xref: /freebsd/crypto/openssl/doc/man3/OPENSSL_LH_stats.pod (revision b077aed33b7b6aefca7b17ddb250cf521f938613)

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=head1 NAME

OPENSSL_LH_stats, OPENSSL_LH_node_stats, OPENSSL_LH_node_usage_stats,
OPENSSL_LH_stats_bio,
OPENSSL_LH_node_stats_bio, OPENSSL_LH_node_usage_stats_bio - LHASH statistics

=head1 SYNOPSIS

 #include <openssl/lhash.h>

 void OPENSSL_LH_stats(LHASH *table, FILE *out);
 void OPENSSL_LH_node_stats(LHASH *table, FILE *out);
 void OPENSSL_LH_node_usage_stats(LHASH *table, FILE *out);

 void OPENSSL_LH_stats_bio(LHASH *table, BIO *out);
 void OPENSSL_LH_node_stats_bio(LHASH *table, BIO *out);
 void OPENSSL_LH_node_usage_stats_bio(LHASH *table, BIO *out);

=head1 DESCRIPTION

The B<LHASH> structure records statistics about most aspects of
accessing the hash table.

OPENSSL_LH_stats() prints out statistics on the size of the hash table and how
many entries are in it. For historical reasons, this function also outputs a
number of additional statistics, but the tracking of these statistics is no
longer supported and these statistics are always reported as zero.

OPENSSL_LH_node_stats() prints the number of entries for each 'bucket' in the
hash table.

OPENSSL_LH_node_usage_stats() prints out a short summary of the state of the
hash table.  It prints the 'load' and the 'actual load'.  The load is
the average number of data items per 'bucket' in the hash table.  The
'actual load' is the average number of items per 'bucket', but only
for buckets which contain entries.  So the 'actual load' is the
average number of searches that will need to find an item in the hash
table, while the 'load' is the average number that will be done to
record a miss.

OPENSSL_LH_stats_bio(), OPENSSL_LH_node_stats_bio() and OPENSSL_LH_node_usage_stats_bio()
are the same as the above, except that the output goes to a B<BIO>.

=head1 RETURN VALUES

These functions do not return values.

=head1 NOTE

These calls should be made under a read lock. Refer to
L<OPENSSL_LH_COMPFUNC(3)/NOTE> for more details about the locks required
when using the LHASH data structure.

=head1 SEE ALSO

L<bio(7)>, L<OPENSSL_LH_COMPFUNC(3)>

=head1 COPYRIGHT

Copyright 2000-2022 The OpenSSL Project Authors. All Rights Reserved.

Licensed under the Apache License 2.0 (the "License").  You may not use
this file except in compliance with the License.  You can obtain a copy
in the file LICENSE in the source distribution or at
L<https://www.openssl.org/source/license.html>.

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