unsplit_lib.md

#Module unsplit_lib#

• Description
• Function Index
• Function Details

Predefined merge functions.

Authors: : Ulf Wiger (ulf.wiger@erlang-solutions.com).

##Description##

This module implements a few merge functions that can be used.

##Function Index##

bag/2	Default bag merge; removes duplicate objects.
last_modified/2	Keeps the last modified object, based on the modified attribute.
last_version/2	Picks the object with the greatest value of a given attribute.
no_action/2	Minimal merge action - does nothing.
vclock/2

##Function Details##

###bag/2##

bag(Objs::Phase, S0::State) -> merge_ret()

Default bag merge; removes duplicate objects

###last_modified/2##

last_modified(Other::Phase, S0::State) -> merge_ret()

Keeps the last modified object, based on the modified attribute

This function assumes that the table to be merged contains objects with a modified attribute.

###last_version/2##

last_version(Objs::Phase, S::State) -> merge_ret()

Picks the object with the greatest value of a given attribute

This function assumes that an attribute name is passed as an extra argument.
e.g. by adding the following user property to the table:

{unsplit_method, {unsplit_lib, last_version, [Attr]}}

The function will choose the object that has the greatest value in the position given by Attr.

###no_action/2##

no_action(X1::init, X2::State) -> stop

Minimal merge action - does nothing

###vclock/2##

vclock(Objs, S) -> any()