As to hash improvement in general - test avalanche/distribution for your data sets on these:
OP's additive hash fails to treat permutations, i.e., “xyz”, “zyx”, and “xzy” all result in the same hash value.
And if the original hash is "slow", then so will these be. Did you try instrumtenting your code, or using a profiler? ...before you decided the hash algorithm was the bottleneck.
I have a file with a format of
A,2
B,2
G,3
A,2
A,3
A,2
D,7
A,2
E,2
A,2
I need to create a sum of each alphabet with the numbers assigned to it using awk. (2 Replies)
I have a script with dynamic hash of hashes , and I want to print the entire hash (with all other hashes).
Itried to do it recursively by checking if the current key is a hash and if yes call the current function again with refference to the sub hash.
Most of the printing seems to be OK but in... (1 Reply)
I analysed disk performance with blktrace and get some data:
read:
8,3 4 2141 2.882115217 3342 Q R 195732187 + 32
8,3 4 2142 2.882116411 3342 G R 195732187 + 32
8,3 4 2144 2.882117647 3342 I R 195732187 + 32
8,3 4 2145 ... (1 Reply)
Hello,
I have a hash in hsh. I need to assign it to another hash globalHsh. I think the below statement does not work
$globalHsh{$id} = %hsh;
What is the right way to assign it?
Thanks (3 Replies)
Can Someone explain me why even using Tie::IxHash I can not get the output data in the same order that it was inserted? See code below.
#!/usr/bin/perl
use warnings;
use Tie::IxHash;
use strict;
tie (my %programs, "Tie::IxHash");
while (my $line = <DATA>) {
chomp $line;
my(... (1 Reply)
Hi,
In Perl, is it possible to use a range of numbers with '..' as a key in a hash?
Something in like:
%hash = (
'768..1536' => '1G',
'1537..2560' => '2G'
);
That is, the range operation is evaluated, and all members of the range are... (3 Replies)
Hi,
I have an hashes of hash, where hash is dynamic, it can be n number of hash. i need to compare data_count values of all .
my %result (
$abc => {
'data_count' => '10',
'ID' => 'ABC122',
}
$def => {
'data_count' => '20',
'ID' => 'defASe',
... (1 Reply)
Hi, I have a hash of hash where it has
name, activities and count
i have data like this -
$result->{$name}->{$activities} = $value;
content of that are -
name - robert tom cat peter
activities - running, eating, sleeping , drinking, work
i need to print output as below
... (3 Replies)
Discussion started by: asak
3 Replies
LEARN ABOUT OSX
hmac_final
HMAC(3) OpenSSL HMAC(3)NAME
HMAC, HMAC_Init, HMAC_Update, HMAC_Final, HMAC_cleanup - HMAC message authentication code
SYNOPSIS
#include <openssl/hmac.h>
unsigned char *HMAC(const EVP_MD *evp_md, const void *key,
int key_len, const unsigned char *d, int n,
unsigned char *md, unsigned int *md_len);
void HMAC_CTX_init(HMAC_CTX *ctx);
void HMAC_Init(HMAC_CTX *ctx, const void *key, int key_len,
const EVP_MD *md);
void HMAC_Init_ex(HMAC_CTX *ctx, const void *key, int key_len,
const EVP_MD *md, ENGINE *impl);
void HMAC_Update(HMAC_CTX *ctx, const unsigned char *data, int len);
void HMAC_Final(HMAC_CTX *ctx, unsigned char *md, unsigned int *len);
void HMAC_CTX_cleanup(HMAC_CTX *ctx);
void HMAC_cleanup(HMAC_CTX *ctx);
DESCRIPTION
HMAC is a MAC (message authentication code), i.e. a keyed hash function used for message authentication, which is based on a hash function.
HMAC() computes the message authentication code of the n bytes at d using the hash function evp_md and the key key which is key_len bytes
long.
It places the result in md (which must have space for the output of the hash function, which is no more than EVP_MAX_MD_SIZE bytes). If md
is NULL, the digest is placed in a static array. The size of the output is placed in md_len, unless it is NULL.
evp_md can be EVP_sha1(), EVP_ripemd160() etc. key and evp_md may be NULL if a key and hash function have been set in a previous call to
HMAC_Init() for that HMAC_CTX.
HMAC_CTX_init() initialises a HMAC_CTX before first use. It must be called.
HMAC_CTX_cleanup() erases the key and other data from the HMAC_CTX and releases any associated resources. It must be called when an
HMAC_CTX is no longer required.
HMAC_cleanup() is an alias for HMAC_CTX_cleanup() included for back compatibility with 0.9.6b, it is deprecated.
The following functions may be used if the message is not completely stored in memory:
HMAC_Init() initializes a HMAC_CTX structure to use the hash function evp_md and the key key which is key_len bytes long. It is deprecated
and only included for backward compatibility with OpenSSL 0.9.6b.
HMAC_Init_ex() initializes or reuses a HMAC_CTX structure to use the function evp_md and key key. Either can be NULL, in which case the
existing one will be reused. HMAC_CTX_init() must have been called before the first use of an HMAC_CTX in this function. N.B. HMAC_Init()
had this undocumented behaviour in previous versions of OpenSSL - failure to switch to HMAC_Init_ex() in programs that expect it will cause
them to stop working.
HMAC_Update() can be called repeatedly with chunks of the message to be authenticated (len bytes at data).
HMAC_Final() places the message authentication code in md, which must have space for the hash function output.
RETURN VALUES
HMAC() returns a pointer to the message authentication code.
HMAC_CTX_init(), HMAC_Init_ex(), HMAC_Update(), HMAC_Final() and HMAC_CTX_cleanup() do not return values.
CONFORMING TO
RFC 2104
SEE ALSO sha(3), evp(3)HISTORY
HMAC(), HMAC_Init(), HMAC_Update(), HMAC_Final() and HMAC_cleanup() are available since SSLeay 0.9.0.
HMAC_CTX_init(), HMAC_Init_ex() and HMAC_CTX_cleanup() are available since OpenSSL 0.9.7.
0.9.8 2009-04-03 HMAC(3)