Artifact 76cc206f7397ab20d320fbdd0d88b3ee02bdf75b

File tools/cvs2fossil/lib/c2f_patopsort.tcl part of check-in [66c85b4db4] - Investigation of changeset order differences between running passes 1 to 6 and pass 6 alone show why the topological sort passes are separate in cvs2svn. The breaking of cycles can change the order of things due to different timeranges and dependencies of the broken changesets. Created two new passes for the sorting. The break passes 7 and 8 are now passes 8 and 9, and the new sort passes are 7 and 10. by aku on 2007-11-25 02:59:21.

## -*- tcl -*-
# # ## ### ##### ######## ############# #####################
## Copyright (c) 2007 Andreas Kupries.
#
# This software is licensed as described in the file LICENSE, which
# you should have received as part of this distribution.
#
# This software consists of voluntary contributions made by many
# individuals.  For exact contribution history, see the revision
# history and logs, available at http://fossil-scm.hwaci.com/fossil
# # ## ### ##### ######## ############# #####################

## Pass X. This pass goes over all changesets and sorts them
## topologically. It assumes that there are no cycles which could
## impede it, any remaining having been broken by the previous two
## passes, and aborts if that condition doesn't hold.

# # ## ### ##### ######## ############# #####################
## Requirements

package require Tcl 8.4                                   ; # Required runtime.
package require snit                                      ; # OO system.
package require struct::list                              ; # Higher order list operations.
package require vc::tools::log                            ; # User feedback.
package require vc::fossil::import::cvs::cyclebreaker     ; # Breaking dependency cycles.
package require vc::fossil::import::cvs::state            ; # State storage.
package require vc::fossil::import::cvs::project::rev     ; # Project level changesets

# # ## ### ##### ######## ############# #####################
## Register the pass with the management

vc::fossil::import::cvs::pass define \
    AllTopologicalSort \
    {Topologically Sort All ChangeSets} \
    ::vc::fossil::import::cvs::pass::atopsort

# # ## ### ##### ######## ############# #####################
## 

snit::type ::vc::fossil::import::cvs::pass::atopsort {
    # # ## ### ##### ######## #############
    ## Public API

    typemethod setup {} {
	# Define the names and structure of the persistent state of
	# this pass.

	state reading csorder

	state writing cstimestamp {
	    -- Commit order of all changesets based on their
	    -- dependencies, plus a monotonically increasing
	    -- timestamp.

	    cid  INTEGER  NOT NULL  REFERENCES changeset,
	    pos  INTEGER  NOT NULL,
	    date INTEGER  NOT NULL,
	    UNIQUE (cid),
	    UNIQUE (pos),
	    UNIQUE (date)
	}
	return
    }

    typemethod load {} {
	# Pass manager interface. Executed to load data computed by
	# this pass into memory when this pass is skipped instead of
	# executed.
	return
    }

    typemethod run {} {
	# Pass manager interface. Executed to perform the
	# functionality of the pass.

	cyclebreaker savecmd  [myproc SaveTimestamps]

	state transaction {
	    LoadSymbolChangesets
	    cyclebreaker run break-all [myproc Changesets]
	}
	return
    }

    typemethod discard {} {
	# Pass manager interface. Executed for all passes after the
	# run passes, to remove all data of this pass from the state,
	# as being out of date.

	state discard cstimestamp
	return
    }

    # # ## ### ##### ######## #############
    ## Internal methods

    proc Changesets {} { project::rev all }

    proc LoadSymbolChangesets {} {
	set mysymchangesets [struct::list filter [project::rev all] [myproc IsBySymbol]]
	return
    }

    proc SaveTimestamps {graph at cset} {
	set cid [$cset id]

	set date [GetTime [lindex [$graph node get $cset timerange] 1] \
		      [struct::set contain $mysymchangesets $cset]]

	log write 4 atopsort "Changeset @ $at: [$cset str]"
	state run {
	    INSERT INTO cstimestamp (cid,  pos, date)
	    VALUES                  ($cid, $at, $date)
	}
	return
    }

    proc GetTime {stamp expectchange} {
	::variable mylasttimestamp
	if {$stamp > $mymaxtimestamp} {
	    # A timestamp in the future is believed to be bogus and
	    # shifted backwars in time to prevent it from forcing
	    # other timestamps to be pushed even further in the
	    # future.

	    # From cvs2svn: Note that this is not nearly a complete
	    # solution to the bogus timestamp problem.  A timestamp in
	    # the future still affects the ordering of changesets, and
	    # a changeset having such a timestamp will not be
	    # committed until all changesets with earlier timestamps
	    # have been committed, even if other changesets with even
	    # earlier timestamps depend on this one.

	    incr mylasttimestamp
	    if {!$expectchange} {
		log write 4 atopsort "Timestamp [clock format $stamp] is in the future; shifted back to [clock format $mylasttimestamp]"
	    }
	} elseif {$stamp < ($mylasttimestamp)+1} {
	    incr mylasttimestamp
	    if {!$expectchange} {
		log write 4 atopsort "Timestamp [clock format $stamp] adjusted to [clock format $mylasttimestamp]"
	    }
	} else {
	    set mylasttimestamp $stamp
	}
	return $mylasttimestamp
    }

    typevariable mysymchangesets {} ; # Set of the symbol changesets.
    typevariable mylasttimestamp 0  ; # Last delivered timestamp.
    typevariable mymaxtimestamp 

    typeconstructor {
	# The maximum timestamp considered as reasonable is
	# "now + 1 day".
	set  mymaxtimestamp [clock seconds]
	incr mymaxtimestamp 86400 ; # 24h * 60min * 60sec
	return
    }

    # # ## ### ##### ######## #############
    ## Configuration

    pragma -hasinstances   no ; # singleton
    pragma -hastypeinfo    no ; # no introspection
    pragma -hastypedestroy no ; # immortal

    # # ## ### ##### ######## #############
}

namespace eval ::vc::fossil::import::cvs::pass {
    namespace export atopsort
    namespace eval atopsort {
	namespace import ::vc::fossil::import::cvs::cyclebreaker
	namespace import ::vc::fossil::import::cvs::state
	namespace eval project {
	    namespace import ::vc::fossil::import::cvs::project::rev
	}
	namespace import ::vc::tools::log
	log register atopsort
    }
}

# # ## ### ##### ######## ############# #####################
## Ready

package provide vc::fossil::import::cvs::pass::atopsort 1.0
return