data.h 20.3 KB
Newer Older
Jelte Jansen's avatar
Jelte Jansen committed
1
// Copyright (C) 2010  Internet Systems Consortium, Inc. ("ISC")
2 3 4 5 6 7 8 9 10 11 12 13 14 15 16
//
// Permission to use, copy, modify, and/or distribute this software for any
// purpose with or without fee is hereby granted, provided that the above
// copyright notice and this permission notice appear in all copies.
//
// THE SOFTWARE IS PROVIDED "AS IS" AND ISC DISCLAIMS ALL WARRANTIES WITH
// REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF MERCHANTABILITY
// AND FITNESS.  IN NO EVENT SHALL ISC BE LIABLE FOR ANY SPECIAL, DIRECT,
// INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM
// LOSS OF USE, DATA OR PROFITS, WHETHER IN AN ACTION OF CONTRACT, NEGLIGENCE
// OR OTHER TORTIOUS ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR
// PERFORMANCE OF THIS SOFTWARE.

// $Id$

17 18 19 20 21 22 23
#ifndef _ISC_DATA_H
#define _ISC_DATA_H 1

#include <string>
#include <vector>
#include <map>
#include <boost/shared_ptr.hpp>
24
#include <stdexcept>
25
#include <exceptions/exceptions.h>
26

Jelte Jansen's avatar
Jelte Jansen committed
27
namespace isc { namespace data {
28

29 30 31 32 33 34 35 36 37
class Element;
// todo: describe the rationale behind ElementPtr?
typedef boost::shared_ptr<Element> ElementPtr;

///
/// \brief A standard Data module exception that is thrown if a function
/// is called for an Element that has a wrong type (e.g. int_value on a
/// ListElement)
///
38
class TypeError : public isc::Exception {
39
public:
Jelte Jansen's avatar
Jelte Jansen committed
40
    TypeError(const char* file, size_t line, const char* what) :
41
        isc::Exception(file, line, what) {}
42 43 44 45 46 47
};

///
/// \brief A standard Data module exception that is thrown if a parse
/// error is encountered when constructing an Element from a string
///
Jelte Jansen's avatar
Jelte Jansen committed
48 49 50
// i'd like to use Exception here but we need one that is derived from
// runtime_error (as this one is directly based on external data, and
// i want to add some values to any static data string that is provided)
51
class JSONError : public isc::Exception {
52
public:
53 54
    JSONError(const char* file, size_t line, const char* what) :
        isc::Exception(file, line, what) {}
55 56 57 58 59 60 61 62 63 64 65
};

///
/// \brief The \c Element class represents a piece of data, used by
/// the command channel and configuration parts.
///
/// An \c Element can contain simple types (int, real, string, bool and
/// None), and composite types (list and string->element maps)
///
/// Elements should in calling functions usually be referenced through
/// an \c ElementPtr, which can be created using the factory functions
66
/// \c Element::create() and \c Element::fromJSON()
67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85
///
/// Notes to developers: Element is a base class, implemented by a
/// specific subclass for each type (IntElement, BoolElement, etc).
/// Element does define all functions for all types, and defaults to
/// raising a \c TypeError for functions that are not supported for
/// the type in question.
///
class Element {
    
private:
    // technically the type could be omitted; is it useful?
    // should we remove it or replace it with a pure virtual
    // function getType?
    int type;

protected:
    Element(int t) { type = t; }

public:
86 87
    // any is a special type used in list specifications, specifying
    // that the elements can be of any type
88
    enum types { integer, real, boolean, null, string, list, map, any };
89 90 91 92
    // base class; make dtor virtual
    virtual ~Element() {};

    /// \return the type of this element
JINMEI Tatuya's avatar
JINMEI Tatuya committed
93
    int getType() { return (type); }
94

95 96 97
    /// Returns a string representing the Element and all its
    /// child elements; note that this is different from stringValue(),
    /// which only returns the single value of a StringElement
Jelte Jansen's avatar
Jelte Jansen committed
98 99
    ///
    /// The resulting string will contain the Element in JSON format.
100 101
    ///
    /// \return std::string containing the string representation
102
    std::string str();
103 104 105 106 107

    /// Returns the wireformat for the Element and all its child
    /// elements.
    ///
    /// \return std::string containing the element in wire format
108
    std::string toWire();
Jelte Jansen's avatar
Jelte Jansen committed
109
    void toWire(std::ostream& out);
110

111
    /// \name pure virtuals, every derived class must implement these
Jelte Jansen's avatar
Jelte Jansen committed
112

113 114 115 116
    /// \returns true if the other ElementPtr has the same type and
    ///          value
    virtual bool equals(ElementPtr other) = 0;
    
Jelte Jansen's avatar
Jelte Jansen committed
117 118
    /// Converts the Element to JSON format and appends it to
    /// the given stringstream.
119
    virtual void toJSON(std::ostream& ss) = 0;
Jelte Jansen's avatar
Jelte Jansen committed
120

121 122 123 124 125 126 127 128
    /// \name Type-specific getters
    ///
    /// \brief These functions only
    /// work on their corresponding Element type. For all other
    /// types, a TypeError is thrown.
    /// If you want an exception-safe getter method, use
    /// getValue() below
    //@{
Jelte Jansen's avatar
Jelte Jansen committed
129
    virtual long int intValue() { isc_throw(TypeError, "intValue() called on non-integer Element"); };
JINMEI Tatuya's avatar
JINMEI Tatuya committed
130 131 132 133 134
    virtual double doubleValue() { isc_throw(TypeError, "doubleValue() called on non-double Element"); };
    virtual bool boolValue() { isc_throw(TypeError, "boolValue() called on non-Bool Element"); };
    virtual std::string stringValue() { isc_throw(TypeError, "stringValue() called on non-string Element"); };
    virtual const std::vector<boost::shared_ptr<Element> >& listValue() { isc_throw(TypeError, "listValue() called on non-list Element"); }; // replace with real exception or empty vector?
    virtual const std::map<std::string, boost::shared_ptr<Element> >& mapValue() { isc_throw(TypeError, "mapValue() called on non-map Element"); }; // replace with real exception or empty map?
135 136 137 138 139 140 141 142 143 144 145
    //@}

    /// \name Exception-safe getters
    ///
    /// \brief The getValue() functions return false if the given reference
    /// is of another type than the element contains
    /// By default it always returns false; the derived classes
    /// override the function for their type, copying their
    /// data to the given reference and returning true
    ///
    //@{
Jelte Jansen's avatar
Jelte Jansen committed
146
    virtual bool getValue(long int& t);
147 148 149 150 151
    virtual bool getValue(double& t);
    virtual bool getValue(bool& t);
    virtual bool getValue(std::string& t);
    virtual bool getValue(std::vector<ElementPtr>& t);
    virtual bool getValue(std::map<std::string, ElementPtr>& t);
152
    //@}
153

154 155 156 157 158 159 160 161
    ///
    /// \name Exception-safe setters.
    ///
    /// \brief Return false if the Element is not
    /// the right type. Set the value and return true if the Elements
    /// is of the correct type
    ///
    //@{
Jelte Jansen's avatar
Jelte Jansen committed
162
    virtual bool setValue(const long int v);
163 164 165 166 167
    virtual bool setValue(const double v);
    virtual bool setValue(const bool t);
    virtual bool setValue(const std::string& v);
    virtual bool setValue(const std::vector<ElementPtr>& v);
    virtual bool setValue(const std::map<std::string, ElementPtr>& v);
168 169 170 171 172 173 174 175 176 177 178 179 180 181
    //@}



    // Other functions for specific subtypes

    /// \name ListElement functions
    ///
    /// \brief If the Element on which these functions are called are not
    /// an instance of ListElement, a TypeError exception is thrown.
    //@{
    /// Returns the ElementPtr at the given index. If the index is out
    /// of bounds, this function throws an std::out_of_range exception.
    /// \param i The position of the ElementPtr to return
182
    virtual ElementPtr get(const int i);
183

184 185 186 187
    /// Sets the ElementPtr at the given index. If the index is out
    /// of bounds, this function throws an std::out_of_range exception.
    /// \param i The position of the ElementPtr to set
    /// \param element The ElementPtr to set at the position
188
    virtual void set(const size_t i, ElementPtr element);
189

190 191
    /// Adds an ElementPtr to the list
    /// \param element The ElementPtr to add
192
    virtual void add(ElementPtr element);
193

194 195 196
    /// Removes the element at the given position. If the index is out
    /// of nothing happens.
    /// \param i The index of the element to remove.
197
    virtual void remove(const int i);
198

199
    /// Returns the number of elements in the list.
200
    virtual size_t size();
201
    //@}
202

203 204 205 206 207 208 209 210 211
    
    /// \name MapElement functions
    ///
    /// \brief If the Element on which these functions are called are not
    /// an instance of MapElement, a TypeError exception is thrown.
    //@{
    /// Returns the ElementPtr at the given key
    /// \param name The key of the Element to return
    /// \return The ElementPtr at the given key
212
    virtual ElementPtr get(const std::string& name);
213

214 215
    /// Sets the ElementPtr at the given key
    /// \param name The key of the Element to set
216
    virtual void set(const std::string& name, ElementPtr element);
217

218 219
    /// Remove the ElementPtr at the given key
    /// \param name The key of the Element to remove
220
    virtual void remove(const std::string& name);
221

222 223 224
    /// Checks if there is data at the given key
    /// \param name The key of the Element to remove
    /// \return true if there is data at the key, false if not.
225
    virtual bool contains(const std::string& name);
226

227 228 229 230 231 232 233 234 235 236 237 238 239
    /// Recursively finds any data at the given identifier. The
    /// identifier is a /-separated list of names of nested maps, with
    /// the last name being the leaf that is returned.
    ///
    /// For instance, if you have a MapElement that contains another
    /// MapElement at the key "foo", and that second MapElement contains
    /// Another Element at key "bar", the identifier for that last
    /// element from the first is "foo/bar".
    ///
    /// \param identifier The identifier of the element to find
    /// \return The ElementPtr at the given identifier. Returns a
    /// null ElementPtr if it is not found, which can be checked with
    /// Element::is_null(ElementPtr e).
240
    virtual ElementPtr find(const std::string& identifier);
241

242 243 244 245
    /// See \c Element::find()
    /// \param identifier The identifier of the element to find
    /// \param t Reference to store the resulting ElementPtr, if found.
    /// \return true if the element was found, false if not.
246
    virtual bool find(const std::string& identifier, ElementPtr& t);
247 248
    //@}

249

250
    /// \name Factory functions
251
    
252 253 254 255 256 257 258 259
    // TODO: should we move all factory functions to a different class
    // so as not to burden the Element base with too many functions?
    // and/or perhaps even to a separate header?

    /// \name Direct factory functions
    /// \brief These functions simply wrap the given data directly
    /// in an Element object, and return a reference to it, in the form
    /// of an \c ElementPtr.
260 261 262
    /// These factory functions are exception-free (unless there is
    /// no memory available, in which case bad_alloc is raised by the
    /// underlying system).
263 264
    /// (Note that that is different from an NullElement, which
    /// represents an empty value, and is created with Element::create())
265
    //@{
266
    static ElementPtr create();
Jelte Jansen's avatar
Jelte Jansen committed
267
    static ElementPtr create(const long int i);
JINMEI Tatuya's avatar
JINMEI Tatuya committed
268
    static ElementPtr create(const int i) { return (create(static_cast<long int>(i))); };
269 270 271 272 273
    static ElementPtr create(const double d);
    static ElementPtr create(const bool b);
    static ElementPtr create(const std::string& s);
    // need both std:string and char *, since c++ will match
    // bool before std::string when you pass it a char *
JINMEI Tatuya's avatar
JINMEI Tatuya committed
274
    static ElementPtr create(const char *s) { return (create(std::string(s))); }
275 276 277

    /// \brief Creates an empty ListElement type ElementPtr.
    static ElementPtr createList();
278

279 280
    /// \brief Creates an empty MapElement type ElementPtr.
    static ElementPtr createMap();
281 282
    //@}

283

284 285
    /// \name Compound factory functions

Jelte Jansen's avatar
Jelte Jansen committed
286 287
    /// \brief These functions will parse the given string (JSON)
    /// representation  of a compound element. If there is a parse
Jelte Jansen's avatar
Jelte Jansen committed
288
    /// error, an exception of the type isc::data::JSONError is thrown.
289 290

    //@{
291
    /// Creates an Element from the given JSON string
292 293 294
    /// \param in The string to parse the element from
    /// \return An ElementPtr that contains the element(s) specified
    /// in the given string.
295
    static ElementPtr fromJSON(const std::string& in);
Jelte Jansen's avatar
Jelte Jansen committed
296

297 298 299
    /// Creates an Element from the given input stream containing JSON
    /// formatted data.
    ///
300 301 302
    /// \param in The string to parse the element from
    /// \return An ElementPtr that contains the element(s) specified
    /// in the given input stream.
Jelte Jansen's avatar
Jelte Jansen committed
303 304
    static ElementPtr fromJSON(std::istream& in) throw(JSONError);
    static ElementPtr fromJSON(std::istream& in, const std::string& file_name) throw(JSONError);
305

306 307 308 309 310 311 312 313 314 315 316
    /// Creates an Element from the given input stream, where we keep
    /// track of the location in the stream for error reporting.
    ///
    /// \param in The string to parse the element from
    /// \param line A reference to the int where the function keeps
    /// track of the current line.
    /// \param line A reference to the int where the function keeps
    /// track of the current position within the current line.
    /// \return An ElementPtr that contains the element(s) specified
    /// in the given input stream.
    // make this one private?
Jelte Jansen's avatar
Jelte Jansen committed
317
    static ElementPtr fromJSON(std::istream& in, const std::string& file, int& line, int &pos) throw(JSONError);
318 319
    //@}

320 321 322 323 324 325 326 327 328 329 330 331 332 333 334 335
    /// \name Type name conversion functions

    /// Returns the name of the given type as a string
    ///
    /// \param type The type to return the name of
    /// \return The name of the type, or "unknown" if the type
    ///         is not known.
    static std::string typeToName(Element::types type);

    /// Converts the string to the corresponding type
    /// Throws a TypeError if the name is unknown.
    ///
    /// \param type_name The name to get the type of
    /// \return the corresponding type value
    static Element::types nameToType(const std::string& type_name);

336 337 338 339 340
    /// \name Wire format factory functions

    /// These function pparse the wireformat at the given stringstream
    /// (of the given length). If there is a parse error an exception
    /// of the type isc::cc::DecodeError is raised.
341
    
342 343 344
    //@{
    /// Creates an Element from the wire format in the given
    /// stringstream of the given length.
Jelte Jansen's avatar
Jelte Jansen committed
345
    /// Since the wire format is JSON, thise is the same as
346
    /// fromJSON, and could be removed.
Jelte Jansen's avatar
Jelte Jansen committed
347
    ///
348 349 350 351
    /// \param in The input stringstream.
    /// \param length The length of the wireformat data in the stream
    /// \return ElementPtr with the data that is parsed.
    static ElementPtr fromWire(std::stringstream& in, int length);
Jelte Jansen's avatar
Jelte Jansen committed
352

353
    /// Creates an Element from the wire format in the given string
Jelte Jansen's avatar
Jelte Jansen committed
354
    /// Since the wire format is JSON, thise is the same as
355
    /// fromJSON, and could be removed.
Jelte Jansen's avatar
Jelte Jansen committed
356
    ///
357 358 359 360 361 362 363
    /// \param s The input string
    /// \return ElementPtr with the data that is parsed.
    static ElementPtr fromWire(const std::string& s);
    //@}
};

class IntElement : public Element {
Jelte Jansen's avatar
Jelte Jansen committed
364
    long int i;
365 366

public:
JINMEI Tatuya's avatar
JINMEI Tatuya committed
367 368
    IntElement(long int v) : Element(integer), i(v) { }
    long int intValue() { return (i); }
369
    using Element::getValue;
JINMEI Tatuya's avatar
JINMEI Tatuya committed
370
    bool getValue(long int& t) { t = i; return (true); }
371
    using Element::setValue;
JINMEI Tatuya's avatar
JINMEI Tatuya committed
372
    bool setValue(const long int v) { i = v; return (true); }
373
    void toJSON(std::ostream& ss);
374
    bool equals(ElementPtr other);
375 376 377 378 379 380 381
};

class DoubleElement : public Element {
    double d;

public:
    DoubleElement(double v) : Element(real), d(v) {};
JINMEI Tatuya's avatar
JINMEI Tatuya committed
382
    double doubleValue() { return (d); }
383
    using Element::getValue;
JINMEI Tatuya's avatar
JINMEI Tatuya committed
384
    bool getValue(double& t) { t = d; return (true); }
385
    using Element::setValue;
JINMEI Tatuya's avatar
JINMEI Tatuya committed
386
    bool setValue(const double v) { d = v; return (true); }
387
    void toJSON(std::ostream& ss);
388
    bool equals(ElementPtr other);
389 390 391 392 393 394 395
};

class BoolElement : public Element {
    bool b;

public:
    BoolElement(const bool v) : Element(boolean), b(v) {};
JINMEI Tatuya's avatar
JINMEI Tatuya committed
396
    bool boolValue() { return (b); }
397
    using Element::getValue;
JINMEI Tatuya's avatar
JINMEI Tatuya committed
398
    bool getValue(bool& t) { t = b; return (true); }
399
    using Element::setValue;
JINMEI Tatuya's avatar
JINMEI Tatuya committed
400
    bool setValue(const bool v) { b = v; return (true); }
401
    void toJSON(std::ostream& ss);
402 403 404 405 406 407
    bool equals(ElementPtr other);
};

class NullElement : public Element {
public:
    NullElement() : Element(null) {};
408
    void toJSON(std::ostream& ss);
409
    bool equals(ElementPtr other);
410 411 412 413 414 415 416
};

class StringElement : public Element {
    std::string s;

public:
    StringElement(std::string v) : Element(string), s(v) {};
JINMEI Tatuya's avatar
JINMEI Tatuya committed
417
    std::string stringValue() { return (s); }
418
    using Element::getValue;
JINMEI Tatuya's avatar
JINMEI Tatuya committed
419
    bool getValue(std::string& t) { t = s; return (true); }
420
    using Element::setValue;
JINMEI Tatuya's avatar
JINMEI Tatuya committed
421
    bool setValue(const std::string& v) { s = v; return (true); }
422
    void toJSON(std::ostream& ss);
423
    bool equals(ElementPtr other);
424 425 426 427 428 429
};

class ListElement : public Element {
    std::vector<ElementPtr> l;

public:
430
    ListElement() : Element(list), l(std::vector<ElementPtr>()) {};
JINMEI Tatuya's avatar
JINMEI Tatuya committed
431
    const std::vector<ElementPtr>& listValue() { return (l); }
432
    using Element::getValue;
JINMEI Tatuya's avatar
JINMEI Tatuya committed
433
    bool getValue(std::vector<ElementPtr>& t) { t = l; return (true); }
434
    using Element::setValue;
JINMEI Tatuya's avatar
JINMEI Tatuya committed
435
    bool setValue(const std::vector<ElementPtr>& v) { l = v; return (true); }
436
    using Element::get;
JINMEI Tatuya's avatar
JINMEI Tatuya committed
437
    ElementPtr get(int i) { return (l.at(i)); }
438
    using Element::set;
439 440
    void set(size_t i, ElementPtr e) { if (i <= l.size()) {l[i] = e;} else { throw std::out_of_range("vector::_M_range_check"); } };
    void add(ElementPtr e) { l.push_back(e); };
441
    using Element::remove;
442
    void remove(int i) { l.erase(l.begin() + i); };
443
    void toJSON(std::ostream& ss);
JINMEI Tatuya's avatar
JINMEI Tatuya committed
444
    size_t size() { return (l.size()); }
445
    bool equals(ElementPtr other);
446 447 448 449 450 451
};

class MapElement : public Element {
    std::map<std::string, ElementPtr> m;

public:
452 453
    MapElement() : Element(map), m(std::map<std::string, ElementPtr>()) {};
    // TODO: should we have direct iterators instead of exposing the std::map here?
JINMEI Tatuya's avatar
JINMEI Tatuya committed
454
    const std::map<std::string, ElementPtr>& mapValue() { return (m); }
455
    using Element::getValue;
JINMEI Tatuya's avatar
JINMEI Tatuya committed
456
    bool getValue(std::map<std::string, ElementPtr>& t) { t = m; return (true); }
457
    using Element::setValue;
JINMEI Tatuya's avatar
JINMEI Tatuya committed
458
    bool setValue(std::map<std::string, ElementPtr>& v) { m = v; return (true); }
459
    using Element::get;
JINMEI Tatuya's avatar
JINMEI Tatuya committed
460
    ElementPtr get(const std::string& s) { if (contains(s)) { return (m[s]); } else { return (ElementPtr());} }
461
    using Element::set;
462
    void set(const std::string& key, ElementPtr value);
463
    using Element::remove;
464
    void remove(const std::string& s) { m.erase(s); }
JINMEI Tatuya's avatar
JINMEI Tatuya committed
465
    bool contains(const std::string& s) { return (m.find(s) != m.end()); }
466
    void toJSON(std::ostream& ss);
467 468 469 470 471 472 473 474 475 476 477 478 479
    
    // we should name the two finds better...
    // find the element at id; raises TypeError if one of the
    // elements at path except the one we're looking for is not a
    // mapelement.
    // returns an empty element if the item could not be found
    ElementPtr find(const std::string& id);

    // find the Element at 'id', and store the element pointer in t
    // returns true if found, or false if not found (either because
    // it doesnt exist or one of the elements in the path is not
    // a MapElement)
    bool find(const std::string& id, ElementPtr& t);
480 481

    bool equals(ElementPtr other);
482 483 484 485 486 487 488
};

/// Checks whether the given ElementPtr is a NULL pointer
/// \param p The ElementPtr to check
/// \return true if it is NULL, false if not.
bool isNull(ElementPtr p);

489 490
///
/// \brief Remove all values from the first ElementPtr that are
491
/// equal in the second. Both ElementPtrs MUST be MapElements
492 493 494 495 496
/// The use for this function is to end up with a MapElement that
/// only contains new and changed values (for ModuleCCSession and
/// configuration update handlers)
/// Raises a TypeError if a or b are not MapElements
void removeIdentical(ElementPtr a, const ElementPtr b);
497

498 499 500 501 502
/// \brief Merges the data from other into element.
/// (on the first level). Both elements must be
/// MapElements.
/// Every string,value pair in other is copied into element
/// (the ElementPtr of value is copied, this is not a new object)
Jelte Jansen's avatar
Jelte Jansen committed
503 504 505 506 507 508
/// Unless the value is a NullElement, in which case the
/// key is removed from element, rather than setting the value to
/// the given NullElement.
/// This way, we can remove values from for instance maps with
/// configuration data (which would then result in reverting back
/// to the default).
509 510 511
/// Raises a TypeError if either ElementPtr is not a MapElement
void merge(ElementPtr element, const ElementPtr other);

512 513 514 515 516 517 518 519 520 521 522 523 524 525 526
///
/// \brief Insert the Element as a string into stream.
///
/// This method converts the \c ElemetPtr into a string with
/// \c Element::str() and inserts it into the
/// output stream \c out.
///
/// This function overloads the global operator<< to behave as described in
/// ostream::operator<< but applied to \c ElementPtr objects.
///
/// \param os A \c std::ostream object on which the insertion operation is
/// performed.
/// \param e The \c ElementPtr object to insert.
/// \return A reference to the same \c std::ostream object referenced by
/// parameter \c os after the insertion operation.
Jelte Jansen's avatar
Jelte Jansen committed
527
std::ostream& operator <<(std::ostream &out, const isc::data::ElementPtr& e);
528

529
bool operator==(const isc::data::ElementPtr a, const isc::data::ElementPtr b);
JINMEI Tatuya's avatar
JINMEI Tatuya committed
530
} }
531

532
#endif // _ISC_DATA_H
533 534 535 536

// Local Variables: 
// mode: c++
// End: