-Pre 1.1 todo
-
-* For now only the last argument gets integer encoded, so make sure that: 1) every multi bulk commands implemented will have the last arg that is indeed a value, and not used otherwise. 2) to explicitly call the function to encode the object in MSET and other commands where there are multiple "values".
-
-After 1.1 todo
-
-* Expiring algorithm should be adaptive, if there are a lot of keys with an expire set and many of this happen to be already expired it should be, proportionally, more aggressive.
- * Add a command to inspect the currently selected DB index
- * Consistent hashing implemented in all the client libraries having an user base
- * SORT: Don't copy the list into a vector when BY argument is constant.
- * SORT ... STORE keyname. Instead to return the SORTed data set it into key.
- * Profiling and optimization in order to limit the CPU usage at minimum
- * Write the hash table size of every db in the dump, so that Redis can resize the hash table just one time when loading a big DB.
- * Elapsed time in logs for SAVE when saving is going to take more than 2 seconds
- * LOCK / TRYLOCK / UNLOCK as described many times in the google group
- * Replication automated tests
- * some kind of sorted type, example:
- ZADD mykey foo 100
- ZADD mykey bar 50
- ZRANGE mykey 0 1 => bar foo
- This is able to take elements sorted because a binary tree is used to store
- the elements by 'score', with the actual value being the key. On the other
- side the type also takes an hash table with key->score mapping, so that when
- there is an update we lookup the current score and can traverse the tree.
- * BITMAP / BYTEARRAY type?
- * LRANGE 4 0 should return the same elements as LRANGE 0 4 but in reverse order (only if we get enough motivated requests about it)
- * zmalloc() should avoid to add a private header for archs where there is some other kind of libc-specific way to get the size of a malloced block.
-
-FUTURE HINTS
-
-- In memory compression: if in-memory values compression will be implemented, make sure to implement this so that addReply() is able to handle compressed objects, just creating an uncompressed version on the fly and adding this to the output queue instead of the original one. When insetad we need to look at the object string value (SORT BY for example), call a function that will turn the object into an uncompresed one.
+Redis TODO and Roadmap
+----------------------
+
+VERSION 2.2 TODO (Optimizations and latency)
+============================================
+
+* Lower the CPU usage.
+* Lower the RAM usage everywhere possible.
+* Specially encoded Sets (like Hashes).
+* Implement an UDP interface for low-latency operations.
+* What about a special coding that is about storing the "rdb" serialized format instead of the actual value? This can be used when we have LRU in order to super-compress data into memory, for data not accessed frequetly. It's a VM-alike strategy but fully in memory, may reduce the space to hold some dataset in an impressive way. Trivial to implement.
+* Another idea: LRU does not need to be super precise right? Maybe it's a good idea to just put into the skiplist implementing the LRU just the pointer to the key without evne incr/decr business, nor the need to remove the pointer when the key is deleted. There is to think more about that.
+
+VERSION 2.x TODO
+================
+
+* BRPOPLPUSH
+* Save dataset / fsync() on SIGTERM
+* Change the implementation of ZCOUNT to use the augmented skiplist in order to be much faster.
+
+Virtual Memory optimizations:
+* Use multiple open FDs against the VM file, one for thread.
+* Check what happens performance-wise if instead of creating threads again and again the same threads are reused forever. Note: this requires a way to disable this clients in the child, but waiting for empty new jobs queue can be enough.
+* Implement LEN, PEEK, POKE, SETBIT, GETBIT
+
+OTHER IMPORTANT THINGS THAT WILL BE ADDED BUT I'M NOT SURE WHEN
+===============================================================
+
+BIG ONES:
+
+* Specially encoded memory-saving integer sets.
+* A command to export a JSON dump (there should be mostly working patch needing major reworking).
+* Specially encoded sets of integers (this includes a big refactoring providing an higher level layer for Sets manipulation)
+
+SMALL ONES:
+
+* If sizeof(double) == sizeof(void*) we could store the double value of sorted sets directly in place of the pointer instead of allocating it in the heap.
+* Delete on writes against expire policy should only happen after argument parsing for commands doing their own arg parsing stuff.
+* Give errors when incrementing a key that does not look like an integer, when providing as a sorted set score something can't be parsed as a double, and so forth.
+* MSADD (n keys) (n values). See this thread in the Redis google group: http://groups.google.com/group/redis-db/browse_thread/thread/e766d84eb375cd41
+* Don't save empty lists / sets / zsets on disk with snapshotting.
+* Remove keys when a list / set / zset reaches length of 0.
+* An option to exec a command slave-side if the master connection is lost: even cooler: if the script returns "0" the slave elects itself as master, otherwise continue trying to reconnect.
+* PING the master from time to time to check if it's gone.
+
+THE "MAYBE" TODO LIST: things that may or may not get implemented
+=================================================================
+
+Most of this can be seen just as proposals, the fact they are in this list
+it's not a guarantee they'll ever get implemented ;)
+
+* Move dict.c from hash table to skip list, in order to avoid the blocking resize operation needed for the hash table.
+* FORK command (fork()s executing the commands received by the current
+ client in the new process). Hint: large SORTs can use more cores,
+ copy-on-write will avoid memory problems.
+* DUP command? DUP srckey dstkey, creates an exact clone of srckey value in dstkey.
+* SORT: Don't copy the list into a vector when BY argument is constant.
+* Write the hash table size of every db in the dump, so that Redis can resize the hash table just one time when loading a big DB.
+* LOCK / TRYLOCK / UNLOCK as described many times in the google group
+* Replication automated tests
+* Byte Array type (BA prefixed commands): BASETBIT BAGETBIT BASETU8 U16 U32 U64 S8 S16 S32 S64, ability to atomically INCRBY all the base types. BARANGE to get a range of bytes as a bulk value, BASETRANGE to set a range of bytes.
+* zmalloc() should avoid to add a private header for archs where there is some other kind of libc-specific way to get the size of a malloced block. Already done for Mac OS X.
+* Read-only mode.
+* Pattern-matching replication.
+* Add an option to relax the delete-expiring-keys-on-write semantic *denying* replication and AOF when this is on? Can be handy sometimes, when using Redis for non persistent state, but can create problems. For instance should rename and move also "move" the timeouts? How does this affect other commands?
+* Multiple BY in SORT.
+
+KNOWN BUGS
+==========
+
+* LRANGE and other commands are using 32 bit integers for ranges, and overflows are not detected. So LRANGE mylist 0 23498204823094823904823904 will have random effects.
projects / redis.git / blobdiff