dbus/values_util.cc

   1 // Copyright (c) 2012 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 "dbus/values_util.h"
   6
   7 #include "base/json/json_writer.h"
   8 #include "base/logging.h"
   9 #include "base/memory/scoped_ptr.h"
  10 #include "base/values.h"
  11 #include "dbus/message.h"
  12
  13 namespace dbus {
  14
  15 namespace {
  16
  17 // Returns whether |value| is exactly representable by double or not.
  18 template<typename T>
  19 bool IsExactlyRepresentableByDouble(T value) {
  20   return value == static_cast<T>(static_cast<double>(value));
  21 }
  22
  23 // Pops values from |reader| and appends them to |list_value|.
  24 bool PopListElements(MessageReader* reader, base::ListValue* list_value) {
  25   while (reader->HasMoreData()) {
  26     base::Value* element_value = PopDataAsValue(reader);
  27     if (!element_value)
  28       return false;
  29     list_value->Append(element_value);
  30   }
  31   return true;
  32 }
  33
  34 // Pops dict-entries from |reader| and sets them to |dictionary_value|
  35 bool PopDictionaryEntries(MessageReader* reader,
  36                           base::DictionaryValue* dictionary_value) {
  37   while (reader->HasMoreData()) {
  38     DCHECK_EQ(Message::DICT_ENTRY, reader->GetDataType());
  39     MessageReader entry_reader(NULL);
  40     if (!reader->PopDictEntry(&entry_reader))
  41       return false;
  42     // Get key as a string.
  43     std::string key_string;
  44     if (entry_reader.GetDataType() == Message::STRING) {
  45       // If the type of keys is STRING, pop it directly.
  46       if (!entry_reader.PopString(&key_string))
  47         return false;
  48     } else {
  49       // If the type of keys is not STRING, convert it to string.
  50       scoped_ptr<base::Value> key(PopDataAsValue(&entry_reader));
  51       if (!key)
  52         return false;
  53       // Use JSONWriter to convert an arbitrary value to a string.
  54       base::JSONWriter::Write(*key, &key_string);
  55     }
  56     // Get the value and set the key-value pair.
  57     base::Value* value = PopDataAsValue(&entry_reader);
  58     if (!value)
  59       return false;
  60     dictionary_value->SetWithoutPathExpansion(key_string, value);
  61   }
  62   return true;
  63 }
  64
  65 // Gets the D-Bus type signature for the value.
  66 std::string GetTypeSignature(const base::Value& value) {
  67   switch (value.GetType()) {
  68     case base::Value::TYPE_BOOLEAN:
  69       return "b";
  70     case base::Value::TYPE_INTEGER:
  71       return "i";
  72     case base::Value::TYPE_DOUBLE:
  73       return "d";
  74     case base::Value::TYPE_STRING:
  75       return "s";
  76     case base::Value::TYPE_BINARY:
  77       return "ay";
  78     case base::Value::TYPE_DICTIONARY:
  79       return "a{sv}";
  80     case base::Value::TYPE_LIST:
  81       return "av";
  82     default:
  83       DLOG(ERROR) << "Unexpected type " << value.GetType();
  84       return std::string();
  85   }
  86 }
  87
  88 }  // namespace
  89
  90 base::Value* PopDataAsValue(MessageReader* reader) {
  91   base::Value* result = NULL;
  92   switch (reader->GetDataType()) {
  93     case Message::INVALID_DATA:
  94       // Do nothing.
  95       break;
  96     case Message::BYTE: {
  97       uint8 value = 0;
  98       if (reader->PopByte(&value))
  99         result = new base::FundamentalValue(value);
 100       break;
 101     }
 102     case Message::BOOL: {
 103       bool value = false;
 104       if (reader->PopBool(&value))
 105         result = new base::FundamentalValue(value);
 106       break;
 107     }
 108     case Message::INT16: {
 109       int16 value = 0;
 110       if (reader->PopInt16(&value))
 111         result = new base::FundamentalValue(value);
 112       break;
 113     }
 114     case Message::UINT16: {
 115       uint16 value = 0;
 116       if (reader->PopUint16(&value))
 117         result = new base::FundamentalValue(value);
 118       break;
 119     }
 120     case Message::INT32: {
 121       int32 value = 0;
 122       if (reader->PopInt32(&value))
 123         result = new base::FundamentalValue(value);
 124       break;
 125     }
 126     case Message::UINT32: {
 127       uint32 value = 0;
 128       if (reader->PopUint32(&value))
 129         result = new base::FundamentalValue(static_cast<double>(value));
 130       break;
 131     }
 132     case Message::INT64: {
 133       int64 value = 0;
 134       if (reader->PopInt64(&value)) {
 135         DLOG_IF(WARNING, !IsExactlyRepresentableByDouble(value)) <<
 136             value << " is not exactly representable by double";
 137         result = new base::FundamentalValue(static_cast<double>(value));
 138       }
 139       break;
 140     }
 141     case Message::UINT64: {
 142       uint64 value = 0;
 143       if (reader->PopUint64(&value)) {
 144         DLOG_IF(WARNING, !IsExactlyRepresentableByDouble(value)) <<
 145             value << " is not exactly representable by double";
 146         result = new base::FundamentalValue(static_cast<double>(value));
 147       }
 148       break;
 149     }
 150     case Message::DOUBLE: {
 151       double value = 0;
 152       if (reader->PopDouble(&value))
 153         result = new base::FundamentalValue(value);
 154       break;
 155     }
 156     case Message::STRING: {
 157       std::string value;
 158       if (reader->PopString(&value))
 159         result = new base::StringValue(value);
 160       break;
 161     }
 162     case Message::OBJECT_PATH: {
 163       ObjectPath value;
 164       if (reader->PopObjectPath(&value))
 165         result = new base::StringValue(value.value());
 166       break;
 167     }
 168     case Message::UNIX_FD: {
 169       // Cannot distinguish a file descriptor from an int
 170       NOTREACHED();
 171       break;
 172     }
 173     case Message::ARRAY: {
 174       MessageReader sub_reader(NULL);
 175       if (reader->PopArray(&sub_reader)) {
 176         // If the type of the array's element is DICT_ENTRY, create a
 177         // DictionaryValue, otherwise create a ListValue.
 178         if (sub_reader.GetDataType() == Message::DICT_ENTRY) {
 179           scoped_ptr<base::DictionaryValue> dictionary_value(
 180               new base::DictionaryValue);
 181           if (PopDictionaryEntries(&sub_reader, dictionary_value.get()))
 182             result = dictionary_value.release();
 183         } else {
 184           scoped_ptr<base::ListValue> list_value(new base::ListValue);
 185           if (PopListElements(&sub_reader, list_value.get()))
 186             result = list_value.release();
 187         }
 188       }
 189       break;
 190     }
 191     case Message::STRUCT: {
 192       MessageReader sub_reader(NULL);
 193       if (reader->PopStruct(&sub_reader)) {
 194         scoped_ptr<base::ListValue> list_value(new base::ListValue);
 195         if (PopListElements(&sub_reader, list_value.get()))
 196           result = list_value.release();
 197       }
 198       break;
 199     }
 200     case Message::DICT_ENTRY:
 201       // DICT_ENTRY must be popped as an element of an array.
 202       NOTREACHED();
 203       break;
 204     case Message::VARIANT: {
 205       MessageReader sub_reader(NULL);
 206       if (reader->PopVariant(&sub_reader))
 207         result = PopDataAsValue(&sub_reader);
 208       break;
 209     }
 210   }
 211   return result;
 212 }
 213
 214 void AppendBasicTypeValueData(MessageWriter* writer, const base::Value& value) {
 215   switch (value.GetType()) {
 216     case base::Value::TYPE_BOOLEAN: {
 217       bool bool_value = false;
 218       bool success = value.GetAsBoolean(&bool_value);
 219       DCHECK(success);
 220       writer->AppendBool(bool_value);
 221       break;
 222     }
 223     case base::Value::TYPE_INTEGER: {
 224       int int_value = 0;
 225       bool success = value.GetAsInteger(&int_value);
 226       DCHECK(success);
 227       writer->AppendInt32(int_value);
 228       break;
 229     }
 230     case base::Value::TYPE_DOUBLE: {
 231       double double_value = 0;
 232       bool success = value.GetAsDouble(&double_value);
 233       DCHECK(success);
 234       writer->AppendDouble(double_value);
 235       break;
 236     }
 237     case base::Value::TYPE_STRING: {
 238       std::string string_value;
 239       bool success = value.GetAsString(&string_value);
 240       DCHECK(success);
 241       writer->AppendString(string_value);
 242       break;
 243     }
 244     default:
 245       DLOG(ERROR) << "Unexpected type " << value.GetType();
 246       break;
 247   }
 248 }
 249
 250 void AppendBasicTypeValueDataAsVariant(MessageWriter* writer,
 251                                        const base::Value& value) {
 252   MessageWriter sub_writer(NULL);
 253   writer->OpenVariant(GetTypeSignature(value), &sub_writer);
 254   AppendBasicTypeValueData(&sub_writer, value);
 255   writer->CloseContainer(&sub_writer);
 256 }
 257
 258 void AppendValueData(MessageWriter* writer, const base::Value& value) {
 259   switch (value.GetType()) {
 260     case base::Value::TYPE_DICTIONARY: {
 261       const base::DictionaryValue* dictionary = NULL;
 262       value.GetAsDictionary(&dictionary);
 263       dbus::MessageWriter array_writer(NULL);
 264       writer->OpenArray("{sv}", &array_writer);
 265       for (base::DictionaryValue::Iterator iter(*dictionary);
 266            !iter.IsAtEnd(); iter.Advance()) {
 267         dbus::MessageWriter dict_entry_writer(NULL);
 268         array_writer.OpenDictEntry(&dict_entry_writer);
 269         dict_entry_writer.AppendString(iter.key());
 270         AppendValueDataAsVariant(&dict_entry_writer, iter.value());
 271         array_writer.CloseContainer(&dict_entry_writer);
 272       }
 273       writer->CloseContainer(&array_writer);
 274       break;
 275     }
 276     case base::Value::TYPE_LIST: {
 277       const base::ListValue* list = NULL;
 278       value.GetAsList(&list);
 279       dbus::MessageWriter array_writer(NULL);
 280       writer->OpenArray("v", &array_writer);
 281       for (base::ListValue::const_iterator iter = list->begin();
 282            iter != list->end(); ++iter) {
 283         const base::Value* value = *iter;
 284         AppendValueDataAsVariant(&array_writer, *value);
 285       }
 286       writer->CloseContainer(&array_writer);
 287       break;
 288     }
 289     case base::Value::TYPE_BOOLEAN:
 290     case base::Value::TYPE_INTEGER:
 291     case base::Value::TYPE_DOUBLE:
 292     case base::Value::TYPE_STRING:
 293       AppendBasicTypeValueData(writer, value);
 294       break;
 295     default:
 296       DLOG(ERROR) << "Unexpected type: " << value.GetType();
 297   }
 298 }
 299
 300 void AppendValueDataAsVariant(MessageWriter* writer, const base::Value& value) {
 301   MessageWriter variant_writer(NULL);
 302   writer->OpenVariant(GetTypeSignature(value), &variant_writer);
 303   AppendValueData(&variant_writer, value);
 304   writer->CloseContainer(&variant_writer);
 305 }
 306
 307 }  // namespace dbus