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qpid/framing/FieldValue.h
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00001 #ifndef _framing_FieldValue_h
00002 #define _framing_FieldValue_h
00003 /*
00004  *
00005  * Licensed to the Apache Software Foundation (ASF) under one
00006  * or more contributor license agreements.  See the NOTICE file
00007  * distributed with this work for additional information
00008  * regarding copyright ownership.  The ASF licenses this file
00009  * to you under the Apache License, Version 2.0 (the
00010  * "License"); you may not use this file except in compliance
00011  * with the License.  You may obtain a copy of the License at
00012  *
00013  *   http://www.apache.org/licenses/LICENSE-2.0
00014  *
00015  * Unless required by applicable law or agreed to in writing,
00016  * software distributed under the License is distributed on an
00017  * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
00018  * KIND, either express or implied.  See the License for the
00019  * specific language governing permissions and limitations
00020  * under the License.
00021  *
00022  */
00023 
00024 #include "qpid/Exception.h"
00025 #include "qpid/framing/amqp_types.h"
00026 #include "qpid/framing/Buffer.h"
00027 #include "qpid/framing/FieldTable.h"
00028 #include "qpid/CommonImportExport.h"
00029 
00030 #include <iostream>
00031 #include <memory>
00032 #include <vector>
00033 
00034 #include <assert.h>
00035 
00036 namespace qpid {
00037 namespace framing {
00038 
00044 class QPID_COMMON_CLASS_EXTERN FieldValueException : public qpid::Exception {};
00045 
00051 struct QPID_COMMON_CLASS_EXTERN InvalidConversionException : public FieldValueException {
00052     InvalidConversionException() {}
00053 };
00054 
00055 class List;
00056 
00062 class QPID_COMMON_CLASS_EXTERN FieldValue {
00063   public:
00064     /*
00065      * Abstract type for content of different types
00066      */
00067     class Data {
00068       public:
00069         virtual ~Data() {};
00070         virtual uint32_t encodedSize() const = 0;
00071         virtual void encode(Buffer& buffer) = 0;
00072         virtual void decode(Buffer& buffer) = 0;
00073         virtual bool operator==(const Data&) const = 0;
00074 
00075         virtual bool convertsToInt() const { return false; }
00076         virtual bool convertsToString() const { return false; }
00077         virtual int64_t getInt() const { throw InvalidConversionException();}
00078         virtual std::string getString() const { throw InvalidConversionException(); }
00079 
00080         virtual void print(std::ostream& out) const = 0;
00081     };
00082 
00083     FieldValue(): data(0) {};
00084     // Default assignment operator is fine
00085     void setType(uint8_t type);
00086     QPID_COMMON_EXTERN uint8_t getType() const;
00087     Data& getData() { return *data; }
00088     uint32_t encodedSize() const { return 1 + data->encodedSize(); };
00089     bool empty() const { return data.get() == 0; }
00090     void encode(Buffer& buffer);
00091     void decode(Buffer& buffer);
00092     QPID_COMMON_EXTERN bool operator==(const FieldValue&) const;
00093     QPID_COMMON_INLINE_EXTERN bool operator!=(const FieldValue& v) const { return !(*this == v); }
00094 
00095     QPID_COMMON_EXTERN void print(std::ostream& out) const;
00096 
00097     template <typename T> bool convertsTo() const { return false; }
00098     template <typename T> T get() const { throw InvalidConversionException(); }
00099 
00100     template <class T, int W> T getIntegerValue() const;
00101     template <class T> T getIntegerValue() const;
00102     template <class T, int W> T getFloatingPointValue() const;
00103     template <int W> void getFixedWidthValue(unsigned char*) const;
00104     template <class T> bool get(T&) const;
00105 
00106   protected:
00107     FieldValue(uint8_t t, Data* d): typeOctet(t), data(d) {}
00108 
00109     QPID_COMMON_EXTERN static uint8_t* convertIfRequired(uint8_t* const octets, int width);
00110 
00111   private:
00112     uint8_t typeOctet;
00113     std::auto_ptr<Data> data;
00114 
00115 };
00116 
00117 template <>
00118 inline bool FieldValue::convertsTo<int>() const { return data->convertsToInt(); }
00119 
00120 template <>
00121 inline bool FieldValue::convertsTo<int64_t>() const { return data->convertsToInt(); }
00122 
00123 template <>
00124 inline bool FieldValue::convertsTo<std::string>() const { return data->convertsToString(); }
00125 
00126 template <>
00127 inline int FieldValue::get<int>() const { return static_cast<int>(data->getInt()); }
00128 
00129 template <>
00130 inline int64_t FieldValue::get<int64_t>() const { return data->getInt(); }
00131 
00132 template <>
00133 inline std::string FieldValue::get<std::string>() const { return data->getString(); }
00134 
00135 inline std::ostream& operator<<(std::ostream& out, const FieldValue& v) {
00136     v.print(out);
00137     return out;
00138 }
00139 
00140 template <int width>
00141 class FixedWidthValue : public FieldValue::Data {
00142     uint8_t octets[width];
00143 
00144   public:
00145     FixedWidthValue() {}
00146     FixedWidthValue(const uint8_t (&data)[width]) : octets(data) {}
00147     FixedWidthValue(const uint8_t* const data)
00148     {
00149         for (int i = 0; i < width; i++) octets[i] = data[i];
00150     }
00151     FixedWidthValue(uint64_t v)
00152     {
00153         for (int i = width; i > 1; --i) {
00154             octets[i-1] = (uint8_t) (0xFF & v); v >>= 8;
00155         }
00156         octets[0] = (uint8_t) (0xFF & v);
00157     }
00158     uint32_t encodedSize() const { return width; }
00159     void encode(Buffer& buffer) { buffer.putRawData(octets, width); }
00160     void decode(Buffer& buffer) { buffer.getRawData(octets, width); }
00161     bool operator==(const Data& d) const {
00162         const FixedWidthValue<width>* rhs = dynamic_cast< const FixedWidthValue<width>* >(&d);
00163         if (rhs == 0) return false;
00164         else return std::equal(&octets[0], &octets[width], &rhs->octets[0]);
00165     }
00166 
00167     bool convertsToInt() const { return true; }
00168     int64_t getInt() const
00169     {
00170         int64_t v = 0;
00171         for (int i = 0; i < width-1; ++i) {
00172             v |= octets[i]; v <<= 8;
00173         }
00174         v |= octets[width-1];
00175         return v;
00176     }
00177     uint8_t* rawOctets() { return octets; }
00178     uint8_t* rawOctets() const { return octets; }
00179 
00180     void print(std::ostream& o) const { o << "F" << width << ":"; };
00181 };
00182 
00183 template <class T, int W>
00184 inline T FieldValue::getIntegerValue() const
00185 {
00186     FixedWidthValue<W>* const fwv = dynamic_cast< FixedWidthValue<W>* const>(data.get());
00187     if (fwv) {
00188         uint8_t* octets = fwv->rawOctets();
00189         T v = 0;
00190         for (int i = 0; i < W-1; ++i) {
00191             v |= octets[i]; v <<= 8;
00192         }
00193         v |= octets[W-1];
00194         return v;
00195     } else {
00196         throw InvalidConversionException();
00197     }
00198 }
00199 
00200 template <class T>
00201 inline T FieldValue::getIntegerValue() const
00202 {
00203     FixedWidthValue<1>* const fwv = dynamic_cast< FixedWidthValue<1>* const>(data.get());
00204     if (fwv) {
00205         uint8_t* octets = fwv->rawOctets();
00206         return octets[0];
00207     } else {
00208         throw InvalidConversionException();
00209     }
00210 }
00211 
00212 template <class T, int W>
00213 inline T FieldValue::getFloatingPointValue() const {
00214     FixedWidthValue<W>* const fwv = dynamic_cast< FixedWidthValue<W>* const>(data.get());
00215     if (fwv) {
00216         T value;
00217         uint8_t* const octets = convertIfRequired(fwv->rawOctets(), W);
00218         uint8_t* const target = reinterpret_cast<uint8_t*>(&value);
00219         for (size_t i = 0; i < W; ++i) target[i] = octets[i];
00220         return value;
00221     } else {
00222         throw InvalidConversionException();
00223     }
00224 }
00225 
00226 template <int W> void FieldValue::getFixedWidthValue(unsigned char* value) const
00227 {
00228     FixedWidthValue<W>* const fwv = dynamic_cast< FixedWidthValue<W>* const>(data.get());
00229     if (fwv) {
00230         for (size_t i = 0; i < W; ++i) value[i] = fwv->rawOctets()[i];
00231     } else {
00232         throw InvalidConversionException();
00233     }
00234 }
00235 
00236 template <>
00237 inline float FieldValue::get<float>() const {
00238     return getFloatingPointValue<float, 4>();
00239 }
00240 
00241 template <>
00242 inline double FieldValue::get<double>() const {
00243     return getFloatingPointValue<double, 8>();
00244 }
00245 
00246 template <>
00247 class FixedWidthValue<0> : public FieldValue::Data {
00248   public:
00249     // Implicit default constructor is fine
00250     uint32_t encodedSize() const { return 0; }
00251     void encode(Buffer&) {};
00252     void decode(Buffer&) {};
00253     bool operator==(const Data& d) const {
00254         const FixedWidthValue<0>* rhs = dynamic_cast< const FixedWidthValue<0>* >(&d);
00255         return rhs != 0;
00256     }
00257     void print(std::ostream& o) const { o << "F0"; };
00258 };
00259 
00260 template <int lenwidth>
00261 class VariableWidthValue : public FieldValue::Data {
00262     std::vector<uint8_t> octets;
00263 
00264   public:
00265     VariableWidthValue() {}
00266     VariableWidthValue(const std::vector<uint8_t>& data) : octets(data) {}
00267     VariableWidthValue(const uint8_t* start, const uint8_t* end) : octets(start, end) {}
00268     uint32_t encodedSize() const { return lenwidth + octets.size(); }
00269     void encode(Buffer& buffer) {
00270         buffer.putUInt<lenwidth>(octets.size());
00271         if (octets.size() > 0)
00272             buffer.putRawData(&octets[0], octets.size());
00273     };
00274     void decode(Buffer& buffer) {
00275         uint32_t len = buffer.getUInt<lenwidth>();
00276         octets.resize(len);
00277         if (len > 0)
00278             buffer.getRawData(&octets[0], len);
00279     }
00280     bool operator==(const Data& d) const {
00281         const VariableWidthValue<lenwidth>* rhs = dynamic_cast< const VariableWidthValue<lenwidth>* >(&d);
00282         if (rhs == 0) return false;
00283         else return octets==rhs->octets;
00284     }
00285 
00286     bool convertsToString() const { return true; }
00287     std::string getString() const { return std::string(octets.begin(), octets.end()); }
00288 
00289     void print(std::ostream& o) const { o << "V" << lenwidth << ":" << octets.size() << ":"; };
00290 };
00291 
00292 template <class T>
00293 class EncodedValue : public FieldValue::Data {
00294     T value;
00295   public:
00296 
00297     EncodedValue() {}
00298     EncodedValue(const T& v) : value(v) {}
00299 
00300     T& getValue() { return value; }
00301     const T& getValue() const { return value; }
00302 
00303     uint32_t encodedSize() const { return value.encodedSize(); }
00304 
00305     void encode(Buffer& buffer) {
00306         value.encode(buffer);
00307     };
00308     void decode(Buffer& buffer) {
00309         value.decode(buffer);
00310     }
00311     bool operator==(const Data& d) const {
00312         const EncodedValue<T>* rhs = dynamic_cast< const EncodedValue<T>* >(&d);
00313         if (rhs == 0) return false;
00314         else return value==rhs->value;
00315     }
00316 
00317     void print(std::ostream& o) const { o << "[" << value << "]"; };
00318 };
00319 
00324 template <class T>
00325 inline bool FieldValue::get(T& t) const
00326 {
00327     const EncodedValue<T>* v = dynamic_cast< EncodedValue<T>* >(data.get());    
00328     if (v != 0) {
00329         t = v->getValue();
00330         return true;
00331     } else {
00332         try {
00333             t = get<T>();
00334             return true;
00335         } catch (const InvalidConversionException&) {
00336             return false;
00337         }
00338     }
00339 }
00340 
00341 class Str8Value : public FieldValue {
00342   public:
00343     QPID_COMMON_EXTERN Str8Value(const std::string& v);
00344 };
00345 
00346 class Str16Value : public FieldValue {
00347   public:
00348     QPID_COMMON_EXTERN Str16Value(const std::string& v);
00349 };
00350 
00351 class Var16Value : public FieldValue {
00352   public:
00353     QPID_COMMON_EXTERN Var16Value(const std::string& v, uint8_t code);
00354 };
00355 
00356 class Var32Value : public FieldValue {
00357   public:
00358     QPID_COMMON_EXTERN Var32Value(const std::string& v, uint8_t code);
00359 };
00360 
00361 class Struct32Value : public FieldValue {
00362   public:
00363     QPID_COMMON_EXTERN Struct32Value(const std::string& v);
00364 };
00365 
00366 class FloatValue : public FieldValue
00367 {
00368   public:
00369     QPID_COMMON_EXTERN FloatValue(float f);
00370 };
00371 class DoubleValue : public FieldValue
00372 {
00373   public:
00374     QPID_COMMON_EXTERN DoubleValue(double f);
00375 };
00376 
00377 /*
00378  * Basic integer value encodes as signed 32 bit
00379  */
00380 class IntegerValue : public FieldValue {
00381   public:
00382     QPID_COMMON_EXTERN IntegerValue(int v);
00383 };
00384 
00385 class TimeValue : public FieldValue {
00386   public:
00387     QPID_COMMON_EXTERN TimeValue(uint64_t v);
00388 };
00389 
00390 class Integer64Value : public FieldValue {
00391   public:
00392     QPID_COMMON_EXTERN Integer64Value(int64_t v);
00393 };
00394 
00395 class Unsigned64Value : public FieldValue {
00396   public:
00397     QPID_COMMON_EXTERN Unsigned64Value(uint64_t v);
00398 };
00399 
00400 class FieldTableValue : public FieldValue {
00401   public:
00402     typedef FieldTable ValueType;
00403     QPID_COMMON_EXTERN FieldTableValue(const FieldTable&);
00404 };
00405 
00406 class ArrayValue : public FieldValue {
00407   public:
00408     QPID_COMMON_EXTERN ArrayValue(const Array&);
00409 };
00410 
00411 class VoidValue : public FieldValue {
00412   public:
00413     QPID_COMMON_EXTERN VoidValue();
00414 };
00415 
00416 class BoolValue : public FieldValue {
00417   public:
00418     QPID_COMMON_EXTERN BoolValue(bool);
00419 };
00420 
00421 class Unsigned8Value : public FieldValue {
00422   public:
00423     QPID_COMMON_EXTERN Unsigned8Value(uint8_t);
00424 };
00425 
00426 class Unsigned16Value : public FieldValue {
00427   public:
00428     QPID_COMMON_EXTERN Unsigned16Value(uint16_t);
00429 };
00430 
00431 class Unsigned32Value : public FieldValue {
00432   public:
00433     QPID_COMMON_EXTERN Unsigned32Value(uint32_t);
00434 };
00435 
00436 class Integer8Value : public FieldValue {
00437   public:
00438     QPID_COMMON_EXTERN Integer8Value(int8_t);
00439 };
00440 
00441 class Integer16Value : public FieldValue {
00442   public:
00443     QPID_COMMON_EXTERN Integer16Value(int16_t);
00444 };
00445 
00446 typedef IntegerValue Integer32Value;
00447 
00448 class ListValue : public FieldValue {
00449   public:
00450     typedef List ValueType;
00451     QPID_COMMON_EXTERN ListValue(const List&);
00452 };
00453 
00454 class UuidValue : public FieldValue {
00455   public:
00456     QPID_COMMON_EXTERN UuidValue(const unsigned char*);
00457 };
00458 
00459 template <class T>
00460 bool getEncodedValue(FieldTable::ValuePtr vptr, T& value)
00461 {
00462     if (vptr) {
00463         const EncodedValue<T>* ev = dynamic_cast< EncodedValue<T>* >(&(vptr->getData()));
00464         if (ev != 0) {
00465             value = ev->getValue();
00466             return true;
00467         }
00468     }
00469     return false;
00470 }
00471 
00472 }} // qpid::framing
00473 
00474 #endif

Qpid C++ API Reference
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