Fix erlang time module compatibility #883
Conversation
nickva
commented
Oct 9, 2017
•
nickva
commented
nickva
force-pushed
the
time-compatibility-module
branch
2 times, most recently
from
f2a6fec
to
52858c0
Compare
src/couch/src/couch_auth_cache.erl
Outdated
| @@ -203,7 +203,8 @@ handle_call({fetch, UserName}, _From, State) -> | |||
| [] -> | |||
| couch_stats:increment_counter([couchdb, auth_cache_misses]), | |||
| Creds = get_user_props_from_db(UserName), | |||
| State1 = add_cache_entry(UserName, Creds, erlang:now(), State), | |||
| ATime = couch_time_compat:unique_integer([monotonic, positive]), | |||
There was a problem hiding this comment.
Seems like this would be more useful as couch_util:unique_integer() that gets left forever rather than replacing all of these with erlang:unique_integer/1 in the future (we do this for a few different things where we always set the same options if memory serves).
There was a problem hiding this comment.
I put it here mainly to hide the ifdef ugliness. But I can move it to couch_util
Though we should probably rename it as well to unique_monotonic_integer since unique_integer/0 is not guaranteed to be always increasing, in theory could jump around like -10, then 100, then -5 etc.
src/couch/src/couch_uuids.erl
Outdated
| list_to_binary(Prefix ++ Suffix). | ||
| Suffix = couch_util:to_hex(crypto:strong_rand_bytes(9)), | ||
| Now = os:timestamp(), | ||
| {UtcRandom, _NextClockSeq} = utc_suffix(Suffix, 0, Now), |
There was a problem hiding this comment.
I'm not 100% on whether we should be hard coding a 0 here for anyone that calls this or if we should be funneling every call through the gen_server (and thus have to change the entire gen_server to always maintain a clock sequence).
Also, near as I can tell exactly zero calls are made to utc_random in the source code which may inform our decision on this bit.
There was a problem hiding this comment.
I thought utc_random could be selected as one of the algorithms in the config. But you're right, it should probably get the same local clock sequence treatment as the utc_id
nickva
force-pushed
the
time-compatibility-module
branch
from
52858c0
to
d11e90c
Compare
src/couch/src/couch_uuids.erl
Outdated
| Then = calendar:datetime_to_gregorian_seconds({{1970, 1, 1}, {0, 0, 0}}), | ||
| Prefix = io_lib:format("~14.16.0b", [(Nowsecs - Then) * 1000000 + Micro]), | ||
| list_to_binary(Prefix ++ Suffix). | ||
| utc_random(ClockSeq) -> |
There was a problem hiding this comment.
Nits but you should move this to after the gen_server behavior callbacks.
There was a problem hiding this comment.
Good idea. Will move utc_suffix as well since it is not exported.
`now/0` is deprecated since Erlang 18.0, and a set of new time related functions are available. Usually `now/0` can be replaced with `os:timestamp/0`, however in some instances it was used effectively to produce monotonically incrementing values rather than timestamps. So added a new `couch_util:unique_monotonic_integer/0`. Most functional changes are in couch_uuid module. There `now/0` was used both as a timestamp and for uniqueness. To emulate previous behavior, a local incrementing clock sequence is used. If `os:timestamp/0` does not advance since last call then the local clock is advanced by 1 microsecond and that's used to generate the next V1 UUIDs. As soon as os:timestamp/0` catches up, the local sequence reset to that latest value. Also exported function `utc_random/0` was not used, after updating the function it wasn't exported anymore.
nickva
force-pushed
the
time-compatibility-module
branch
from
d11e90c
to
5600f10
Compare
…-search * commit 'f84faa532ee7341d76f7cecdd416f8728d72ecc1': (4288 commits) re-add query Update NOTICE: remove autoconf/m4 references and revert react patents note Configurable delay before retrying on missing_doc error Update jiffy to use dedupe_keys Return error 410 on temporary view request fix(peruser_test): on slow CI vms, we can get Cluster timeouts Updating verifyinstall URL whitespace add delay for bulk_delete and create up delay use delay instead use string for w value Update w value for deletion since n=1 feat: port time funs, as per apache#883 fix: peruser tests: use spinlocks instead of timer:sleep() Alias /_node/_local/... to /_node/<nodename>@<hostname>/... Travis: s/20.0/20.1 for build Disable eval() and Function() constructor in JS by default Blacklist some config sections from HTTP PUT/DELETE operations Cleanups for 2.1.1 proper version tagging ... # Conflicts: # Makefile # Makefile.win # dev/run # rebar.config.script # rel/reltool.config
