cat-bookmarker/deps/ecto_sql/lib/ecto/migration/runner.ex

504 lines
15 KiB
Elixir

defmodule Ecto.Migration.Runner do
@moduledoc false
use Agent, restart: :temporary
require Logger
alias Ecto.Migration.Table
alias Ecto.Migration.Index
alias Ecto.Migration.Constraint
alias Ecto.Migration.Command
@doc """
Runs the given migration.
"""
def run(repo, config, version, module, direction, operation, migrator_direction, opts) do
level = Keyword.get(opts, :log, :info)
sql = Keyword.get(opts, :log_migrations_sql, false)
log = %{level: level, sql: sql}
args = {self(), repo, config, module, direction, migrator_direction, log}
{:ok, runner} = DynamicSupervisor.start_child(Ecto.MigratorSupervisor, {__MODULE__, args})
metadata(runner, opts)
log(level, "== Running #{version} #{inspect(module)}.#{operation}/0 #{direction}")
{time, _} = :timer.tc(fn -> perform_operation(repo, module, operation) end)
log(level, "== Migrated #{version} in #{inspect(div(time, 100_000) / 10)}s")
after
stop()
end
@doc """
Stores the runner metadata.
"""
def metadata(runner, opts) do
prefix = opts[:prefix]
Process.put(:ecto_migration, %{runner: runner, prefix: prefix && to_string(prefix)})
end
@doc """
Starts the runner for the specified repo.
"""
def start_link({parent, repo, config, module, direction, migrator_direction, log}) do
Agent.start_link(fn ->
Process.link(parent)
%{
direction: direction,
repo: repo,
migration: module,
migrator_direction: migrator_direction,
command: nil,
subcommands: [],
log: log,
commands: [],
config: config
}
end)
end
@doc """
Stops the runner.
"""
def stop() do
Agent.stop(runner())
end
@doc """
Accesses the given repository configuration.
"""
def repo_config(key, default) do
Agent.get(runner(), &Keyword.get(&1.config, key, default))
end
@doc """
Returns the migrator command (up or down).
* forward + up: up
* forward + down: down
* forward + change: up
* backward + change: down
"""
def migrator_direction do
Agent.get(runner(), & &1.migrator_direction)
end
@doc """
Gets the repo for this migration
"""
def repo do
Agent.get(runner(), & &1.repo)
end
@doc """
Gets the prefix for this migration
"""
def prefix do
case Process.get(:ecto_migration) do
%{prefix: prefix} -> prefix
_ -> raise "could not find migration runner process for #{inspect(self())}"
end
end
@doc """
Executes queue migration commands.
Reverses the order commands are executed when doing a rollback
on a change/0 function and resets commands queue.
"""
def flush do
%{commands: commands, direction: direction, repo: repo, log: log, migration: migration} =
Agent.get_and_update(runner(), fn state -> {state, %{state | commands: []}} end)
commands = if direction == :backward, do: commands, else: Enum.reverse(commands)
for command <- commands do
execute_in_direction(repo, migration, direction, log, command)
end
end
@doc """
Queues command tuples or strings for execution.
Ecto.MigrationError will be raised when the server
is in `:backward` direction and `command` is irreversible.
"""
def execute(command) do
reply =
Agent.get_and_update(runner(), fn
%{command: nil} = state ->
{:ok, %{state | subcommands: [], commands: [command | state.commands]}}
%{command: _} = state ->
{:error, %{state | command: nil}}
end)
case reply do
:ok ->
:ok
:error ->
raise Ecto.MigrationError, "cannot execute nested commands"
end
end
@doc """
Starts a command.
"""
def start_command(command) do
reply =
Agent.get_and_update(runner(), fn
%{command: nil} = state ->
{:ok, %{state | command: command}}
%{command: _} = state ->
{:error, %{state | command: command}}
end)
case reply do
:ok ->
:ok
:error ->
raise Ecto.MigrationError, "cannot execute nested commands"
end
end
@doc """
Queues and clears current command. Must call `start_command/1` first.
"""
def end_command do
Agent.update(runner(), fn state ->
{operation, object} = state.command
command = {operation, object, Enum.reverse(state.subcommands)}
%{state | command: nil, subcommands: [], commands: [command | state.commands]}
end)
end
@doc """
Adds a subcommand to the current command. Must call `start_command/1` first.
"""
def subcommand(subcommand) do
reply =
Agent.get_and_update(runner(), fn
%{command: nil} = state ->
{:error, state}
state ->
{:ok, update_in(state.subcommands, &[subcommand | &1])}
end)
case reply do
:ok ->
:ok
:error ->
raise Ecto.MigrationError, message: "cannot execute command outside of block"
end
end
## Execute
defp execute_in_direction(repo, migration, :forward, log, %Command{up: up}) do
log_and_execute_ddl(repo, migration, log, up)
end
defp execute_in_direction(repo, migration, :forward, log, command) do
log_and_execute_ddl(repo, migration, log, command)
end
defp execute_in_direction(repo, migration, :backward, log, %Command{down: down}) do
log_and_execute_ddl(repo, migration, log, down)
end
defp execute_in_direction(repo, migration, :backward, log, command) do
if reversed = reverse(command) do
log_and_execute_ddl(repo, migration, log, reversed)
else
raise Ecto.MigrationError,
message:
"cannot reverse migration command: #{command(command)}. " <>
"You will need to explicitly define up/0 and down/0 in your migration"
end
end
defp reverse({:create, %Index{} = index}),
do: {:drop, index, :restrict}
defp reverse({:create_if_not_exists, %Index{} = index}),
do: {:drop_if_exists, index, :restrict}
defp reverse({:drop, %Index{} = index, _}),
do: {:create, index}
defp reverse({:drop_if_exists, %Index{} = index, _}),
do: {:create_if_not_exists, index}
defp reverse({:rename, %Index{} = index, new_name}),
do: {:rename, %{index | name: new_name}, index.name}
defp reverse({:create, %Table{} = table, _columns}),
do: {:drop, table, :restrict}
defp reverse({:create_if_not_exists, %Table{} = table, _columns}),
do: {:drop_if_exists, table, :restrict}
defp reverse({:rename, %Table{} = table_current, %Table{} = table_new}),
do: {:rename, table_new, table_current}
defp reverse({:rename, %Table{} = table, current_column, new_column}),
do: {:rename, table, new_column, current_column}
defp reverse({:alter, %Table{} = table, changes}) do
if reversed = table_reverse(changes, []) do
{:alter, table, reversed}
end
end
# It is not a good idea to reverse constraints because
# we can't guarantee data integrity when applying them back.
defp reverse({:create_if_not_exists, %Constraint{} = constraint}),
do: {:drop_if_exists, constraint, :restrict}
defp reverse({:create, %Constraint{} = constraint}),
do: {:drop, constraint, :restrict}
defp reverse(_command), do: false
defp table_reverse([{:remove, name, type, opts} | t], acc) do
table_reverse(t, [{:add, name, type, opts} | acc])
end
defp table_reverse([{:modify, name, type, opts} | t], acc) do
case opts[:from] do
nil ->
false
{reverse_type, from_opts} when is_list(from_opts) ->
reverse_from = {type, Keyword.delete(opts, :from)}
reverse_opts = Keyword.put(from_opts, :from, reverse_from)
table_reverse(t, [{:modify, name, reverse_type, reverse_opts} | acc])
reverse_type ->
reverse_opts = Keyword.put(opts, :from, type)
table_reverse(t, [{:modify, name, reverse_type, reverse_opts} | acc])
end
end
defp table_reverse([{:add, name, type, _opts} | t], acc) do
table_reverse(t, [{:remove, name, type, []} | acc])
end
defp table_reverse([_ | _], _acc) do
false
end
defp table_reverse([], acc) do
acc
end
## Helpers
defp perform_operation(repo, module, operation) do
if function_exported?(repo, :in_transaction?, 0) and repo.in_transaction?() do
if function_exported?(module, :after_begin, 0) do
module.after_begin()
flush()
end
apply(module, operation, [])
flush()
if function_exported?(module, :before_commit, 0) do
module.before_commit()
flush()
end
else
apply(module, operation, [])
flush()
end
end
defp runner do
case Process.get(:ecto_migration) do
%{runner: runner} -> runner
_ -> raise "could not find migration runner process for #{inspect(self())}"
end
end
defp log_and_execute_ddl(repo, migration, log, {instruction, %Index{} = index}) do
maybe_warn_index_ddl_transaction(index, migration)
maybe_warn_index_migration_lock(index, repo, migration)
log_and_execute_ddl(repo, log, {instruction, index})
end
defp log_and_execute_ddl(repo, _migration, log, command) do
log_and_execute_ddl(repo, log, command)
end
defp log_and_execute_ddl(_repo, _log, func) when is_function(func, 0) do
func.()
:ok
end
defp log_and_execute_ddl(repo, %{level: level, sql: sql}, command) do
log(level, command(command))
meta = Ecto.Adapter.lookup_meta(repo.get_dynamic_repo())
{:ok, logs} = repo.__adapter__().execute_ddl(meta, command, timeout: :infinity, log: sql)
Enum.each(logs, fn {ddl_log_level, message, metadata} ->
ddl_log(ddl_log_level, level, message, metadata)
end)
:ok
end
defp ddl_log(_level, false, _msg, _metadata), do: :ok
defp ddl_log(level, _, msg, metadata), do: log(level, msg, metadata)
defp log(level, msg, metadata \\ [])
defp log(false, _msg, _metadata), do: :ok
defp log(true, msg, metadata), do: Logger.log(:info, msg, metadata)
defp log(level, msg, metadata), do: Logger.log(level, msg, metadata)
defp maybe_warn_index_ddl_transaction(%{concurrently: true} = index, migration) do
migration_config = migration.__migration__()
if not migration_config[:disable_ddl_transaction] do
IO.warn(
"""
Migration #{inspect(migration)} has set index `#{index.name}` on table \
`#{index.table}` to concurrently but did not disable ddl transaction. \
Please set:
use Ecto.Migration
@disable_ddl_transaction true
""",
[]
)
end
end
defp maybe_warn_index_ddl_transaction(_index, _migration), do: :ok
defp maybe_warn_index_migration_lock(%{concurrently: true} = index, repo, migration) do
migration_lock_disabled = migration.__migration__()[:disable_migration_lock]
lock_strategy = repo.config()[:migration_lock]
adapter = repo.__adapter__()
case {migration_lock_disabled, adapter, lock_strategy} do
{false, Ecto.Adapters.Postgres, :pg_advisory_lock} ->
:ok
{false, Ecto.Adapters.Postgres, _} ->
IO.warn(
"""
Migration #{inspect(migration)} has set index `#{index.name}` on table \
`#{index.table}` to concurrently but did not disable migration lock. \
Please set:
use Ecto.Migration
@disable_migration_lock true
Alternatively, consider using advisory locks during migrations in the \
repo configuration:
config #{inspect(repo)}, migration_lock: :pg_advisory_lock
""",
[]
)
{false, _adapter, _migration_lock} ->
IO.warn(
"""
Migration #{inspect(migration)} has set index `#{index.name}` on table \
`#{index.table}` to concurrently but did not disable migration lock. \
Please set:
use Ecto.Migration
@disable_migration_lock true
""",
[]
)
_ ->
:ok
end
end
defp maybe_warn_index_migration_lock(_index, _repo, _migration), do: :ok
defp command(ddl) when is_binary(ddl) or is_list(ddl),
do: "execute #{inspect(ddl)}"
defp command({:create, %Table{} = table, _}),
do: "create table #{quote_name(table.prefix, table.name)}"
defp command({:create_if_not_exists, %Table{} = table, _}),
do: "create table if not exists #{quote_name(table.prefix, table.name)}"
defp command({:alter, %Table{} = table, _}),
do: "alter table #{quote_name(table.prefix, table.name)}"
defp command({:drop, %Table{} = table, mode}),
do: "drop table #{quote_name(table.prefix, table.name)}#{drop_mode(mode)}"
defp command({:drop_if_exists, %Table{} = table, mode}),
do: "drop table if exists #{quote_name(table.prefix, table.name)}#{drop_mode(mode)}"
defp command({:create, %Index{} = index}),
do: "create index #{quote_name(index.prefix, index.name)}"
defp command({:create_if_not_exists, %Index{} = index}),
do: "create index if not exists #{quote_name(index.prefix, index.name)}"
defp command({:drop, %Index{} = index, mode}),
do: "drop index #{quote_name(index.prefix, index.name)}#{drop_mode(mode)}"
defp command({:drop_if_exists, %Index{} = index, mode}),
do: "drop index if exists #{quote_name(index.prefix, index.name)}#{drop_mode(mode)}"
defp command({:rename, %Index{} = index_current, new_name}),
do: "rename index #{quote_name(index_current.prefix, index_current.name)} to #{new_name}"
defp command({:rename, %Table{} = current_table, %Table{} = new_table}),
do:
"rename table #{quote_name(current_table.prefix, current_table.name)} to #{quote_name(new_table.prefix, new_table.name)}"
defp command({:rename, %Table{} = table, current_column, new_column}),
do:
"rename column #{current_column} to #{new_column} on table #{quote_name(table.prefix, table.name)}"
defp command({:create, %Constraint{check: nil, exclude: nil}}),
do: raise(ArgumentError, "a constraint must have either a check or exclude option")
defp command({:create, %Constraint{check: check, exclude: exclude}})
when is_binary(check) and is_binary(exclude),
do: raise(ArgumentError, "a constraint must not have both check and exclude options")
defp command({:create, %Constraint{check: check} = constraint}) when is_binary(check),
do:
"create check constraint #{constraint.name} on table #{quote_name(constraint.prefix, constraint.table)}"
defp command({:create, %Constraint{exclude: exclude} = constraint}) when is_binary(exclude),
do:
"create exclude constraint #{constraint.name} on table #{quote_name(constraint.prefix, constraint.table)}"
defp command({:drop, %Constraint{} = constraint, _}),
do:
"drop constraint #{constraint.name} from table #{quote_name(constraint.prefix, constraint.table)}"
defp command({:drop_if_exists, %Constraint{} = constraint, _}),
do:
"drop constraint if exists #{constraint.name} from table #{quote_name(constraint.prefix, constraint.table)}"
defp drop_mode(:restrict), do: ""
defp drop_mode(:cascade), do: " cascade"
defp quote_name(nil, name), do: quote_name(name)
defp quote_name(prefix, name), do: quote_name(prefix) <> "." <> quote_name(name)
defp quote_name(name) when is_atom(name), do: quote_name(Atom.to_string(name))
defp quote_name(name), do: name
end