gnash-0.8.10.tar.gz: gnash-0.8.10/cygnal/libamf/amf.h

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1 // 2 // Copyright (C) 2005, 2006, 2007, 2008, 2009, 2010, 2011, 2012 3 // Free Software Foundation, Inc 4 // 5 // This program is free software; you can redistribute it and/or modify 6 // it under the terms of the GNU General Public License as published by 7 // the Free Software Foundation; either version 3 of the License, or 8 // (at your option) any later version. 9 // 10 // This program is distributed in the hope that it will be useful, 11 // but WITHOUT ANY WARRANTY; without even the implied warranty of 12 // MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the 13 // GNU General Public License for more details. 14 // 15 // You should have received a copy of the GNU General Public License 16 // along with this program; if not, write to the Free Software 17 // Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA 18 19 // This file is for the low level support for encoding and decoding AMF objects. 20 // As this class has no data associated with it, all the methods are static as 21 // they are for convenience only. 22 // All the encoding methods return a Buffer class, which is simply an array on 23 // of unsigned bytes, and a byte count. 24 // The only extraction classes parse either a raw AMF object or the larger 25 // "variable" 26 27 #ifndef _AMF_H_ 28 #define _AMF_H_ 29 30 #include <string> 31 #include <cstring> 32 #include <boost/cstdint.hpp> 33 #include <boost/shared_ptr.hpp> 34 35 #include "element.h" 36 #include "dsodefs.h" 37 38 /// Action Message Format specific classes of libamf. 39 namespace cygnal 40 { 41 42 // forward declaration 43 class Buffer; 44 45 /// All numbers in AMF format are 8 byte doubles. 46 const size_t AMF0_NUMBER_SIZE = 0x08; 47 48 /// \brief The header size in bytes of an common AMF object. 49 /// The size of an AMF header is a type field (1 byte), followed by a 50 /// length field. (short) 51 const boost::uint8_t AMF_HEADER_SIZE = 3; 52 53 /// \brief The header size of a property. 54 /// A property is a little different. It always assumes the the 55 /// first field is a string that's the property name, then the 56 /// type byte like a regular AMF object and length is used for the 57 /// data. So a property object header is then only 5 bytes instead 58 /// of the 6 that one assumes would be used. 59 const boost::uint8_t AMF_PROP_HEADER_SIZE = 5; 60 61 /// AMF version 0 is supported by default 62 const boost::uint8_t AMF_VERSION = 0; 63 64 /// For terminating sequences, a byte with value 0x09 is used. 65 const boost::uint8_t TERMINATOR = 0x09; 66 67 /// \brief The maximum size for a string. 68 /// As if there is a parsing error, we'll often see the symptom of the length 69 /// for the following value is bogus. Although the length field is a short, it 70 /// seems silly to assume we'll ever see a string 65,000 characters long. Still, 71 /// it makes sense to make this an adjustable thing. 72 const boost::uint16_t SANE_STR_SIZE = 65535; 73 74 /// Binary representation of an ActionScript object. 75 // 76 /// AMF is used to send objects, whether to a SharedObject .sol file, 77 /// a memory based LocalConnection segment, or over an RTMP connection 78 /// for streaming. 79 /// 80 class DSOEXPORT AMF { 81 public: 82 83 /// Types of SharedObjects that can be serialized or deserialized. 84 typedef enum { 85 CONNECT = 0x01, 86 DISCONNECT = 0x02, 87 SET_ATTRIBUTE = 0x03, 88 UPDATE_DATA = 0x04, 89 UPDATE_ATTRIBUTE = 0x05, 90 SEND_MESSAGE = 0x06, 91 STATUS = 0x07, 92 CLEAR_DATA = 0x08, 93 DELETE_DATA = 0x09, 94 DELETE_ATTRIBYTE = 0x0a, 95 INITIAL_DATA = 0x0b 96 } shared_obj_types_e; 97 98 /// Type of file being streamed. 99 typedef enum { 100 FILETYPE_ERROR = -1, 101 FILETYPE_NONE = 0, 102 FILETYPE_HTML, 103 FILETYPE_SWF, 104 FILETYPE_VIDEO, 105 FILETYPE_AUDIO, 106 FILETYPE_MP3, 107 FILETYPE_FCS, 108 FILETYPE_OSCP 109 } filetype_e; 110 111 /// Create a new AMF object. 112 // 113 /// As most of the methods in the AMF class a static, this 114 /// is primarily only used when encoding complex objects 115 /// where the byte count is accumulated. 116 /// 117 AMF(); 118 119 /// Delete the allocated AMF object 120 ~AMF(); 121 122 /// @name Encoding methods 123 /// 124 /// Methods for encoding data into big endian formatted 125 /// raw AMF data. Note that while we could have had a 126 /// single overloaded encode method, this is more 127 /// explicit, which when it comes to manipulating binary 128 /// protocols make the code much more readable. 129 /// 130 /// @{ 131 132 /// Encode a string object to its serialized representation. 133 // 134 /// @param str a string value 135 /// 136 /// @return a binary AMF packet in big endian format 137 /// 138 static boost::shared_ptr<Buffer> encodeString(const std::string &str); 139 140 /// Encode an array of ASCII bytes to its serialized representation. 141 // 142 /// @param data The data to serialize into big endian format 143 /// 144 /// @param size The size of the data in bytes 145 /// 146 /// @return a binary AMF packet in big endian format 147 /// 148 static boost::shared_ptr<Buffer> encodeString(boost::uint8_t *data, 149 size_t size); 150 151 /// Encode a String object to its serialized representation. 152 // 153 /// A NULL String is a string with no associated data. 154 /// 155 /// @return a binary AMF packet in big endian format 156 /// 157 static boost::shared_ptr<Buffer> encodeNullString(); 158 159 /// Encode a Boolean object to its serialized representation. 160 // 161 /// @param flag The boolean value to serialize. 162 /// 163 /// @return a binary AMF packet in big endian format 164 /// 165 static boost::shared_ptr<Buffer> encodeBoolean(bool flag); 166 167 /// Encode an "Undefined" object to its serialized representation. 168 // 169 /// @return a binary AMF packet in big endian format 170 /// 171 static boost::shared_ptr<Buffer> encodeUndefined(); 172 173 /// Encode a NULL object to its serialized representation. 174 // 175 /// A NULL object is often used as a placeholder in RTMP. 176 /// 177 /// @return a binary AMF packet in big endian format 178 /// 179 static boost::shared_ptr<Buffer> encodeNull(); 180 181 /// Encode a "Unsupported" object to its serialized representation. 182 // 183 /// @return a binary AMF packet in big endian format 184 /// 185 static boost::shared_ptr<Buffer> encodeUnsupported(); 186 187 /// Encode an XML object to its serialized representation. 188 // 189 /// @param data A pointer to the raw bytes that becomes the XML data. 190 /// 191 /// @param nbytes The number of bytes to serialize. 192 /// 193 /// @return a binary AMF packet in big endian format 194 /// 195 static boost::shared_ptr<Buffer> encodeXMLObject(const boost::uint8_t *data, 196 size_t nbytes); 197 198 /// Encode a Typed Object to its serialized representation. 199 // 200 /// @param data A pointer to the raw bytes that becomes the data. 201 /// 202 /// @param size The number of bytes to serialize. 203 /// 204 /// @return a binary AMF packet in big endian format 205 /// 206 static boost::shared_ptr<Buffer> encodeTypedObject(const cygnal::Element &data); 207 208 /// Encode a Reference to an object to its serialized representation. 209 // 210 /// @param data A pointer to the raw bytes that becomes the data. 211 /// 212 /// @param size The number of bytes to serialize. 213 /// 214 /// @return a binary AMF packet in big endian format (header,data) 215 /// 216 static boost::shared_ptr<Buffer> encodeReference(boost::uint16_t index); 217 218 /// Encode a Movie Clip (swf data) to its serialized representation. 219 // 220 /// @param data A pointer to the raw bytes that becomes the data. 221 /// 222 /// @param size The number of bytes to serialize. 223 /// 224 /// @return a binary AMF packet in big endian format (header,data) 225 /// 226 static boost::shared_ptr<Buffer> encodeMovieClip(const boost::uint8_t *data, 227 size_t size); 228 229 /// Encode an ECMA Array to its serialized representation. 230 // 231 /// An ECMA Array, also called a Mixed Array, contains any 232 /// AMF data type as an item in the array. 233 /// 234 /// @param data A pointer to the raw bytes that becomes the data. 235 /// 236 /// @param size The number of bytes to serialize. 237 /// 238 /// @return a binary AMF packet in big endian format 239 /// 240 static boost::shared_ptr<Buffer> encodeECMAArray(const cygnal::Element &data); 241 242 /// Encode a Long String to its serialized representation. 243 // 244 /// @param data A pointer to the raw bytes that becomes the data. 245 /// 246 /// @param size The number of bytes to serialize. 247 /// 248 /// @return a binary AMF packet in big endian format 249 /// 250 static boost::shared_ptr<Buffer> encodeLongString(const boost::uint8_t *data, 251 size_t size); 252 253 /// Encode a Record Set to its serialized representation. 254 // 255 /// @param data A pointer to the raw bytes that becomes the data. 256 /// 257 /// @param size The number of bytes to serialize. 258 /// 259 /// @return a binary AMF packet in big endian format 260 /// 261 static boost::shared_ptr<Buffer> encodeRecordSet(const boost::uint8_t *data, 262 size_t size); 263 264 /// Encode a Date to its serialized representation. 265 // 266 /// @param data A pointer to the raw bytes that becomes the data. 267 /// 268 /// @return a binary AMF packet in big endian format 269 /// 270 static boost::shared_ptr<Buffer> encodeDate(const boost::uint8_t *data); 271 272 /// Encode a Strict Array to its serialized representation. 273 // 274 /// A Strict Array is one where all the items are the same 275 /// data type, commonly either a number or a string. 276 /// 277 /// @param data A pointer to the raw bytes that becomes the data. 278 /// 279 /// @param size The number of bytes to serialize. 280 /// 281 /// @return a binary AMF packet in big endian format (header,data) 282 /// 283 static boost::shared_ptr<Buffer> encodeStrictArray(const cygnal::Element &data); 284 285 /// Encode an object to its serialized representation. 286 // 287 /// @param el A smart pointer to an Element class. 288 /// 289 /// @return a binary AMF packet in big endian format 290 /// 291 static boost::shared_ptr<Buffer> encodeObject(const cygnal::Element &data); 292 293 /// Encode the end of an object to its serialized representation. 294 // 295 /// @return a binary AMF packet in big endian format 296 /// 297 static boost::shared_ptr<Buffer> encodeObjectEnd(); 298 299 /// Encode a 64 bit number to its serialized representation. 300 // 301 /// @param num A double value to serialize. 302 /// 303 /// @return a binary AMF packet in big endian format 304 /// 305 static boost::shared_ptr<Buffer> encodeNumber(double num); 306 307 /// Encode an Element to its serialized representation. 308 // 309 /// @param el A smart pointer to the Element to encode. 310 /// 311 /// @return a binary AMF packet in big endian format 312 /// 313 static boost::shared_ptr<Buffer> encodeElement(boost::shared_ptr<cygnal::Element> el); 314 315 /// Encode an Element to its serialized representation. 316 // 317 /// @param el the Element to encode. 318 /// 319 /// @return a binary AMF packet in big endian format 320 /// 321 static boost::shared_ptr<Buffer> encodeElement(const cygnal::Element& el); 322 323 /// Encode a variable to its serialized representation. 324 // 325 /// @param el A smart pointer to the Element to encode. 326 /// 327 /// @return a binary AMF packet in big endian format 328 /// 329 boost::shared_ptr<Buffer> encodeProperty(boost::shared_ptr<cygnal::Element> el); 330 331 /// @} end of encoding methods 332 333 /// @name Decoding methods 334 /// 335 /// Methods for extracting data from big endian formatted raw AMF data. 336 /// 337 /// @{ 338 339 /// Extract the AMF0 object type from the header. 340 // 341 /// @param in The raw data to extract values from. 342 /// 343 /// @return The data type from the header 344 /// 345 static Element::amf0_type_e extractElementHeader(boost::uint8_t *in) 346 { return *(reinterpret_cast<Element::amf0_type_e *>(in)); }; 347 348 /// Extract an AMF object from an array of raw bytes. 349 // 350 /// An AMF object is one of the support data types. 351 /// 352 /// @param in A real pointer to the raw data to start parsing from. 353 /// 354 /// @param tooFar A pointer to one-byte-past the last valid memory 355 /// address within the buffer. 356 /// 357 /// @return A smart ptr to an Element. 358 /// 359 /// @remarks May throw a ParserException 360 /// 361 boost::shared_ptr<cygnal::Element> extractAMF(boost::uint8_t *in, boost::uint8_t* tooFar); 362 363 /// Extract an AMF object from an array of raw bytes. 364 // 365 /// @param buf A smart pointer to a Buffer to parse the data from. 366 /// 367 /// @return A smart ptr to an Element. 368 /// 369 /// @remarks May throw a ParserException 370 /// 371 boost::shared_ptr<cygnal::Element> extractAMF(boost::shared_ptr<Buffer> buf); 372 373 /// Extract a Property. 374 // 375 /// A Property is a standard AMF object preceeded by a 376 /// length and an ASCII name field. These are only used 377 /// with higher level ActionScript objects. 378 /// 379 /// @param in A real pointer to the raw data to start parsing from. 380 /// 381 /// @param tooFar A pointer to one-byte-past the last valid memory 382 /// address within the buffer. 383 /// 384 /// @return A smart ptr to an Element. 385 /// 386 /// @remarks May throw a ParserException 387 /// 388 boost::shared_ptr<cygnal::Element> extractProperty(boost::uint8_t *in, boost::uint8_t* tooFar); 389 390 /// Extract a Property. 391 // 392 /// A Property is a standard AMF object preceeded by a 393 /// length and an ASCII name field. These are only used 394 /// with higher level ActionScript objects. 395 /// 396 /// @param buf A smart pointer to an Buffer to parse the data from. 397 /// 398 /// @return A smart ptr to an Element. 399 /// 400 /// @remarks May throw a ParserException 401 /// 402 boost::shared_ptr<cygnal::Element> extractProperty(boost::shared_ptr<Buffer> buf); 403 404 /// @} end of decoding methods 405 406 /// Get the total number of allocated bytes used when serializing. 407 // 408 /// @return The total allocated bytes. 409 /// 410 size_t totalsize() { return _totalsize; } 411 412 private: 413 414 /// The total number of bytes in serialized ActionScript object. 415 size_t _totalsize; 416 417 }; 418 419 /// Swap bytes in raw data. 420 // 421 /// This only swaps bytes if the host byte order is little endian. 422 /// 423 /// @param word The address of the data to byte swap. 424 /// 425 /// @param size The number of bytes in the data. 426 /// 427 /// @return A pointer to the raw data. 428 /// 429 DSOEXPORT void *swapBytes(void *word, size_t size); 430 431 432 } // end of amf namespace 433 434 // end of _AMF_H_ 435 #endif 436 437 // local Variables: 438 // mode: C++ 439 // indent-tabs-mode: t 440 // End: