# -*- tcl -*- # # Searching for Tcl Modules. Defines a procedure, declares it as the primary # command for finding packages, however also uses the former 'package unknown' # command as a fallback. # # Locates all possible packages in a directory via a less restricted glob. The # targeted directory is derived from the name of the requested package, i.e. # the TM scan will look only at directories which can contain the requested # package. It will register all packages it found in the directory so that # future requests have a higher chance of being fulfilled by the ifneeded # database without having to come to us again. # # We do not remember where we have been and simply rescan targeted directories # when invoked again. The reasoning is this: # # - The only way we get back to the same directory is if someone is trying to # [package require] something that wasn't there on the first scan. # # Either # 1) It is there now: If we rescan, you get it; if not you don't. # # This covers the possibility that the application asked for a package # late, and the package was actually added to the installation after the # application was started. It shoukld still be able to find it. # # 2) It still is not there: Either way, you don't get it, but the rescan # takes time. This is however an error case and we dont't care that much # about it # # 3) It was there the first time; but for some reason a "package forget" has # been run, and "package" doesn't know about it anymore. # # This can be an indication that the application wishes to reload some # functionality. And should work as well. # # Note that this also strikes a balance between doing a glob targeting a # single package, and thus most likely requiring multiple globs of the same # directory when the application is asking for many packages, and trying to # glob for _everything_ in all subdirectories when looking for a package, # which comes with a heavy startup cost. # # We scan for regular packages only if no satisfying module was found. namespace eval ::tcl::tm { # Default paths. None yet. variable paths {} # The regex pattern a file name has to match to make it a Tcl Module. set pkgpattern {^([_[:alpha:]][:_[:alnum:]]*)-([[:digit:]].*)[.]tm$} # Export the public API namespace export path namespace ensemble create -command path -subcommands {add remove list} } # ::tcl::tm::path implementations -- # # Public API to the module path. See specification. # # Arguments # cmd - The subcommand to execute # args - The paths to add/remove. Must not appear querying the # path with 'list'. # # Results # No result for subcommands 'add' and 'remove'. A list of paths for # 'list'. # # Sideeffects # The subcommands 'add' and 'remove' manipulate the list of paths to # search for Tcl Modules. The subcommand 'list' has no sideeffects. proc ::tcl::tm::add {args} { # PART OF THE ::tcl::tm::path ENSEMBLE # # The path is added at the head to the list of module paths. # # The command enforces the restriction that no path may be an ancestor # directory of any other path on the list. If the new path violates this # restriction an error wil be raised. # # If the path is already present as is no error will be raised and no # action will be taken. variable paths # We use a copy of the path as source during validation, and extend it as # well. Because we not only have to detect if the new paths are bogus with # respect to the existing paths, but also between themselves. Otherwise we # can still add bogus paths, by specifying them in a single call. This # makes the use of the new paths simpler as well, a trivial assignment of # the collected paths to the official state var. set newpaths $paths foreach p $args { if {$p in $newpaths} { # Ignore a path already on the list. continue } # Search for paths which are subdirectories of the new one. If there # are any then the new path violates the restriction about ancestors. set pos [lsearch -glob $newpaths ${p}/*] # Cannot use "in", we need the position for the message. if {$pos >= 0} { return -code error \ "$p is ancestor of existing module path [lindex $newpaths $pos]." } # Now look for existing paths which are ancestors of the new one. This # reverse question forces us to loop over the existing paths, as each # element is the pattern, not the new path :( foreach ep $newpaths { if {[string match ${ep}/* $p]} { return -code error \ "$p is subdirectory of existing module path $ep." } } set newpaths [linsert $newpaths 0 $p] } # The validation of the input is complete and successful, and everything # in newpaths is either an old path, or added. We can now extend the # official list of paths, a simple assignment is sufficient. set paths $newpaths return } proc ::tcl::tm::remove {args} { # PART OF THE ::tcl::tm::path ENSEMBLE # # Removes the path from the list of module paths. The command is silently # ignored if the path is not on the list. variable paths foreach p $args { set pos [lsearch -exact $paths $p] if {$pos >= 0} { set paths [lreplace $paths $pos $pos] } } } proc ::tcl::tm::list {} { # PART OF THE ::tcl::tm::path ENSEMBLE variable paths return $paths } # ::tcl::tm::UnknownHandler -- # # Unknown handler for Tcl Modules, i.e. packages in module form. # # Arguments # original - Original [package unknown] procedure. # name - Name of desired package. # version - Version of desired package. Can be the # empty string. # exact - Either -exact or ommitted. # # Name, version, and exact are used to determine satisfaction. The # original is called iff no satisfaction was achieved. The name is also # used to compute the directory to target in the search. # # Results # None. # # Sideeffects # May populate the package ifneeded database with additional provide # scripts. proc ::tcl::tm::UnknownHandler {original name args} { # Import the list of paths to search for packages in module form. # Import the pattern used to check package names in detail. variable paths variable pkgpattern # Without paths to search we can do nothing. (Except falling back to the # regular search). if {[llength $paths]} { set pkgpath [string map {:: /} $name] set pkgroot [file dirname $pkgpath] if {$pkgroot eq "."} { set pkgroot "" } # We don't remember a copy of the paths while looping. Tcl Modules are # unable to change the list while we are searching for them. This also # simplifies the loop, as we cannot get additional directories while # iterating over the list. A simple foreach is sufficient. set satisfied 0 foreach path $paths { if {![interp issafe] && ![file exists $path]} { continue } set currentsearchpath [file join $path $pkgroot] if {![interp issafe] && ![file exists $currentsearchpath]} { continue } set strip [llength [file split $path]] # Get the module files out of the subdirectories. # - Safe Base interpreters have a restricted "glob" command that # works in this case. # - The "catch" was essential when there was no safe glob and every # call in a safe interp failed; it is retained only for corner # cases in which the eventual call to glob returns an error. catch { # We always look for _all_ possible modules in the current # path, to get the max result out of the glob. foreach file [glob -nocomplain -directory $currentsearchpath *.tm] { set pkgfilename [join [lrange [file split $file] $strip end] ::] if {![regexp -- $pkgpattern $pkgfilename --> pkgname pkgversion]} { # Ignore everything not matching our pattern for # package names. continue } try { package vcompare $pkgversion 0 } on error {} { # Ignore everything where the version part is not # acceptable to "package vcompare". continue } if {([package ifneeded $pkgname $pkgversion] ne {}) && (![interp issafe]) } { # There's already a provide script registered for # this version of this package. Since all units of # code claiming to be the same version of the same # package ought to be identical, just stick with # the one we already have. # This does not apply to Safe Base interpreters because # the token-to-directory mapping may have changed. continue } # We have found a candidate, generate a "provide script" # for it, and remember it. Note that we are using ::list # to do this; locally [list] means something else without # the namespace specifier. # NOTE. When making changes to the format of the provide # command generated below CHECK that the 'LOCATE' # procedure in core file 'platform/shell.tcl' still # understands it, or, if not, update its implementation # appropriately. # # Right now LOCATE's implementation assumes that the path # of the package file is the last element in the list. package ifneeded $pkgname $pkgversion \ "[::list package provide $pkgname $pkgversion];[::list source -encoding utf-8 $file]" # We abort in this unknown handler only if we got a # satisfying candidate for the requested package. # Otherwise we still have to fallback to the regular # package search to complete the processing. if {($pkgname eq $name) && [package vsatisfies $pkgversion {*}$args]} { set satisfied 1 # We do not abort the loop, and keep adding provide # scripts for every candidate in the directory, just # remember to not fall back to the regular search # anymore. } } } } if {$satisfied} { return } } # Fallback to previous command, if existing. See comment above about # ::list... if {[llength $original]} { uplevel 1 $original [::linsert $args 0 $name] } } # ::tcl::tm::Defaults -- # # Determines the default search paths. # # Arguments # None # # Results # None. # # Sideeffects # May add paths to the list of defaults. proc ::tcl::tm::Defaults {} { global env tcl_platform regexp {^(\d+)\.(\d+)} [package provide Tcl] - major minor set exe [file normalize [info nameofexecutable]] # Note that we're using [::list], not [list] because [list] means # something other than [::list] in this namespace. roots [::list \ [file dirname [info library]] \ [file join [file dirname [file dirname $exe]] lib] \ ] if {$tcl_platform(platform) eq "windows"} { set sep ";" } else { set sep ":" } for {set n $minor} {$n >= 0} {incr n -1} { foreach ev [::list \ TCL${major}.${n}_TM_PATH \ TCL${major}_${n}_TM_PATH \ ] { if {![info exists env($ev)]} continue foreach p [split $env($ev) $sep] { path add $p } } } return } # ::tcl::tm::roots -- # # Public API to the module path. See specification. # # Arguments # paths - List of 'root' paths to derive search paths from. # # Results # No result. # # Sideeffects # Calls 'path add' to paths to the list of module search paths. proc ::tcl::tm::roots {paths} { regexp {^(\d+)\.(\d+)} [package provide Tcl] - major minor foreach pa $paths { set p [file join $pa tcl$major] for {set n $minor} {$n >= 0} {incr n -1} { set px [file join $p ${major}.${n}] if {![interp issafe]} {set px [file normalize $px]} path add $px } set px [file join $p site-tcl] if {![interp issafe]} {set px [file normalize $px]} path add $px } return } # Initialization. Set up the default paths, then insert the new handler into # the chain. if {![interp issafe]} {::tcl::tm::Defaults}