source: gs2-extensions/tdb/trunk/perllib/DBDrivers/SQLITE.pm@ 30330

Last change on this file since 30330 was 30330, checked in by jmt12, 8 years ago

Renamed to all uppercase for simplicity
  • Property svn:executable set to *
File size: 14.8 KB
RevLine 
[30330]1###############################################################################
2#
3# DBDrivers/SQLITE.pm -- utility functions for writing to sqlite databases
4#
5# A component of the Greenstone digital library software from the New Zealand
6# Digital Library Project at the University of Waikato, New Zealand.
7#
8# Copyright (C) 2009-2010 DL Consulting Ltd.
9# Copyright (C) 2009-2015 New Zealand Digital Library Project
10#
11# This program is free software; you can redistribute it and/or modify it under
12# the terms of the GNU General Public License as published by the Free Software
13# Foundation; either version 2 of the License, or (at your option) any later
14# version.
15#
16# This program is distributed in the hope that it will be useful, but WITHOUT
17# ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
18# FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for
19# more details.
20#
21# You should have received a copy of the GNU General Public License along with
22# this program; if not, write to the Free Software Foundation, Inc., 675 Mass
23# Ave, Cambridge, MA 02139, USA.
24#
25###############################################################################
26
27package DBDrivers::SQLITE;
28
29# Pragma
30use strict;
31
32# Libraries
33use util;
34use parent 'DBDrivers::BaseDBDriver';
35
36sub BEGIN
37{
38 if (!defined $ENV{'GSDLHOME'} || !defined $ENV{'GSDLOS'}) {
39 die("Error! Environment must be prepared by sourcing setup.bash\n");
40 }
41 @DBDrivers::SQLITE::ISA = ( 'DBDrivers::BaseDBDriver' );
42}
43
44sub new
45{
46 my $class = shift(@_);
47 my $self = DBDrivers::BaseDBDriver->new();
48 $self->{'default_file_extension'} = 'db';
49 # Please set db_fast to 1 if you wish to enable faster I/O to the database
50 # by using optimisations such as PRAGMA journal_mode (MEMORY instead of
51 # DELETE) and synchronous (OFF instead of FULL)
52 # Please be aware that in this case it will be less secure and the database
53 # file may become corrupted if the if the operating system crashes or the
54 # computer loses power before that data has been written to the disk. But
55 # the speed gain is about 50x.
56 $self->{'db_fast'} = 0;
57 # Set to 1 to enable Write Ahead Logging - which is supposed to allow
58 # multiple readers/writers on a SQLite database (incompatible with
59 # db_fast). From SQLite 3.7 onwards, WAL offers limited parallel reader/
60 # writer support but is limited to single computers (doesn't work over
61 # networked filesystems). For details see:
62 # http://www.sqlite.org/draft/wal.html
63 $self->{'db_wal'} = 0;
64 # Sanity checking
65 if ($self->{'db_fast'} && $self->{'db_wal'}) {
66 print "Warning! Write-Ahead Logging is incompatible with certain SQLite optimizations; db_fast flag will be ignored.\n";
67 }
68 # The SQLite path we are using
69 $self->{'sqlite_executable'} = '';
70 bless($self, $class);
71 return $self;
72}
73
74# -----------------------------------------------------------------------------
75# SQLITE IMPLEMENTATION
76# -----------------------------------------------------------------------------
77
78## Protected
79
80## @function _getExecutable
81#
82sub _getExecutable
83{
84 my $self = shift(@_);
85 my $sqlite3_exe = $self->{'sqlite_executable'};
86 if ($sqlite3_exe eq '') {
87 # Try a full path first - SQLite3 may live in the Greenstone bin
88 # directory
89 $sqlite3_exe = &util::filename_cat($ENV{'GSDLHOME'}, 'bin', $ENV{'GSDLOS'}, 'sqlite3' . &util::get_os_exe());
90 if (!-e "$sqlite3_exe") {
91 print "Warning! Didn't find SQLite3 on expected path, \"$sqlite3_exe\", let's hope its on the system path.\n";
92 $sqlite3_exe = 'sqlite3' . &util::get_os_exe();
93 }
94 $self->{'sqlite_executable'} = $sqlite3_exe;
95 }
96 return $sqlite3_exe;
97}
98## _getExecutable() => string ##
99
100
101## @function _readInfoDBCmd(string, string) => string
102#
103sub _readInfoDBCmd
104{
105 my $self = shift(@_);
106 my $infodb_file_path = shift(@_);
107 my $sqlcmd = shift(@_);
108 my $result = "";
109 $self->_debugPrint('("' . $infodb_file_path . '", "' . $sqlcmd . '")');
110 my $sqlite3_exe = $self->_getExecutable();
111 my $infodb_handle = undef;
112 my $cmd = "\"$sqlite3_exe\" \"$infodb_file_path\" \"$sqlcmd\"";
113 if (!open($infodb_handle, "$cmd |")) {
114 print STDERR "Unable to execute: $cmd\n";
115 print STDERR "$!\n";
116 }
117 else {
118 binmode($infodb_handle, ":utf8");
119 my $line;
120 while (defined($line=<$infodb_handle>)) {
121 $result .= $line;
122 }
123 close($infodb_handle);
124 }
125 return $result;
126}
127## _readInfoDBCmd(string, string) => string ##
128
129
130## @function _sqliteSafe(string) => string
131#
132sub _sqliteSafe
133{
134 my $self = shift(@_);
135 my $value = shift(@_);
136 # Escape any single quotes in the value
137 $value =~ s/\'/\'\'/g;
138 return $value;
139}
140## _sqliteSafe(string) => string ##
141
142
143## Public
144
145
146# Handled by BaseDBDriver
147# sub get_infodb_file_path {}
148
149
150## @function open_infodb_write_handle(string, string) => handle
151#
152sub open_infodb_write_handle
153{
154 my $self = shift(@_);
155 my $infodb_file_path = shift(@_);
156 my $opt_append = shift(@_);
157
158 if (!defined $opt_append) {
159 $opt_append = '';
160 }
161
162 $self->_debugPrint('("' . $infodb_file_path . '","' . $opt_append . '")');
163
164 my $sqlite3_exe = $self->_getExecutable();
165 my $infodb_handle = undef;
166
167 # running sqlite3 with the pragma journal_mode=memory, causes sqlite to
168 # print out the word "memory". While this is not a problem usually, in our
169 # case, this ends up going out to the web page first, as part of the web
170 # page's headers, thus ruining the web page which causes an Internal
171 # Server Error (500). Therefore, we redirect sqlite's output to the null
172 # device instead. WAL mode (which also changes the journal) suffers a
173 # similar issue.
174 my $nul_device="";
175 if($self->{'db_fast'} == 1 || $self->{'db_wal'} == 1) {
176 if($ENV{'GSDLOS'} =~ m/windows/) {
177 $nul_device=">NUL";
178 } else {
179 $nul_device=">/dev/null"; # linux, mac
180 }
181 }
182
183 if(!open($infodb_handle, "| \"$sqlite3_exe\" \"$infodb_file_path\"$nul_device"))
184 {
185 print STDERR "Error! Failed to open pipe to \"" . $sqlite3_exe . "\" \"" . $infodb_file_path . "\"\n" . $! . "\n";
186 return undef;
187 }
188
189 binmode($infodb_handle,":utf8");
190
191 # Allow parallel readers/writers by using a Write Ahead Logger
192 if ($self->{'db_wal'}) {
193 print $infodb_handle "PRAGMA journal_mode=WAL;\n";
194 }
195 # Add extra optimisations, less secure but with a massive gain in performan-
196 # ce with large databases which are often updated. They should be set before
197 # the transaction begins. Incompatible with WAL.
198 elsif ($self->{'db_fast'}) {
199 print $infodb_handle "PRAGMA synchronous=OFF;\n";
200 print $infodb_handle "PRAGMA journal_mode=MEMORY;\n";
201 }
202 # If we are *not* appending, drop the table for a fresh start
203 if ($opt_append ne "append") {
204 print $infodb_handle "DROP TABLE IF EXISTS data;\n";
205 print $infodb_handle "DROP TABLE IF EXISTS document_metadata;\n";
206 }
207 print $infodb_handle "CREATE TABLE IF NOT EXISTS data (key TEXT PRIMARY KEY, value TEXT);\n";
208 print $infodb_handle "CREATE TABLE IF NOT EXISTS document_metadata (id INTEGER PRIMARY KEY, docOID TEXT, element TEXT, value TEXT);\n";
209 # These are crucial for efficiency when importing large amounts of data
210 print $infodb_handle "CREATE INDEX IF NOT EXISTS dmd ON document_metadata(docOID);\n";
211 print $infodb_handle "CREATE INDEX IF NOT EXISTS dme ON document_metadata(element);\n";
212 # This is very important for efficiency, otherwise each command will be act-
213 # ioned one at a time
214 print $infodb_handle "BEGIN TRANSACTION;\n";
215 return $infodb_handle;
216}
217## open_infodb_write_handle(string, string) => handle ##
218
219
220## @function close_infodb_write_handle(handle) => void
221#
222sub close_infodb_write_handle
223{
224 my $self = shift(@_);
225 my $infodb_handle = shift(@_);
226 $self->_debugPrint('(<handle>)');
227 # Close the transaction we began when opening the file
228 print $infodb_handle "END TRANSACTION;\n";
229 close($infodb_handle);
230}
231## close_infodb_write_handle(handle) => void ##
232
233
234## @function read_infodb_file(string, hashmap) => void
235#
236sub read_infodb_file
237{
238 my $self = shift(@_);
239 my $infodb_file_path = shift(@_);
240 my $infodb_map = shift(@_);
241 $self->_debugPrint('("' . $infodb_file_path . '", <hashmap>)');
242 my $keys_str = $self->_readInfoDBCmd($infodb_file_path,"SELECT key FROM data ORDER BY key;");
243 my @keys = split(/\n/,$keys_str);
244 foreach my $k (@keys) {
245 my $k_safe = $self->_sqliteSafe($k);
246 my $select_val_cmd = "SELECT value FROM data WHERE key='$k_safe';";
247 my $val_str = $self->_readInfoDBCmd($infodb_file_path,$select_val_cmd);
248 $infodb_map->{$k} = $val_str;
249 }
250}
251## read_infodb_file(string, hashmap) => void ##
252
253
254## @function read_infodb_keys(string, hashmap) => void
255#
256sub read_infodb_keys
257{
258 my $self = shift(@_);
259 my $infodb_file_path = shift(@_);
260 my $infodb_map = shift(@_);
261 $self->_debugPrint('("' . $infodb_file_path . '", <hashmap>)');
262 my $keys_str = $self->_readInfoDBCmd($infodb_file_path,"SELECT key FROM data;");
263 my @keys = split(/\n/,$keys_str);
264 foreach my $key (@keys)
265 {
266 $infodb_map->{$key} = 1;
267 }
268}
269## read_infodb_keys(string, hashmap) => void ##
270
271
272## @function read_infodb_rawentry(string, string) => string
273#
274sub read_infodb_rawentry
275{
276 my $self = shift(@_);
277 my $infodb_file_path = shift(@_);
278 my $infodb_key = shift(@_);
279 $self->_debugPrint('("' . $infodb_file_path . '", "' . $infodb_key . '")');
280 my $key_safe = $self->_sqliteSafe($infodb_key);
281 my $select_val_cmd = "SELECT value FROM data WHERE key='$key_safe';";
282 my $val_str = $self->_readInfoDBCmd($infodb_file_path,$select_val_cmd);
283 return $val_str
284}
285## read_infodb_rawentry(string, string) => string ##
286
287
288## @function read_infodb_entry(string, string) => hashmap
289#
290sub read_infodb_entry
291{
292 my $self = shift(@_);
293 my $infodb_file_path = shift(@_);
294 my $infodb_key = shift(@_);
295 $self->_debugPrint('("' . $infodb_file_path . '", "' . $infodb_key . '")');
296 my $val_str = $self->read_infodb_rawentry($infodb_file_path,$infodb_key);
297 my $rec_hash = &dbutil::convert_infodb_string_to_hash($val_str);
298 return $rec_hash;
299}
300## read_infodb_entry(string, string) => hashmap ##
301
302
303## @function write_infodb_entry(handle, string, hashmap) => void
304#
305sub write_infodb_entry
306{
307 my $self = shift(@_);
308 my $infodb_handle = shift(@_);
309 my $infodb_key = shift(@_);
310 my $infodb_map = shift(@_);
311 $self->_debugPrint('(<handle>, "' . $infodb_key . '", <hashmap>)');
312 # Add the key -> value mapping into the "data" table
313 my $infodb_entry_value = "";
314 foreach my $infodb_value_key (keys(%$infodb_map)) {
315 foreach my $infodb_value (@{$infodb_map->{$infodb_value_key}}) {
316 $infodb_entry_value .= "<$infodb_value_key>" . $infodb_value . "\n";
317 }
318 }
319
320 my $safe_infodb_key = $self->_sqliteSafe($infodb_key);
321 print $infodb_handle "INSERT OR REPLACE INTO data (key, value) VALUES ('" . $safe_infodb_key . "', '" . $self->_sqliteSafe($infodb_entry_value) . "');\n";
322
323 # If this infodb entry is for a document, add all the interesting document
324 # metadata to the "document_metadata" table (for use by the dynamic
325 # classifiers)
326 if ($infodb_key !~ /\./ && $infodb_entry_value =~ /\<doctype\>doc\n/) {
327 print $infodb_handle "DELETE FROM document_metadata WHERE docOID='" . $safe_infodb_key . "';\n";
328 foreach my $infodb_value_key (keys(%$infodb_map)) {
329 # We're not interested in most of the automatically added document metadata
330 next if ($infodb_value_key eq "archivedir" ||
331 $infodb_value_key eq "assocfilepath" ||
332 $infodb_value_key eq "childtype" ||
333 $infodb_value_key eq "contains" ||
334 $infodb_value_key eq "docnum" ||
335 $infodb_value_key eq "doctype" ||
336 $infodb_value_key eq "Encoding" ||
337 $infodb_value_key eq "FileSize" ||
338 $infodb_value_key eq "hascover" ||
339 $infodb_value_key eq "hastxt" ||
340 $infodb_value_key eq "lastmodified" ||
341 $infodb_value_key eq "metadataset" ||
342 $infodb_value_key eq "thistype" ||
343 $infodb_value_key =~ /^metadatafreq\-/ ||
344 $infodb_value_key =~ /^metadatalist\-/);
345 foreach my $infodb_value (@{$infodb_map->{$infodb_value_key}}) {
346 print $infodb_handle "INSERT INTO document_metadata (docOID, element, value) VALUES ('" . $safe_infodb_key . "', '" . $self->_sqliteSafe($infodb_value_key) . "', '" . $self->_sqliteSafe($infodb_value) . "');\n";
347 }
348 }
349 }
350
351 #### DEBUGGING
352 #my $new_file = "D:\\sql.txt";
353 #open(FOUT, ">>$new_file") or die "Unable to open $new_file for writing out sql statements...ERROR: $!\n";
354 #print FOUT "BEGIN;\n".$insertStatementsBuffer."\nEND;\n";
355 #close(FOUT);
356 #print STDERR $insertStatementsBuffer;
357 #### END DEBUGGING
358}
359## write_infodb_entry(handle, string, hashmap) => void ##
360
361
362## @function write_infodb_rawentry(handle, string, string) => void
363#
364sub write_infodb_rawentry
365{
366 my $self = shift(@_);
367 my $infodb_handle = shift(@_);
368 my $infodb_key = shift(@_);
369 my $infodb_val = shift(@_);
370 $self->_debugPrint('(<handle>, "' . $infodb_key . '", "' . $infodb_val . '")');
371 my $safe_infodb_key = $self->_sqliteSafe($infodb_key);
372 print $infodb_handle "INSERT OR REPLACE INTO data (key, value) VALUES ('" . $safe_infodb_key . "', '" . $self->_sqliteSafe($infodb_val) . "');\n";
373}
374## write_infodb_rawentry(handle, string, string) => void ##
375
376
377## @function set_infodb_entry(string, string, hashmap) => integer
378#
379sub set_infodb_entry
380{
381 my $self = shift(@_);
382 my $infodb_file_path = shift(@_);
383 my $infodb_key = shift(@_);
384 my $infodb_map = shift(@_);
385 $self->_debugPrint('("' . $infodb_file_path . '", "' . $infodb_key . '", <hashmap>)');
386 my $infodb_handle = $self->open_infodb_write_handle($infodb_file_path, "append");
387 if (!defined $infodb_handle) {
388 print STDERR "Error: Failed to open infodb write handle\n";
389 return -1;
390 }
391 else {
392 $self->write_infodb_entry($infodb_handle,$infodb_key,$infodb_map);
393 $self->close_infodb_write_handle($infodb_handle);
394 }
395 # Not currently checking for errors on write to DB
396 return 0;
397}
398## set_infodb_entry(string, string, hashmap) => integer ##
399
400
401## @function delete_infodb_entry(handle, string) => void
402#
403sub delete_infodb_entry
404{
405 my $self = shift(@_);
406 my $infodb_handle = shift(@_);
407 my $infodb_key = shift(@_);
408 $self->_debugPrint('(<handle>, "' . $infodb_key . '")');
409 # Delete the key from the "data" table
410 my $safe_infodb_key = $self->_sqliteSafe($infodb_key);
411 print $infodb_handle "DELETE FROM data WHERE key='" . $safe_infodb_key . "';\n";
412 # If this infodb entry is for a document, delete the "document_metadata"
413 # table entry also (for use by the dynamic classifiers)
414 if ($infodb_key !~ /\./) {
415 # Possible for there not to be a docOID matching this infodb_key
416 # (entries are only made when <doctype> == doc
417 # Attempt to delete it, and don't complain if one isn't found
418 print $infodb_handle "DELETE FROM document_metadata WHERE docOID='" . $safe_infodb_key . "';\n";
419 }
420}
421## delete_infodb_entry(handle, string) => void ##
422
423
4241;
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