libpqxx: tablereader.hxx Source File

libpqxx 4.0.1

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tablereader.hxx
1 /*-------------------------------------------------------------------------
2 *
3 * FILE
4 * pqxx/tablereader.hxx
5 *
6 * DESCRIPTION
7 * definition of the pqxx::tablereader class.
8 * pqxx::tablereader enables optimized batch reads from a database table
9 * DO NOT INCLUDE THIS FILE DIRECTLY; include pqxx/tablereader instead.
10 *
11 * Copyright (c) 2001-2011, Jeroen T. Vermeulen <jtv@xs4all.nl>
12 *
13 * See COPYING for copyright license. If you did not receive a file called
14 * COPYING with this source code, please notify the distributor of this mistake,
15 * or contact the author.
16 *
17 *-------------------------------------------------------------------------
18 */
19 #ifndef PQXX_H_TABLEREADER
20 #define PQXX_H_TABLEREADER
21 #include "pqxx/compiler-public.hxx"
22 #include "pqxx/compiler-internal-pre.hxx"
23 #include "pqxx/result"
24 #include "pqxx/tablestream"
25 namespace pqxx
26 {
28
31 class PQXX_LIBEXPORT tablereader : public tablestream
32 {
33 public:
34 tablereader(transaction_base &,
35 const PGSTD::string &Name,
36 const PGSTD::string &Null=PGSTD::string());
37 template<typename ITER>
38 tablereader(transaction_base &,
39 const PGSTD::string &Name,
40 ITER begincolumns,
41 ITER endcolumns);
42 template<typename ITER> tablereader(transaction_base &,
43 const PGSTD::string &Name,
44 ITER begincolumns,
45 ITER endcolumns,
46 const PGSTD::string &Null);
47 ~tablereader() throw ();
48 template<typename TUPLE> tablereader &operator>>(TUPLE &);
49 operator bool() const throw () { return !m_Done; }
50 bool operator!() const throw () { return m_Done; }
51 bool get_raw_line(PGSTD::string &Line);
52 template<typename TUPLE>
53 void tokenize(PGSTD::string, TUPLE &) const;
54 virtual void complete();
55 private:
56 void setup(transaction_base &T,
57 const PGSTD::string &RName,
58 const PGSTD::string &Columns=PGSTD::string());
59 void PQXX_PRIVATE reader_close();
60 PGSTD::string extract_field(const PGSTD::string &,
61 PGSTD::string::size_type &) const;
62 bool m_Done;
63 };
64 template<typename ITER> inline
65 tablereader::tablereader(transaction_base &T,
66 const PGSTD::string &Name,
67 ITER begincolumns,
68 ITER endcolumns) :
69 namedclass(Name, "tablereader"),
70 tablestream(T, PGSTD::string()),
71 m_Done(true)
72 {
73 setup(T, Name, columnlist(begincolumns, endcolumns));
74 }
75 template<typename ITER> inline
76 tablereader::tablereader(transaction_base &T,
77 const PGSTD::string &Name,
78 ITER begincolumns,
79 ITER endcolumns,
80 const PGSTD::string &Null) :
81 namedclass(Name, "tablereader"),
82 tablestream(T, Null),
83 m_Done(true)
84 {
85 setup(T, Name, columnlist(begincolumns, endcolumns));
86 }
87 template<typename TUPLE>
88 inline void tablereader::tokenize(PGSTD::string Line, TUPLE &T) const
89 {
90 PGSTD::back_insert_iterator<TUPLE> ins = PGSTD::back_inserter(T);
91 PGSTD::string::size_type here=0;
92 while (here < Line.size()) *ins++ = extract_field(Line, here);
93 }
94 template<typename TUPLE>
95 inline tablereader &pqxx::tablereader::operator>>(TUPLE &T)
96 {
97 PGSTD::string Line;
98 if (get_raw_line(Line)) tokenize(Line, T);
99 return *this;
100 }
101 } // namespace pqxx
102 #include "pqxx/compiler-internal-post.hxx"
103 #endif