The type used for storing the state of the RNG is changed from
`unsigned int` to `long int` since the former has a minimal range
of [0, 65,535] while the RNG function itself has a range of
[1, 2147483646]. A `long int` must be capable of
[−2147483647, +2147483647] and is also the return type of `random()`,
which is what zeek::prng() aims to roughly parity.
This also updates all usages of the deprecated Val ctor to use
either IntervalVal, TimeVal, or DoubleVal ctors. The reason for
doing away with the old constructor is that using it with TYPE_INTERVAL
isn't strictly correct since there exists a more specific subclass,
IntervalVal, with overriden ValDescribe() method that ought to be used
to print such values in a more descriptive way.
* Deprecated ComputeHash() methods and replaced with MakeHashKey()
which returns std::unique_ptr<HashKey>
* Deprecated RecoverIndex() and replaced with RecreateIndex()
which takes HashKey& and returns IntrusivePtr.
* Updated the new TableVal Assign()/Remove() methods to take either
std::unique_ptr<HashKey> or HashKey& as appropriate for clarity of
ownership expectations.
This commit moves some of the hash datastructures and code from
util.cc into Hash.cc - where it seems more appropriate.
It also starts to make more Keyed hash functions available - still
using siphash as the default 64 bit keyed hash, but also making
128 and 256 bit highway hashes available.
There already are a few other functions that are defined but not
yet implemented - these will be "static" keyed hashes - which use
an installation specific key. These will be used to, e.g., get
rid of md5 hashing for the generation of file UIDs.
Currently, siphash is used for strings up to 36 bytes. hmac-md5 is used
for longer strings.
This switch-over is a remnant of the previous hash-function that was
used, which apparently was slower with longer input strings.
This change serves no purpose anymore. I performed a few performance tests
on strings of varying sizes:
For a 40 byte string with 10 million iterations:
siphash: 0.31 seconds
hmac-md5: 3.8 seconds
For a 1080 byte string with 10 million iterations:
siphash: 4.2 seconds
hmac-md5: 17 seconds
For a 18360 byte string with 10 million iterations:
siphash: 69 seconds
hmac-md5: 240 seconds
Hence, this commit removes the use of hmac-md5.
This change causes reordering of lines in a few logs.
This commit also changes the datastructure for the seed in probabilistic/Hasher
to get rid of a type-punning warning.
If a bloomfilter doesn't have a type, that just means no
bloomfilter_add() has been called yet, so seems undesirable to emit an
error for a lookup against something that's known to be empty.
