After checking with the community via Twitter (here:
https://twitter.com/antirez/status/915130876861788161) the verdict was to
use ":". However I later realized, after users lamented the fact that
it's hard to copy IDs just with double click, that this was the reason
why I moved to "." in the first instance. Fortunately "-", that was the
other option with most votes, also gets selected with double click on
most terminal applications on Linux and MacOS.
So my reasoning was:
1) We can't retain "." because it's actually confusing to newcomers, it
looks like a floating number, people may be tricked into thinking they
can order IDs numerically as floats.
2) Moving to a double-click-to-select format is much better. People will
work with such IDs for long time when coding / debugging. Why making now
a choice that will impact this for the next years?
The only other viable option was "-", and that's what I did. Thanks.
getLongLongFromObject calls string2ll which has this line:
/* Return if not all bytes were used. */
so if you pass an sds with 3 characters "1\01" it will fail.
but getLongDoubleFromObject calls strtold, and considers it ok if eptr[0]==`\0`
i.e. if the end of the string found by strtold ends with null terminator
127.0.0.1:6379> set a 1
OK
127.0.0.1:6379> setrange a 2 2
(integer) 3
127.0.0.1:6379> get a
"1\x002"
127.0.0.1:6379> incrbyfloat a 2
"3"
127.0.0.1:6379> get a
"3"
64 bit double math is not enough to make the test passing, and rounding
to 1.2999999 instead of 1.23 is not an error in the implementation.
Valgrind and sometimes other archs are not able to work with 80 bit
doubles.
HINCRBY* tests later used the value "tmp" that was sometimes generated
by the random key generation function. The result was ovewriting what
Tcl expected to be inside Redis with another value, causing the next
HSTRLEN test to fail.
This additional info may provide more clues about the test randomly
failing from time to time. Probably the failure is due to some previous
test that overwrites the logical content in the Tcl variable, but this
will make the problem more obvious.
1. HVSTRLEN -> HSTRLEN. It's unlikely one needs the length of the key,
not clear how the API would work (by value does not make sense) and
there will be better names anyway.
2. Default is to return 0 when field is missing.
3. Default is to return 0 when key is missing.
4. The implementation was slower than needed, and produced unnecessary COW.
Related issue #2415.
This removes:
- list-max-ziplist-entries
- list-max-ziplist-value
This adds:
- list-max-ziplist-size
- list-compress-depth
Also updates config file with new sections and updates
tests to use quicklist settings instead of old list settings.
This replaces individual ziplist vs. linkedlist representations
for Redis list operations.
Big thanks for all the reviews and feedback from everybody in
https://github.com/antirez/redis/pull/2143
spopCommand() now runs spopWithCountCommand() in case the <count> param is found.
Added intsetRandomMembers() to Intset: Copies N random members from the set into inputted 'values' array. Uses either the Knuth or Floyd sample algos depending on ratio count/size.
Added setTypeRandomElements() to SET type: Returns a number of random elements from a non empty set. This is a version of setTypeRandomElement() that is modified in order to return multiple entries, using dictGetRandomKeys() and intsetRandomMembers().
Added tests for SPOP with <count>: unit/type/set, unit/scripting, integration/aof
--
Cleaned up code a bit to match with required Redis coding style
Behrad Zari discovered [1] and Josiah reported [2]: if you block
and wait for a list to exist, but the list creates from
a non-push command, the blocked client never gets notified.
This commit adds notification of blocked clients into
the DB layer and away from individual commands.
Lists can be created by [LR]PUSH, SORT..STORE, RENAME, MOVE,
and RESTORE. Previously, blocked client notifications were
only triggered by [LR]PUSH. Your client would never get
notified if a list were created by SORT..STORE or RENAME or
a RESTORE, etc.
Blocked client notification now happens in one unified place:
- dbAdd() triggers notification when adding a list to the DB
Two new tests are added that fail prior to this commit.
All test pass.
Fixes#1668
[1]: https://groups.google.com/forum/#!topic/redis-db/k4oWfMkN1NU
[2]: #1668
SDIFF used an algorithm that was O(N) where N is the total number
of elements of all the sets involved in the operation.
The algorithm worked like that:
ALGORITHM 1:
1) For the first set, add all the members to an auxiliary set.
2) For all the other sets, remove all the members of the set from the
auxiliary set.
So it is an O(N) algorithm where N is the total number of elements in
all the sets involved in the diff operation.
Cristobal Viedma suggested to modify the algorithm to the following:
ALGORITHM 2:
1) Iterate all the elements of the first set.
2) For every element, check if the element also exists in all the other
remaining sets.
3) Add the element to the auxiliary set only if it does not exist in any
of the other sets.
The complexity of this algorithm on the worst case is O(N*M) where N is
the size of the first set and M the total number of sets involved in the
operation.
However when there are elements in common, with this algorithm we stop
the computation for a given element as long as we find a duplicated
element into another set.
I (antirez) added an additional step to algorithm 2 to make it faster,
that is to sort the set to subtract from the biggest to the
smallest, so that it is more likely to find a duplicate in a larger sets
that are checked before the smaller ones.
WHAT IS BETTER?
None of course, for instance if the first set is much larger than the
other sets the second algorithm does a lot more work compared to the
first algorithm.
Similarly if the first set is much smaller than the other sets, the
original algorithm will less work.
So this commit makes Redis able to guess the number of operations
required by each algorithm, and select the best at runtime according
to the input received.
However, since the second algorithm has better constant times and can do
less work if there are duplicated elements, an advantage is given to the
second algorithm.
So instead to reply with a generic error like:
-ERR ... wrong kind of value ...
now it replies with:
-WRONGTYPE ... wrong kind of value ...
This makes this particular error easy to check without resorting to
(fragile) pattern matching of the error string (however the error string
used to be consistent already).
Client libraries should return a specific exeption type for this error.
Most of the commit is about fixing unit tests.
