes = kRepHeaderSize + sizeof(old_rep->elements[0]) * new_size;
68 if (arena == nullptr) {
69 rep_ = reinterpret_cast<Rep*>(::operator new(bytes));
70 } else {
71 rep_ = reinterpret_cast<Rep*>(Arena::CreateArray<char>(arena, num_elements: bytes));
72 }
73 const int old_total_size = total_size_;
74 total_size_ = new_size;
75 if (old_rep) {
76 if (old_rep->allocated_size > 0) {
77 memcpy(dest: rep_->elements, src: old_rep->elements,
78 n: old_rep->allocated_size * sizeof(rep_->elements[0]));
79 }
80 rep_->allocated_size = old_rep->allocated_size;
81
82 const size_t old_size =
83 old_total_size * sizeof(rep_->elements[0]) + kRepHeaderSize;
84 if (arena == nullptr) {
85 internal::SizedDelete(p: old_rep, size: old_size);
86 } else {
87 arena_->ReturnArrayMemory(p: old_rep, size: old_size);
88 }
89 } else {
90 rep_->allocated_size = 0;
91 }
92 return &rep_->elements[current_size_];
93}
94
95void RepeatedPtrFieldBase::Reserve(int new_size) {
96 if (new_size > current_size_) {
97 InternalExtend(extend_amount: new_size - current_size_);
98 }
99}
100
101void RepeatedPtrFieldBase::DestroyProtos() {
102 GOOGLE_DCHECK(rep_);
103 GOOGLE_DCHECK(arena_ == nullptr);
104 int n = rep_->allocated_size;
105 void* const* elements = rep_->elements;
106 for (int i = 0; i < n; i++) {
107 delete static_cast<MessageLite*>(elements[i]);
108 }
109 const size_t size = total_size_ * sizeof(elements[0]) + kRepHeaderSize;
110 internal::SizedDelete(p: rep_, size);
111 rep_ = nullptr;
112}
113
114void* RepeatedPtrFieldBase::AddOutOfLineHelper(void* obj) {
115 if (!rep_ || rep_->allocated_size == total_size_) {
116 InternalExtend(extend_amount: 1); // Equivalent to "Reserve(total_size_ + 1)"
117 }
118 ++rep_->allocated_size;
119 rep_->elements[current_size_++] = obj;
120 return obj;
121}
122
123void RepeatedPtrFieldBase::CloseGap(int start, int num) {
124 if (rep_ == nullptr) return;
125 // Close up a gap of "num" elements starting at offset "start".
126 for (int i = start + num; i < rep_->allocated_size; ++i)
127 rep_->elements[i - num] = rep_->elements[i];
128 current_size_ -= num;
129 rep_->allocated_size -= num;
130}
131
132MessageLite* RepeatedPtrFieldBase::AddWeak(const MessageLite* prototype) {
133 if (rep_ != nullptr && current_size_ < rep_->allocated_size) {
134 return reinterpret_cast<MessageLite*>(rep_->elements[current_size_++]);
135 }
136 if (!rep_ || rep_->allocated_size == total_size_) {
137 Reserve(new_size: total_size_ + 1);
138 }
139 ++rep_->allocated_size;
140 MessageLite* result = prototype
141 ? prototype->New(arena: arena_)
142 : Arena::CreateMessage<ImplicitWeakMessage>(arena: arena_);
143 rep_->elements[current_size_++] = result;
144 return result;
145}
146
147} // namespace internal
148
149} // namespace protobuf
150} // namespace google
151
152#include <google/protobuf/port_undef.inc>
153