Branch data Line data Source code
1 : : // Copyright (C) 2010 Internet Systems Consortium, Inc. ("ISC")
2 : : //
3 : : // Permission to use, copy, modify, and/or distribute this software for any
4 : : // purpose with or without fee is hereby granted, provided that the above
5 : : // copyright notice and this permission notice appear in all copies.
6 : : //
7 : : // THE SOFTWARE IS PROVIDED "AS IS" AND ISC DISCLAIMS ALL WARRANTIES WITH
8 : : // REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF MERCHANTABILITY
9 : : // AND FITNESS. IN NO EVENT SHALL ISC BE LIABLE FOR ANY SPECIAL, DIRECT,
10 : : // INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM
11 : : // LOSS OF USE, DATA OR PROFITS, WHETHER IN AN ACTION OF CONTRACT, NEGLIGENCE
12 : : // OR OTHER TORTIOUS ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR
13 : : // PERFORMANCE OF THIS SOFTWARE.
14 : :
15 : : #ifndef __NSAS_ENTRY_H
16 : : #define __NSAS_ENTRY_H
17 : :
18 : : #include <boost/enable_shared_from_this.hpp>
19 : : #include <iostream>
20 : :
21 : : #include <exceptions/exceptions.h>
22 : : #include <util/lru_list.h>
23 : :
24 : : #include "hash_key.h"
25 : : #include "hash_table.h"
26 : :
27 : : namespace isc {
28 : : namespace nsas {
29 : :
30 : : /// \brief Invalid Iterator
31 : : ///
32 : : /// Thrown if an attempt was made to access the iterator - the pointer into
33 : : /// the LRU list where this element is located - when it is marked as invalid.
34 : 0 : class InvalidLruIterator : public isc::Exception {
35 : : public:
36 : 0 : InvalidLruIterator(const char* file, size_t line, const char* what) :
37 [ # # ][ # # ]: 0 : Exception(file, line, what)
38 : 0 : {}
39 : : };
40 : :
41 : : /// \brief Element of NSAS Internal Lists
42 : : ///
43 : : /// This defines an element of the NSAS lists. All elements stored in these
44 : : /// lists *MUST* be derived from this object.
45 : : ///
46 : : /// The class provides two properties:
47 : : ///
48 : : /// # The method hashKey(), which returns a hash key associated with the
49 : : /// object.
50 : : /// # Storage for a pointer into the LRU list, used to quickly locate the
51 : : /// element when it is being "touched".
52 : : ///
53 : : /// Although it would be possible to require classes stored in the list
54 : : /// to have particular methods (and so eliminate the inheritance), this
55 : : /// would require the implementor to know something about the list and to
56 : : /// provide the appropriate logic.
57 : : ///
58 : : /// Unfortunately, using a base class does not simplify the definition of
59 : : /// the list classes (by allowing the list to be defined as a list
60 : : /// of base class objects), as the lists are a list of shared pointers to
61 : : /// objects, not a list of pointers to object. Arguments are shared
62 : : /// pointers, but a shared pointer to a base class is not a subclass of a
63 : : /// shared pointer to a derived class. For this reason, the type of element
64 : : /// being stored is a template parameter.
65 : : ///
66 : : /// This class is inherited from boost::enable_shared_from_this class
67 : : /// So within a member function a shared_ptr to current object can be obtained
68 : : template <typename T>
69 : : class NsasEntry : public boost::enable_shared_from_this <T> {
70 : : public:
71 : :
72 : : /// \brief Default Constructor
73 : : ///
74 : : /// Ensures that the handle into the LRU list is invalid.
75 : 1341 : NsasEntry() : valid_(false)
76 : : {}
77 : :
78 : : /// \brief Virtual Destructor
79 : 0 : virtual ~NsasEntry()
80 : 0 : {}
81 : :
82 : : /// Copy constructor and assignment operator OK for this class
83 : :
84 : : /// \brief Hash Key
85 : : ///
86 : : /// Returns the hash key for this element.
87 : : ///
88 : : /// TODO: Consider returning a reference to an internal object, for speed
89 : : virtual HashKey hashKey() const = 0;
90 : :
91 : : /// \brief Sets the iterator of the object
92 : : ///
93 : : /// Sets the iterator of an object and, as a side effect, marks it as valid.
94 : : ///
95 : : /// \param iterator Iterator of this element in the list
96 : 2363 : virtual void setLruIterator(typename isc::util::LruList<T>::iterator iterator) {
97 : 2363 : iterator_ = iterator;
98 : 2363 : valid_ = true;
99 : 2363 : }
100 : :
101 : : /// \brief Return Iterator
102 : : ///
103 : : /// \return iterator Iterator of this element in the list.
104 : : ///
105 : : /// \exception InvalidLruIterator Thrown if the iterator is not valid.
106 : 2154 : virtual typename isc::util::LruList<T>::iterator getLruIterator() const {
107 [ - + ][ - + ]: 2154 : if (! valid_) {
[ - + ]
108 [ # # ][ # # ]: 0 : isc_throw(InvalidLruIterator,
[ # # ][ # # ]
[ # # ][ # # ]
[ # # ]
109 : : "pointer of element into LRU list was not valid");
110 : : }
111 : 2154 : return iterator_;
112 : : }
113 : :
114 : : /// \brief Iterator Valid
115 : : ///
116 : : /// \return true if the stored iterator is valid.
117 : 2159 : virtual bool iteratorValid() const {
118 : 2159 : return valid_;
119 : : }
120 : :
121 : : /// \brief Invalidate Iterator
122 : : ///
123 : : /// Marks the iterator as invalid; it can oly be set valid again by a call
124 : : /// to setLruIterator.
125 : 27 : virtual void invalidateIterator() {
126 : 27 : valid_ = false;
127 : 27 : }
128 : :
129 : : private:
130 : : typename isc::util::LruList<T>::iterator iterator_; ///< Handle into the LRU List
131 : : bool valid_; ///< true if handle is valid
132 : : };
133 : :
134 : : } // namespace nsas
135 : : } // namespace isc
136 : :
137 : :
138 : : #endif // __NSAS_ENTRY_H
|
