source: gsdl/trunk/perllib/GDBMUtils.pm@ 17285

Last change on this file since 17285 was 17285, checked in by kjdon, 13 years ago

fixed a couple of typos in function calls

  • Property svn:keywords set to Author Date Id Revision
File size: 4.8 KB
Line 
1package GDBMUtils;
2
3use strict;
4use util;
5
6my $debug = 0;
7
8# /** Global variables to hold a strings containing:
9# * the last collection, oid and value
10# * a gdbmCachedCollectionGet() was performed on.
11# */
12my $gdbmget_previous_collection = "";
13my $gdbmget_previous_oid = "";
14my $gdbmget_previous_value = "";
15
16
17
18sub gdbmDatabaseGet
19 {
20 my ($database, $oid) = @_;
21
22 # Are we in windows? Do we need .exe?
23 my $exe = &util::get_os_exe();
24
25 # Retrieve the raw document content
26 print STDERR "#Get document\ncmd: gdbmget$exe \"$database\" \"$oid\"\n" if $debug;
27 my $value = `gdbmget$exe "$database" "$oid"`;
28
29 # Done
30 return $value;
31 }
32
33sub gdbmDatabaseAppend
34 {
35 my ($database, $oid, $value) = @_;
36
37 # Are we in windows? Do we need .exe?
38 my $exe = &util::get_os_exe();
39
40 # Escape any speech marks in the value
41 $value =~ s/\"/\\\"/g;
42 # Set the document content
43 print STDERR "#Set document\ncmd: gdbmset$exe \"$database\" \"$oid\" \"$value\" append\n" if $debug;
44 `gdbmset$exe "$database" "$oid" "$value" append`;
45}
46
47
48sub gdbmDatabaseSet
49 {
50 my ($database, $oid, $value) = @_;
51
52 # Are we in windows? Do we need .exe?
53 my $exe = &util::get_os_exe();
54
55 # Escape any speech marks in the value
56 $value =~ s/\"/\\\"/g;
57 # Set the document content
58 print STDERR "#Set document\ncmd: gdbmset$exe \"$database\" \"$oid\" \"$value\"\n" if $debug;
59 `gdbmset$exe "$database" "$oid" "$value"`;
60}
61
62
63sub gdbmDatabaseRemove
64 {
65 my ($database, $oid) = @_;
66
67 # Are we in windows? Do we need .exe?
68 my $exe = &util::get_os_exe();
69
70 # Remove the document from the database
71 print STDERR "#Set document\ncmd: gdbmset$exe \"$database\" \"$oid\"\n" if $debug;
72
73 # Think it would be clearer if this funcctionality was done
74 # by a separate executable, e.g. gdbmremove
75 `gdbmset$exe "$database" "$oid"`;
76}
77
78
79
80# /** This wraps John T's gdbmget executable to get the gdbm database entry for
81# * a particular OID.
82# *
83# * @param $collection is the collection name.
84# * @param $oid is the internal document id.
85# *
86# *
87# * @author John Rowe, DL Consulting Ltd.
88# * @author John Thompson, DL Consulting Ltd.
89# */
90sub gdbmCachedCollectionGet
91 {
92 my ($collection, $oid) = @_;
93 # Start by checking if this request is the same as the previous one, and if
94 # so return the cache version instead. This is an optimization to improve
95 # performance when checking if a certain GDBM document exists before
96 # creating a new node object
97 if($collection eq $gdbmget_previous_collection
98 && $oid eq $gdbmget_previous_oid)
99 {
100 print STDERR "#Get document - using cached value\n" if $debug;
101 return $gdbmget_previous_value;
102 }
103
104 # Where's the database?
105 my $database = _getDatabasePath($collection);
106
107 my $value = gdbmDatabaseGet($database,$oid);
108
109 # Tidy up the ever growing number of newlines at the end of the value
110 $value =~ s/(\r?\n)+/$1/g;
111 # Why do we need the above line? At the very least it would seem
112 # better that the data going in to the database through 'set' is
113 # monitored for superfluous \r\n which are then removed before being
114 # saved in GDBM
115
116 # Cache this result
117 $gdbmget_previous_collection = $collection;
118 $gdbmget_previous_oid = $oid;
119 $gdbmget_previous_value = $value;
120
121 # Done
122 return $value;
123 }
124# /** gdbmCachedCollectionGet **/
125
126# /** This wraps John T's gdbmset executable to set the gdbm database entry for
127# * a particular OID. This does not yet report errors.
128# *
129# * @param $collection is the collection name.
130# * @param $oid is the internal document id.
131# * @param $value is the new value to set for the oid.
132# *
133# * @author John Rowe, DL Consulting Ltd.
134# */
135sub gdbmCachedCollectionSet
136 {
137 my ($collection, $oid, $value) = @_;
138
139 # Where's the database?
140 my $database = _getDatabasePath($collection);
141
142
143 # Check whether value is set
144 if (defined($value))
145 {
146 gdbmDatabaseSet($database,$oid,$value);
147 }
148 else
149 {
150 gdbmDatabaseRemove($database,$oid);
151 }
152
153 # Empty any cached values, as they may now be invalid
154
155 # Cache this result
156 $gdbmget_previous_collection = "";
157 $gdbmget_previous_oid = "";
158 $gdbmget_previous_value = 0;
159 }
160# /** gdbmCollectionSet **/
161
162# /** This works out the database path and returns it to the calling
163# * calling function.
164# *
165# * @param $collection The current collection name
166# *
167# * @author John Rowe, DL Consulting Ltd.
168# */
169
170sub _getDatabasePath
171 {
172 my $collection = shift(@_);
173
174 # Find out the database extension
175 my $ext = &util::is_little_endian() ? ".ldb" : ".bdb";
176
177 # Now return the full filename of the database
178
179 return &util::filename_cat($ENV{'GSDLHOME'}, "collect", $collection, "index", "text", $collection.$ext);
180 }
181# /** getDatabasePath **/
182
1831;
Note: See TracBrowser for help on using the repository browser.