The PR introduces shard_repair_task_impl which represents a repair task
that spans over a single shard repair.
repair_info is replaced with shard_repair_task_impl, since both serve
similar purpose.
Closes#12066
* github.com:scylladb/scylladb:
repair: reindent
repair: replace repair_info with shard_repair_task_impl
repair: move repair_info methods to shard_repair_task_impl
repair: rename methods of repair_module
repair: change type of repair_module::_repairs
repair: keep a reference to shard_repair_task_impl in row_level_repair
repair: move repair_range method to shard_repair_task_impl
repair: make do_repair_ranges a method of shard_repair_task_impl
repair: copy repair_info methods to shard_repair_task_impl
repair: corutinize shard task creation
repair: define run for shard_repair_task_impl
repair: add shard_repair_task_impl
task_manager has some members with the same names as types from
namespace scope. gcc (rightfully) complains that this changes
the meaning of the name. Qualify the types to disambiguate.
As a preparation to replacing repair_info with shard_repair_task_impl,
type of _repairs in repair module is changed from
std::unordered_map<int, lw_shared_ptr<repair_info>> to
std::unordered_map<int, tasks::task_id>.
Currently in start() method a task is run even if it was already
aborted.
When start() is called on an aborted task, its state is set to
task_manager::task_state::failed and it doesn't run.
Task manager tasks should be created with make_task method since
it properly sets information about child-parent relationship
between tasks. Though, sometimes we may want to keep additional
task data in classes inheriting from task_manager::task::impl.
Doing it with existing make_task method makes it impossible since
implementation objects are created internally.
The commit adds a new make_task that allows to provide a task
implementation pointer created by caller. All the fields except
for the one connected with children and parent should be set before.
parent_data struct contains info that is common for each task,
not only in parent-child relationship context. To use it this way
without confusion, its name is changed to task_info.
In order to be able to widely and comfortably use task_info,
it is moved from tasks/task_manager.hh to tasks/types.hh
and slightly extended.
It is convenient to create many different tasks implementations
representing more and more specific parts of the operation in
a module. Presenting all of them through the api makes it cumbersome
for user to navigate and track, though.
Flag internal is added to task_manager::task::impl so that the tasks
could be filtered before they are sent to user.
The implementation of a test api that helps testing task manager
api. It provides methods to simulate the operations that can happen
on modules and theirs task. Through the api user can: register
and unregister the test module and the tasks belonging to the module,
and finish the tasks with success or custom error.
Implementation of a task manager that allows tracking
and managing asynchronous tasks.
The tasks are represented by task_manager::task class providing
members common to all types of tasks. The methods that differ
among tasks of different module can be overriden in a class
inheriting from task_manager::task::impl class. Each task stores
its status containing parameters like id, sequence number, begin
and end time, state etc. After the task finishes, it is kept
in memory for configurable time or until it is unregistered.
Tasks need to be created with make_task method.
Each module is represented by task_manager::module type and should
have an access to task manager through task_manager::module methods.
That allows to easily separate and collectively manage data
belonging to each module.
