Re: [nodejs] UUID's in javascript
Axel, that's interesting. I was noticing the same issue, mainly that I have to
create uuid's in batches, in the browser, and Date.now() was not granular
enough, so they were all getting the same prefix. Didn't seem very useful.
Seems like there's no way to create strong, fast uuid's in the browser, but
probably good enough for what I'm doing. I will run a test at some point to
see how frequently collisions actually occur.
Ted
On Aug 7, 2012, at 7:28 AM, Axel Kittenberger axk...@gmail.com wrote:
This is what I do to create compact 96 bit UIDs in a fast way. 4 bits
are per 6 characters but thats ok for me.
var uid = function() {
var mime
='ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789+/';
var ua = [];
for(var a = 0; a 3; a++) {
var r32 = Math.floor(0x1 * Math.random());
for(var b = 0; b 6; b++) {
ua.push(mime[r32 0x3F]);
r32 = r32 6;
}
}
return ua.join('');
};
I considered adding Date(), but figured it doesnt help me at all for
possible collisions generated in the very moment (from multiple hosts)
It may vary on the use case but I can handle collisions well with UIDs
generated long ago, but not with the ones created in parallell. So in
that case the space taken by Date() is far better used by yet another
random() entity. I also use this notation to save space rather than
the standarized UID type 4 things.
Yes it is also not cryptographically strong, but in my case that isn't
an issue and speed is more important. Also the web clients need to be
able to create UIDs and that cancels out a lot possibilities anyway
that might be available in node.
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Re: [nodejs] UUID's in javascript
My use of UUIDs as DB keys has nothing to do with security. Just global
uniqueness. The term UUID doesn't imply any security.
On Mon, Aug 6, 2012 at 9:29 PM, Tim Caswell t...@creationix.com wrote:
Isaac is correct. Date.now is pretty guessable from a security standpoint
and so is Math.random. I was suggesting it for cases where that's not an
issue.
On Aug 6, 2012 8:11 PM, Isaac Schlueter i...@izs.me wrote:
That looks like I was responding to Mark Hahn's commnet about sorting; I
wasn't.
Of course it's fine to put the date on there *also*, but my point is
merely that (Date.now() + Math.random()) is not sufficiently random to
call it a uuid.
On Mon, Aug 6, 2012 at 6:09 PM, Isaac Schlueter i...@izs.me wrote:
Math.random() is not cryptographically secure entropy, and Date.now()
is extremely guessable. If you are worried about someone *wanting* to
cause collisions, then that's not so great.
If you don't care about the IETF, and you are writing your program in
Node, then the simplest approach is something like:
var uuid = crypto.randomBytes(24).toString('base64')
To do it asynchronously (since the crypto ops are a little slow):
crypto.randomBytes(24, function (er, bytes) {
var uuid = bytes.toString('base64')
})
Make the number bigger or smaller to adjust the amount of entropy.
Note that IETF uuids are only 16 bytes of entropy, so if you do want
IETF-style uuids, you can do this:
var uuid = crypto.randomBytes(16).toString('hex')
var ietfStyle = uuid.replace(/^(.{8})(.{4})(.{4})(.{4})(.{12})$/,
'$1-$2-$3-$4-$5')
I'm going to be moving npm to just use base64 random bytes for salt
eventually, just never got around to it.
On Mon, Aug 6, 2012 at 4:02 PM, Mark Hahn m...@hahnca.com wrote:
The advantage of starting off with the time is that the UUIDs sort by
order
generated which is useful for DB ids. Coding a time into base 36 is a
bit
dangerous though as it may not sort right at some time in the future.
That
time may be centuries from now, not sure. Sorting by hex is known to
be far
in the future.
On Mon, Aug 6, 2012 at 3:56 PM, Mark Hahn m...@hahnca.com wrote:
FWIW, here is the code to exactly match couchdb.
UUID = - '0' + (new Date().getTime() * 1e3).toString(16) +
Math.floor(Math.random() * 1e18).toString(16)
On Mon, Aug 6, 2012 at 3:43 PM, Rick Waldron waldron.r...@gmail.com
wrote:
On Mon, Aug 6, 2012 at 6:28 PM, Mark Hahn m...@hahnca.com wrote:
That isn't a hack. It is almost a copy of what couchdb offers. I
use
it all the time.
One is an IETF (RFC) and the other isn't.
http://www.ietf.org/rfc/rfc4122.txt
On Mon, Aug 6, 2012 at 2:17 PM, Ted Young t...@radicaldesigns.org
wrote:
Thanks for the feedback, glad to know I found the defacto solution.
Tim, that's funny, your hack is more or less what I started with,
but I
became suspicious that it was too easy somehow. Maybe I'll switch
back to
that if file-size/performance becomes an issue (which it won't).
Ted
On Aug 6, 2012, at 8:27 PM, Tim Caswell t...@creationix.com
wrote:
Depending on how strict your requirements are, I often just use:
Date.now.toString(36) + - + (Math.random() *
0x1000).toString(36)
Date.now is unique every ms and Math.random has a keyspace of
2^32, so
collisions are statistically impossible in most practical
applications.
On Mon, Aug 6, 2012 at 1:01 PM, Rick Waldron
waldron.r...@gmail.com
wrote:
On Monday, August 6, 2012 at 1:38 PM, Martin Cooper wrote:
On Mon, Aug 6, 2012 at 10:28 AM, Ted Young t...@radicaldesigns.org
wrote:
Hey y'all,
So, I have a need for global unique id's. Googling about, I've
found
the
following implementations that seem decent:
https://github.com/broofa/node-uuid
FWIW, this is the package that npm uses.
+1
I've been using Robert Keiffer's impl in projects since before it
was
even
on npm—I consider it a go to
Rick
--
Martin Cooper
https://gist.github.com/1308368
Not really sure why I would pick one over the other (besides file
size), or
if there are any js-specific issues I should be aware of. Any
advice?
Cheers,
Ted
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Re: [nodejs] UUID's in javascript
On Monday, August 6, 2012 at 1:38 PM, Martin Cooper wrote: On Mon, Aug 6, 2012 at 10:28 AM, Ted Young t...@radicaldesigns.org wrote: Hey y'all, So, I have a need for global unique id's. Googling about, I've found the following implementations that seem decent: https://github.com/broofa/node-uuid FWIW, this is the package that npm uses. +1 I've been using Robert Keiffer's impl in projects since before it was even on npm—I consider it a go to Rick -- Martin Cooper https://gist.github.com/1308368 Not really sure why I would pick one over the other (besides file size), or if there are any js-specific issues I should be aware of. Any advice? Cheers, Ted -- Job Board: http://jobs.nodejs.org/ Posting guidelines: https://github.com/joyent/node/wiki/Mailing-List-Posting-Guidelines You received this message because you are subscribed to the Google Groups nodejs group. To post to this group, send email to nodejs@googlegroups.com To unsubscribe from this group, send email to nodejs+unsubscr...@googlegroups.com For more options, visit this group at http://groups.google.com/group/nodejs?hl=en?hl=en -- Job Board: http://jobs.nodejs.org/ Posting guidelines: https://github.com/joyent/node/wiki/Mailing-List-Posting-Guidelines You received this message because you are subscribed to the Google Groups nodejs group. To post to this group, send email to nodejs@googlegroups.com To unsubscribe from this group, send email to nodejs+unsubscr...@googlegroups.com For more options, visit this group at http://groups.google.com/group/nodejs?hl=en?hl=en -- Job Board: http://jobs.nodejs.org/ Posting guidelines: https://github.com/joyent/node/wiki/Mailing-List-Posting-Guidelines You received this message because you are subscribed to the Google Groups nodejs group. To post to this group, send email to nodejs@googlegroups.com To unsubscribe from this group, send email to nodejs+unsubscr...@googlegroups.com For more options, visit this group at http://groups.google.com/group/nodejs?hl=en?hl=en
Re: [nodejs] UUID's in javascript
Depending on how strict your requirements are, I often just use: Date.now.toString(36) + - + (Math.random() * 0x1000).toString(36) Date.now is unique every ms and Math.random has a keyspace of 2^32, so collisions are statistically impossible in most practical applications. On Mon, Aug 6, 2012 at 1:01 PM, Rick Waldron waldron.r...@gmail.com wrote: On Monday, August 6, 2012 at 1:38 PM, Martin Cooper wrote: On Mon, Aug 6, 2012 at 10:28 AM, Ted Young t...@radicaldesigns.org wrote: Hey y'all, So, I have a need for global unique id's. Googling about, I've found the following implementations that seem decent: https://github.com/broofa/node-uuid FWIW, this is the package that npm uses. +1 I've been using Robert Keiffer's impl in projects since before it was even on npm—I consider it a go to Rick -- Martin Cooper https://gist.github.com/1308368 Not really sure why I would pick one over the other (besides file size), or if there are any js-specific issues I should be aware of. Any advice? Cheers, Ted -- Job Board: http://jobs.nodejs.org/ Posting guidelines: https://github.com/joyent/node/wiki/Mailing-List-Posting-Guidelines You received this message because you are subscribed to the Google Groups nodejs group. To post to this group, send email to nodejs@googlegroups.com To unsubscribe from this group, send email to nodejs+unsubscr...@googlegroups.com For more options, visit this group at http://groups.google.com/group/nodejs?hl=en?hl=en -- Job Board: http://jobs.nodejs.org/ Posting guidelines: https://github.com/joyent/node/wiki/Mailing-List-Posting-Guidelines You received this message because you are subscribed to the Google Groups nodejs group. To post to this group, send email to nodejs@googlegroups.com To unsubscribe from this group, send email to nodejs+unsubscr...@googlegroups.com For more options, visit this group at http://groups.google.com/group/nodejs?hl=en?hl=en -- Job Board: http://jobs.nodejs.org/ Posting guidelines: https://github.com/joyent/node/wiki/Mailing-List-Posting-Guidelines You received this message because you are subscribed to the Google Groups nodejs group. To post to this group, send email to nodejs@googlegroups.com To unsubscribe from this group, send email to nodejs+unsubscr...@googlegroups.com For more options, visit this group at http://groups.google.com/group/nodejs?hl=en?hl=en -- Job Board: http://jobs.nodejs.org/ Posting guidelines: https://github.com/joyent/node/wiki/Mailing-List-Posting-Guidelines You received this message because you are subscribed to the Google Groups nodejs group. To post to this group, send email to nodejs@googlegroups.com To unsubscribe from this group, send email to nodejs+unsubscr...@googlegroups.com For more options, visit this group at http://groups.google.com/group/nodejs?hl=en?hl=en
Re: [nodejs] UUID's in javascript
That isn't a hack. It is almost a copy of what couchdb offers. I use it all the time. On Mon, Aug 6, 2012 at 2:17 PM, Ted Young t...@radicaldesigns.org wrote: Thanks for the feedback, glad to know I found the defacto solution. Tim, that's funny, your hack is more or less what I started with, but I became suspicious that it was too easy somehow. Maybe I'll switch back to that if file-size/performance becomes an issue (which it won't). Ted On Aug 6, 2012, at 8:27 PM, Tim Caswell t...@creationix.com wrote: Depending on how strict your requirements are, I often just use: Date.now.toString(36) + - + (Math.random() * 0x1000).toString(36) Date.now is unique every ms and Math.random has a keyspace of 2^32, so collisions are statistically impossible in most practical applications. On Mon, Aug 6, 2012 at 1:01 PM, Rick Waldron waldron.r...@gmail.com wrote: On Monday, August 6, 2012 at 1:38 PM, Martin Cooper wrote: On Mon, Aug 6, 2012 at 10:28 AM, Ted Young t...@radicaldesigns.org wrote: Hey y'all, So, I have a need for global unique id's. Googling about, I've found the following implementations that seem decent: https://github.com/broofa/node-uuid FWIW, this is the package that npm uses. +1 I've been using Robert Keiffer's impl in projects since before it was even on npm—I consider it a go to Rick -- Martin Cooper https://gist.github.com/1308368 Not really sure why I would pick one over the other (besides file size), or if there are any js-specific issues I should be aware of. Any advice? Cheers, Ted -- Job Board: http://jobs.nodejs.org/ Posting guidelines: https://github.com/joyent/node/wiki/Mailing-List-Posting-Guidelines You received this message because you are subscribed to the Google Groups nodejs group. To post to this group, send email to nodejs@googlegroups.com To unsubscribe from this group, send email to nodejs+unsubscr...@googlegroups.com For more options, visit this group at http://groups.google.com/group/nodejs?hl=en?hl=en -- Job Board: http://jobs.nodejs.org/ Posting guidelines: https://github.com/joyent/node/wiki/Mailing-List-Posting-Guidelines You received this message because you are subscribed to the Google Groups nodejs group. To post to this group, send email to nodejs@googlegroups.com To unsubscribe from this group, send email to nodejs+unsubscr...@googlegroups.com For more options, visit this group at http://groups.google.com/group/nodejs?hl=en?hl=en -- Job Board: http://jobs.nodejs.org/ Posting guidelines: https://github.com/joyent/node/wiki/Mailing-List-Posting-Guidelines You received this message because you are subscribed to the Google Groups nodejs group. To post to this group, send email to nodejs@googlegroups.com To unsubscribe from this group, send email to nodejs+unsubscr...@googlegroups.com For more options, visit this group at http://groups.google.com/group/nodejs?hl=en?hl=en -- Job Board: http://jobs.nodejs.org/ Posting guidelines: https://github.com/joyent/node/wiki/Mailing-List-Posting-Guidelines You received this message because you are subscribed to the Google Groups nodejs group. To post to this group, send email to nodejs@googlegroups.com To unsubscribe from this group, send email to nodejs+unsubscr...@googlegroups.com For more options, visit this group at http://groups.google.com/group/nodejs?hl=en?hl=en -- Job Board: http://jobs.nodejs.org/ Posting guidelines: https://github.com/joyent/node/wiki/Mailing-List-Posting-Guidelines You received this message because you are subscribed to the Google Groups nodejs group. To post to this group, send email to nodejs@googlegroups.com To unsubscribe from this group, send email to nodejs+unsubscr...@googlegroups.com For more options, visit this group at http://groups.google.com/group/nodejs?hl=en?hl=en -- Job Board: http://jobs.nodejs.org/ Posting guidelines: https://github.com/joyent/node/wiki/Mailing-List-Posting-Guidelines You received this message because you are subscribed to the Google Groups nodejs group. To post to this group, send email to nodejs@googlegroups.com To unsubscribe from this group, send email to nodejs+unsubscr...@googlegroups.com For more options, visit this group at http://groups.google.com/group/nodejs?hl=en?hl=en
Re: [nodejs] UUID's in javascript
On Mon, Aug 6, 2012 at 6:28 PM, Mark Hahn m...@hahnca.com wrote: That isn't a hack. It is almost a copy of what couchdb offers. I use it all the time. One is an IETF (RFC) and the other isn't. http://www.ietf.org/rfc/rfc4122.txt On Mon, Aug 6, 2012 at 2:17 PM, Ted Young t...@radicaldesigns.org wrote: Thanks for the feedback, glad to know I found the defacto solution. Tim, that's funny, your hack is more or less what I started with, but I became suspicious that it was too easy somehow. Maybe I'll switch back to that if file-size/performance becomes an issue (which it won't). Ted On Aug 6, 2012, at 8:27 PM, Tim Caswell t...@creationix.com wrote: Depending on how strict your requirements are, I often just use: Date.now.toString(36) + - + (Math.random() * 0x1000).toString(36) Date.now is unique every ms and Math.random has a keyspace of 2^32, so collisions are statistically impossible in most practical applications. On Mon, Aug 6, 2012 at 1:01 PM, Rick Waldron waldron.r...@gmail.com wrote: On Monday, August 6, 2012 at 1:38 PM, Martin Cooper wrote: On Mon, Aug 6, 2012 at 10:28 AM, Ted Young t...@radicaldesigns.org wrote: Hey y'all, So, I have a need for global unique id's. Googling about, I've found the following implementations that seem decent: https://github.com/broofa/node-uuid FWIW, this is the package that npm uses. +1 I've been using Robert Keiffer's impl in projects since before it was even on npm—I consider it a go to Rick -- Martin Cooper https://gist.github.com/1308368 Not really sure why I would pick one over the other (besides file size), or if there are any js-specific issues I should be aware of. Any advice? Cheers, Ted -- Job Board: http://jobs.nodejs.org/ Posting guidelines: https://github.com/joyent/node/wiki/Mailing-List-Posting-Guidelines You received this message because you are subscribed to the Google Groups nodejs group. To post to this group, send email to nodejs@googlegroups.com To unsubscribe from this group, send email to nodejs+unsubscr...@googlegroups.com For more options, visit this group at http://groups.google.com/group/nodejs?hl=en?hl=en -- Job Board: http://jobs.nodejs.org/ Posting guidelines: https://github.com/joyent/node/wiki/Mailing-List-Posting-Guidelines You received this message because you are subscribed to the Google Groups nodejs group. To post to this group, send email to nodejs@googlegroups.com To unsubscribe from this group, send email to nodejs+unsubscr...@googlegroups.com For more options, visit this group at http://groups.google.com/group/nodejs?hl=en?hl=en -- Job Board: http://jobs.nodejs.org/ Posting guidelines: https://github.com/joyent/node/wiki/Mailing-List-Posting-Guidelines You received this message because you are subscribed to the Google Groups nodejs group. To post to this group, send email to nodejs@googlegroups.com To unsubscribe from this group, send email to nodejs+unsubscr...@googlegroups.com For more options, visit this group at http://groups.google.com/group/nodejs?hl=en?hl=en -- Job Board: http://jobs.nodejs.org/ Posting guidelines: https://github.com/joyent/node/wiki/Mailing-List-Posting-Guidelines You received this message because you are subscribed to the Google Groups nodejs group. To post to this group, send email to nodejs@googlegroups.com To unsubscribe from this group, send email to nodejs+unsubscr...@googlegroups.com For more options, visit this group at http://groups.google.com/group/nodejs?hl=en?hl=en -- Job Board: http://jobs.nodejs.org/ Posting guidelines: https://github.com/joyent/node/wiki/Mailing-List-Posting-Guidelines You received this message because you are subscribed to the Google Groups nodejs group. To post to this group, send email to nodejs@googlegroups.com To unsubscribe from this group, send email to nodejs+unsubscr...@googlegroups.com For more options, visit this group at http://groups.google.com/group/nodejs?hl=en?hl=en -- Job Board: http://jobs.nodejs.org/ Posting guidelines: https://github.com/joyent/node/wiki/Mailing-List-Posting-Guidelines You received this message because you are subscribed to the Google Groups nodejs group. To post to this group, send email to nodejs@googlegroups.com To unsubscribe from this group, send email to nodejs+unsubscr...@googlegroups.com For more options, visit this group at http://groups.google.com/group/nodejs?hl=en?hl=en -- Job Board: http://jobs.nodejs.org/ Posting guidelines: https://github.com/joyent/node/wiki/Mailing-List-Posting-Guidelines You received this message because you are subscribed to the Google Groups nodejs group. To post to this group, send email to nodejs@googlegroups.com To unsubscribe from this group, send email to nodejs+unsubscr...@googlegroups.com For more options, visit this group at http://groups.google.com/group/nodejs?hl=en?hl=en
Re: [nodejs] UUID's in javascript
FWIW, here is the code to exactly match couchdb. UUID = - '0' + (new Date().getTime() * 1e3).toString(16) + Math.floor(Math.random() * 1e18).toString(16) On Mon, Aug 6, 2012 at 3:43 PM, Rick Waldron waldron.r...@gmail.com wrote: On Mon, Aug 6, 2012 at 6:28 PM, Mark Hahn m...@hahnca.com wrote: That isn't a hack. It is almost a copy of what couchdb offers. I use it all the time. One is an IETF (RFC) and the other isn't. http://www.ietf.org/rfc/rfc4122.txt On Mon, Aug 6, 2012 at 2:17 PM, Ted Young t...@radicaldesigns.org wrote: Thanks for the feedback, glad to know I found the defacto solution. Tim, that's funny, your hack is more or less what I started with, but I became suspicious that it was too easy somehow. Maybe I'll switch back to that if file-size/performance becomes an issue (which it won't). Ted On Aug 6, 2012, at 8:27 PM, Tim Caswell t...@creationix.com wrote: Depending on how strict your requirements are, I often just use: Date.now.toString(36) + - + (Math.random() * 0x1000).toString(36) Date.now is unique every ms and Math.random has a keyspace of 2^32, so collisions are statistically impossible in most practical applications. On Mon, Aug 6, 2012 at 1:01 PM, Rick Waldron waldron.r...@gmail.com wrote: On Monday, August 6, 2012 at 1:38 PM, Martin Cooper wrote: On Mon, Aug 6, 2012 at 10:28 AM, Ted Young t...@radicaldesigns.org wrote: Hey y'all, So, I have a need for global unique id's. Googling about, I've found the following implementations that seem decent: https://github.com/broofa/node-uuid FWIW, this is the package that npm uses. +1 I've been using Robert Keiffer's impl in projects since before it was even on npm—I consider it a go to Rick -- Martin Cooper https://gist.github.com/1308368 Not really sure why I would pick one over the other (besides file size), or if there are any js-specific issues I should be aware of. Any advice? Cheers, Ted -- Job Board: http://jobs.nodejs.org/ Posting guidelines: https://github.com/joyent/node/wiki/Mailing-List-Posting-Guidelines You received this message because you are subscribed to the Google Groups nodejs group. To post to this group, send email to nodejs@googlegroups.com To unsubscribe from this group, send email to nodejs+unsubscr...@googlegroups.com For more options, visit this group at http://groups.google.com/group/nodejs?hl=en?hl=en -- Job Board: http://jobs.nodejs.org/ Posting guidelines: https://github.com/joyent/node/wiki/Mailing-List-Posting-Guidelines You received this message because you are subscribed to the Google Groups nodejs group. To post to this group, send email to nodejs@googlegroups.com To unsubscribe from this group, send email to nodejs+unsubscr...@googlegroups.com For more options, visit this group at http://groups.google.com/group/nodejs?hl=en?hl=en -- Job Board: http://jobs.nodejs.org/ Posting guidelines: https://github.com/joyent/node/wiki/Mailing-List-Posting-Guidelines You received this message because you are subscribed to the Google Groups nodejs group. To post to this group, send email to nodejs@googlegroups.com To unsubscribe from this group, send email to nodejs+unsubscr...@googlegroups.com For more options, visit this group at http://groups.google.com/group/nodejs?hl=en?hl=en -- Job Board: http://jobs.nodejs.org/ Posting guidelines: https://github.com/joyent/node/wiki/Mailing-List-Posting-Guidelines You received this message because you are subscribed to the Google Groups nodejs group. To post to this group, send email to nodejs@googlegroups.com To unsubscribe from this group, send email to nodejs+unsubscr...@googlegroups.com For more options, visit this group at http://groups.google.com/group/nodejs?hl=en?hl=en -- Job Board: http://jobs.nodejs.org/ Posting guidelines: https://github.com/joyent/node/wiki/Mailing-List-Posting-Guidelines You received this message because you are subscribed to the Google Groups nodejs group. To post to this group, send email to nodejs@googlegroups.com To unsubscribe from this group, send email to nodejs+unsubscr...@googlegroups.com For more options, visit this group at http://groups.google.com/group/nodejs?hl=en?hl=en -- Job Board: http://jobs.nodejs.org/ Posting guidelines: https://github.com/joyent/node/wiki/Mailing-List-Posting-Guidelines You received this message because you are subscribed to the Google Groups nodejs group. To post to this group, send email to nodejs@googlegroups.com To unsubscribe from this group, send email to nodejs+unsubscr...@googlegroups.com For more options, visit this group at http://groups.google.com/group/nodejs?hl=en?hl=en -- Job Board: http://jobs.nodejs.org/ Posting guidelines: https://github.com/joyent/node/wiki/Mailing-List-Posting-Guidelines You received this message because you are subscribed to the Google Groups nodejs group. To post to this group, send email to
Re: [nodejs] UUID's in javascript
The advantage of starting off with the time is that the UUIDs sort by order generated which is useful for DB ids. Coding a time into base 36 is a bit dangerous though as it may not sort right at some time in the future. That time may be centuries from now, not sure. Sorting by hex is known to be far in the future. On Mon, Aug 6, 2012 at 3:56 PM, Mark Hahn m...@hahnca.com wrote: FWIW, here is the code to exactly match couchdb. UUID = - '0' + (new Date().getTime() * 1e3).toString(16) + Math.floor(Math.random() * 1e18).toString(16) On Mon, Aug 6, 2012 at 3:43 PM, Rick Waldron waldron.r...@gmail.comwrote: On Mon, Aug 6, 2012 at 6:28 PM, Mark Hahn m...@hahnca.com wrote: That isn't a hack. It is almost a copy of what couchdb offers. I use it all the time. One is an IETF (RFC) and the other isn't. http://www.ietf.org/rfc/rfc4122.txt On Mon, Aug 6, 2012 at 2:17 PM, Ted Young t...@radicaldesigns.orgwrote: Thanks for the feedback, glad to know I found the defacto solution. Tim, that's funny, your hack is more or less what I started with, but I became suspicious that it was too easy somehow. Maybe I'll switch back to that if file-size/performance becomes an issue (which it won't). Ted On Aug 6, 2012, at 8:27 PM, Tim Caswell t...@creationix.com wrote: Depending on how strict your requirements are, I often just use: Date.now.toString(36) + - + (Math.random() * 0x1000).toString(36) Date.now is unique every ms and Math.random has a keyspace of 2^32, so collisions are statistically impossible in most practical applications. On Mon, Aug 6, 2012 at 1:01 PM, Rick Waldron waldron.r...@gmail.com wrote: On Monday, August 6, 2012 at 1:38 PM, Martin Cooper wrote: On Mon, Aug 6, 2012 at 10:28 AM, Ted Young t...@radicaldesigns.org wrote: Hey y'all, So, I have a need for global unique id's. Googling about, I've found the following implementations that seem decent: https://github.com/broofa/node-uuid FWIW, this is the package that npm uses. +1 I've been using Robert Keiffer's impl in projects since before it was even on npm—I consider it a go to Rick -- Martin Cooper https://gist.github.com/1308368 Not really sure why I would pick one over the other (besides file size), or if there are any js-specific issues I should be aware of. Any advice? Cheers, Ted -- Job Board: http://jobs.nodejs.org/ Posting guidelines: https://github.com/joyent/node/wiki/Mailing-List-Posting-Guidelines You received this message because you are subscribed to the Google Groups nodejs group. To post to this group, send email to nodejs@googlegroups.com To unsubscribe from this group, send email to nodejs+unsubscr...@googlegroups.com For more options, visit this group at http://groups.google.com/group/nodejs?hl=en?hl=en -- Job Board: http://jobs.nodejs.org/ Posting guidelines: https://github.com/joyent/node/wiki/Mailing-List-Posting-Guidelines You received this message because you are subscribed to the Google Groups nodejs group. To post to this group, send email to nodejs@googlegroups.com To unsubscribe from this group, send email to nodejs+unsubscr...@googlegroups.com For more options, visit this group at http://groups.google.com/group/nodejs?hl=en?hl=en -- Job Board: http://jobs.nodejs.org/ Posting guidelines: https://github.com/joyent/node/wiki/Mailing-List-Posting-Guidelines You received this message because you are subscribed to the Google Groups nodejs group. To post to this group, send email to nodejs@googlegroups.com To unsubscribe from this group, send email to nodejs+unsubscr...@googlegroups.com For more options, visit this group at http://groups.google.com/group/nodejs?hl=en?hl=en -- Job Board: http://jobs.nodejs.org/ Posting guidelines: https://github.com/joyent/node/wiki/Mailing-List-Posting-Guidelines You received this message because you are subscribed to the Google Groups nodejs group. To post to this group, send email to nodejs@googlegroups.com To unsubscribe from this group, send email to nodejs+unsubscr...@googlegroups.com For more options, visit this group at http://groups.google.com/group/nodejs?hl=en?hl=en -- Job Board: http://jobs.nodejs.org/ Posting guidelines: https://github.com/joyent/node/wiki/Mailing-List-Posting-Guidelines You received this message because you are subscribed to the Google Groups nodejs group. To post to this group, send email to nodejs@googlegroups.com To unsubscribe from this group, send email to nodejs+unsubscr...@googlegroups.com For more options, visit this group at http://groups.google.com/group/nodejs?hl=en?hl=en -- Job Board: http://jobs.nodejs.org/ Posting guidelines: https://github.com/joyent/node/wiki/Mailing-List-Posting-Guidelines You received this message because you are subscribed to the Google Groups nodejs group. To post to this group, send email to nodejs@googlegroups.com To unsubscribe from this group, send email to
Re: [nodejs] UUID's in javascript
Math.random() is not cryptographically secure entropy, and Date.now()
is extremely guessable. If you are worried about someone *wanting* to
cause collisions, then that's not so great.
If you don't care about the IETF, and you are writing your program in
Node, then the simplest approach is something like:
var uuid = crypto.randomBytes(24).toString('base64')
To do it asynchronously (since the crypto ops are a little slow):
crypto.randomBytes(24, function (er, bytes) {
var uuid = bytes.toString('base64')
})
Make the number bigger or smaller to adjust the amount of entropy.
Note that IETF uuids are only 16 bytes of entropy, so if you do want
IETF-style uuids, you can do this:
var uuid = crypto.randomBytes(16).toString('hex')
var ietfStyle = uuid.replace(/^(.{8})(.{4})(.{4})(.{4})(.{12})$/,
'$1-$2-$3-$4-$5')
I'm going to be moving npm to just use base64 random bytes for salt
eventually, just never got around to it.
On Mon, Aug 6, 2012 at 4:02 PM, Mark Hahn m...@hahnca.com wrote:
The advantage of starting off with the time is that the UUIDs sort by order
generated which is useful for DB ids. Coding a time into base 36 is a bit
dangerous though as it may not sort right at some time in the future. That
time may be centuries from now, not sure. Sorting by hex is known to be far
in the future.
On Mon, Aug 6, 2012 at 3:56 PM, Mark Hahn m...@hahnca.com wrote:
FWIW, here is the code to exactly match couchdb.
UUID = - '0' + (new Date().getTime() * 1e3).toString(16) +
Math.floor(Math.random() * 1e18).toString(16)
On Mon, Aug 6, 2012 at 3:43 PM, Rick Waldron waldron.r...@gmail.com
wrote:
On Mon, Aug 6, 2012 at 6:28 PM, Mark Hahn m...@hahnca.com wrote:
That isn't a hack. It is almost a copy of what couchdb offers. I use
it all the time.
One is an IETF (RFC) and the other isn't.
http://www.ietf.org/rfc/rfc4122.txt
On Mon, Aug 6, 2012 at 2:17 PM, Ted Young t...@radicaldesigns.org
wrote:
Thanks for the feedback, glad to know I found the defacto solution.
Tim, that's funny, your hack is more or less what I started with, but I
became suspicious that it was too easy somehow. Maybe I'll switch back to
that if file-size/performance becomes an issue (which it won't).
Ted
On Aug 6, 2012, at 8:27 PM, Tim Caswell t...@creationix.com wrote:
Depending on how strict your requirements are, I often just use:
Date.now.toString(36) + - + (Math.random() *
0x1000).toString(36)
Date.now is unique every ms and Math.random has a keyspace of 2^32, so
collisions are statistically impossible in most practical
applications.
On Mon, Aug 6, 2012 at 1:01 PM, Rick Waldron waldron.r...@gmail.com
wrote:
On Monday, August 6, 2012 at 1:38 PM, Martin Cooper wrote:
On Mon, Aug 6, 2012 at 10:28 AM, Ted Young t...@radicaldesigns.org
wrote:
Hey y'all,
So, I have a need for global unique id's. Googling about, I've found
the
following implementations that seem decent:
https://github.com/broofa/node-uuid
FWIW, this is the package that npm uses.
+1
I've been using Robert Keiffer's impl in projects since before it was
even
on npm—I consider it a go to
Rick
--
Martin Cooper
https://gist.github.com/1308368
Not really sure why I would pick one over the other (besides file
size), or
if there are any js-specific issues I should be aware of. Any advice?
Cheers,
Ted
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Re: [nodejs] UUID's in javascript
That looks like I was responding to Mark Hahn's commnet about sorting; I wasn't.
Of course it's fine to put the date on there *also*, but my point is
merely that (Date.now() + Math.random()) is not sufficiently random to
call it a uuid.
On Mon, Aug 6, 2012 at 6:09 PM, Isaac Schlueter i...@izs.me wrote:
Math.random() is not cryptographically secure entropy, and Date.now()
is extremely guessable. If you are worried about someone *wanting* to
cause collisions, then that's not so great.
If you don't care about the IETF, and you are writing your program in
Node, then the simplest approach is something like:
var uuid = crypto.randomBytes(24).toString('base64')
To do it asynchronously (since the crypto ops are a little slow):
crypto.randomBytes(24, function (er, bytes) {
var uuid = bytes.toString('base64')
})
Make the number bigger or smaller to adjust the amount of entropy.
Note that IETF uuids are only 16 bytes of entropy, so if you do want
IETF-style uuids, you can do this:
var uuid = crypto.randomBytes(16).toString('hex')
var ietfStyle = uuid.replace(/^(.{8})(.{4})(.{4})(.{4})(.{12})$/,
'$1-$2-$3-$4-$5')
I'm going to be moving npm to just use base64 random bytes for salt
eventually, just never got around to it.
On Mon, Aug 6, 2012 at 4:02 PM, Mark Hahn m...@hahnca.com wrote:
The advantage of starting off with the time is that the UUIDs sort by order
generated which is useful for DB ids. Coding a time into base 36 is a bit
dangerous though as it may not sort right at some time in the future. That
time may be centuries from now, not sure. Sorting by hex is known to be far
in the future.
On Mon, Aug 6, 2012 at 3:56 PM, Mark Hahn m...@hahnca.com wrote:
FWIW, here is the code to exactly match couchdb.
UUID = - '0' + (new Date().getTime() * 1e3).toString(16) +
Math.floor(Math.random() * 1e18).toString(16)
On Mon, Aug 6, 2012 at 3:43 PM, Rick Waldron waldron.r...@gmail.com
wrote:
On Mon, Aug 6, 2012 at 6:28 PM, Mark Hahn m...@hahnca.com wrote:
That isn't a hack. It is almost a copy of what couchdb offers. I use
it all the time.
One is an IETF (RFC) and the other isn't.
http://www.ietf.org/rfc/rfc4122.txt
On Mon, Aug 6, 2012 at 2:17 PM, Ted Young t...@radicaldesigns.org
wrote:
Thanks for the feedback, glad to know I found the defacto solution.
Tim, that's funny, your hack is more or less what I started with, but I
became suspicious that it was too easy somehow. Maybe I'll switch back
to
that if file-size/performance becomes an issue (which it won't).
Ted
On Aug 6, 2012, at 8:27 PM, Tim Caswell t...@creationix.com wrote:
Depending on how strict your requirements are, I often just use:
Date.now.toString(36) + - + (Math.random() *
0x1000).toString(36)
Date.now is unique every ms and Math.random has a keyspace of 2^32, so
collisions are statistically impossible in most practical
applications.
On Mon, Aug 6, 2012 at 1:01 PM, Rick Waldron waldron.r...@gmail.com
wrote:
On Monday, August 6, 2012 at 1:38 PM, Martin Cooper wrote:
On Mon, Aug 6, 2012 at 10:28 AM, Ted Young t...@radicaldesigns.org
wrote:
Hey y'all,
So, I have a need for global unique id's. Googling about, I've found
the
following implementations that seem decent:
https://github.com/broofa/node-uuid
FWIW, this is the package that npm uses.
+1
I've been using Robert Keiffer's impl in projects since before it was
even
on npm—I consider it a go to
Rick
--
Martin Cooper
https://gist.github.com/1308368
Not really sure why I would pick one over the other (besides file
size), or
if there are any js-specific issues I should be aware of. Any advice?
Cheers,
Ted
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For more
Re: [nodejs] UUID's in javascript
Isaac is correct. Date.now is pretty guessable from a security standpoint
and so is Math.random. I was suggesting it for cases where that's not an
issue.
On Aug 6, 2012 8:11 PM, Isaac Schlueter i...@izs.me wrote:
That looks like I was responding to Mark Hahn's commnet about sorting; I
wasn't.
Of course it's fine to put the date on there *also*, but my point is
merely that (Date.now() + Math.random()) is not sufficiently random to
call it a uuid.
On Mon, Aug 6, 2012 at 6:09 PM, Isaac Schlueter i...@izs.me wrote:
Math.random() is not cryptographically secure entropy, and Date.now()
is extremely guessable. If you are worried about someone *wanting* to
cause collisions, then that's not so great.
If you don't care about the IETF, and you are writing your program in
Node, then the simplest approach is something like:
var uuid = crypto.randomBytes(24).toString('base64')
To do it asynchronously (since the crypto ops are a little slow):
crypto.randomBytes(24, function (er, bytes) {
var uuid = bytes.toString('base64')
})
Make the number bigger or smaller to adjust the amount of entropy.
Note that IETF uuids are only 16 bytes of entropy, so if you do want
IETF-style uuids, you can do this:
var uuid = crypto.randomBytes(16).toString('hex')
var ietfStyle = uuid.replace(/^(.{8})(.{4})(.{4})(.{4})(.{12})$/,
'$1-$2-$3-$4-$5')
I'm going to be moving npm to just use base64 random bytes for salt
eventually, just never got around to it.
On Mon, Aug 6, 2012 at 4:02 PM, Mark Hahn m...@hahnca.com wrote:
The advantage of starting off with the time is that the UUIDs sort by
order
generated which is useful for DB ids. Coding a time into base 36 is a
bit
dangerous though as it may not sort right at some time in the future.
That
time may be centuries from now, not sure. Sorting by hex is known to
be far
in the future.
On Mon, Aug 6, 2012 at 3:56 PM, Mark Hahn m...@hahnca.com wrote:
FWIW, here is the code to exactly match couchdb.
UUID = - '0' + (new Date().getTime() * 1e3).toString(16) +
Math.floor(Math.random() * 1e18).toString(16)
On Mon, Aug 6, 2012 at 3:43 PM, Rick Waldron waldron.r...@gmail.com
wrote:
On Mon, Aug 6, 2012 at 6:28 PM, Mark Hahn m...@hahnca.com wrote:
That isn't a hack. It is almost a copy of what couchdb offers. I
use
it all the time.
One is an IETF (RFC) and the other isn't.
http://www.ietf.org/rfc/rfc4122.txt
On Mon, Aug 6, 2012 at 2:17 PM, Ted Young t...@radicaldesigns.org
wrote:
Thanks for the feedback, glad to know I found the defacto solution.
Tim, that's funny, your hack is more or less what I started with,
but I
became suspicious that it was too easy somehow. Maybe I'll switch
back to
that if file-size/performance becomes an issue (which it won't).
Ted
On Aug 6, 2012, at 8:27 PM, Tim Caswell t...@creationix.com wrote:
Depending on how strict your requirements are, I often just use:
Date.now.toString(36) + - + (Math.random() *
0x1000).toString(36)
Date.now is unique every ms and Math.random has a keyspace of 2^32,
so
collisions are statistically impossible in most practical
applications.
On Mon, Aug 6, 2012 at 1:01 PM, Rick Waldron
waldron.r...@gmail.com
wrote:
On Monday, August 6, 2012 at 1:38 PM, Martin Cooper wrote:
On Mon, Aug 6, 2012 at 10:28 AM, Ted Young t...@radicaldesigns.org
wrote:
Hey y'all,
So, I have a need for global unique id's. Googling about, I've found
the
following implementations that seem decent:
https://github.com/broofa/node-uuid
FWIW, this is the package that npm uses.
+1
I've been using Robert Keiffer's impl in projects since before it
was
even
on npm—I consider it a go to
Rick
--
Martin Cooper
https://gist.github.com/1308368
Not really sure why I would pick one over the other (besides file
size), or
if there are any js-specific issues I should be aware of. Any
advice?
Cheers,
Ted
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Re: [nodejs] UUID's in javascript
This is what I do to create compact 96 bit UIDs in a fast way. 4 bits
are per 6 characters but thats ok for me.
var uid = function() {
var mime
='ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789+/';
var ua = [];
for(var a = 0; a 3; a++) {
var r32 = Math.floor(0x1 * Math.random());
for(var b = 0; b 6; b++) {
ua.push(mime[r32 0x3F]);
r32 = r32 6;
}
}
return ua.join('');
};
I considered adding Date(), but figured it doesnt help me at all for
possible collisions generated in the very moment (from multiple hosts)
It may vary on the use case but I can handle collisions well with UIDs
generated long ago, but not with the ones created in parallell. So in
that case the space taken by Date() is far better used by yet another
random() entity. I also use this notation to save space rather than
the standarized UID type 4 things.
Yes it is also not cryptographically strong, but in my case that isn't
an issue and speed is more important. Also the web clients need to be
able to create UIDs and that cancels out a lot possibilities anyway
that might be available in node.
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