net/der/input.cc

   1 // Copyright 2015 The Chromium Authors. All rights reserved.
   2 // Use of this source code is governed by a BSD-style license that can be
   3 // found in the LICENSE file.
   4
   5 #include <string.h>
   6
   7 #include "base/logging.h"
   8 #include "net/der/input.h"
   9
  10 namespace net {
  11
  12 namespace der {
  13
  14 Input::Input() : data_(nullptr), len_(0) {
  15 }
  16
  17 Input::Input(const uint8_t* data, size_t len) : data_(data), len_(len) {
  18 }
  19
  20 bool Input::Equals(const Input& other) const {
  21   if (len_ != other.len_)
  22     return false;
  23   return memcmp(data_, other.data_, len_) == 0;
  24 }
  25
  26 ByteReader::ByteReader(const Input& in)
  27     : data_(in.UnsafeData()), len_(in.Length()) {
  28 }
  29
  30 bool ByteReader::ReadByte(uint8_t* byte_p) {
  31   if (!HasMore())
  32     return false;
  33   *byte_p = *data_;
  34   Advance(1);
  35   return true;
  36 }
  37
  38 bool ByteReader::ReadBytes(size_t len, Input* out) {
  39   if (len > len_)
  40     return false;
  41   *out = Input(data_, len);
  42   Advance(len);
  43   return true;
  44 }
  45
  46 // Returns whether there is any more data to be read.
  47 bool ByteReader::HasMore() {
  48   return len_ > 0;
  49 }
  50
  51 Mark ByteReader::NewMark() {
  52   return Mark(data_);
  53 }
  54
  55 bool ByteReader::AdvanceToMark(Mark mark) {
  56   if (mark.ptr_ < data_)
  57     return false;
  58   // mark.ptr_ >= data_, so no concern of integer underflow here.
  59   size_t advance_len = mark.ptr_ - data_;
  60   if (advance_len > len_)
  61     return false;
  62   Advance(advance_len);
  63   return true;
  64 }
  65
  66 bool ByteReader::ReadToMark(Mark mark, Input* out) {
  67   if (mark.ptr_ < data_)
  68     return false;
  69   // mark.ptr_ >= data_, so no concern of integer underflow here.
  70   size_t len = mark.ptr_ - data_;
  71   return ReadBytes(len, out);
  72 }
  73
  74 void ByteReader::Advance(size_t len) {
  75   CHECK_LE(len, len_);
  76   data_ += len;
  77   len_ -= len;
  78 }
  79
  80 Mark Mark::NullMark() {
  81   return Mark();
  82 }
  83
  84 bool Mark::IsEmpty() {
  85   return ptr_ == nullptr;
  86 }
  87
  88 Mark::Mark(const uint8_t* ptr) : ptr_(ptr) {
  89 }
  90
  91 Mark::Mark() : ptr_(nullptr) {
  92 }
  93
  94 }  // namespace der
  95
  96 }  // namespace net