1// Protocol Buffers - Google's data interchange format
2// Copyright 2008 Google Inc.  All rights reserved.
3// https://developers.google.com/protocol-buffers/
4//
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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/repeated_field.h>
38#include <google/protobuf/stubs/logging.h>
39#include <google/protobuf/stubs/common.h>
40
41namespace google {
42namespace protobuf {
43
44namespace internal {
45
46void** RepeatedPtrFieldBase::InternalExtend(int extend_amount) {
47  int new_size = current_size_ + extend_amount;
48  if (total_size_ >= new_size) {
49    // N.B.: rep_ is non-NULL because extend_amount is always > 0, hence
50    // total_size must be non-zero since it is lower-bounded by new_size.
51    return &rep_->elements[current_size_];
52  }
53  Rep* old_rep = rep_;
54  Arena* arena = GetArenaNoVirtual();
55  new_size = std::max(kMinRepeatedFieldAllocationSize,
56                      std::max(total_size_ * 2, new_size));
57  GOOGLE_CHECK_LE(new_size,
58           (std::numeric_limits<size_t>::max() - kRepHeaderSize) /
59           sizeof(old_rep->elements[0]))
60      << "Requested size is too large to fit into size_t.";
61  if (arena == NULL) {
62    rep_ = reinterpret_cast<Rep*>(
63        new char[kRepHeaderSize + sizeof(old_rep->elements[0]) * new_size]);
64  } else {
65    rep_ = reinterpret_cast<Rep*>(
66        ::google::protobuf::Arena::CreateArray<char>(arena,
67            kRepHeaderSize + sizeof(old_rep->elements[0]) * new_size));
68  }
69  total_size_ = new_size;
70  if (old_rep && old_rep->allocated_size > 0) {
71    memcpy(rep_->elements, old_rep->elements,
72           old_rep->allocated_size * sizeof(rep_->elements[0]));
73    rep_->allocated_size = old_rep->allocated_size;
74  } else {
75    rep_->allocated_size = 0;
76  }
77  if (arena == NULL) {
78    delete [] reinterpret_cast<char*>(old_rep);
79  }
80  return &rep_->elements[current_size_];
81}
82
83void RepeatedPtrFieldBase::Reserve(int new_size) {
84  if (new_size > current_size_) {
85    InternalExtend(new_size - current_size_);
86  }
87}
88
89void RepeatedPtrFieldBase::CloseGap(int start, int num) {
90  if (rep_ == NULL) return;
91  // Close up a gap of "num" elements starting at offset "start".
92  for (int i = start + num; i < rep_->allocated_size; ++i)
93    rep_->elements[i - num] = rep_->elements[i];
94  current_size_ -= num;
95  rep_->allocated_size -= num;
96}
97
98}  // namespace internal
99
100
101}  // namespace protobuf
102}  // namespace google
103