Thanks for your comments. Let me try to provide you with a little more
information.
On Thu, Jan 8, 2009 at 4:38 AM, Ian Eslick <esl...@media.mit.edu> wrote:
>
> On Jan 8, 2009, at 3:22 AM, Elliott Slaughter wrote:
>
> > Another issue is that the cache-style declaration in persistent
> > classes doesn't get inherited by default. This particularly annoying
> > since this throws an error merely by inheriting cached slots from a
> > superclass.
>
> Hmmmm...it should inherit by default unless you are overriding the
> base class slot. I'll look into this too.
It looks like cache-style is inherited when no new cached slots are
declared. But when new cached slots are declared, it produces a rather
strange error. I have attached a test case for you to examine.
> That said, I could probably avoid reading indexed slots if I used
> > the query language discussed on another thread. (Currently I use get-
> > instances-by-value to cons a list of objects, and then sort by the
> > indexed slot to effectively iterate over two sorted slots.)
>
> The query system would basically do this:
>
> (let ((a (map-inverted-index #'identity 'slot1 :collect t :oids t))
> (b (map-inverted-index #'identity 'slot2 :collect t :oids t)))
> (mapcar #'elephant::controller-recreate-instance
> (merge-unique (sort a #'<) (sort b #'<))
What I need to do is more like
(let ((list (map-inverted-index #'identity 'slot1 :value foo :collect t)))
(sort list #'< :key #'slot2))
which is effectively what I am currently doing with get-instances-by-value.
Is there a better way to efficiently iterate over one value in the first
slot, with the ordering of the second slot? (Should I look into creating
another level of btree for holding each subset of object in order?)
You can also do map-inverted-index and accumulate only values matching
> the second value as discussed earlier using an accumulation closure as
> an argument. For small sets on the first slot, this is probably
> faster. In general mapping is always more efficient than get-
> instances...
Most of the time, the sets will be close in size. Less frequently, the
second set will be much larger.
> I get roughly the same results as you on the micro-benchmarks. When
> > using checkout caching in the game, I get about a 2x speed increase.
> > It is still about 3x slower than no database.
>
> It would be interesting to see some profile data on this to see what,
> if anything, in BDB/Elephant could be improved.
Do you want profile results from my package, or from Elephant internals?
Either way, I have attached to profile reports. I hope you find them
helpful.
On Thu, Jan 8, 2009 at 5:02 AM, Ian Eslick <esl...@media.mit.edu> wrote:
> By the way, a write through mode is complex because if a transaction
> is rolled back your index could differ from your memory state so you
> would then have to keep track if slot writes to undo them on rollback...
I don't currently (or expect to) rollback changes, so this isn't an issue
with my particular application.
Are you caching blocks of objects for short term operations or long
> term ones?
>
I would like to cache all objects in the current room, so the only major
context switches should be when the player moves between rooms. So long
term.
--
Elliott Slaughter
"Any road followed precisely to its end leads precisely nowhere." - Frank
Herbert
;;; rm -rf test.db && sbcl --load class_cache-style_inheritence_bug.lisp
(asdf:oos 'asdf:load-op :elephant)
(use-package :ele)
(ensure-directories-exist "test.db/")
(open-store '(:bdb "test.db/"))
(defpclass foo () ((a :initarg :a :cached t)) (:cache-style :checkout))
(defpclass bar (foo)
((b :initarg :b :cached t))
;; To fix the following code, change #+ to #-
#+omit (:cache-style :checkout))
(defvar *bar* (make-instance 'bar :a 5))
seconds | consed | calls | sec/call | name
----------------------------------------------------------
0.476 | 11,291,472 | 66,102 | 0.000007 | ELEPHANT:CURSOR-NEXT
0.405 | 437,096 | 66,966 | 0.000006 | ELEPHANT:FIND-INVERTED-INDEX
0.370 | 266,200 | 66,868 | 0.000006 | ELEPHANT:CURSOR-SET
0.306 | 8,287,600 | 66,975 | 0.000005 | ELEPHANT:MAKE-CURSOR
0.162 | 1,216,552 | 33,858 | 0.000005 | ELEPHANT:TRANSLATE-AND-INTERN-S
YMBOL
0.158 | 13,668,968 | 66,868 | 0.000002 | ELEPHANT:MAP-BTREE
0.109 | 6,448,184 | 1 | 0.108992 | ELEPHANT:OPEN-STORE
0.091 | 0 | 66,975 | 0.000001 | ELEPHANT:CURSOR-CLOSE
0.032 | 1,763,752 | 2 | 0.015997 | ELEPHANT:ADD-INDEX
0.016 | 127,936 | 101 | 0.000158 | ELEPHANT:PERSISTENT-CHECKOUT
0.015 | 184,304 | 2,592 | 0.000006 | ELEPHANT:GET-VALUE
0.015 | 8,192 | 105 | 0.000143 | ELEPHANT:CURSOR-GET-BOTH
0.010 | 0 | 66,409 | 0.0000002 | ELEPHANT:CURSOR-INITIALIZED-P
0.000 | 511,504 | 5 | 0.000000 | ELEPHANT:MAKE-DUP-BTREE
0.000 | 12,328 | 2 | 0.000000 | ELEPHANT:MAP-CLASS
0.000 | 0 | 2 | 0.000000 | ELEPHANT:CURSOR-PSET
0.000 | 0 | 1 | 0.000000 | ELEPHANT:FLUSH-INSTANCE-CACHE
0.000 | 8,192 | 101 | 0.000000 | ELEPHANT:PERSISTENT-CHECKIN
0.000 | 1,699,320 | 66,862 | 0.000000 | ELEPHANT:MAP-INVERTED-INDEX
0.000 | 8,192 | 208 | 0.000000 | GET-INSTANCE-BY-VALUE
0.000 | 57,328 | 64 | 0.000000 | ELEPHANT:STRUCT-CONSTRUCTOR
0.000 | 0 | 105 | 0.000000 | ELEPHANT:REMOVE-KV-PAIR
0.000 | 0 | 216 | 0.000000 | ELEPHANT:KEY-FN
0.000 | 8,192 | 214 | 0.000000 | ELEPHANT:REMOVE-KV
0.000 | 0 | 133,724 | 0.000000 | GET-INSTANCES-BY-VALUE
0.000 | 161,632 | 2 | 0.000000 | ELEPHANT:MAP-INDEX
0.000 | 32,744 | 202 | 0.000000 | ELEPHANT:CURSOR-PNEXT-DUP
0.000 | 0 | 2 | 0.000000 | ELEPHANT:GET-INDEX
0.000 | 8,192 | 105 | 0.000000 | ELEPHANT:CURSOR-DELETE
0.000 | 0 | 2 | 0.000000 | ELEPHANT:KEY-FORM
----------------------------------------------------------
2.166 | 46,207,880 | 705,639 | | Total
estimated total profiling overhead: 0.57 seconds
overhead estimation parameters:
0.0s/call, 8.12e-7s total profiling, 3.1e-7s internal profiling seconds | consed | calls | sec/call | name
-----------------------------------------------------------
1.233 | 19,183,304 | 97,294 | 0.000013 | IMAGE
1.095 | 8,122,056 | 97,285 | 0.000011 | OFFSET
1.012 | 62,808,984 | 55,894 | 0.000018 | RECT
0.718 | 14,013,416 | 56,156 | 0.000013 | GET-INSTANCES-BY-VALUE
0.603 | 6,208,360 | 27,738 | 0.000022 | UPDATE
0.490 | 4,677,144 | 64,998 | 0.000008 | ELEVATION
0.241 | 2,653,496 | 28,970 | 0.000008 | VELOC
0.222 | 6,730,720 | 1 | 0.222339 | MAIN
0.156 | 8,248,720 | 1 | 0.156000 | CREATE-DATABASE
0.135 | 2,400,888 | 13,800 | 0.000010 | VISIBLE
0.077 | 216,976 | 41,538 | 0.000002 | RENDER
0.056 | 1,069,024 | 13,800 | 0.000004 | ACCEL
0.049 | 581,072 | 41,747 | 0.000001 | SURFACE
0.031 | 1,072,024 | 1 | 0.031000 | SETUP-REPL-STREAMS
0.016 | 49,128 | 1 | 0.016000 | CLOSE-DATABASE
0.016 | 957,280 | 208 | 0.000076 | GET-INSTANCE-BY-VALUE
0.016 | 352,600 | 102 | 0.000155 | ENTER
0.015 | 973,016 | 1 | 0.015000 | HANDLE-KEY-DOWN
0.000 | 0 | 1 | 0.000000 | TITLE-CAPTION
0.000 | 0 | 372 | 0.000000 | VELOC-X
0.000 | 0 | 313 | 0.000000 | VELOC-Y
0.000 | 0 | 1 | 0.000000 | USE-ROOT
0.000 | 8,192 | 28,078 | 0.000000 | CHILDREN
0.000 | 0 | 2 | 0.000000 | SIZE
0.000 | 69,552 | 201 | 0.000000 | ACTIVE
0.000 | 8,184 | 102 | 0.000000 | LEAVE
0.000 | 0 | 1 | 0.000000 | EXIT
0.000 | 0 | 478 | 0.000000 | ROOT
0.000 | 0 | 84,319 | 0.000000 | Y
0.000 | 16,352 | 84,429 | 0.000000 | X
0.000 | 0 | 142 | 0.000000 | INPUT-MODE
0.000 | 0 | 1 | 0.000000 | KEY-REPEAT
-----------------------------------------------------------
6.182 | 140,420,488 | 737,975 | | Total
estimated total profiling overhead: 0.58 seconds
overhead estimation parameters:
0.0s/call, 7.8200003e-7s total profiling, 3.38e-7s internal profiling
Short description of the first several most expensive functions:
image: Slot read containing a persisted vector, which is then accessed.
offset: Slot read containing a complex number.
rect: Transient slot operation.
get-instances-by-value: From Elephant.
update: Iterates over objects with a certain slot value (after sorting them
according to a second slot), and recursively calls update on each. Additional
before and after methods may do several slot reads or writes.
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