indexing
	description: "Managers that control the data transactions"
	legal: "See notice at end of class."
	status: "See notice at end of class."
	date: "$Date: 2006-01-22 18:25:44 -0800 (Sun, 22 Jan 2006) $"
	revision: "$Revision: 56675 $"

class interface
	TRANSFER_MANAGER

create 
	make
			-- Create manager.


create {TRANSFER_MANAGER}
	make_filled (n: INTEGER_32)
			-- Allocate list with `n' items.
			-- (`n' may be zero for empty list.)
			-- This list will be full.
			-- (from ARRAYED_LIST)
		require -- from ARRAYED_LIST
			valid_number_of_items: n >= 0
		ensure -- from ARRAYED_LIST
			correct_position: before
			filled: full

feature -- Access

	generating_type: STRING_8
			-- Name of current object's generating type
			-- (type of which it is a direct instance)
			-- (from ANY)

	generator: STRING_8
			-- Name of current object's generating class
			-- (base class of the type of which it is a direct instance)
			-- (from ANY)

	has (v: like transaction): BOOLEAN
			-- Does current include `v'?
			-- (Reference or object equality,
			-- based on object_comparison.)
			-- (from ARRAYED_LIST)
		require -- from  CONTAINER
			True
		ensure -- from CONTAINER
			not_found_in_empty: Result implies not is_empty

	index: INTEGER_32
			-- Index of `item', if valid.
			-- (from ARRAYED_LIST)

	index_of (v: like transaction; i: INTEGER_32): INTEGER_32
			-- Index of `i'-th occurrence of item identical to `v'.
			-- (Reference or object equality,
			-- based on object_comparison.)
			-- 0 if none.
			-- (from CHAIN)
		require -- from LINEAR
			positive_occurrences: i > 0
		ensure -- from LINEAR
			non_negative_result: Result >= 0

	transaction: TRANSACTION
			-- Current item
			-- (from ARRAYED_LIST)
		require -- from TRAVERSABLE
			not_off: not off
		require -- from ACTIVE
			readable: readable
		require -- from  TRANSACTION_CONTAINER
			True
		require else -- from ARRAYED_LIST
			index_is_valid: valid_index (index)

	source: DATA_RESOURCE
			-- Selected source

	target: DATA_RESOURCE
			-- Selected target
	
feature -- Measurement

	count: INTEGER_32
			-- Number of items.
			-- (from ARRAYED_LIST)

	finished_transactions: INTEGER_32
			-- Number of already finished transactions

	occurrences (v: like transaction): INTEGER_32
			-- Number of times `v' appears.
			-- (Reference or object equality,
			-- based on object_comparison.)
			-- (from CHAIN)
		require -- from  BAG
			True
		require -- from  LINEAR
			True
		ensure -- from BAG
			non_negative_occurrences: Result >= 0

	total_count: INTEGER_32
			-- Total number of transactions
		ensure
			index_unchanged: index = old index
	
feature -- Comparison

	frozen deep_equal (some: ANY; other: like arg #1): BOOLEAN
			-- Are `some' and `other' either both void
			-- or attached to isomorphic object structures?
			-- (from ANY)
		ensure -- from ANY
			shallow_implies_deep: standard_equal (some, other) implies Result
			both_or_none_void: (some = Void) implies (Result = (other = Void))
			same_type: (Result and (some /= Void)) implies some.same_type (other)
			symmetric: Result implies deep_equal (other, some)

	frozen equal (some: ANY; other: like arg #1): BOOLEAN
			-- Are `some' and `other' either both void or attached
			-- to objects considered equal?
			-- (from ANY)
		ensure -- from ANY
			definition: Result = (some = Void and other = Void) or else ((some /= Void and other /= Void) and then some.is_equal (other))

	is_equal (other: like Current): BOOLEAN
			-- Does `other' contain the same elements?
			-- (from LIST)
		require -- from ANY
			other_not_void: other /= Void
		ensure -- from ANY
			symmetric: Result implies other.is_equal (Current)
			consistent: standard_is_equal (other) implies Result
		ensure then -- from LIST
			indices_unchanged: index = old index and other.index = old other.index
			true_implies_same_size: Result implies count = other.count

	frozen standard_equal (some: ANY; other: like arg #1): BOOLEAN
			-- Are `some' and `other' either both void or attached to
			-- field-by-field identical objects of the same type?
			-- Always uses default object comparison criterion.
			-- (from ANY)
		ensure -- from ANY
			definition: Result = (some = Void and other = Void) or else ((some /= Void and other /= Void) and then some.standard_is_equal (other))

	frozen standard_is_equal (other: like Current): BOOLEAN
			-- Is `other' attached to an object of the same type
			-- as current object, and field-by-field identical to it?
			-- (from ANY)
		require -- from ANY
			other_not_void: other /= Void
		ensure -- from ANY
			same_type: Result implies same_type (other)
			symmetric: Result implies other.standard_is_equal (Current)
	
feature -- Status report

	after: BOOLEAN
			-- Is there no valid cursor position to the right of cursor?
			-- (from LIST)
		require -- from  LINEAR
			True

	before: BOOLEAN
			-- Is there no valid cursor position to the left of cursor?
			-- (from LIST)
		require -- from  BILINEAR
			True

	changeable_comparison_criterion: BOOLEAN
			-- May object_comparison be changed?
			-- (Answer: yes by default.)
			-- (from CONTAINER)

	conforms_to (other: ANY): BOOLEAN
			-- Does type of current object conform to type
			-- of `other' (as per Eiffel: The Language, chapter 13)?
			-- (from ANY)
		require -- from ANY
			other_not_void: other /= Void

	error: BOOLEAN
			-- Has an error occurred in any transaction?
		require
			not_empty: not is_empty

	error_reason: STRING_8
			-- Reason of most recent error
		require
			error_exists: error
		ensure
			non_empty_string: Result /= Void and then not Result.is_empty
			index_unchanged: index = old index

	error_stops: BOOLEAN
			-- Is transfer stopped on error?
			-- (from TRANSACTION_CONTAINER)

	exhausted: BOOLEAN
			-- Has structure been completely explored?
			-- (from LINEAR)
		ensure -- from LINEAR
			exhausted_when_off: off implies Result

	extendible: BOOLEAN is True
			-- May new items be added? (Answer: yes.)
			-- (from DYNAMIC_CHAIN)

	full: BOOLEAN
			-- Is structure filled to capacity?
			-- (from ARRAYED_LIST)
		require -- from  BOX
			True

	insertable (t: TRANSACTION): BOOLEAN
			-- Can transaction `t' be added?
		require -- from TRANSACTION_CONTAINER
			transaction_exists: t /= Void

	is_empty: BOOLEAN
			-- Is structure empty?
			-- (from FINITE)

	is_inserted (v: TRANSACTION): BOOLEAN
			-- Has `v' been inserted at the end by the most recent put or
			-- extend?
			-- (from ARRAYED_LIST)
		require -- from  COLLECTION
			True

	object_comparison: BOOLEAN
			-- Must search operations use equal rather than `='
			-- for comparing references? (Default: no, use `='.)
			-- (from CONTAINER)

	off: BOOLEAN
			-- Is there no current item?
			-- (from CHAIN)
		require -- from  TRAVERSABLE
			True

	prunable: BOOLEAN
			-- May items be removed? (Answer: yes.)
			-- (from ARRAYED_LIST)
		require -- from  COLLECTION
			True

	readable: BOOLEAN
			-- Is there a current item that may be read?
			-- (from SEQUENCE)
		require -- from  ACTIVE
			True

	same_type (other: ANY): BOOLEAN
			-- Is type of current object identical to type of `other'?
			-- (from ANY)
		require -- from ANY
			other_not_void: other /= Void
		ensure -- from ANY
			definition: Result = (conforms_to (other) and other.conforms_to (Current))

	transactions_succeeded: BOOLEAN
			-- Have all transactions succeeded?
		require
			not_empty: not is_empty

	transfer_finished: BOOLEAN
			-- Has a transfer taken place?

	writable: BOOLEAN
			-- Is there a current item that may be modified?
			-- (from SEQUENCE)
		require -- from  ACTIVE
			True
	
feature {ANY} -- Status report

	valid_cursor_index (i: INTEGER_32): BOOLEAN
			-- Is `i' correctly bounded for cursor movement?
			-- (from CHAIN)
		ensure -- from CHAIN
			valid_cursor_index_definition: Result = ((i >= 0) and (i <= count + 1))

	valid_index (i: INTEGER_32): BOOLEAN
			-- Is `i' a valid index?
			-- (from ARRAYED_LIST)
		require -- from  TABLE
			True
		require -- from  TO_SPECIAL
			True
		ensure then -- from INDEXABLE
			only_if_in_index_set: Result implies ((i >= index_set.lower) and (i <= index_set.upper))
		ensure then -- from CHAIN
			valid_index_definition: Result = ((i >= 1) and (i <= count))
	
feature -- Status setting

	compare_objects
			-- Ensure that future search operations will use equal
			-- rather than `=' for comparing references.
			-- (from CONTAINER)
		require -- from CONTAINER
			changeable_comparison_criterion: changeable_comparison_criterion
		ensure -- from CONTAINER
			object_comparison

	compare_references
			-- Ensure that future search operations will use `='
			-- rather than equal for comparing references.
			-- (from CONTAINER)
		require -- from CONTAINER
			changeable_comparison_criterion: changeable_comparison_criterion
		ensure -- from CONTAINER
			reference_comparison: not object_comparison

	continue_on_error
			-- Error does not stop action.
			-- (from TRANSACTION_CONTAINER)
		ensure -- from TRANSACTION_CONTAINER
			does_not_stop: not error_stops

	reset_status
			-- Reset status flags.
		ensure
			finished_flag_reset: not transfer_finished
			no_error: not error

	stop_on_error
			-- Error stops action.
			-- (from TRANSACTION_CONTAINER)
		ensure -- from TRANSACTION_CONTAINER
			stop: error_stops
	
feature -- Cursor movement

	back
			-- Move cursor one position backward.
			-- (from ARRAYED_LIST)
		require -- from BILINEAR
			not_before: not before

	finish
			-- Move cursor to last position if any.
			-- (from ARRAYED_LIST)
		require -- from  LINEAR
			True
		ensure then -- from CHAIN
			at_last: not is_empty implies islast
		ensure then -- from ARRAYED_LIST
			before_when_empty: is_empty implies before

	forth
			-- Move cursor one position forward.
			-- (from ARRAYED_LIST)
		require -- from LINEAR
			not_after: not after
		ensure then -- from LIST
			moved_forth: index = old index + 1

	select_transaction (i: INTEGER_32)
			-- Move cursor to `i'-th position.
			-- (from ARRAYED_LIST)
		require -- from CHAIN
			valid_cursor_index: valid_cursor_index (i)
		require -- from TRANSACTION_CONTAINER
			not_empty: not is_empty
			index_in_range: 1 <= i and i <= count
		ensure -- from CHAIN
			position_expected: index = i
		ensure -- from TRANSACTION_CONTAINER
			selected: index = i

	search (v: like transaction)
			-- Move to first position (at or after current
			-- position) where `item' and `v' are equal.
			-- If structure does not include `v' ensure that
			-- exhausted will be true.
			-- (Reference or object equality,
			-- based on object_comparison.)
			-- (from ARRAYED_LIST)
		require -- from  LINEAR
			True
		ensure -- from LINEAR
			object_found: (not exhausted and object_comparison) implies equal (v, transaction)
			item_found: (not exhausted and not object_comparison) implies v = transaction

	start
			-- Move cursor to first position if any.
			-- (from ARRAYED_LIST)
		require -- from  TRAVERSABLE
			True
		ensure then -- from CHAIN
			at_first: not is_empty implies isfirst
		ensure then -- from ARRAYED_LIST
			after_when_empty: is_empty implies after
	
feature -- Element change

	add_transaction (t: TRANSACTION)
			-- Add transaction.
			-- (from TRANSACTION_CONTAINER)
		require -- from TRANSACTION_CONTAINER
			transaction_exists: t /= Void
			transaction_correct: t.is_correct
		ensure -- from TRANSACTION_CONTAINER
			one_more_item: count = old count + 1
			index_unchanged: not old is_empty implies index = old index

	append (s: SEQUENCE [TRANSACTION])
			-- Append a copy of `s'.
			-- (from ARRAYED_LIST)
		require -- from SEQUENCE
			argument_not_void: s /= Void
		ensure -- from SEQUENCE
			new_count: count >= old count

	extend (v: like transaction)
			-- Add `v' to end.
			-- Do not move cursor.
			-- Was declared in ARRAYED_LIST as synonym of force.
			-- (from ARRAYED_LIST)
		require -- from COLLECTION
			extendible: extendible
		ensure -- from COLLECTION
			item_inserted: is_inserted (v)
		ensure then -- from BAG
			one_more_occurrence: occurrences (v) = old (occurrences (v)) + 1

	fill (other: CONTAINER [TRANSACTION])
			-- Fill with as many items of `other' as possible.
			-- The representations of `other' and current structure
			-- need not be the same.
			-- (from CHAIN)
		require -- from COLLECTION
			other_not_void: other /= Void
			extendible: extendible

	force (v: like transaction)
			-- Add `v' to end.
			-- Do not move cursor.
			-- Was declared in ARRAYED_LIST as synonym of extend.
			-- (from ARRAYED_LIST)
		require -- from SEQUENCE
			extendible: extendible
		ensure then -- from SEQUENCE
			new_count: count = old count + 1
			item_inserted: has (v)

	put (v: like transaction)
			-- Replace current item by `v'.
			-- (Synonym for replace)
			-- (from CHAIN)
		require -- from COLLECTION
			extendible: extendible
		ensure -- from COLLECTION
			item_inserted: is_inserted (v)
		ensure then -- from CHAIN
			same_count: count = old count
		ensure then -- from SEQUENCE
			new_count: count = old count + 1

	replace (v: like first)
			-- Replace current item by `v'.
			-- (from ARRAYED_LIST)
		require -- from ACTIVE
			writable: writable
		ensure -- from ACTIVE
			item_replaced: transaction = v
	
feature -- Removal

	prune (v: like transaction)
			-- Remove first occurrence of `v', if any,
			-- after cursor position.
			-- Move cursor to right neighbor.
			-- (or after if no right neighbor or `v' does not occur)
			-- (from ARRAYED_LIST)
		require -- from COLLECTION
			prunable: prunable

	prune_all (v: like transaction)
			-- Remove all occurrences of `v'.
			-- (Reference or object equality,
			-- based on object_comparison.)
			-- (from ARRAYED_LIST)
		require -- from COLLECTION
			prunable: prunable
		ensure -- from COLLECTION
			no_more_occurrences: not has (v)
		ensure then -- from DYNAMIC_CHAIN
			is_exhausted: exhausted
		ensure then -- from ARRAYED_LIST
			is_after: after

	remove
			-- Remove current item.
			-- Move cursor to right neighbor
			-- (or after if no right neighbor)
			-- (from ARRAYED_LIST)
		require -- from ACTIVE
			prunable: prunable
			writable: writable
		ensure then -- from DYNAMIC_LIST
			after_when_empty: is_empty implies after
		ensure then -- from ARRAYED_LIST
			index: index = old index

	remove_transaction (n: INTEGER_32)
			-- Remove `n'-th transaction.
		require
			not_empty: not is_empty
			index_in_range: 1 <= n and n <= count
		ensure
			one_less_item: count = count - 1
			index_unchanged: (old index < old count) implies (index = old index)
			index_adapted: (old index = old count) implies (index = old index - 1)

	wipe_out
			-- Remove all items.
			-- (from ARRAYED_LIST)
		require -- from COLLECTION
			prunable: prunable
		ensure -- from COLLECTION
			wiped_out: is_empty
		ensure then -- from DYNAMIC_LIST
			is_before: before
	
feature -- Conversion

	linear_representation: LINEAR [TRANSACTION]
			-- Representation as a linear structure
			-- (from LINEAR)
		require -- from  CONTAINER
			True
	
feature -- Duplication

	copy (other: like Current)
			-- Reinitialize by copying all the items of `other'.
			-- (This is also used by clone.)
			-- (from ARRAY)
		require -- from ANY
			other_not_void: other /= Void
			type_identity: same_type (other)
		ensure -- from ANY
			is_equal: is_equal (other)
		ensure then -- from ARRAY
			equal_areas: area.is_equal (other.area)

	frozen deep_copy (other: like Current)
			-- Effect equivalent to that of:
			--		copy (`other' . deep_twin)
			-- (from ANY)
		require -- from ANY
			other_not_void: other /= Void
		ensure -- from ANY
			deep_equal: deep_equal (Current, other)

	frozen deep_twin: like Current
			-- New object structure recursively duplicated from Current.
			-- (from ANY)
		ensure -- from ANY
			deep_equal: deep_equal (Current, Result)

	frozen standard_copy (other: like Current)
			-- Copy every field of `other' onto corresponding field
			-- of current object.
			-- (from ANY)
		require -- from ANY
			other_not_void: other /= Void
			type_identity: same_type (other)
		ensure -- from ANY
			is_standard_equal: standard_is_equal (other)

	frozen standard_twin: like Current
			-- New object field-by-field identical to `other'.
			-- Always uses default copying semantics.
			-- (from ANY)
		ensure -- from ANY
			standard_twin_not_void: Result /= Void
			equal: standard_equal (Result, Current)

	frozen twin: like Current
			-- New object equal to `Current'
			-- twin calls copy; to change copying/twining semantics, redefine copy.
			-- (from ANY)
		ensure -- from ANY
			twin_not_void: Result /= Void
			is_equal: Result.is_equal (Current)
	
feature -- Basic operations

	frozen default: like Current
			-- Default value of object's type
			-- (from ANY)

	frozen default_pointer: POINTER
			-- Default value of type `POINTER'
			-- (Avoid the need to write `p'.default for
			-- some `p' of type `POINTER'.)
			-- (from ANY)

	default_rescue
			-- Process exception for routines with no Rescue clause.
			-- (Default: do nothing.)
			-- (from ANY)

	frozen do_nothing
			-- Execute a null action.
			-- (from ANY)

	execute_transaction
			-- Execute selected transaction.
		ensure
			counter_updated: not transaction.error implies finished_transactions = old finished_transactions + transaction.count

	transfer
			-- Execute all transactions.
		require
			not_empty: not is_empty
			flags_reset: not (transfer_finished and transactions_succeeded)
		ensure
			transfer_flag_set: transfer_finished
	
feature -- Iteration

	do_all (action: PROCEDURE [ANY, TUPLE [TRANSACTION]])
			-- Apply `action' to every item.
			-- Semantics not guaranteed if `action' changes the structure;
			-- in such a case, apply iterator to clone of structure instead.
			-- (from LINEAR)
		require -- from TRAVERSABLE
			action_exists: action /= Void
		require -- from ARRAY
			action_not_void: action /= Void

	do_if (action: PROCEDURE [ANY, TUPLE [TRANSACTION]]; test: FUNCTION [ANY, TUPLE [TRANSACTION], BOOLEAN])
			-- Apply `action' to every item that satisfies `test'.
			-- Semantics not guaranteed if `action' or `test' changes the structure;
			-- in such a case, apply iterator to clone of structure instead.
			-- (from LINEAR)
		require -- from TRAVERSABLE
			action_exists: action /= Void
			test_exits: test /= Void
		require -- from ARRAY
			action_not_void: action /= Void
			test_not_void: test /= Void

	for_all (test: FUNCTION [ANY, TUPLE [TRANSACTION], BOOLEAN]): BOOLEAN
			-- Is `test' true for all items?
			-- Semantics not guaranteed if `test' changes the structure;
			-- in such a case, apply iterator to clone of structure instead.
			-- (from LINEAR)
		require -- from TRAVERSABLE
			test_exits: test /= Void
		require -- from ARRAY
			test_not_void: test /= Void
		ensure then -- from LINEAR
			empty: is_empty implies Result

	there_exists (test: FUNCTION [ANY, TUPLE [TRANSACTION], BOOLEAN]): BOOLEAN
			-- Is `test' true for at least one item?
			-- Semantics not guaranteed if `test' changes the structure;
			-- in such a case, apply iterator to clone of structure instead.
			-- (from LINEAR)
		require -- from TRAVERSABLE
			test_exits: test /= Void
		require -- from ARRAY
			test_not_void: test /= Void
	
feature -- Output

	io: STD_FILES
			-- Handle to standard file setup
			-- (from ANY)

	out: STRING_8
			-- New string containing terse printable representation
			-- of current object
			-- Was declared in ANY as synonym of tagged_out.
			-- (from ANY)

	print (some: ANY)
			-- Write terse external representation of `some'
			-- on standard output.
			-- (from ANY)

	frozen tagged_out: STRING_8
			-- New string containing terse printable representation
			-- of current object
			-- Was declared in ANY as synonym of out.
			-- (from ANY)
	
feature -- Platform

	operating_environment: OPERATING_ENVIRONMENT
			-- Objects available from the operating system
			-- (from ANY)
	
invariant
	finished_transaction_range: 0 <= finished_transactions and finished_transactions <= total_count

		-- from TRANSACTION_CONTAINER
	empty_definition: is_empty = (count = 0)
	index_in_range: not is_empty implies (1 <= index and index <= count)

		-- from ACTIVE
	writable_constraint: writable implies readable
	empty_constraint: is_empty implies (not readable) and (not writable)

		-- from ANY
	reflexive_equality: standard_is_equal (Current)
	reflexive_conformance: conforms_to (Current)

		-- from BILINEAR
	not_both: not (after and before)
	before_constraint: before implies off

		-- from LINEAR
	after_constraint: after implies off

		-- from TRAVERSABLE
	empty_constraint: is_empty implies off

		-- from FINITE
	empty_definition: is_empty = (count = 0)
	non_negative_count: count >= 0

		-- from ARRAYED_LIST
	prunable: prunable
	starts_from_one: lower = 1
	empty_means_storage_empty: is_empty implies all_default

		-- from ARRAY
	area_exists: area /= Void
	consistent_size: capacity = upper - lower + 1
	non_negative_count: count >= 0
	index_set_has_same_count: valid_index_set

		-- from RESIZABLE
	increase_by_at_least_one: minimal_increase >= 1

		-- from BOUNDED
	valid_count: count <= capacity
	full_definition: full = (count = capacity)

		-- from INDEXABLE
	index_set_not_void: index_set /= Void

		-- from LIST
	before_definition: before = (index = 0)
	after_definition: after = (index = count + 1)

		-- from CHAIN
	non_negative_index: index >= 0
	index_small_enough: index <= count + 1
	off_definition: off = ((index = 0) or (index = count + 1))
	isfirst_definition: isfirst = ((not is_empty) and (index = 1))
	islast_definition: islast = ((not is_empty) and (index = count))
	item_corresponds_to_index: (not off) implies (transaction = i_th (index))
	index_set_has_same_count: index_set.count = count

		-- from DYNAMIC_CHAIN
	extendible: extendible

indexing
	copyright: "Copyright (c) 1984-2006, Eiffel Software and others"
	license: "Eiffel Forum License v2 (see http://www.eiffel.com/licensing/forum.txt)"
	source: "[
		Eiffel Software
		356 Storke Road, Goleta, CA 93117 USA
		Telephone 805-685-1006, Fax 805-685-6869
		Website http://www.eiffel.com
		Customer support http://support.eiffel.com
	]"

end -- class TRANSFER_MANAGER