Qpid Proton C++ API  0.37.0
decoder.hpp
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1 #ifndef PROTON_CODEC_DECODER_HPP
2 #define PROTON_CODEC_DECODER_HPP
3 
4 /*
5  *
6  * Licensed to the Apache Software Foundation (ASF) under one
7  * or more contributor license agreements. See the NOTICE file
8  * distributed with this work for additional information
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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 
36 
37 namespace proton {
38 
39 class annotation_key;
40 class message_id;
41 class scalar;
42 class value;
43 
44 namespace internal {
45 class value_base;
46 }
47 
48 namespace codec {
49 
56 class decoder : public internal::data {
57  public:
61  explicit decoder(const data& d, bool exact=false) : data(d), exact_(exact) {}
62 
65  PN_CPP_EXTERN explicit decoder(const internal::value_base&, bool exact=false);
66 
69  PN_CPP_EXTERN void decode(const char* buffer, size_t size);
70 
73  PN_CPP_EXTERN void decode(const std::string&);
74 
76  PN_CPP_EXTERN bool more();
77 
83  PN_CPP_EXTERN type_id next_type();
84 
91  PN_CPP_EXTERN decoder& operator>>(bool&);
92  PN_CPP_EXTERN decoder& operator>>(uint8_t&);
93  PN_CPP_EXTERN decoder& operator>>(int8_t&);
94  PN_CPP_EXTERN decoder& operator>>(uint16_t&);
95  PN_CPP_EXTERN decoder& operator>>(int16_t&);
96  PN_CPP_EXTERN decoder& operator>>(uint32_t&);
97  PN_CPP_EXTERN decoder& operator>>(int32_t&);
98  PN_CPP_EXTERN decoder& operator>>(wchar_t&);
99  PN_CPP_EXTERN decoder& operator>>(uint64_t&);
100  PN_CPP_EXTERN decoder& operator>>(int64_t&);
101  PN_CPP_EXTERN decoder& operator>>(timestamp&);
102  PN_CPP_EXTERN decoder& operator>>(float&);
103  PN_CPP_EXTERN decoder& operator>>(double&);
104  PN_CPP_EXTERN decoder& operator>>(decimal32&);
105  PN_CPP_EXTERN decoder& operator>>(decimal64&);
106  PN_CPP_EXTERN decoder& operator>>(decimal128&);
107  PN_CPP_EXTERN decoder& operator>>(uuid&);
108  PN_CPP_EXTERN decoder& operator>>(std::string&);
109  PN_CPP_EXTERN decoder& operator>>(symbol&);
110  PN_CPP_EXTERN decoder& operator>>(binary&);
111  PN_CPP_EXTERN decoder& operator>>(message_id&);
112  PN_CPP_EXTERN decoder& operator>>(annotation_key&);
113  PN_CPP_EXTERN decoder& operator>>(scalar&);
114  PN_CPP_EXTERN decoder& operator>>(internal::value_base&);
115  PN_CPP_EXTERN decoder& operator>>(null&);
116  PN_CPP_EXTERN decoder& operator>>(decltype(nullptr)&);
118 
123  PN_CPP_EXTERN decoder& operator>>(start&);
124 
127  PN_CPP_EXTERN decoder& operator>>(const finish&);
128 
130  template <class T> struct sequence_ref { T& ref; sequence_ref(T& r) : ref(r) {} };
131  template <class T> struct associative_ref { T& ref; associative_ref(T& r) : ref(r) {} };
132  template <class T> struct pair_sequence_ref { T& ref; pair_sequence_ref(T& r) : ref(r) {} };
133 
134  template <class T> static sequence_ref<T> sequence(T& x) { return sequence_ref<T>(x); }
135  template <class T> static associative_ref<T> associative(T& x) { return associative_ref<T>(x); }
136  template <class T> static pair_sequence_ref<T> pair_sequence(T& x) { return pair_sequence_ref<T>(x); }
138 
142  template <class T> decoder& operator>>(sequence_ref<T> r) {
143  start s;
144  *this >> s;
145  if (s.is_described) next();
146  r.ref.resize(s.size);
147  for (typename T::iterator i = r.ref.begin(); i != r.ref.end(); ++i)
148  *this >> *i;
149  return *this;
150  }
151 
153  template <class T> decoder& operator>>(associative_ref<T> r) {
154  using namespace internal;
155  start s;
156  *this >> s;
157  assert_type_equal(MAP, s.type);
158  r.ref.clear();
159  for (size_t i = 0; i < s.size/2; ++i) {
160  typename std::remove_const<typename T::key_type>::type k;
161  typename std::remove_const<typename T::mapped_type>::type v;
162  *this >> k >> v;
163  r.ref[k] = v;
164  }
165  return *this;
166  }
167 
170  template <class T> decoder& operator>>(pair_sequence_ref<T> r) {
171  using namespace internal;
172  start s;
173  *this >> s;
174  assert_type_equal(MAP, s.type);
175  r.ref.clear();
176  for (size_t i = 0; i < s.size/2; ++i) {
177  typedef typename T::value_type value_type;
178  typename std::remove_const<typename value_type::first_type>::type k;
179  typename std::remove_const<typename value_type::second_type>::type v;
180  *this >> k >> v;
181  r.ref.push_back(value_type(k, v));
182  }
183  return *this;
184  }
185 
186  private:
187  type_id pre_get();
188  template <class T, class U> decoder& extract(T& x, U (*get)(pn_data_t*));
189  bool exact_;
190 
191  friend class message;
192 };
193 
196 template<class T> T get(decoder& d) {
197  assert_type_equal(internal::type_id_of<T>::value, d.next_type());
198  T x;
199  d >> x;
200  return x;
201 }
203 
206 template <class T> typename std::enable_if<internal::is_unknown_integer<T>::value, decoder&>::type
207 operator>>(decoder& d, T& i) {
208  using namespace internal;
209  typename integer_type<sizeof(T), std::is_signed<T>::value>::type v;
210  d >> v; // Extract as a known integer type
211  i = v; // C++ conversion to the target type.
212  return d;
213 }
214 
215 } // codec
216 } // proton
217 
218 #endif // PROTON_CODEC_DECODER_HPP
A key for use with AMQP annotation maps.
Definition: annotation_key.hpp:38
Arbitrary binary data.
Definition: binary.hpp:40
Unsettled API - A stream-like decoder from AMQP bytes to C++ values.
Definition: decoder.hpp:56
decoder & operator>>(start &)
Start decoding a container type, such as an ARRAY, LIST or MAP.
decoder & operator>>(const finish &)
Finish decoding a container type, and move on to the next value in the stream.
void decode(const char *buffer, size_t size)
Decode AMQP data from a buffer and add it to the end of the decoders stream.
void decode(const std::string &)
Decode AMQP data from a std::string and add it to the end of the decoders stream.
decoder & operator>>(associative_ref< T > r)
Extract an AMQP MAP to a C++ associative container.
Definition: decoder.hpp:153
bool more()
Return true if there are more value to extract at the current level.
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:142
decoder(const data &d, bool exact=false)
Wrap a Proton C data object.
Definition: decoder.hpp:61
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:170
decoder(const internal::value_base &, bool exact=false)
Attach decoder to a proton::value.
type_id next_type()
Get the type of the next value that will be read by operator>>.
A 128-bit decimal floating-point value.
Definition: decimal.hpp:52
A 32-bit decimal floating-point value.
Definition: decimal.hpp:46
A 64-bit decimal floating-point value.
Definition: decimal.hpp:49
An AMQP message ID.
Definition: message_id.hpp:47
An AMQP message.
Definition: message.hpp:48
A holder for an instance of any scalar AMQP type.
Definition: scalar.hpp:37
A string that represents the AMQP symbol type.
Definition: symbol.hpp:35
A 64-bit timestamp in milliseconds since the Unix epoch.
Definition: timestamp.hpp:35
A 16-byte universally unique identifier.
Definition: uuid.hpp:37
Unsettled API - Shared codec functions.
std::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:207
Unsettled API - Finish inserting or extracting a complex type.
Definition: common.hpp:57
Unsettled API - Start encoding a complex type.
Definition: common.hpp:34
The main Proton namespace.
Definition: annotation_key.hpp:33
T get(const scalar &s)
Get a contained value of type T.
Definition: scalar.hpp:60
type_id
An identifier for AMQP types.
Definition: type_id.hpp:37
@ MAP
A sequence of key-value pairs.
Definition: type_id.hpp:62
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.