Does it also return 8 bytes in 32-bit Windows?
06.06.2020, 01:09, "Doug Coleman" <doug.cole...@gmail.com>:
Actually, I can be more helpful. ``nano-count`` returns a ``uint64_t`` so you need 8 bytes.In vm/os-genunix.cpp:uint64_t nano_count() {
struct timespec t;
int ret = clock_gettime(CLOCK_MONOTONIC, &t);
if (ret != 0)
fatal_error("clock_gettime failed", 0);
return (uint64_t)t.tv_sec * 1000000000 + t.tv_nsec;
},,On Fri, Jun 5, 2020 at 5:00 PM Doug Coleman <doug.cole...@gmail.com> wrote:As long as you can fully round-trip the integer, it doesn't matter how many bytes you use.nano-count dup 4 >be be> = .fnano-count dup 8 >be be> = .tnano-count dup 128 >be be> = .t``log2 1 +`` will give you the required number of bits to store an integer. You will want to round up to a power of 8 bits or a power of two bytes.USE: math.bitwisenano-count dup dup log2 1 + bits =On Fri, Jun 5, 2020 at 4:44 PM Alexander Ilin <ajs...@yandex.ru> wrote:Hello again!My specific example is the following. I want to put the output of `nano-count` into a `byte-array`, which is fed into a hash. The current value of `nano-count` is one of the sources of randomness gathered from the system and poured into the hash. To convert the integer value into a `byte-array` there are `>le` and `>be`, but they require the number of bytes as a parameter. The question is, what should I supply for the value received from `nano-count`?And the bigger question is, given an integer value, is there a way to interrogate it about its byte size, i.e. the minimum number of bytes it takes to hold the value without truncation and without leading zeroes:Value -- MinSize0 -- 1255 -- 1256 -- 265535 -- 265536 -- 3etc.I would expect such information to be available somewhere without doing the power of two calculations in a loop._______________________________________________23.03.2020, 05:41, "Doug Coleman" <doug.cole...@gmail.com>:For Factor, integers are either fixnum or bignum size. For C, you tell it how many bytes it occupies according to the C header. Generally the sizes are the same across platforms. If they aren't, you might need two different STRUCT: declarations like in basis/unix/stat/linux/32/32.factor and basis/unix/stat/linux/64/64.factor.The main point -- function signatures and struct declarations usually handle the integer sizes and you shouldn't have to think much about it. Do you have a specific example?Earlier I wrote:One more question. I want to convert an integer into a byte-array containing its bytes. In my use case it was the return value of the nano-count, but the question is general: how can I get the bytes of an integer.For floats there are primitives like float>bits and double>bits, and for integers there is >le and >be, but for the latter two I need to specify the size in bytes. Is there a way to ask an integer how many bytes it occupies? Because from the documentation it's not clear at all how many bytes nano-count would return, and it may vary depending on the current platform. What am I missing?
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