Hi Pablo, On Tue, Aug 1, 2017 at 12:36 PM, tesonep@gmail.com <tesonep@gmail.com> wrote:
Hi again, thanks for the clarification, I haven't understood the question initially, but now I think I can answer it.
Hermes is only exporting the classes, not objects. so it does not have to handle complex graphs of objects. Basically it serializes the definition of the classes, traits and methods. Then they are loaded in sequence. The only caring during the generation is to serialize first the superclasses, and then the subclasses. There is no way of serializing objects outside the classes, methods, traits and literals in a method.
Classes, traits, methods, literals *are* a graph of objects :-). The Parcel architecture, from which Fuel derived its architecture, was designed for loading code in VisualWorks. In fact, last time I looked Parcels were used only to store code and not as a general purpose (de)serializer. So the answer is that is not using Parcels or Fuel architecture because
they are intended for different uses.
Well, I don't think that's the reason ;-), but fine. I understand that it doesn't use this architecture. Thanks.
Also the format itself has no special design or considerations to be fast to generate or fast to read (as It happens with Fuel)
Cheers, Pablo
On Tue, Aug 1, 2017 at 9:16 PM, Eliot Miranda <eliot.miranda@gmail.com> wrote:
Hi Pablo,
I understand that Hermes has its own format. My question was about architecture. The Parcels/Fuel architecture is, AFAIA, the best architecture for binary storage because it is virtual, is fast to load and cleanly separates loading from initialization. What do I mean?
- concrete formats like ImageSegment are tied to internal representations in the VM and do are difficult to read in forever FB systems and very hard to write in foreign systems. So a virtual format (like BOSS, Fuel, Parcels, etc) is better but unless done well can be slow
- a first generation system like BOSS is a flattening of a graph traversal using a simple grammar. Each phrase is either an object reference (object id) or an object definition (object is followed by type info and contents, contents being a sequence of phrases. This is slow to parse (because each phrase must be decoded), and has invalid intermediate states (e.g. a Set whose contents are not all present, hence whose external hash may change during loading, etc). A second generation system like Parcels and Fuel separates objects from references (nodes from arcs) and batches object creation, grouping all instances of a given class for bulk, and hence fast, instantiation. Following my the objects are the references. So loading has three phases: - instantiate the objects - connect the graph by filling in object references - initialize the objects that require it (e.g. rehash sets)
Consequently the writer must be two pass, the first pass to collect the objects in the graph and sort them by class, the second to write the nodes followed by the references
So let me ask again, does Hermes use the Parcels/Fuel architecture?
_,,,^..^,,,_ (phone)
On Aug 1, 2017, at 11:52 AM, "tesonep@gmail.com" <tesonep@gmail.com> wrote:
Hi Eliot,
The last version of Hermes, that I have generated today and have to be tested for real yet, is able to load and save from and to 32 and 64 bits, handling the conversion. Because the Hermes representation (if we can call it like that, because is really simple, does not care about the architecture).
Hermes is using a custom format completely separated from Fuel or any other tool.
This is a consequence of the design of Hermes. Hermes has been designed to only work as light way of loading code during the bootstrap. So that, it is heavily coupled with Pharo (it can be changed, for example implementing another loader / installer) and uses only really core classes.
Of course it can be extended and used in another Smalltalk dialects, but I am not sure if the tool can be useful for them, or even for the Pharo community outside the Pharo bootstrap process.
Today to be useful outside the bootstrap process, some work has to be done (perhaps a lot), but mainly new use cases have to be thinked. Once the Compiler, Monticello or Metacello is available, there is no need for Hermes. It is only used to generate some binary loadable packages for the compiler from the source code.
Again, it was only thinked as a tool to improve the speed during the bootstrap. However, if somebody has ideas to use it or want to collaborate are of course welcomed.
Hermes is actually in Github, because to me is more comfortable to have it there, but if somebody is really wanting to use it.... we can manage to have an export process to Smalltalkhub.
I hope I have clarified a little the idea behind Hermes.
Maybe you have better ideas of what can we do with it.
On Tue, Aug 1, 2017 at 7:59 PM, Eliot Miranda <eliot.miranda@gmail.com> wrote:
Hi Guille,
On Aug 1, 2017, at 4:29 AM, Guillermo Polito <guillermopolito@gmail.com> wrote:
On Tue, Aug 1, 2017 at 12:57 PM, philippe.back@highoctane.be < philippe.back@gmail.com> wrote:
Massive.
What is in the super small image? Is Hermes going to be a generic binary content loader?
There is still work to do in this front. - Hermes only works for 32bits format. We should adapt it to 64 bits (immediate floats and so on...) - There is no format validation. We should add one for safety.
Will Hermes be able to save on 32-bits and load on 64-bits and vice verse?
Does Hermes use the Parcels/Fuel architecture of saving nodes, grouped by class, followed by the arcs?
If yes to both of these, are you willing to keep it in Monticello and collaborate with the Squeak & Cuis communities in developing Hermes?
Phil
On Aug 1, 2017 12:36, "Stephane Ducasse" <stepharo.self@gmail.com> wrote:
Hi Pavel
This is super excellent! IMPRESSIVE. An image without the compiler and a reloadable compiler. Super cool.
Stef
On Tue, Aug 1, 2017 at 11:57 AM, Pavel Krivanek <pavel.krivanek@gmail.com> wrote:
Hello,
we are checking a huge pull request #177 (https://github.com/pharo-project/pharo/pull/177) that will change some basics of the bootstrap process:
Now we will bootstrap a smaller image that will not include compiler/parser. Compiler and related packages are exported and loaded using a binary exporter named Hermes. The compiler is then used to load FileSystem and Monticello. The rest of the bootstrap process will be the same as before. As the result we will have faster bootstrap and better system modularization and possibilities.
It required some modularization efforts:
- simplified initialization scripts - Use Zinc converters and encoders instead of FilePathEncoder and old TextConverter - Use Stdio instead of FileStream - Using File instead of FileSystem - Deprecated FileStream & childs (Moved to Deprecated70) - Extracted Path classes to their on package: FileSystem-Path - Moved OpalEncoders to their own package. They are required by the runtime (not only for compilation) - Introduced AsciiCharset in the kernel to answer to #isLetter #isUppercase and so on without requiring full Unicode tables from the beginning - Cleaning up a bit the full exception logging infrastructure (streams, transcript, files, stack printing...) - Split Ring methods required for system navigation to the Ring-Navigation package - Remove usages of #translated in the kernel - Refactored the bootstrapping classes to remove duplications - Cleaning up dependencies in CompiledMethod>>printOn: - fix path printing
We need to merge these changes at once and of course it can cause some conflicts with the existing pull requests or external code. Anyway, we need to merge it as soon as possible.
So please, try to look at the PR and test the resultant image [1] to avoid some major problems.
[1] https://ci.inria.fr/pharo/view/7.0/job/70-PR-Check-Load/last SuccessfulBuild/artifact/bootstrap-cache/Pharo7.0-32bit-9c0691d.zip
Cheers, -- Pavel
--
Guille Polito
Research Engineer
French National Center for Scientific Research - *http://www.cnrs.fr* <http://www.cnrs.fr>
*Web:* *http://guillep.github.io* <http://guillep.github.io>
*Phone: *+33 06 52 70 66 13 <+33%206%2052%2070%2066%2013>
-- Pablo Tesone. tesonep@gmail.com
-- Pablo Tesone. tesonep@gmail.com
-- _,,,^..^,,,_ best, Eliot