Filename | /usr/lib/perl5/5.14/Tie/Hash.pm |
Statements | Executed 7 statements in 1.25ms |
Calls | P | F | Exclusive Time |
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1 | 1 | 1 | 197µs | 277µs | BEGIN@188 | Tie::Hash::
1 | 1 | 1 | 17µs | 234µs | BEGIN@189 | Tie::Hash::
1 | 1 | 1 | 9µs | 9µs | TIEHASH | Tie::StdHash::
0 | 0 | 0 | 0s | 0s | CLEAR | Tie::ExtraHash::
0 | 0 | 0 | 0s | 0s | DELETE | Tie::ExtraHash::
0 | 0 | 0 | 0s | 0s | EXISTS | Tie::ExtraHash::
0 | 0 | 0 | 0s | 0s | FETCH | Tie::ExtraHash::
0 | 0 | 0 | 0s | 0s | FIRSTKEY | Tie::ExtraHash::
0 | 0 | 0 | 0s | 0s | NEXTKEY | Tie::ExtraHash::
0 | 0 | 0 | 0s | 0s | SCALAR | Tie::ExtraHash::
0 | 0 | 0 | 0s | 0s | STORE | Tie::ExtraHash::
0 | 0 | 0 | 0s | 0s | TIEHASH | Tie::ExtraHash::
0 | 0 | 0 | 0s | 0s | CLEAR | Tie::Hash::
0 | 0 | 0 | 0s | 0s | EXISTS | Tie::Hash::
0 | 0 | 0 | 0s | 0s | TIEHASH | Tie::Hash::
0 | 0 | 0 | 0s | 0s | new | Tie::Hash::
0 | 0 | 0 | 0s | 0s | CLEAR | Tie::StdHash::
0 | 0 | 0 | 0s | 0s | DELETE | Tie::StdHash::
0 | 0 | 0 | 0s | 0s | EXISTS | Tie::StdHash::
0 | 0 | 0 | 0s | 0s | FETCH | Tie::StdHash::
0 | 0 | 0 | 0s | 0s | FIRSTKEY | Tie::StdHash::
0 | 0 | 0 | 0s | 0s | NEXTKEY | Tie::StdHash::
0 | 0 | 0 | 0s | 0s | SCALAR | Tie::StdHash::
0 | 0 | 0 | 0s | 0s | STORE | Tie::StdHash::
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1 | package Tie::Hash; | ||||
2 | |||||
3 | 1 | 1µs | our $VERSION = '1.04'; | ||
4 | |||||
5 | =head1 NAME | ||||
6 | |||||
7 | Tie::Hash, Tie::StdHash, Tie::ExtraHash - base class definitions for tied hashes | ||||
8 | |||||
9 | =head1 SYNOPSIS | ||||
10 | |||||
11 | package NewHash; | ||||
12 | require Tie::Hash; | ||||
13 | |||||
14 | @ISA = qw(Tie::Hash); | ||||
15 | |||||
16 | sub DELETE { ... } # Provides needed method | ||||
17 | sub CLEAR { ... } # Overrides inherited method | ||||
18 | |||||
19 | |||||
20 | package NewStdHash; | ||||
21 | require Tie::Hash; | ||||
22 | |||||
23 | @ISA = qw(Tie::StdHash); | ||||
24 | |||||
25 | # All methods provided by default, define only those needing overrides | ||||
26 | # Accessors access the storage in %{$_[0]}; | ||||
27 | # TIEHASH should return a reference to the actual storage | ||||
28 | sub DELETE { ... } | ||||
29 | |||||
30 | package NewExtraHash; | ||||
31 | require Tie::Hash; | ||||
32 | |||||
33 | @ISA = qw(Tie::ExtraHash); | ||||
34 | |||||
35 | # All methods provided by default, define only those needing overrides | ||||
36 | # Accessors access the storage in %{$_[0][0]}; | ||||
37 | # TIEHASH should return an array reference with the first element being | ||||
38 | # the reference to the actual storage | ||||
39 | sub DELETE { | ||||
40 | $_[0][1]->('del', $_[0][0], $_[1]); # Call the report writer | ||||
41 | delete $_[0][0]->{$_[1]}; # $_[0]->SUPER::DELETE($_[1]) | ||||
42 | } | ||||
43 | |||||
44 | |||||
45 | package main; | ||||
46 | |||||
47 | tie %new_hash, 'NewHash'; | ||||
48 | tie %new_std_hash, 'NewStdHash'; | ||||
49 | tie %new_extra_hash, 'NewExtraHash', | ||||
50 | sub {warn "Doing \U$_[1]\E of $_[2].\n"}; | ||||
51 | |||||
52 | =head1 DESCRIPTION | ||||
53 | |||||
54 | This module provides some skeletal methods for hash-tying classes. See | ||||
55 | L<perltie> for a list of the functions required in order to tie a hash | ||||
56 | to a package. The basic B<Tie::Hash> package provides a C<new> method, as well | ||||
57 | as methods C<TIEHASH>, C<EXISTS> and C<CLEAR>. The B<Tie::StdHash> and | ||||
58 | B<Tie::ExtraHash> packages | ||||
59 | provide most methods for hashes described in L<perltie> (the exceptions | ||||
60 | are C<UNTIE> and C<DESTROY>). They cause tied hashes to behave exactly like standard hashes, | ||||
61 | and allow for selective overwriting of methods. B<Tie::Hash> grandfathers the | ||||
62 | C<new> method: it is used if C<TIEHASH> is not defined | ||||
63 | in the case a class forgets to include a C<TIEHASH> method. | ||||
64 | |||||
65 | For developers wishing to write their own tied hashes, the required methods | ||||
66 | are briefly defined below. See the L<perltie> section for more detailed | ||||
67 | descriptive, as well as example code: | ||||
68 | |||||
69 | =over 4 | ||||
70 | |||||
71 | =item TIEHASH classname, LIST | ||||
72 | |||||
73 | The method invoked by the command C<tie %hash, classname>. Associates a new | ||||
74 | hash instance with the specified class. C<LIST> would represent additional | ||||
75 | arguments (along the lines of L<AnyDBM_File> and compatriots) needed to | ||||
76 | complete the association. | ||||
77 | |||||
78 | =item STORE this, key, value | ||||
79 | |||||
80 | Store datum I<value> into I<key> for the tied hash I<this>. | ||||
81 | |||||
82 | =item FETCH this, key | ||||
83 | |||||
84 | Retrieve the datum in I<key> for the tied hash I<this>. | ||||
85 | |||||
86 | =item FIRSTKEY this | ||||
87 | |||||
88 | Return the first key in the hash. | ||||
89 | |||||
90 | =item NEXTKEY this, lastkey | ||||
91 | |||||
92 | Return the next key in the hash. | ||||
93 | |||||
94 | =item EXISTS this, key | ||||
95 | |||||
96 | Verify that I<key> exists with the tied hash I<this>. | ||||
97 | |||||
98 | The B<Tie::Hash> implementation is a stub that simply croaks. | ||||
99 | |||||
100 | =item DELETE this, key | ||||
101 | |||||
102 | Delete the key I<key> from the tied hash I<this>. | ||||
103 | |||||
104 | =item CLEAR this | ||||
105 | |||||
106 | Clear all values from the tied hash I<this>. | ||||
107 | |||||
108 | =item SCALAR this | ||||
109 | |||||
110 | Returns what evaluating the hash in scalar context yields. | ||||
111 | |||||
112 | B<Tie::Hash> does not implement this method (but B<Tie::StdHash> | ||||
113 | and B<Tie::ExtraHash> do). | ||||
114 | |||||
115 | =back | ||||
116 | |||||
117 | =head1 Inheriting from B<Tie::StdHash> | ||||
118 | |||||
119 | The accessor methods assume that the actual storage for the data in the tied | ||||
120 | hash is in the hash referenced by C<tied(%tiedhash)>. Thus overwritten | ||||
121 | C<TIEHASH> method should return a hash reference, and the remaining methods | ||||
122 | should operate on the hash referenced by the first argument: | ||||
123 | |||||
124 | package ReportHash; | ||||
125 | our @ISA = 'Tie::StdHash'; | ||||
126 | |||||
127 | sub TIEHASH { | ||||
128 | my $storage = bless {}, shift; | ||||
129 | warn "New ReportHash created, stored in $storage.\n"; | ||||
130 | $storage | ||||
131 | } | ||||
132 | sub STORE { | ||||
133 | warn "Storing data with key $_[1] at $_[0].\n"; | ||||
134 | $_[0]{$_[1]} = $_[2] | ||||
135 | } | ||||
136 | |||||
137 | |||||
138 | =head1 Inheriting from B<Tie::ExtraHash> | ||||
139 | |||||
140 | The accessor methods assume that the actual storage for the data in the tied | ||||
141 | hash is in the hash referenced by C<(tied(%tiedhash))-E<gt>[0]>. Thus overwritten | ||||
142 | C<TIEHASH> method should return an array reference with the first | ||||
143 | element being a hash reference, and the remaining methods should operate on the | ||||
144 | hash C<< %{ $_[0]->[0] } >>: | ||||
145 | |||||
146 | package ReportHash; | ||||
147 | our @ISA = 'Tie::ExtraHash'; | ||||
148 | |||||
149 | sub TIEHASH { | ||||
150 | my $class = shift; | ||||
151 | my $storage = bless [{}, @_], $class; | ||||
152 | warn "New ReportHash created, stored in $storage.\n"; | ||||
153 | $storage; | ||||
154 | } | ||||
155 | sub STORE { | ||||
156 | warn "Storing data with key $_[1] at $_[0].\n"; | ||||
157 | $_[0][0]{$_[1]} = $_[2] | ||||
158 | } | ||||
159 | |||||
160 | The default C<TIEHASH> method stores "extra" arguments to tie() starting | ||||
161 | from offset 1 in the array referenced by C<tied(%tiedhash)>; this is the | ||||
162 | same storage algorithm as in TIEHASH subroutine above. Hence, a typical | ||||
163 | package inheriting from B<Tie::ExtraHash> does not need to overwrite this | ||||
164 | method. | ||||
165 | |||||
166 | =head1 C<SCALAR>, C<UNTIE> and C<DESTROY> | ||||
167 | |||||
168 | The methods C<UNTIE> and C<DESTROY> are not defined in B<Tie::Hash>, | ||||
169 | B<Tie::StdHash>, or B<Tie::ExtraHash>. Tied hashes do not require | ||||
170 | presence of these methods, but if defined, the methods will be called in | ||||
171 | proper time, see L<perltie>. | ||||
172 | |||||
173 | C<SCALAR> is only defined in B<Tie::StdHash> and B<Tie::ExtraHash>. | ||||
174 | |||||
175 | If needed, these methods should be defined by the package inheriting from | ||||
176 | B<Tie::Hash>, B<Tie::StdHash>, or B<Tie::ExtraHash>. See L<perltie/"SCALAR"> | ||||
177 | to find out what happens when C<SCALAR> does not exist. | ||||
178 | |||||
179 | =head1 MORE INFORMATION | ||||
180 | |||||
181 | The packages relating to various DBM-related implementations (F<DB_File>, | ||||
182 | F<NDBM_File>, etc.) show examples of general tied hashes, as does the | ||||
183 | L<Config> module. While these do not utilize B<Tie::Hash>, they serve as | ||||
184 | good working examples. | ||||
185 | |||||
186 | =cut | ||||
187 | |||||
188 | 2 | 63µs | 2 | 356µs | # spent 277µs (197+80) within Tie::Hash::BEGIN@188 which was called:
# once (197µs+80µs) by POSIX::SigRt::BEGIN@58 at line 188 # spent 277µs making 1 call to Tie::Hash::BEGIN@188
# spent 80µs making 1 call to Exporter::import |
189 | 2 | 1.17ms | 2 | 451µs | # spent 234µs (17+217) within Tie::Hash::BEGIN@189 which was called:
# once (17µs+217µs) by POSIX::SigRt::BEGIN@58 at line 189 # spent 234µs making 1 call to Tie::Hash::BEGIN@189
# spent 217µs making 1 call to warnings::register::import |
190 | |||||
191 | sub new { | ||||
192 | my $pkg = shift; | ||||
193 | $pkg->TIEHASH(@_); | ||||
194 | } | ||||
195 | |||||
196 | # Grandfather "new" | ||||
197 | |||||
198 | sub TIEHASH { | ||||
199 | my $pkg = shift; | ||||
200 | my $pkg_new = $pkg -> can ('new'); | ||||
201 | |||||
202 | if ($pkg_new and $pkg ne __PACKAGE__) { | ||||
203 | my $my_new = __PACKAGE__ -> can ('new'); | ||||
204 | if ($pkg_new == $my_new) { | ||||
205 | # | ||||
206 | # Prevent recursion | ||||
207 | # | ||||
208 | croak "$pkg must define either a TIEHASH() or a new() method"; | ||||
209 | } | ||||
210 | |||||
211 | warnings::warnif ("WARNING: calling ${pkg}->new since " . | ||||
212 | "${pkg}->TIEHASH is missing"); | ||||
213 | $pkg -> new (@_); | ||||
214 | } | ||||
215 | else { | ||||
216 | croak "$pkg doesn't define a TIEHASH method"; | ||||
217 | } | ||||
218 | } | ||||
219 | |||||
220 | sub EXISTS { | ||||
221 | my $pkg = ref $_[0]; | ||||
222 | croak "$pkg doesn't define an EXISTS method"; | ||||
223 | } | ||||
224 | |||||
225 | sub CLEAR { | ||||
226 | my $self = shift; | ||||
227 | my $key = $self->FIRSTKEY(@_); | ||||
228 | my @keys; | ||||
229 | |||||
230 | while (defined $key) { | ||||
231 | push @keys, $key; | ||||
232 | $key = $self->NEXTKEY(@_, $key); | ||||
233 | } | ||||
234 | foreach $key (@keys) { | ||||
235 | $self->DELETE(@_, $key); | ||||
236 | } | ||||
237 | } | ||||
238 | |||||
239 | # The Tie::StdHash package implements standard perl hash behaviour. | ||||
240 | # It exists to act as a base class for classes which only wish to | ||||
241 | # alter some parts of their behaviour. | ||||
242 | |||||
243 | package Tie::StdHash; | ||||
244 | # @ISA = qw(Tie::Hash); # would inherit new() only | ||||
245 | |||||
246 | 1 | 12µs | # spent 9µs within Tie::StdHash::TIEHASH which was called:
# once (9µs+0s) by installer::epmfile::BEGIN@42 at line 65 of POSIX.pm | ||
247 | sub STORE { $_[0]->{$_[1]} = $_[2] } | ||||
248 | sub FETCH { $_[0]->{$_[1]} } | ||||
249 | sub FIRSTKEY { my $a = scalar keys %{$_[0]}; each %{$_[0]} } | ||||
250 | sub NEXTKEY { each %{$_[0]} } | ||||
251 | sub EXISTS { exists $_[0]->{$_[1]} } | ||||
252 | sub DELETE { delete $_[0]->{$_[1]} } | ||||
253 | sub CLEAR { %{$_[0]} = () } | ||||
254 | sub SCALAR { scalar %{$_[0]} } | ||||
255 | |||||
256 | package Tie::ExtraHash; | ||||
257 | |||||
258 | sub TIEHASH { my $p = shift; bless [{}, @_], $p } | ||||
259 | sub STORE { $_[0][0]{$_[1]} = $_[2] } | ||||
260 | sub FETCH { $_[0][0]{$_[1]} } | ||||
261 | sub FIRSTKEY { my $a = scalar keys %{$_[0][0]}; each %{$_[0][0]} } | ||||
262 | sub NEXTKEY { each %{$_[0][0]} } | ||||
263 | sub EXISTS { exists $_[0][0]->{$_[1]} } | ||||
264 | sub DELETE { delete $_[0][0]->{$_[1]} } | ||||
265 | sub CLEAR { %{$_[0][0]} = () } | ||||
266 | sub SCALAR { scalar %{$_[0][0]} } | ||||
267 | |||||
268 | 1 | 9µs | 1; |