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diff --git a/hurd/translator.mdwn b/hurd/translator.mdwn deleted file mode 100644 index d504b41f..00000000 --- a/hurd/translator.mdwn +++ /dev/null @@ -1,165 +0,0 @@ -[[!meta copyright="Copyright © 2007, 2008, 2009, 2010, 2011, 2012 Free Software -Foundation, Inc."]] - -[[!meta license="""[[!toggle id="license" text="GFDL 1.2+"]][[!toggleable -id="license" text="Permission is granted to copy, distribute and/or modify this -document under the terms of the GNU Free Documentation License, Version 1.2 or -any later version published by the Free Software Foundation; with no Invariant -Sections, no Front-Cover Texts, and no Back-Cover Texts. A copy of the license -is included in the section entitled [[GNU Free Documentation -License|/fdl]]."]]"""]] - -[[!tag stable_URL]] - -[[!toc]] - - -# General Information - -A translator is simply a normal program acting as -an object server and participating in the Hurd's -distributed [[virtual_file_system]]. It is so-called -because it typically exports a file system -(although need not: cf. [[auth]], [[proc]] -and [[pfinet]]) and thus translates object invocations -into calls appropriate for the backing store -(e.g., ext2 file system, nfs server, etc.). - -Another way of putting it is that it translates from one representation of a -data structure into another representation, for example from the on-disk -[[ext2|ext2fs]] data layout to a traditional file system hierarchy, or from a -XML file to a virtual hierarchical manifestation. This translation can be a -bidirectional process, but it need not be. - -A translator is usually registered with a specific file system node by using -the [[`settrans`|settrans]] command. - -Translators do not require any special privilege -to run. The privilege they require is simply -that to access the indiviudal resources they use. -This is primarily the [[backing_store]] and the node -they attach to. Typically, a translator can -only be attached to a node by the node's owner. -On [[Unix]] this is not possible because file systems -and the virtual file system are implemented in the -kernel and thus have absolute access to the machine. -As the protocols do not require any special privilege -to implement, this is not an issue on the Hurd. - -In Mach parlance, a *translator* is what they name a *server*: a process that -participates in [[RPC]] interactions. In the Hurd, a translator is a server -that is additionally attached to a filesystem node. Thus, it is quite common, -even in the Hurd context, to speak about *server*s if you're stressing the RPC -part, and on the other hand about *translator*s if you're stressing the -filesystem part: a translator implements the [[interface/fs]] and -[[interface/io]] interfaces. For example: *the [[pfinet]] server implements -the socket API calls (which are mapped by [[glibc]] to equivalent RPC calls)*, -compared to *a [[libdiskfs]]-based translator implements a filesystem, based on -a backing store*. - -To learn how to write a translator, read the code! -It is well documented, in particular, the header files. -The [[Hurd_Hacking_Guide]] also has a tutorial. - -Also there is an [[writing/example]] about how to write a simple translator. - -See some [[examples]] about how to use translators. - -There is a [[documentation/translator_primer]]. - -Marcus Brinkmann has written a document about [[documentation/translators]]. - -Here are some [[hints_about_debugging_translators|debugging/translator]] -available. - -Read about translator [[short-circuiting]]. - -The [[concept|concepts]] of translators creates its own problems, too: -[[open_issues/translators_set_up_by_untrusted_users]], and -[[open_issues/trust_the_behavior_of_translators]]. - - -# Existing Translators - -* [[hello]] -* [[auth]] -* [[exec]] -* [[pfinet]] -* [[pflocal]] -* [[hostmux]] -* [[storeio]] -* [[ext2fs]] -* [[fatfs]] -* [[magic]] -* [[unionfs]] -* [[nfs]] -* ... - - -# Translators Being Under Development - -* [[random]] -* [[emailfs]] -- email as a filesystem -* [[cvsfs]] -* [[tmpfs]] -* [[procfs]] -* [[nsmux]] -* [[netio]] -* [[tarfs]] -* [[gopherfs]] -* ... - -# Translators (only) in Hurdextras - -*These Translators are available in the [hurdextras repository](http://savannah.nongnu.org/cvs/?group=hurdextras) but not yet described on this website. They are in varying stages of Development.* - -* [jfs](http://www.nongnu.org/hurdextras/#jfs) -* [httpfs](http://www.nongnu.org/hurdextras/#httpfs) -* [gopherfs](http://www.nongnu.org/hurdextras/#cvsfs) -* [memfs](http://www.nongnu.org/hurdextras/#gopherfs) -* [notice](http://www.nongnu.org/hurdextras/#notice) -* [pith](http://www.nongnu.org/hurdextras/#pith) -* [pptop](http://www.nongnu.org/hurdextras/#pptop) -* [run](http://www.nongnu.org/hurdextras/#run) -* [smbfs](http://www.nongnu.org/hurdextras/#smbfs) -* [xmlfs](http://www.nongnu.org/hurdextras/#xmlfs) -* [mboxfs](http://www.nongnu.org/hurdextras/#mboxfs) - - -# Translator Wishlists - - * [[wishlist_1]] - * [[wishlist_2]] - * [[open_issues/network_file_system_by_just_forwarding_RPCs]] - * [[libguestfs]] - - -# Internally - -## `*_demuxer` Functions - - * IRC, unknown channel, unknown date - - <jim-crow> what is a main idea of _demuxer functions in translators? - <neal> jim-crow: Think of a web server. - <neal> jim-crow: A typical web server must process many different requests. - <neal> jim-crow: There are different types of requests. - <neal> jim-crow: For instance, static pages and dynamically gnereated content. - <neal> the static pages are processed by one function - <neal> and the dynamic pages by another - <neal> the thing that makes the decision which of these functions to pass the request to is the demuxer. - <jim-crow> neal: ok, I see - <jim-crow> but what is actually it doing in trivfs_demuxer? - <neal> it looks at the message id and calls the right server stub - <jim-crow> for example it calls trivfs_io_server function, but I can't find its implementation - <jim-crow> that's my main question :-) - <neal> look at the files mig generates - <jim-crow> neal: ok, thanks - <jim-crow> neal: is this functions where actually stubs are called? - <neal> I think so. - - -# Bounties - -There is a [[!FF_project 280]][[!tag bounty]] on some translator improvement -tasks. |