1//
2// NamePool.cpp
3//
4// Library: XML
5// Package: XML
6// Module: NamePool
7//
8// Copyright (c) 2004-2006, Applied Informatics Software Engineering GmbH.
9// and Contributors.
10//
11// SPDX-License-Identifier: BSL-1.0
12//
13
14
15#include "Poco/XML/NamePool.h"
16#include "Poco/Exception.h"
17#include "Poco/Random.h"
18
19
20namespace Poco {
21namespace XML {
22
23
24class NamePoolItem
25{
26public:
27 NamePoolItem(): _used(false)
28 {
29 }
30
31 ~NamePoolItem()
32 {
33 }
34
35 bool set(const XMLString& qname, const XMLString& namespaceURI, const XMLString& localName)
36 {
37 if (!_used)
38 {
39 _name.assign(qname, namespaceURI, localName);
40 _used = true;
41 return true;
42 }
43 else return _name.equals(qname, namespaceURI, localName);
44 }
45
46 const Name& get() const
47 {
48 return _name;
49 }
50
51 bool used() const
52 {
53 return _used;
54 }
55
56private:
57 Name _name;
58 bool _used;
59};
60
61
62NamePool::NamePool(unsigned long size):
63 _size(size),
64 _salt(0),
65 _rc(1)
66{
67 poco_assert (size > 1);
68
69 _pItems = new NamePoolItem[size];
70
71 Poco::Random rnd;
72 rnd.seed();
73 _salt = rnd.next();
74}
75
76
77NamePool::~NamePool()
78{
79 delete [] _pItems;
80}
81
82
83void NamePool::duplicate()
84{
85 ++_rc;
86}
87
88
89void NamePool::release()
90{
91 if (--_rc == 0)
92 delete this;
93}
94
95
96const Name& NamePool::insert(const XMLString& qname, const XMLString& namespaceURI, const XMLString& localName)
97{
98 unsigned long i = 0;
99 unsigned long n = (hash(qname, namespaceURI, localName) ^ _salt) % _size;
100
101 while (!_pItems[n].set(qname, namespaceURI, localName) && i++ < _size)
102 n = (n + 1) % _size;
103
104 if (i > _size) throw Poco::PoolOverflowException("XML name pool");
105
106 return _pItems[n].get();
107}
108
109
110const Name& NamePool::insert(const Name& name)
111{
112 return insert(name.qname(), name.namespaceURI(), name.localName());
113}
114
115
116unsigned long NamePool::hash(const XMLString& qname, const XMLString& namespaceURI, const XMLString& localName)
117{
118 unsigned long h = 0;
119 XMLString::const_iterator it = qname.begin();
120 XMLString::const_iterator end = qname.end();
121 while (it != end) h = (h << 5) + h + (unsigned long) *it++;
122 it = namespaceURI.begin();
123 end = namespaceURI.end();
124 while (it != end) h = (h << 5) + h + (unsigned long) *it++;
125 it = localName.begin();
126 end = localName.end();
127 while (it != end) h = (h << 5) + h + (unsigned long) *it++;
128 return h;
129}
130
131
132} } // namespace Poco::XML
133