Add empty 'virtual' .ALL hierarchies as needed.
[usenet/newsstats.git] / NewsStats.pm
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1# NewsStats.pm
2#
3# Library functions for the NewsStats package.
4#
edd250f2 5# Copyright (c) 2010-2012 Thomas Hochstein <thh@inter.net>
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6#
7# This module can be redistributed and/or modified under the same terms under
8# which Perl itself is published.
9
10package NewsStats;
11
12use strict;
13use warnings;
14our ($VERSION, @ISA, @EXPORT, @EXPORT_OK, %EXPORT_TAGS);
15
16require Exporter;
17@ISA = qw(Exporter);
18@EXPORT = qw(
741336c2 19 $MyVersion
f6d15ca7 20 $PackageVersion
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21 $FullPath
22 $HomePath
23 ShowVersion
24 ShowPOD
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25 ReadConfig
26 OverrideConfig
27 InitDB
edd250f2 28 Bleat
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29);
30@EXPORT_OK = qw(
31 GetTimePeriod
32 LastMonth
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33 SplitPeriod
34 ListMonth
35 ListNewsgroups
ad609792 36 ReadGroupList
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37 OutputData
38 FormatOutput
39 SQLHierarchies
edd250f2 40 SQLSortOrder
741336c2 41 SQLGroupList
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42 SQLSetBounds
43 SQLBuildClause
d3b6810d 44 GetMaxLength
741336c2 45);
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46%EXPORT_TAGS = ( TimePeriods => [qw(GetTimePeriod LastMonth SplitPeriod
47 ListMonth)],
741336c2 48 Output => [qw(OutputData FormatOutput)],
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49 SQLHelper => [qw(SQLHierarchies SQLSortOrder SQLGroupList
50 SQLSetBounds SQLBuildClause GetMaxLength)]);
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51$VERSION = '0.01';
52our $PackageVersion = '0.01';
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53
54use Data::Dumper;
55use File::Basename;
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56
57use Config::Auto;
58use DBI;
59
60#####-------------------------------- Vars --------------------------------#####
61
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62# trim the path
63our $FullPath = $0;
64our $HomePath = dirname($0);
65$0 =~ s%.*/%%;
66# set version string
67our $MyVersion = "$0 $::VERSION (NewsStats.pm $VERSION)";
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68
69#####------------------------------- Basics -------------------------------#####
70
71################################################################################
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72
73################################################################################
74sub ShowVersion {
75################################################################################
76### display version and exit
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77 print "NewsStats v$PackageVersion\n$MyVersion\n";
78 print "Copyright (c) 2010-2012 Thomas Hochstein <thh\@inter.net>\n";
79 print "This program is free software; you may redistribute it ".
80 "and/or modify it under the same terms as Perl itself.\n";
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81 exit(100);
82};
83################################################################################
84
85################################################################################
86sub ShowPOD {
87################################################################################
88### feed myself to perldoc and exit
edd250f2 89 exec('perldoc', $FullPath);
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90 exit(100);
91};
92################################################################################
93
94################################################################################
95sub ReadConfig {
96################################################################################
97### read config via Config::Auto
98### IN : $ConfFile: config filename
99### OUT: reference to a hash containing the configuration
100 my ($ConfFile) = @_;
101 return Config::Auto::parse($ConfFile, format => 'equal');
102};
103################################################################################
104
105################################################################################
edd250f2 106sub OverrideConfig {
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107################################################################################
108### override configuration values
109### IN : $ConfigR : reference to configuration hash
110### $OverrideR: reference to a hash containing overrides
111 my ($ConfigR,$OverrideR) = @_;
112 my %Override = %$OverrideR;
3430c898 113 # Config hash empty?
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114 &Bleat(1,"Empty configuration hash passed to OverrideConfig()")
115 if ( keys %$ConfigR < 1);
3430c898 116 # return if no overrides
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117 return if (keys %Override < 1 or keys %$ConfigR < 1);
118 foreach my $Key (keys %Override) {
119 $$ConfigR{$Key} = $Override{$Key};
120 };
121};
122################################################################################
123
124################################################################################
125sub InitDB {
126################################################################################
127### initialise database connection
128### IN : $ConfigR: reference to configuration hash
3430c898 129### $Die : if TRUE, die if connection fails
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130### OUT: DBHandle
131 my ($ConfigR,$Die) = @_;
132 my %Conf = %$ConfigR;
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133 my $DBHandle = DBI->connect(sprintf('DBI:%s:database=%s;host=%s',
134 $Conf{'DBDriver'},$Conf{'DBDatabase'},
135 $Conf{'DBHost'}), $Conf{'DBUser'},
136 $Conf{'DBPw'}, { PrintError => 0 });
741336c2 137 if (!$DBHandle) {
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138 &Bleat(2,$DBI::errstr) if (defined($Die) and $Die);
139 &Bleat(1,$DBI::errstr);
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140 };
141 return $DBHandle;
142};
143################################################################################
144
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145################################################################################
146sub Bleat {
147################################################################################
148### print warning or error messages and terminate in case of error
149### IN : $Level : 1 = warning, 2 = error
150### $Message: warning or error message
151 my ($Level,$Message) = @_;
152 if ($Level == 1) {
153 warn "$0 W: $Message\n"
154 } elsif ($Level == 2) {
155 die "$0 E: $Message\n"
156 } else {
157 print "$0: $Message\n"
158 }
159};
160################################################################################
161
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162#####------------------------------ GetStats ------------------------------#####
163
164################################################################################
165sub ListNewsgroups {
166################################################################################
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167### explode a (scalar) list of newsgroup names to a list of newsgroup and
168### hierarchy names where every newsgroup and hierarchy appears only once:
169### de.alt.test,de.alt.admin -> de.ALL, de.alt.ALL, de.alt.test, de.alt.admin
ad609792 170### IN : $Newsgroups : a list of newsgroups (content of Newsgroups: header)
89db2f90 171### $TLH : top level hierarchy (all other newsgroups are ignored)
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172### $ValidGroupsR: reference to a hash containing all valid newsgroups
173### as keys
174### OUT: %Newsgroups : hash containing all newsgroup and hierarchy names as keys
89db2f90 175 my ($Newsgroups,$TLH,$ValidGroupsR) = @_;
ad609792 176 my %ValidGroups = %{$ValidGroupsR} if $ValidGroupsR;
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177 my %Newsgroups;
178 chomp($Newsgroups);
179 # remove whitespace from contents of Newsgroups:
180 $Newsgroups =~ s/\s//;
181 # call &HierarchyCount for each newsgroup in $Newsgroups:
182 for (split /,/, $Newsgroups) {
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183 # don't count newsgroup/hierarchy in wrong TLH
184 next if($TLH and !/^$TLH/);
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185 # don't count invalid newsgroups
186 if(%ValidGroups and !defined($ValidGroups{$_})) {
0dc13b39 187 warn (sprintf("DROPPED: %s\n",$_));
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188 next;
189 }
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190 # add original newsgroup to %Newsgroups
191 $Newsgroups{$_} = 1;
192 # add all hierarchy elements to %Newsgroups, amended by '.ALL',
193 # i.e. de.alt.ALL and de.ALL
194 foreach (ParseHierarchies($_)) {
195 $Newsgroups{$_.'.ALL'} = 1;
196 }
197 };
198 return %Newsgroups;
199};
200
201################################################################################
202sub ParseHierarchies {
203################################################################################
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204### return a list of all hierarchy levels a newsgroup belongs to
205### (for de.alt.test.moderated that would be de/de.alt/de.alt.test)
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206### IN : $Newsgroup : a newsgroup name
207### OUT: @Hierarchies: array containing all hierarchies the newsgroup belongs to
208 my ($Newsgroup) = @_;
209 my @Hierarchies;
210 # strip trailing dots
211 $Newsgroup =~ s/(.+)\.+$/$1/;
212 # butcher newsgroup name by "." and add each hierarchy to @Hierarchies
213 # i.e. de.alt.test: "de.alt" and "de"
214 while ($Newsgroup =~ /\./) {
215 $Newsgroup =~ s/^((?:\.?[^.]+)*)\.[^.]+$/$1/;
216 push @Hierarchies, $Newsgroup;
217 };
218 return @Hierarchies;
219};
220
221################################################################################
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222sub ReadGroupList {
223################################################################################
224### read a list of valid newsgroups from file (each group on one line,
225### ignoring everything after the first whitespace and so accepting files
226### in checkgroups format as well as (parts of) an INN active file)
227### IN : $Filename : file to read
228### OUT: \%ValidGroups: hash containing all valid newsgroups
229 my ($Filename) = @_;
230 my %ValidGroups;
edd250f2 231 open (my $LIST,"<$Filename") or &Bleat(2,"Cannot read $Filename: $!");
ad609792 232 while (<$LIST>) {
7662b106 233 s/^\s*(\S+).*$/$1/;
ad609792 234 chomp;
7662b106 235 next if /^$/;
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236 $ValidGroups{$_} = '1';
237 };
238 close $LIST;
239 return \%ValidGroups;
240};
241
242################################################################################
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243
244#####----------------------------- TimePeriods ----------------------------#####
245
246################################################################################
247sub GetTimePeriod {
248################################################################################
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249### get a time period to act on from --month option;
250### if empty, default to last month
251### IN : $Month: may be empty, 'YYYY-MM', 'YYYY-MM:YYYY-MM' or 'all'
252### OUT: $Verbal,$SQL: verbal description and WHERE-clause
253### of the chosen time period
254 my ($Month) = @_;
255 # define result variables
256 my ($Verbal, $SQL);
257 # define a regular expression for a month
258 my $REMonth = '\d{4}-\d{2}';
259
260 # default to last month if option is not set
261 if(!$Month) {
262 $Month = &LastMonth;
263 }
264
265 # check for valid input
266 if ($Month =~ /^$REMonth$/) {
267 # single month (YYYY-MM)
268 ($Month) = &CheckMonth($Month);
269 $Verbal = $Month;
270 $SQL = sprintf("month = '%s'",$Month);
271 } elsif ($Month =~ /^$REMonth:$REMonth$/) {
272 # time period (YYYY-MM:YYYY-MM)
273 $Verbal = sprintf('%s to %s',&SplitPeriod($Month));
274 $SQL = sprintf("month BETWEEN '%s' AND '%s'",&SplitPeriod($Month));
275 } elsif ($Month =~ /^all$/i) {
276 # special case: ALL
277 $Verbal = 'all time';
278 $SQL = '';
741336c2 279 } else {
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280 # invalid input
281 return (undef,undef);
282 }
283
284 return ($Verbal,$SQL);
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285};
286
287################################################################################
288sub LastMonth {
289################################################################################
3430c898 290### get last month from todays date in YYYY-MM format
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291### OUT: last month as YYYY-MM
292 # get today's date
293 my (undef,undef,undef,undef,$Month,$Year,undef,undef,undef) = localtime(time);
294 # $Month is already defined from 0 to 11, so no need to decrease it by 1
295 $Year += 1900;
296 if ($Month < 1) {
297 $Month = 12;
298 $Year--;
299 };
300 # return last month
301 return sprintf('%4d-%02d',$Year,$Month);
302};
303
304################################################################################
305sub CheckMonth {
306################################################################################
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307### check if input (in YYYY-MM form) is valid with MM between 01 and 12;
308### otherwise, fix it
309### IN : @Month: array of month
310### OUT: @Month: a valid month
311 my (@Month) = @_;
312 foreach my $Month (@Month) {
313 my ($OldMonth) = $Month;
314 my ($CalMonth) = substr ($Month, -2);
315 if ($CalMonth < 1 or $CalMonth > 12) {
316 $CalMonth = '12' if $CalMonth > 12;
317 $CalMonth = '01' if $CalMonth < 1;
318 substr($Month, -2) = $CalMonth;
319 &Bleat(1,sprintf("'%s' is an invalid date (MM must be between '01' ".
320 "and '12'), set to '%s'.",$OldMonth,$Month));
321 }
322 }
323 return @Month;
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324};
325
326################################################################################
327sub SplitPeriod {
328################################################################################
3430c898 329### split a time period denoted by YYYY-MM:YYYY-MM into start and end month
741336c2 330### IN : $Period: time period
edd250f2 331### OUT: $StartMonth, $EndMonth
741336c2 332 my ($Period) = @_;
741336c2 333 my ($StartMonth, $EndMonth) = split /:/, $Period;
edd250f2 334 ($StartMonth,$EndMonth) = CheckMonth($StartMonth,$EndMonth);
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335 # switch parameters as necessary
336 if ($EndMonth gt $StartMonth) {
337 return ($StartMonth, $EndMonth);
338 } else {
339 return ($EndMonth, $StartMonth);
340 };
341};
342
343################################################################################
344sub ListMonth {
345################################################################################
3430c898 346### return a list of months (YYYY-MM) between start and end month
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347### IN : $MonthExpression ('YYYY-MM' or 'YYYY-MM to YYYY-MM')
348### OUT: @Months: array containing all months from $MonthExpression enumerated
349 my ($MonthExpression )= @_;
350 # return if single month
351 return ($MonthExpression) if ($MonthExpression =~ /^\d{4}-\d{2}$/);
352 # parse $MonthExpression
353 my ($StartMonth, $EndMonth) = split(' to ',$MonthExpression);
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354 # set $Year, $Month from $StartMonth
355 my ($Year, $Month) = split /-/, $StartMonth;
356 # define @Months
357 my (@Months);
358 until ("$Year-$Month" gt $EndMonth) {
359 push @Months, "$Year-$Month";
360 $Month = "$Month"; # force string context
361 $Month++;
362 if ($Month > 12) {
363 $Month = '01';
364 $Year++;
365 };
366 };
367 return @Months;
368};
369
370#####---------------------------- OutputFormats ---------------------------#####
371
372################################################################################
373sub OutputData {
374################################################################################
3430c898 375### read database query results from DBHandle and print results with formatting
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376### IN : $Format : format specifier
377### $Comments : print or suppress all comments for machine-readable output
378### $GroupBy : primary sorting order (month or key)
379### $Precision: number of digits right of decimal point (0 or 2)
380### $ValidKeys: reference to a hash containing all valid keys
381### $FileTempl: file name template (--filetemplate): filetempl-YYYY-MM
382### $DBQuery : database query handle with executed query,
78389b28 383### containing $Month, $Key, $Value
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384### $PadGroup : padding length for key field (optional) for 'pretty'
385 my ($Format, $Comments, $GroupBy, $Precision, $ValidKeys, $FileTempl,
386 $DBQuery, $PadGroup) = @_;
387 my %ValidKeys = %{$ValidKeys} if $ValidKeys;
388 my ($FileName, $Handle, $OUT);
78389b28 389 our $LastIteration;
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390
391 # define output types
392 my %LegalOutput;
393 @LegalOutput{('dump',,'list','pretty')} = ();
394 # bail out if format is unknown
395 &Bleat(2,"Unknown output type '$Format'!") if !exists($LegalOutput{$Format});
396
741336c2 397 while (my ($Month, $Key, $Value) = $DBQuery->fetchrow_array) {
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398 # don't display invalid keys
399 if(%ValidKeys and !defined($ValidKeys{$Key})) {
400 # FIXME
401 # &Bleat(1,sprintf("DROPPED: %s",$Key));
402 next;
403 };
404 # care for correct sorting order and abstract from month and keys:
405 # $Caption will be $Month or $Key, according to sorting order,
406 # and $Key will be $Key or $Month, respectively
407 my $Caption;
408 if ($GroupBy eq 'key') {
409 $Caption = $Key;
410 $Key = $Month;
411 } else {
412 $Caption = $Month;
413 }
78389b28 414 # set output file handle
edd250f2 415 if (!$FileTempl) {
78389b28 416 $Handle = *STDOUT{IO}; # set $Handle to a reference to STDOUT
edd250f2 417 } elsif (!defined($LastIteration) or $LastIteration ne $Caption) {
78389b28 418 close $OUT if ($LastIteration);
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419 # safeguards for filename creation:
420 # replace potential problem characters with '_'
421 $FileName = sprintf('%s-%s',$FileTempl,$Caption);
422 $FileName =~ s/[^a-zA-Z0-9_-]+/_/g;
423 open ($OUT,">$FileName")
424 or &Bleat(2,sprintf("Cannot open output file '%s': $!",
425 $FileName));
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426 $Handle = $OUT;
427 };
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428 print $Handle &FormatOutput($Format, $Comments, $Caption, $Key, $Value,
429 $Precision, $PadGroup);
430 $LastIteration = $Caption;
741336c2 431 };
edd250f2 432 close $OUT if ($FileTempl);
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433};
434
435################################################################################
436sub FormatOutput {
437################################################################################
3430c898 438### format information for output according to format specifier
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439### IN : $Format : format specifier
440### $Comments : print or suppress all comments for machine-readable output
441### $Caption : month (as YYYY-MM) or $Key, according to sorting order
442### $Key : newsgroup, client, ... or $Month, as above
443### $Value : number of postings with that attribute
444### $Precision: number of digits right of decimal point (0 or 2)
445### $PadGroup : padding length for key field (optional) for 'pretty'
741336c2 446### OUT: $Output: formatted output
edd250f2 447 my ($Format, $Comments, $Caption, $Key, $Value, $Precision, $PadGroup) = @_;
741336c2 448 my ($Output);
edd250f2 449 # keep last caption in mind
741336c2 450 our ($LastIteration);
edd250f2 451 # create one line of output
741336c2 452 if ($Format eq 'dump') {
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453 # output as dump (key value)
454 $Output = sprintf ("# %s:\n",$Caption)
455 if ($Comments and (!defined($LastIteration) or $Caption ne $LastIteration));
456 $Output .= sprintf ("%s %u\n",$Key,$Value);
741336c2 457 } elsif ($Format eq 'list') {
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458 # output as list (caption key value)
459 $Output = sprintf ("%s %s %u\n",$Caption,$Key,$Value);
741336c2 460 } elsif ($Format eq 'pretty') {
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461 # output as a table
462 $Output = sprintf ("# ----- %s:\n",$Caption)
463 if ($Comments and (!defined($LastIteration) or $Caption ne $LastIteration));
464 $Output .= sprintf ($PadGroup ? sprintf("%%-%us %%10.*f\n",$PadGroup) :
465 "%s %.*f\n",$Key,$Precision,$Value);
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466 };
467 return $Output;
468};
469
470#####------------------------- QueryModifications -------------------------#####
471
472################################################################################
473sub SQLHierarchies {
474################################################################################
3430c898
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475### add exclusion of hierarchy levels (de.alt.ALL) from SQL query by
476### amending the WHERE clause if $ShowHierarchies is false (or don't, if it is
477### true, accordingly)
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478### IN : $ShowHierarchies: boolean value
479### OUT: SQL code
480 my ($ShowHierarchies) = @_;
edd250f2 481 return $ShowHierarchies ? '' : "newsgroup NOT LIKE '%.ALL'";
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482};
483
484################################################################################
d3b6810d 485sub GetMaxLength {
741336c2 486################################################################################
3430c898 487### get length of longest field in future query result
edd250f2
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488### IN : $DBHandle : database handel
489### $Table : table to query
490### $Field : field to check
491### $WhereClause : WHERE clause
492### $HavingClause: HAVING clause
493### @BindVars : bind variables for WHERE clause
741336c2 494### OUT: $Length: length of longest instnace of $Field
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495 my ($DBHandle,$Table,$Field,$WhereClause,$HavingClause,@BindVars) = @_;
496 my $DBQuery = $DBHandle->prepare(sprintf("SELECT MAX(LENGTH(%s)) ".
497 "FROM %s %s %s",$Field,$Table,
498 $WhereClause,$HavingClause ?
499 'GROUP BY newsgroup' . $HavingClause .
500 ' ORDER BY LENGTH(newsgroup) '.
501 'DESC LIMIT 1': ''));
502 $DBQuery->execute(@BindVars) or &Bleat(1,sprintf("Can't get field length ".
503 "for '%s' from table '%s': ".
504 "$DBI::errstr",$Field,$Table));
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505 my ($Length) = $DBQuery->fetchrow_array;
506 return $Length;
507};
508
509################################################################################
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510sub SQLSortOrder {
511################################################################################
512### build a SQL 'ORDER BY' clause from $OptGroupBy (primary sorting) and
513### $OptOrderBy (secondary sorting), both ascending or descending;
514### descending sorting order is done by adding '-desc'
515### IN : $GroupBy: primary sort by 'month' (default) or 'newsgroups'
516### $OrderBy: secondary sort by month/newsgroups (default)
517### or number of 'postings'
518### OUT: a SQL ORDER BY clause
519 my ($GroupBy,$OrderBy) = @_;
520 my ($GroupSort,$OrderSort) = ('','');
521 # $GroupBy (primary sorting)
522 if (!$GroupBy) {
523 $GroupBy = 'month';
524 } else {
525 ($GroupBy, $GroupSort) = SQLParseOrder($GroupBy);
526 if ($GroupBy =~ /group/i) {
527 $GroupBy = 'newsgroup';
528 } else {
529 $GroupBy = 'month';
530 }
531 }
532 my $Secondary = ($GroupBy eq 'month') ? 'newsgroup' : 'month';
533 # $OrderBy (secondary sorting)
534 if (!$OrderBy) {
535 $OrderBy = $Secondary;
536 } else {
537 ($OrderBy, $OrderSort) = SQLParseOrder($OrderBy);
538 if ($OrderBy =~ /posting/i) {
539 $OrderBy = "postings $OrderSort, $Secondary";
540 } else {
541 $OrderBy = "$Secondary $OrderSort";
542 }
543 }
544 return ($GroupBy,&SQLBuildClause('order',"$GroupBy $GroupSort",$OrderBy));
545};
546
547################################################################################
548sub SQLParseOrder {
549################################################################################
550### parse $OptGroupBy or $OptOrderBy option of the form param[-desc], e.g.
551### 'month', 'month-desc', 'newsgroups-desc', but also just 'desc'
552### IN : $OrderOption: order option (see above)
553### OUT: parameter to sort by,
554### sort order ('DESC' or nothing, meaning 'ASC')
555 my ($OrderOption) = @_;
556 my $SortOrder = '';
557 if ($OrderOption =~ s/-?desc$//i) {
558 $SortOrder = 'DESC';
559 } else {
560 $OrderOption =~ s/-?asc$//i
561 }
562 return ($OrderOption,$SortOrder);
563};
564
565################################################################################
741336c2
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566sub SQLGroupList {
567################################################################################
edd250f2
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568### explode list of newsgroups separated by : (with wildcards)
569### to a SQL 'WHERE' expression
741336c2 570### IN : $Newsgroups: list of newsgroups (group.one.*:group.two:group.three.*)
edd250f2
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571### OUT: SQL code to become part of a 'WHERE' clause,
572### list of newsgroups for SQL bindings
741336c2 573 my ($Newsgroups) = @_;
edd250f2 574 # substitute '*' wildcard with SQL wildcard character '%'
741336c2 575 $Newsgroups =~ s/\*/%/g;
edd250f2
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576 # just one newsgroup?
577 return (SQLGroupWildcard($Newsgroups),$Newsgroups) if $Newsgroups !~ /:/;
578 # list of newsgroups separated by ':'
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579 my $SQL = '(';
580 my @GroupList = split /:/, $Newsgroups;
581 foreach (@GroupList) {
582 $SQL .= ' OR ' if $SQL gt '(';
edd250f2 583 $SQL .= SQLGroupWildcard($_);
741336c2
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584 };
585 $SQL .= ')';
586 return ($SQL,@GroupList);
587};
588
edd250f2
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589################################################################################
590sub SQLGroupWildcard {
591################################################################################
592### build a valid SQL 'WHERE' expression with or without wildcards
593### IN : $Newsgroup: newsgroup expression, probably with wildcard
594### (group.name or group.name.%)
595### OUT: SQL code to become part of a 'WHERE' clause
596 my ($Newsgroup) = @_;
597 # FIXME: check for validity
598 if ($Newsgroup !~ /%/) {
599 return 'newsgroup = ?';
600 } else {
601 return 'newsgroup LIKE ?';
602 }
603};
604
605################################################################################
606sub SQLSetBounds {
607################################################################################
608### set upper and/or lower boundary (number of postings)
609### IN : $Type: 'level', 'average', 'sum' or 'default'
610### $LowBound,$UppBound: lower/upper boundary, respectively
611### OUT: SQL code to become part of a WHERE or HAVING clause
612 my ($Type,$LowBound,$UppBound) = @_;
613 ($LowBound,$UppBound) = SQLCheckNumber($LowBound,$UppBound);
614 if($LowBound and $UppBound and $LowBound > $UppBound) {
615 &Bleat(1,"Lower boundary $LowBound is larger than Upper boundary ".
616 "$UppBound, exchanging boundaries.");
617 ($LowBound,$UppBound) = ($UppBound,$LowBound);
618 }
619 # default to 'default'
620 my $WhereHavingFunction = 'postings';
621 # set $LowBound to SQL statement:
622 # 'WHERE postings >=', 'HAVING MIN(postings) >=' or 'HAVING AVG(postings) >='
623 if ($Type eq 'level') {
624 $WhereHavingFunction = 'MIN(postings)'
625 } elsif ($Type eq 'average') {
626 $WhereHavingFunction = 'AVG(postings)'
627 } elsif ($Type eq 'sum') {
628 $WhereHavingFunction = 'SUM(postings)'
629 }
630 $LowBound = sprintf('%s >= '.$LowBound,$WhereHavingFunction) if ($LowBound);
631 # set $LowBound to SQL statement:
632 # 'WHERE postings <=', 'HAVING MAX(postings) <=' or 'HAVING AVG(postings) <='
633 if ($Type eq 'level') {
634 $WhereHavingFunction = 'MAX(postings)'
635 } elsif ($Type eq 'average') {
636 $WhereHavingFunction = 'AVG(postings)'
637 } elsif ($Type eq 'sum') {
638 $WhereHavingFunction = 'SUM(postings)'
639 }
640 $UppBound = sprintf('%s <= '.$UppBound,$WhereHavingFunction) if ($UppBound);
641 return ($LowBound,$UppBound);
642};
643
644################################################################################
645sub SQLCheckNumber {
646################################################################################
647### check if input is a valid positive integer; otherwise, make it one
648### IN : @Numbers: array of parameters
649### OUT: @Numbers: a valid positive integer
650 my (@Numbers) = @_;
651 foreach my $Number (@Numbers) {
652 if ($Number and $Number < 0) {
653 &Bleat(1,"Boundary $Number is < 0, set to ".-$Number);
654 $Number = -$Number;
655 }
656 $Number = '' if ($Number and $Number !~ /^\d+$/);
657 }
658 return @Numbers;
659};
660
661################################################################################
662sub SQLBuildClause {
663################################################################################
664### build a valid SQL WHERE, GROUP BY, ORDER BY or HAVING clause
665### from multiple expressions which *may* be empty
666### IN : $Type: 'where', 'having', 'group' or 'order'
667### @Expressions: array of expressions
668### OUT: $SQLClause: a SQL clause
669 my ($Type,@Expressions) = @_;
670 my ($SQLClause,$Separator,$Statement);
671 # set separator ('AND' or ',')
672 if ($Type eq 'where' or $Type eq 'having') {
673 $Separator = 'AND';
674 } else {
675 $Separator = ',';
676 }
677 # set statement
678 if ($Type eq 'where') {
679 $Statement = 'WHERE';
680 } elsif ($Type eq 'order') {
681 $Statement = 'ORDER BY';
682 } elsif ($Type eq 'having') {
683 $Statement = 'HAVING';
684 } else {
685 $Statement = 'GROUP BY';
686 }
687 # build query from expressions with separators
688 foreach my $Expression (@Expressions) {
689 if ($Expression) {
690 $SQLClause .= " $Separator " if ($SQLClause);
691 $SQLClause .= $Expression;
692 }
693 }
694 # add statement in front if not already present
695 $SQLClause = " $Statement " . $SQLClause
696 if ($SQLClause and $SQLClause !~ /$Statement/);
697 return $SQLClause;
698};
699
700
741336c2
TH
701#####------------------------------- done ---------------------------------#####
7021;
703
704
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