There were two problems with the implementation.
1) "save" was not correctly processed when no save point was configured,
as reported in issue #1416.
2) The way the code checked if an option existed in the "processed"
dictionary was wrong, as we add the element with as a key associated
with a NULL value, so dictFetchValue() can't be used to check for
existance, but dictFind() must be used, that returns NULL only if the
entry does not exist at all.
With this commit options not explicitly rewritten by CONFIG REWRITE are
not touched at all. These include new options that may not have support
for REWRITE, and other special cases like rename-command and include.
At the end of the file, CONFIG REWRITE adds a comment line that:
# Generated by CONFIG REWRITE
Followed by the additional config options required. However this was
added again and again at every rewrite in praticular conditions (when a
given set of options change in a given time during the time).
Now if it was alrady encountered, it is not added a second time.
This is especially important for Sentinel that rewrites the config at
every state change.
All the internal state of cluster involving time is now using mstime_t
and mstime() in order to use milliseconds resolution.
Also the clusterCron() function is called with a 10 hz frequency instead
of 1 hz.
The cluster node_timeout must be also configured in milliseconds by the
user in redis.conf.
Previously two string encodings were used for string objects:
1) REDIS_ENCODING_RAW: a string object with obj->ptr pointing to an sds
stirng.
2) REDIS_ENCODING_INT: a string object where the obj->ptr void pointer
is casted to a long.
This commit introduces a experimental new encoding called
REDIS_ENCODING_EMBSTR that implements an object represented by an sds
string that is not modifiable but allocated in the same memory chunk as
the robj structure itself.
The chunk looks like the following:
+--------------+-----------+------------+--------+----+
| robj data... | robj->ptr | sds header | string | \0 |
+--------------+-----+-----+------------+--------+----+
| ^
+-----------------------+
The robj->ptr points to the contiguous sds string data, so the object
can be manipulated with the same functions used to manipulate plan
string objects, however we need just on malloc and one free in order to
allocate or release this kind of objects. Moreover it has better cache
locality.
This new allocation strategy should benefit both the memory usage and
the performances. A performance gain between 60 and 70% was observed
during micro-benchmarks, however there is more work to do to evaluate
the performance impact and the memory usage behavior.
This feature allows the user to specify the minimum number of
connected replicas having a lag less or equal than the specified
amount of seconds for writes to be accepted.
Also the logfile option was modified to always have an explicit value
and to log to stdout when an empty string is used as log file.
Previously there was special handling of the string "stdout" that set
the logfile to NULL, this always required some special handling.
This is just to make the code exactly like the above instance used for
requirepass. No actual change nor the original code violated the Redis
coding style.
Usually this does not happens since we trim for " \t\r\n", but if there
are other chars that return true with isspace(), we may end with an
empty argv. Better to handle the condition in an explicit way.
