- cl-prevalence-devel@common-lisp.net - mailman3.common-lisp.net

[cl-prevalence-devel] A useful macro?
by Anthony Fairchild 07 Nov '11

07 Nov '11

Hi cl-prevalence devs, I have been playing around a bit with cl-prevalence and found the following macro useful: (defmacro deftxn (name (system &rest args) &body body) (let ((tx-name (intern (format nil "TX-~A" NAME)))) `(progn (defun ,tx-name (,system ,@args) ,@body) (defun ,name (,system ,@args) (execute-transaction (,tx-name ,system ,@args)))))) So my question is, is this pattern worth abstracting or is there a reason to use the more explicit method of defining a tx-* function then calling (execute (make-transaction ...)) or (execute-transaction ...). Thanks! Anthony

1 0

[cl-prevalence-devel] 2D arrays
by Krzysztof Drewniak 05 Jul '10

05 Jul '10

Is there any major problems with getting 2D arrays (sequences of sequences) serialized? (I'm working on a game and trying to find a serialization libraryt that does what I need) Krzysztof Drewniak -- X-Real-Email-With-Antispam: krzysdrewniak at gmail dot com pgp key on keyserver.ubuntu.com and maybe some other place too

2 2

Re: [cl-prevalence-devel] Patch for serialization of arbitrary data
by Leslie P. Polzer 05 Jul '10

05 Jul '10

Krzysztof Drewniak wrote: > --- src/serialization/xml.lisp.old 2010-06-10 20:50:24.000000000 -0500 > +++ src/serialization/xml.lisp 2010-06-10 21:24:34.000000000 -0500 > @@ -196,6 +196,12 @@ > (write-string "</SLOT>" stream))) > (write-string "</OBJECT>" stream))))) > > +;;anything we don't know about > +(defmethod serialize-xml-internal (object stream serialization-state) > + (declare (ignore serialization-state)) > + (write-string "<ARBITRARY>" stream) > + (print object stream) > + (write-string "</ARBITRARY>" stream)) > > ;;;; DESERIALIZATION > > @@ -283,6 +289,11 @@ > (declare (ignore name attributes parent-seed seed)) > nil)) > > +(defmethod deserialize-xml-finish-element-aux ((name (eql :arbitrary)) > + attributes parent-seed seed) > + (declare (ignore name attributes parent-seed)) > + (read (make-string-input-stream seed))) > + I'm not sure whether this one is good. We're mixing XML and SEXP serialization. Do you have a specific use case? Leslie

1 0

[cl-prevalence-devel] Opening the transaction log - Clozure CL
by William Bruschi 04 Jul '10

04 Jul '10

The Clozure CL implementation has added additional keywords to OPEN, including the :SHARING keyword which controls the access to the stream by multiple threads. The default value is :PRIVATE, which allows access to only the thread that created the stream. More info here: http://openmcl.clozure.com/manual/chapter9.1.html#CCL-Stream-Extensions I was using cl-prevalence as a backend for a Weblocks application when I stumbled upon thread locking errors while accessing the site with multiple browsers. Setting :SHARING to nil fixed my problem. Should this be the default behavior for cl-prevalence? After skimming the code, it appears cl-prevalence has it's own locking mechanisms, making Clozure's extra keyword arguments unnecessary. I also noticed in the TODO file that porting to ccl is on the list. In case anyone is curious, here's how to reproduce the error in Weblocks: 1. Create a new project as outlined in the bottom of http://trac.common-lisp.net/cl-weblocks/wiki/UserManual 2. Edit you init-session.lisp file to this: (defun init-user-session (root) (setf (widget-children root) (list (make-grid-edit)))) (defclass thing () ((id :initform nil :initarg :id :accessor thing-id :type (or null integer)) (name :initform nil :initarg :name :accessor thing-name))) (defun make-grid-edit () (make-instance 'gridedit :data-class 'thing)) 3. Open the site using two different browsers. Add a record using each browser. The second time you add a record, you receive this error: SIMPLE-ERROR: Stream #<BASIC-FILE-CHARACTER-OUTPUT-STREAM ("/<path-to-file>/transaction-log.xml"/15 ISO-8859-1) #x1987FB3E> is private to #<PROCESS Hunchentoot worker (client: 127.0.0.1:47448)(14) [Reset] #x1983AA9E>

2 1

[cl-prevalence-devel] Patch for serialization of arbitrary data
by Krzysztof Drewniak 11 Jun '10

11 Jun '10

This patch allows the xml serialization to serialize anything not explicitly covered by the code (some implementations can print functions etc.). Also, the 3.5 download is broken and I'd look si;;y telling my users pull the latest development code of cl-prevalence. -- X-Real-Email-With-Antispam: krzysdrewniak at gmail dot com pgp key on keyserver.ubuntu.com and maybe some other place too

2 3

[cl-prevalence-devel] 20090926 cummulative patchset
by Alexey Voznyuk 07 Oct '09

07 Oct '09

Hello! Here is what I have done since 20090828 in 'hg diff' format: http://swizard.info/misc/cl-prevalence-3.patch It is going slightly uncomfortable for me to maintain patchfiles, maybe I should make a mercurial branch or something? Detailed changelog: 1. SEXP standard-object serializing: fixed a bug with no-slots objects. 2. Backup method for guarded-prevalence-system: key parameter bugfix. 3. Files external format support for prevalence-system with tests available (test/test-external-format.lisp). 4. Moved from 'copy-file'+'delete-file' to 'rename-file' in snapshot method. Have no idea why it was like that :) 5. Removed reset serialization context invocations in serialize-sexp, deserialize-sexp, serialize-xml and deserialize-xml. Context reset moved to 'snapshot' method. 6. test/test-complex-serialize.lisp: emulation of complex datasets processing under heavy load.

2 4

[cl-prevalence-devel] Keeping state during transactions
by Alexey Voznyuk 26 Sep '09

26 Sep '09

Hello! I've faced annoying cl-prevalence behavior which I don't know how to deal with. For example, consider this code that I want to run within a transaction: (defun tx-add-item (store index item) (declare (ignore store)) (setf (gethash item index) t)) Current cl-prevalence implementation invokes (reset serialization-state) before each (serialize-*) call. So as long as I insert new items into the index, each log entry becomes bigger and bigger because it needs to deeply serialize "index" parameter with all its elements, including the new ones. The problem that the index can contains thousands elements, and each of them can be a complex object itself with maybe more index tables. In such case a single transaction can consume a lot of resource. My proposal is to not reset serialization-state before each transaction serialize step but to keep it until full snapshot is occurred. For me it seems to work correctly, but maybe I miss something?

2 5

[cl-prevalence-devel] [feature proposal][patch] :external-format for file operations
by Alexey Voznyuk 25 Sep '09

25 Sep '09

Hello! Current cl-prevalence version does not allow to set specific :external-format when reading or writing files. This is very uncomfortable when current working encoding in application differs from the system locale's one: cl recodes strings on serializing. Please check this patchset implementing the feature (cumulative with my previous bugfixes for "serialize-sexp-external" and "backup"). Maybe there are some crossplatform-related changes required. % hg diff diff -r 1edf5cd93bb9 src/prevalence.lisp --- a/src/prevalence.lisp Sun Jul 26 11:10:13 2009 +0200 +++ b/src/prevalence.lisp Tue Sep 08 22:44:04 2009 +0400 @@ -103,7 +103,11 @@ (transaction-hook ;; type function :accessor get-transaction-hook :initarg :transaction-hook - :initform #'identity)) + :initform #'identity) + (external-format ;; external encoding for file operations + :reader get-external-format + :initarg :external-format + :initform :utf-8)) (:documentation "Base Prevalence system implementation object")) (defclass guarded-prevalence-system (prevalence-system) @@ -156,7 +160,8 @@ (setf transaction-log-stream (open (get-transaction-log system) :direction :output :if-does-not-exist :create - :if-exists :append))))) + :if-exists :append + :external-format (get-external-format system)))))) (defmethod close-open-streams ((system prevalence-system) &key abort) "Close all open stream associated with system (optionally aborting operations in progress)" @@ -242,7 +247,7 @@ :type (get-file-extension system)) snapshot))) (with-open-file (out snapshot - :direction :output :if-does-not-exist :create :if-exists :supersede) + :direction :output :if-does-not-exist :create :if-exists :supersede :external-format (get-external-format system)) (funcall (get-serializer system) (get-root-objects system) out (get-serialization-state system))) (when (probe-file transaction-log) (copy-file transaction-log (merge-pathnames (make-pathname :name (get-transaction-log-filename system timetag) @@ -273,7 +278,7 @@ (clrhash (get-root-objects system)) (close-open-streams system) (when (probe-file (get-snapshot system)) - (with-open-file (in (get-snapshot system) :direction :input) + (with-open-file (in (get-snapshot system) :direction :input :external-format (get-external-format system)) (setf (get-root-objects system) (funcall (get-deserializer system) in (get-serialization-state system))))) (when (probe-file (get-transaction-log system)) (let ((position 0)) @@ -284,7 +289,7 @@ condition) (truncate-file (get-transaction-log system) position) (return-from restore)))) - (with-open-file (in (get-transaction-log system) :direction :input) + (with-open-file (in (get-transaction-log system) :direction :input :external-format (get-external-format system)) (loop (let ((transaction (funcall (get-deserializer system) in (get-serialization-state system)))) (setf position (file-position in)) @@ -310,7 +315,7 @@ (defmethod backup ((system guarded-prevalence-system) &key directory) "Do a backup on a system controlled by a guard" (funcall (get-guard system) - #'(lambda () (call-next-method system directory)))) + #'(lambda () (call-next-method system :directory directory)))) (defmethod restore ((system guarded-prevalence-system)) "Restore a system controlled by a guard" @@ -343,8 +348,8 @@ (buffer (make-string 4096)) (index 0) (read-count 0)) - (with-open-file (in file :direction :input) - (with-open-file (out tmp-file :direction :output :if-exists :overwrite :if-does-not-exist :create) + (with-open-file (in file :direction :input :external-format (get-external-format system)) + (with-open-file (out tmp-file :direction :output :if-exists :overwrite :if-does-not-exist :create :external-format (get-external-format system)) (when (> position (file-length in)) (return-from truncate-file)) (loop (when (= index position) (return)) @@ -360,8 +365,8 @@ (defun copy-file (source target) (let ((buffer (make-string 4096)) (read-count 0)) - (with-open-file (in source :direction :input) - (with-open-file (out target :direction :output :if-exists :overwrite :if-does-not-exist :create) + (with-open-file (in source :direction :input :external-format (get-external-format system)) + (with-open-file (out target :direction :output :if-exists :overwrite :if-does-not-exist :create :external-format (get-external-format system)) (loop (setf read-count (read-sequence buffer in)) (write-sequence buffer out :end read-count) diff -r 1edf5cd93bb9 src/serialization/sexp.lisp --- a/src/serialization/sexp.lisp Sun Jul 26 11:10:13 2009 +0200 +++ b/src/serialization/sexp.lisp Tue Sep 08 22:44:04 2009 +0400 @@ -145,8 +145,9 @@ (write-string " . " stream) (serialize-sexp-internal (slot-value object slot) stream serialization-state) (write-string ")" stream)) - serializable-slots)) - (write-string " ) )" stream))))) + serializable-slots) + (write-string " )" stream)) + (write-string " )" stream))))) ;;; objects (defmethod serialize-sexp-internal ((object standard-object) stream serialization-state)

2 4

[cl-prevalence-devel] [patch] serialize-sexp-internal bug: serializing object with no slots
by Alexey Voznyuk 31 Aug '09

31 Aug '09

Hello! I didn't get if the cl-prevalence project is still alive but maybe someone will need this patch: --- serialization.lisp.orig 2009-08-28 21:04:00.624489057 +0400 +++ serialization.lisp 2009-08-28 21:16:44.758777912 +0400 @@ -475,6 +475,7 @@ (write-string " . " stream) (serialize-sexp-internal (slot-value object slot) stream serialization-state) - (write-string ")" stream)))) - (write-string " ) )" stream))))) + (write-string ")" stream))) + (princ " )" stream)) + (write-string " )" stream))))) ;;; Deserialize CLOS instances and Lisp primitives from the XML representation

3 7

Re: [cl-prevalence-devel] News
by Leslie P. Polzer 02 Aug '09

02 Aug '09

evrim.ulu(a)core.gen.tr wrote: > It is very unfortunate that the site does not work in your browser. > I am willing to see the error. Can you rephrase that sentence? I didn't get it. >> How does WITH-TRANSACTION work? >> > > It serializes the closure the body as a closure along with its > environment. Ah, that's nice. How do you implement closure serialization? In particular, how do you capture the environment and restore environments shared by multiple closures? > PS: Could you add my email addrss to devel list, > i'm continuatiosly getting bounces from list admin. Sorry, I don't have access to the list admin interface. Please subscribe yourself (and set yourself on holiday mode if you don't want to receive mail). Cheers, Leslie -- http://www.linkedin.com/in/polzer

1 0