1    :  // Copyright 2011 Google Inc. All Rights Reserved.
   2    :  //
   3    :  // Licensed under the Apache License, Version 2.0 (the "License");
   4    :  // you may not use this file except in compliance with the License.
   5    :  // You may obtain a copy of the License at
   6    :  //
   7    :  //     http://www.apache.org/licenses/LICENSE-2.0
   8    :  //
   9    :  // Unless required by applicable law or agreed to in writing, software
  10    :  // distributed under the License is distributed on an "AS IS" BASIS,
  11    :  // WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
  12    :  // See the License for the specific language governing permissions and
  13    :  // limitations under the License.
  14    :  //
  15    :  // Internal implementation details for msf_stream.h. Not meant to be included
  16    :  // directly.
  17    :  
  18    :  #ifndef SYZYGY_MSF_MSF_STREAM_IMPL_H_
  19    :  #define SYZYGY_MSF_MSF_STREAM_IMPL_H_
  20    :  
  21    :  #include <vector>
  22    :  
  23    :  #include "base/logging.h"
  24    :  #include "syzygy/msf/msf_decl.h"
  25    :  
  26    :  namespace msf {
  27    :  namespace detail {
  28    :  
  29    :  namespace {
  30    :  
  31    :  const size_t kInvalidLength = 0xFFFFFFFF;
  32    :  
  33    :  }  // namespace
  34    :  
  35    :  template <MsfFileType T>
  36    :  template <typename ItemType>
  37  E :  bool MsfStreamImpl<T>::Read(ItemType* dest, size_t count, size_t* items_read) {
  38  E :    DCHECK(dest != NULL);
  39  E :    DCHECK(items_read != NULL);
  40    :  
  41  E :    size_t requested_bytes = sizeof(ItemType) * count;
  42  E :    if (requested_bytes == 0) {
  43  i :      *items_read = count;
  44  i :      return true;
  45    :    }
  46    :  
  47  E :    size_t seviceable_bytes = requested_bytes;
  48  E :    if (requested_bytes > bytes_left()) {
  49  E :      seviceable_bytes = bytes_left() - bytes_left() % sizeof(ItemType);
  50    :    }
  51  E :    if (seviceable_bytes == 0) {
  52  E :      *items_read = 0;
  53  E :      return false;
  54    :    }
  55    :  
  56  E :    size_t bytes_read = 0;
  57  E :    bool result = ReadBytes(dest, seviceable_bytes, &bytes_read);
  58  E :    *items_read = bytes_read / sizeof(ItemType);
  59  E :    return result && *items_read == count;
  60  E :  }
  61    :  
  62    :  template <MsfFileType T>
  63    :  template <typename ItemType>
  64  E :  bool MsfStreamImpl<T>::Read(ItemType* dest, size_t count) {
  65  E :    DCHECK(dest != NULL);
  66  E :    size_t items_read = 0;
  67  E :    return Read(dest, count, &items_read) && items_read == count;
  68  E :  }
  69    :  
  70    :  template <MsfFileType T>
  71    :  template <typename ItemType>
  72  E :  bool MsfStreamImpl<T>::Read(std::vector<ItemType>* dest, size_t count) {
  73  E :    DCHECK(dest != NULL);
  74  E :    dest->clear();
  75  E :    if (sizeof(ItemType) * count > bytes_left())
  76  E :      return false;
  77  E :    dest->resize(count);
  78    :  
  79  E :    if (count == 0)
  80  E :      return true;
  81    :  
  82  E :    size_t items_read = 0;
  83  E :    bool result = Read(&dest->at(0), count, &items_read);
  84  E :    dest->resize(items_read);
  85  E :    return result;
  86  E :  }
  87    :  
  88    :  template <MsfFileType T>
  89    :  template <typename ItemType>
  90  E :  bool MsfStreamImpl<T>::Read(std::vector<ItemType>* dest) {
  91  E :    DCHECK(dest != NULL);
  92  E :    dest->clear();
  93  E :    if ((bytes_left() % sizeof(ItemType)) != 0)
  94  E :      return false;
  95  E :    return Read(dest, bytes_left() / sizeof(ItemType));
  96  E :  }
  97    :  
  98    :  template <MsfFileType T>
  99    :  MsfStreamImpl<T>::MsfStreamImpl(size_t length)
 100  E :      : length_(length == kInvalidLength ? 0 : length), pos_(0) {
 101  E :  }
 102    :  
 103    :  template <MsfFileType T>
 104  E :  MsfStreamImpl<T>::~MsfStreamImpl() {
 105  E :  }
 106    :  
 107    :  template <MsfFileType T>
 108  E :  bool MsfStreamImpl<T>::Seek(size_t pos) {
 109  E :    if (pos > length_)
 110  E :      return false;
 111    :  
 112  E :    pos_ = pos;
 113  E :    return true;
 114  E :  }
 115    :  
 116    :  }  // namespace detail
 117    :  }  // namespace msf
 118    :  
 119    :  #endif  // SYZYGY_MSF_MSF_STREAM_IMPL_H_