DBI::ProfileDumper(3) User Contributed Perl DocumentationDBI::ProfileDumper(3)NAMEDBI::ProfileDumper - profile DBI usage and output data to a file
SYNOPSIS
To profile an existing program using DBI::ProfileDumper, set the
DBI_PROFILE environment variable and run your program as usual. For
example, using bash:
DBI_PROFILE=DBI::ProfileDumper program.pl
Then analyze the generated file (dbi.prof) with dbiprof:
dbiprof
You can also activate DBI::ProfileDumper from within your code:
use DBI;
# profile with default path (2) and output file (dbi.prof)
$dbh->{Profile} = "DBI::ProfileDumper";
# same thing, spelled out
$dbh->{Profile} = "2/DBI::ProfileDumper/File/dbi.prof";
# another way to say it
use DBI::Profile qw(DBIprofile_Statement);
$dbh->{Profile} = DBI::ProfileDumper->new(
Path => [ DBIprofile_Statement ]
File => 'dbi.prof' );
# using a custom path
$dbh->{Profile} = DBI::ProfileDumper->new( Path => [ "foo", "bar" ],
File => 'dbi.prof' );
DESCRIPTIONDBI::ProfileDumper is a subclass of DBI::Profile which dumps profile
data to disk instead of printing a summary to your screen. You can
then use dbiprof to analyze the data in a number of interesting ways,
or you can roll your own analysis using DBI::ProfileData.
NOTE: For Apache/mod_perl applications, use DBI::ProfileDumper::Apache.
USAGE
One way to use this module is just to enable it in your "$dbh":
$dbh->{Profile} = "DBI::ProfileDumper";
This will write out profile data by statement into a file called
dbi.prof. If you want to modify either of these properties, you can
construct the DBI::ProfileDumper object yourself:
use DBI::Profile qw(DBIprofile_Statement);
$dbh->{Profile} = DBI::ProfileDumper->new(
Path => [ DBIprofile_Statement ]
File => 'dbi.prof' );
The "Path" option takes the same values as in DBI::Profile. The "File"
option gives the name of the file where results will be collected. If
it already exists it will be overwritten.
You can also activate this module by setting the DBI_PROFILE environ‐
ment variable:
$ENV{DBI_PROFILE} = "DBI::ProfileDumper";
This will cause all DBI handles to share the same profiling object.
METHODS
The following methods are available to be called using the profile
object. You can get access to the profile object from the Profile key
in any DBI handle:
my $profile = $dbh->{Profile};
$profile->flush_to_disk()
Flushes all collected profile data to disk and empties the Data
hash. This method may be called multiple times during a program
run.
$profile->empty()
Clears the Data hash without writing to disk.
DATA FORMAT
The data format written by DBI::ProfileDumper starts with a header con‐
taining the version number of the module used to generate it. Then a
block of variable declarations describes the profile. After two new‐
lines, the profile data forms the body of the file. For example:
DBI::ProfileDumper 1.0
Path = [ DBIprofile_Statement, DBIprofile_MethodName ]
Program = t/42profile_data.t
+ 1 SELECT name FROM users WHERE id = ?
+ 2 prepare
= 1 0.0312958955764771 0.000490069389343262 0.000176072120666504 0.00140702724456787 1023115819.83019 1023115819.86576
+ 2 execute
1 0.0312958955764771 0.000490069389343262 0.000176072120666504 0.00140702724456787 1023115819.83019 1023115819.86576
+ 2 fetchrow_hashref
= 1 0.0312958955764771 0.000490069389343262 0.000176072120666504 0.00140702724456787 1023115819.83019 1023115819.86576
+ 1 UPDATE users SET name = ? WHERE id = ?
+ 2 prepare
= 1 0.0312958955764771 0.000490069389343262 0.000176072120666504 0.00140702724456787 1023115819.83019 1023115819.86576
+ 2 execute
= 1 0.0312958955764771 0.000490069389343262 0.000176072120666504 0.00140702724456787 1023115819.83019 1023115819.86576
The lines beginning with "+" signs signify keys. The number after the
"+" sign shows the nesting level of the key. Lines beginning with "="
are the actual profile data, in the same order as in DBI::Profile.
Note that the same path may be present multiple times in the data file
since "format()" may be called more than once. When read by DBI::Pro‐
fileData the data points will be merged to produce a single data set
for each distinct path.
The key strings are transformed in three ways. First, all backslashes
are doubled. Then all newlines and carriage-returns are transformed
into "\n" and "\r" respectively. Finally, any NULL bytes ("\0") are
entirely removed. When DBI::ProfileData reads the file the first two
transformations will be reversed, but NULL bytes will not be restored.
AUTHOR
Sam Tregar <sam@tregar.com>
COPYRIGHT AND LICENSE
Copyright (C) 2002 Sam Tregar
This program is free software; you can redistribute it and/or modify it
under the same terms as Perl 5 itself.
3rd Berkeley Distribution perl v5.6.1 DBI::ProfileDumper(3)