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#
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# IndexedFileStore.pm
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#
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# Originally Written by Christopher Williams
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#
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# Description
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#
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# Interface
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# ---------
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# new(storedir) : A new IndexedFileStore object based in storedir
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# store(key,file) : store a key/file combination
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# filename(key) : return the filename corresponding to a given key
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# - generate one if it dosn't already exist
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# file(key) : return the filename only if it already exists
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# delete(key) : remove from cache key
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# clear() : clear cache
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# filestore() : Return the directory to download files to
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# updatenumber(key) : return an integer number indicating update sequence
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# - this number increased by one each time store is
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# called
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package Utilities::IndexedFileStore;
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require 5.004;
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use Utilities::HashDB;
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sub new {
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my $class=shift;
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$self={};
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bless $self, $class;
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$self->_init(@_);
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return $self;
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}
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sub store {
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my $self=shift;
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my $key=shift;
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my $file=shift;
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# store as relative to filestore if applicable - relocatable stores
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my $filestore=$self->filestore();
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$file=~s/^\Q$filestore\E\///;
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$self->{keyDB}->deletedata($key);
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$self->{keyDB}->setdata($file,$key);
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$self->{keyDB}->store($self->{cacheindex});
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# Keep a track of changes
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my ($sequencenumber)=$self->{keyDBupdate}->getdata($key);
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if ( ! defined $sequencenumber ) { $sequencenumber=0 };
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$sequencenumber=$sequencenumber+1;
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$self->{keyDBupdate}->deletedata($key);
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$self->{keyDBupdate}->setdata($sequencenumber,$key);
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$self->{keyDBupdate}->store($self->{cacheseqindex});
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}
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sub updatenumber {
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my $self=shift;
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my $key=shift;
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my ($rv)=$self->{keyDBupdate}->getdata($key);
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return ((defined $rv)?$rv:0);
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}
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sub filestore {
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my $self=shift;
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return $self->{cachedir};
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}
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sub filename {
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my $self=shift;
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my $key=shift;
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my $filenumber;
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my $file=$self->file($key);
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if ( $file eq "" ) {
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# need to generate a new filename - a random number will do
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srand();
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do {
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$filenumber=int(rand 99999999)+1;
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$file=$self->filestore()."/".$filenumber;
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} until ( ! ( -e $file ) );
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}
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return $file;
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}
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sub file {
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my $self=shift;
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my $key=shift;
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my @found=$self->{keyDB}->getdata($key);
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my $file=( ($#found == -1)?"":$found[0]);
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# expand any files to include the path (unless complete path names)
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if ( ($file ne "") && ($file!~/^\//) ) {
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$file=$self->filestore()."/".$file;
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}
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return $file;
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}
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sub clear {
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my $self=shift;
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foreach $item ( $self->{keyDB}->match() ) {
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$self->delete($item->keys());
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}
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}
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sub delete {
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my $self=shift;
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my $key=shift;
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unlink ($self->{keyDB}->getdata($URL));
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$self->{keyDB}->deletedata($key);
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$self->{keyDB}->store($self->{cacheindex});
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}
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sub location {
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my $self=shift;
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return $self->{cachetop};
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}
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sub _init {
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my $self=shift;
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$self->{cachetop}=shift;
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$self->{cachedir}=$self->{cachetop}."/files";
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AddDir::adddir($self->{cachetop});
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AddDir::adddir($self->{cachedir});
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$self->{cacheindex}=$self->{cachetop}."/index.db";
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$self->{cacheseqindex}=$self->{cachetop}."/seqnumb.db";
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$self->{keyDB}=Utilities::HashDB->new();
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$self->{keyDBupdate}=Utilities::HashDB->new();
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if ( -f $self->{cacheindex} ) {
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$self->{keyDB}->restore($self->{cacheindex});
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}
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else {
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AddDir::adddir($self->{cachedir});
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}
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if ( -f $self->{cacheseqindex} ) {
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$self->{keyDBupdate}->restore($self->{cacheseqindex});
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}
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}
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