Qpid Proton C++  0.17.0
decoder.hpp
1 #ifndef PROTON_CODEC_DECODER_HPP
2 #define PROTON_CODEC_DECODER_HPP
3 
4 /*
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14  * http://www.apache.org/licenses/LICENSE-2.0
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19  * KIND, either express or implied. See the License for the
20  * specific language governing permissions and limitations
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23  */
24 
25 #include "../internal/data.hpp"
26 #include "../internal/type_traits.hpp"
27 #include "../types_fwd.hpp"
28 #include "./common.hpp"
29 
30 #include <proton/type_compat.h>
31 
32 #include <utility>
33 
34 namespace proton {
35 
36 class annotation_key;
37 class message_id;
38 class scalar;
39 class value;
40 
41 namespace internal {
42 class value_base;
43 }
44 
45 namespace codec {
46 
53 class decoder : public internal::data {
54  public:
58  explicit decoder(const data& d, bool exact=false) : data(d), exact_(exact) {}
59 
62  PN_CPP_EXTERN explicit decoder(const internal::value_base&, bool exact=false);
63 
66  PN_CPP_EXTERN void decode(const char* buffer, size_t size);
67 
70  PN_CPP_EXTERN void decode(const std::string&);
71 
73  PN_CPP_EXTERN bool more();
74 
80  PN_CPP_EXTERN type_id next_type();
81 
88  PN_CPP_EXTERN decoder& operator>>(bool&);
89  PN_CPP_EXTERN decoder& operator>>(uint8_t&);
90  PN_CPP_EXTERN decoder& operator>>(int8_t&);
91  PN_CPP_EXTERN decoder& operator>>(uint16_t&);
92  PN_CPP_EXTERN decoder& operator>>(int16_t&);
93  PN_CPP_EXTERN decoder& operator>>(uint32_t&);
94  PN_CPP_EXTERN decoder& operator>>(int32_t&);
95  PN_CPP_EXTERN decoder& operator>>(wchar_t&);
96  PN_CPP_EXTERN decoder& operator>>(uint64_t&);
97  PN_CPP_EXTERN decoder& operator>>(int64_t&);
98  PN_CPP_EXTERN decoder& operator>>(timestamp&);
99  PN_CPP_EXTERN decoder& operator>>(float&);
100  PN_CPP_EXTERN decoder& operator>>(double&);
101  PN_CPP_EXTERN decoder& operator>>(decimal32&);
102  PN_CPP_EXTERN decoder& operator>>(decimal64&);
103  PN_CPP_EXTERN decoder& operator>>(decimal128&);
104  PN_CPP_EXTERN decoder& operator>>(uuid&);
105  PN_CPP_EXTERN decoder& operator>>(std::string&);
106  PN_CPP_EXTERN decoder& operator>>(symbol&);
107  PN_CPP_EXTERN decoder& operator>>(binary&);
108  PN_CPP_EXTERN decoder& operator>>(message_id&);
109  PN_CPP_EXTERN decoder& operator>>(annotation_key&);
110  PN_CPP_EXTERN decoder& operator>>(scalar&);
111  PN_CPP_EXTERN decoder& operator>>(internal::value_base&);
112  PN_CPP_EXTERN decoder& operator>>(null&);
114 
119  PN_CPP_EXTERN decoder& operator>>(start&);
120 
123  PN_CPP_EXTERN decoder& operator>>(const finish&);
124 
126  template <class T> struct sequence_ref { T& ref; sequence_ref(T& r) : ref(r) {} };
127  template <class T> struct associative_ref { T& ref; associative_ref(T& r) : ref(r) {} };
128  template <class T> struct pair_sequence_ref { T& ref; pair_sequence_ref(T& r) : ref(r) {} };
129 
130  template <class T> static sequence_ref<T> sequence(T& x) { return sequence_ref<T>(x); }
131  template <class T> static associative_ref<T> associative(T& x) { return associative_ref<T>(x); }
132  template <class T> static pair_sequence_ref<T> pair_sequence(T& x) { return pair_sequence_ref<T>(x); }
134 
138  template <class T> decoder& operator>>(sequence_ref<T> r) {
139  start s;
140  *this >> s;
141  if (s.is_described) next();
142  r.ref.resize(s.size);
143  for (typename T::iterator i = r.ref.begin(); i != r.ref.end(); ++i)
144  *this >> *i;
145  return *this;
146  }
147 
149  template <class T> decoder& operator>>(associative_ref<T> r) {
150  using namespace internal;
151  start s;
152  *this >> s;
153  assert_type_equal(MAP, s.type);
154  r.ref.clear();
155  for (size_t i = 0; i < s.size/2; ++i) {
156  typename remove_const<typename T::key_type>::type k;
157  typename remove_const<typename T::mapped_type>::type v;
158  *this >> k >> v;
159  r.ref[k] = v;
160  }
161  return *this;
162  }
163 
166  template <class T> decoder& operator>>(pair_sequence_ref<T> r) {
167  using namespace internal;
168  start s;
169  *this >> s;
170  assert_type_equal(MAP, s.type);
171  r.ref.clear();
172  for (size_t i = 0; i < s.size/2; ++i) {
173  typedef typename T::value_type value_type;
174  typename remove_const<typename value_type::first_type>::type k;
175  typename remove_const<typename value_type::second_type>::type v;
176  *this >> k >> v;
177  r.ref.push_back(value_type(k, v));
178  }
179  return *this;
180  }
181 
182  private:
183  type_id pre_get();
184  template <class T, class U> decoder& extract(T& x, U (*get)(pn_data_t*));
185  bool exact_;
186 
187  friend class message;
188 };
189 
192 template<class T> T get(decoder& d) {
193  assert_type_equal(internal::type_id_of<T>::value, d.next_type());
194  T x;
195  d >> x;
196  return x;
197 }
199 
202 template <class T> typename internal::enable_if<internal::is_unknown_integer<T>::value, decoder&>::type
203 operator>>(decoder& d, T& i) {
204  using namespace internal;
205  typename integer_type<sizeof(T), is_signed<T>::value>::type v;
206  d >> v; // Extract as a known integer type
207  i = v; // C++ conversion to the target type.
208  return d;
209 }
210 
211 } // codec
212 } // proton
213 
214 #endif // PROTON_CODEC_DECODER_HPP
A holder for an instance of any scalar AMQP type.
Definition: scalar.hpp:32
An AMQP message.
Definition: message.hpp:47
Experimental - Start encoding a complex type.
Definition: common.hpp:31
A key for use with AMQP annotation maps.
Definition: annotation_key.hpp:35
A sequence of key-value pairs.
Definition: type_id.hpp:63
A 16-byte universally unique identifier.
Definition: uuid.hpp:34
decoder & operator>>(sequence_ref< T > r)
Extract any AMQP sequence (ARRAY, LIST or MAP) to a C++ sequence container of T if the elements types...
Definition: decoder.hpp:138
decoder & operator>>(associative_ref< T > r)
Extract an AMQP MAP to a C++ associative container.
Definition: decoder.hpp:149
64-bit decimal floating point.
Definition: decimal.hpp:49
A std::string that represents the AMQP symbol type.
Definition: symbol.hpp:32
Arbitrary binary data.
Definition: binary.hpp:37
128-bit decimal floating point.
Definition: decimal.hpp:52
type_id
An identifier for AMQP types.
Definition: type_id.hpp:38
32-bit decimal floating point.
Definition: decimal.hpp:46
A 64-bit timestamp in milliseconds since the Unix epoch.
Definition: timestamp.hpp:32
decoder & operator>>(pair_sequence_ref< T > r)
Extract an AMQP MAP to a C++ push_back sequence of pairs preserving encoded order.
Definition: decoder.hpp:166
void assert_type_equal(type_id want, type_id got)
Throw a conversion_error if want != got with a message including the names of the types...
internal::enable_if< internal::is_unknown_integer< T >::value, decoder & >::type operator>>(decoder &d, T &i)
operator>> for integer types that are not covered by the standard overrides.
Definition: decoder.hpp:203
Experimental - Finish inserting or extracting a complex type.
Definition: common.hpp:54
decoder(const data &d, bool exact=false)
Wrap a Proton C data object.
Definition: decoder.hpp:58
The main Proton namespace.
Definition: annotation_key.hpp:30
Experimental - Stream-like decoder from AMQP bytes to C++ values.
Definition: decoder.hpp:53
An AMQP message ID.
Definition: message_id.hpp:44