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 std::string Input::AsString() const {
  27   return std::string(reinterpret_cast<const char*>(data_), len_);
  28 }
  29
  30 ByteReader::ByteReader(const Input& in)
  31     : data_(in.UnsafeData()), len_(in.Length()) {
  32 }
  33
  34 bool ByteReader::ReadByte(uint8_t* byte_p) {
  35   if (!HasMore())
  36     return false;
  37   *byte_p = *data_;
  38   Advance(1);
  39   return true;
  40 }
  41
  42 bool ByteReader::ReadBytes(size_t len, Input* out) {
  43   if (len > len_)
  44     return false;
  45   *out = Input(data_, len);
  46   Advance(len);
  47   return true;
  48 }
  49
  50 // Returns whether there is any more data to be read.
  51 bool ByteReader::HasMore() {
  52   return len_ > 0;
  53 }
  54
  55 Mark ByteReader::NewMark() {
  56   return Mark(data_);
  57 }
  58
  59 bool ByteReader::AdvanceToMark(Mark mark) {
  60   if (mark.ptr_ < data_)
  61     return false;
  62   // mark.ptr_ >= data_, so no concern of integer underflow here.
  63   size_t advance_len = mark.ptr_ - data_;
  64   if (advance_len > len_)
  65     return false;
  66   Advance(advance_len);
  67   return true;
  68 }
  69
  70 bool ByteReader::ReadToMark(Mark mark, Input* out) {
  71   if (mark.ptr_ < data_)
  72     return false;
  73   // mark.ptr_ >= data_, so no concern of integer underflow here.
  74   size_t len = mark.ptr_ - data_;
  75   return ReadBytes(len, out);
  76 }
  77
  78 void ByteReader::Advance(size_t len) {
  79   CHECK_LE(len, len_);
  80   data_ += len;
  81   len_ -= len;
  82 }
  83
  84 Mark Mark::NullMark() {
  85   return Mark();
  86 }
  87
  88 bool Mark::IsEmpty() {
  89   return ptr_ == nullptr;
  90 }
  91
  92 Mark::Mark(const uint8_t* ptr) : ptr_(ptr) {
  93 }
  94
  95 Mark::Mark() : ptr_(nullptr) {
  96 }
  97
  98 }  // namespace der
  99
 100 }  // namespace net