/usr/lib/ruby/vendor_ruby/sequel/adapters/shared/sqlite.rb is in ruby-sequel 4.1.1-1.
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module Sequel
module SQLite
# No matter how you connect to SQLite, the following Database options
# can be used to set PRAGMAs on connections in a thread-safe manner:
# :auto_vacuum, :foreign_keys, :synchronous, and :temp_store.
module DatabaseMethods
extend Sequel::Database::ResetIdentifierMangling
AUTO_VACUUM = [:none, :full, :incremental].freeze
PRIMARY_KEY_INDEX_RE = /\Asqlite_autoindex_/.freeze
SYNCHRONOUS = [:off, :normal, :full].freeze
TABLES_FILTER = "type = 'table' AND NOT name = 'sqlite_sequence'".freeze
TEMP_STORE = [:default, :file, :memory].freeze
VIEWS_FILTER = "type = 'view'".freeze
TRANSACTION_MODE = {
:deferred => "BEGIN DEFERRED TRANSACTION".freeze,
:immediate => "BEGIN IMMEDIATE TRANSACTION".freeze,
:exclusive => "BEGIN EXCLUSIVE TRANSACTION".freeze,
nil => Sequel::Database::SQL_BEGIN,
}.freeze
# Whether to use integers for booleans in the database. SQLite recommends
# booleans be stored as integers, but historically Sequel has used 't'/'f'.
attr_accessor :integer_booleans
# A symbol signifying the value of the auto_vacuum PRAGMA.
def auto_vacuum
AUTO_VACUUM[pragma_get(:auto_vacuum).to_i]
end
# Set the auto_vacuum PRAGMA using the given symbol (:none, :full, or
# :incremental). See pragma_set. Consider using the :auto_vacuum
# Database option instead.
def auto_vacuum=(value)
value = AUTO_VACUUM.index(value) || (raise Error, "Invalid value for auto_vacuum option. Please specify one of :none, :full, :incremental.")
pragma_set(:auto_vacuum, value)
end
# Set the case_sensitive_like PRAGMA using the given boolean value, if using
# SQLite 3.2.3+. If not using 3.2.3+, no error is raised. See pragma_set.
# Consider using the :case_sensitive_like Database option instead.
def case_sensitive_like=(value)
pragma_set(:case_sensitive_like, !!value ? 'on' : 'off') if sqlite_version >= 30203
end
# A symbol signifying the value of the default transaction mode
attr_reader :transaction_mode
# Set the default transaction mode.
def transaction_mode=(value)
if TRANSACTION_MODE.include?(value)
@transaction_mode = value
else
raise Error, "Invalid value for transaction_mode. Please specify one of :deferred, :immediate, :exclusive, nil"
end
end
# SQLite uses the :sqlite database type.
def database_type
:sqlite
end
# Boolean signifying the value of the foreign_keys PRAGMA, or nil
# if not using SQLite 3.6.19+.
def foreign_keys
pragma_get(:foreign_keys).to_i == 1 if sqlite_version >= 30619
end
# Set the foreign_keys PRAGMA using the given boolean value, if using
# SQLite 3.6.19+. If not using 3.6.19+, no error is raised. See pragma_set.
# Consider using the :foreign_keys Database option instead.
def foreign_keys=(value)
pragma_set(:foreign_keys, !!value ? 'on' : 'off') if sqlite_version >= 30619
end
# Return the array of foreign key info hashes using the foreign_key_list PRAGMA,
# including information for the :on_update and :on_delete entries.
def foreign_key_list(table, opts=OPTS)
m = output_identifier_meth
h = {}
metadata_dataset.with_sql("PRAGMA foreign_key_list(?)", input_identifier_meth.call(table)).each do |row|
if r = h[row[:id]]
r[:columns] << m.call(row[:from])
r[:key] << m.call(row[:to]) if r[:key]
else
h[row[:id]] = {:columns=>[m.call(row[:from])], :table=>m.call(row[:table]), :key=>([m.call(row[:to])] if row[:to]), :on_update=>on_delete_sql_to_sym(row[:on_update]), :on_delete=>on_delete_sql_to_sym(row[:on_delete])}
end
end
h.values
end
# Use the index_list and index_info PRAGMAs to determine the indexes on the table.
def indexes(table, opts=OPTS)
m = output_identifier_meth
im = input_identifier_meth
indexes = {}
metadata_dataset.with_sql("PRAGMA index_list(?)", im.call(table)).each do |r|
next if r[:name] =~ PRIMARY_KEY_INDEX_RE
indexes[m.call(r[:name])] = {:unique=>r[:unique].to_i==1}
end
indexes.each do |k, v|
v[:columns] = metadata_dataset.with_sql("PRAGMA index_info(?)", im.call(k)).map(:name).map{|x| m.call(x)}
end
indexes
end
# Get the value of the given PRAGMA.
def pragma_get(name)
self["PRAGMA #{name}"].single_value
end
# Set the value of the given PRAGMA to value.
#
# This method is not thread safe, and will not work correctly if there
# are multiple connections in the Database's connection pool. PRAGMA
# modifications should be done when the connection is created, using
# an option provided when creating the Database object.
def pragma_set(name, value)
execute_ddl("PRAGMA #{name} = #{value}")
end
# Set the integer_booleans option using the passed in :integer_boolean option.
def set_integer_booleans
@integer_booleans = @opts.has_key?(:integer_booleans) ? typecast_value_boolean(@opts[:integer_booleans]) : true
end
# The version of the server as an integer, where 3.6.19 = 30619.
# If the server version can't be determined, 0 is used.
def sqlite_version
return @sqlite_version if defined?(@sqlite_version)
@sqlite_version = begin
v = get{sqlite_version{}}
[10000, 100, 1].zip(v.split('.')).inject(0){|a, m| a + m[0] * Integer(m[1])}
rescue
0
end
end
# SQLite supports CREATE TABLE IF NOT EXISTS syntax since 3.3.0.
def supports_create_table_if_not_exists?
sqlite_version >= 30300
end
# SQLite 3.6.19+ supports deferrable foreign key constraints.
def supports_deferrable_foreign_key_constraints?
sqlite_version >= 30619
end
# SQLite 3.6.8+ supports savepoints.
def supports_savepoints?
sqlite_version >= 30608
end
# Override the default setting for whether to use timezones in timestamps.
# For backwards compatibility, it is set to +true+ by default.
# Anyone wanting to use SQLite's datetime functions should set it to +false+
# using this method. It's possible that the default will change in a future version,
# so anyone relying on timezones in timestamps should set this to +true+.
attr_writer :use_timestamp_timezones
# SQLite supports timezones in timestamps, since it just stores them as strings,
# but it breaks the usage of SQLite's datetime functions.
def use_timestamp_timezones?
defined?(@use_timestamp_timezones) ? @use_timestamp_timezones : (@use_timestamp_timezones = false)
end
# A symbol signifying the value of the synchronous PRAGMA.
def synchronous
SYNCHRONOUS[pragma_get(:synchronous).to_i]
end
# Set the synchronous PRAGMA using the given symbol (:off, :normal, or :full). See pragma_set.
# Consider using the :synchronous Database option instead.
def synchronous=(value)
value = SYNCHRONOUS.index(value) || (raise Error, "Invalid value for synchronous option. Please specify one of :off, :normal, :full.")
pragma_set(:synchronous, value)
end
# Array of symbols specifying the table names in the current database.
#
# Options:
# * :server - Set the server to use.
def tables(opts=OPTS)
tables_and_views(TABLES_FILTER, opts)
end
# A symbol signifying the value of the temp_store PRAGMA.
def temp_store
TEMP_STORE[pragma_get(:temp_store).to_i]
end
# Set the temp_store PRAGMA using the given symbol (:default, :file, or :memory). See pragma_set.
# Consider using the :temp_store Database option instead.
def temp_store=(value)
value = TEMP_STORE.index(value) || (raise Error, "Invalid value for temp_store option. Please specify one of :default, :file, :memory.")
pragma_set(:temp_store, value)
end
# Array of symbols specifying the view names in the current database.
#
# Options:
# * :server - Set the server to use.
def views(opts=OPTS)
tables_and_views(VIEWS_FILTER, opts)
end
private
# Run all alter_table commands in a transaction. This is technically only
# needed for drop column.
def apply_alter_table(table, ops)
fks = foreign_keys
self.foreign_keys = false if fks
transaction do
if ops.length > 1 && ops.all?{|op| op[:op] == :add_constraint}
# If you are just doing constraints, apply all of them at the same time,
# as otherwise all but the last one get lost.
alter_table_sql_list(table, [{:op=>:add_constraints, :ops=>ops}]).flatten.each{|sql| execute_ddl(sql)}
else
# Run each operation separately, as later operations may depend on the
# results of earlier operations.
ops.each{|op| alter_table_sql_list(table, [op]).flatten.each{|sql| execute_ddl(sql)}}
end
end
ensure
self.foreign_keys = true if fks
end
# SQLite supports limited table modification. You can add a column
# or an index. Dropping columns is supported by copying the table into
# a temporary table, dropping the table, and creating a new table without
# the column inside of a transaction.
def alter_table_sql(table, op)
case op[:op]
when :add_index, :drop_index
super
when :add_column
if op[:unique] || op[:primary_key]
duplicate_table(table){|columns| columns.push(op)}
else
super
end
when :drop_column
ocp = lambda{|oc| oc.delete_if{|c| c.to_s == op[:name].to_s}}
duplicate_table(table, :old_columns_proc=>ocp){|columns| columns.delete_if{|s| s[:name].to_s == op[:name].to_s}}
when :rename_column
ncp = lambda{|nc| nc.map!{|c| c.to_s == op[:name].to_s ? op[:new_name] : c}}
duplicate_table(table, :new_columns_proc=>ncp){|columns| columns.each{|s| s[:name] = op[:new_name] if s[:name].to_s == op[:name].to_s}}
when :set_column_default
duplicate_table(table){|columns| columns.each{|s| s[:default] = op[:default] if s[:name].to_s == op[:name].to_s}}
when :set_column_null
duplicate_table(table){|columns| columns.each{|s| s[:null] = op[:null] if s[:name].to_s == op[:name].to_s}}
when :set_column_type
duplicate_table(table){|columns| columns.each{|s| s.merge!(op) if s[:name].to_s == op[:name].to_s}}
when :drop_constraint
case op[:type]
when :primary_key
duplicate_table(table){|columns| columns.each{|s| s[:primary_key] = nil}}
when :foreign_key
if op[:columns]
duplicate_table(table, :skip_foreign_key_columns=>op[:columns])
else
duplicate_table(table, :no_foreign_keys=>true)
end
else
duplicate_table(table)
end
when :add_constraint
duplicate_table(table, :constraints=>[op])
when :add_constraints
duplicate_table(table, :constraints=>op[:ops])
else
raise Error, "Unsupported ALTER TABLE operation: #{op[:op].inspect}"
end
end
def begin_new_transaction(conn, opts)
mode = opts[:mode] || @transaction_mode
sql = TRANSACTION_MODE[mode] or raise Error, "transaction :mode must be one of: :deferred, :immediate, :exclusive, nil"
log_connection_execute(conn, sql)
set_transaction_isolation(conn, opts)
end
# A name to use for the backup table
def backup_table_name(table, opts=OPTS)
table = table.gsub('`', '')
(opts[:times]||1000).times do |i|
table_name = "#{table}_backup#{i}"
return table_name unless table_exists?(table_name)
end
end
# Surround default with parens to appease SQLite
def column_definition_default_sql(sql, column)
sql << " DEFAULT (#{literal(column[:default])})" if column.include?(:default)
end
# Add null/not null SQL fragment to column creation SQL.
def column_definition_null_sql(sql, column)
column = column.merge(:null=>false) if column[:primary_key]
super(sql, column)
end
# Array of PRAGMA SQL statements based on the Database options that should be applied to
# new connections.
def connection_pragmas
ps = []
v = typecast_value_boolean(opts.fetch(:foreign_keys, 1))
ps << "PRAGMA foreign_keys = #{v ? 1 : 0}"
v = typecast_value_boolean(opts.fetch(:case_sensitive_like, 1))
ps << "PRAGMA case_sensitive_like = #{v ? 1 : 0}"
[[:auto_vacuum, AUTO_VACUUM], [:synchronous, SYNCHRONOUS], [:temp_store, TEMP_STORE]].each do |prag, con|
if v = opts[prag]
raise(Error, "Value for PRAGMA #{prag} not supported, should be one of #{con.join(', ')}") unless v = con.index(v.to_sym)
ps << "PRAGMA #{prag} = #{v}"
end
end
ps
end
# SQLite support creating temporary views.
def create_view_prefix_sql(name, options)
"CREATE #{'TEMPORARY 'if options[:temp]}VIEW #{quote_schema_table(name)}"
end
DATABASE_ERROR_REGEXPS = {
/is not unique\z/ => UniqueConstraintViolation,
/foreign key constraint failed\z/ => ForeignKeyConstraintViolation,
/\A(SQLITE ERROR 19 \(CONSTRAINT\) : )?constraint failed\z/ => ConstraintViolation,
/may not be NULL\z/ => NotNullConstraintViolation,
}.freeze
def database_error_regexps
DATABASE_ERROR_REGEXPS
end
# The array of column schema hashes for the current columns in the table
def defined_columns_for(table)
cols = parse_pragma(table, {})
cols.each do |c|
c[:default] = LiteralString.new(c[:default]) if c[:default]
c[:type] = c[:db_type]
end
cols
end
# Duplicate an existing table by creating a new table, copying all records
# from the existing table into the new table, deleting the existing table
# and renaming the new table to the existing table's name.
def duplicate_table(table, opts=OPTS)
remove_cached_schema(table)
def_columns = defined_columns_for(table)
old_columns = def_columns.map{|c| c[:name]}
opts[:old_columns_proc].call(old_columns) if opts[:old_columns_proc]
yield def_columns if block_given?
constraints = (opts[:constraints] || []).dup
pks = []
def_columns.each{|c| pks << c[:name] if c[:primary_key]}
if pks.length > 1
constraints << {:type=>:primary_key, :columns=>pks}
def_columns.each{|c| c[:primary_key] = false if c[:primary_key]}
end
# If dropping a foreign key constraint, drop all foreign key constraints,
# as there is no way to determine which one to drop.
unless opts[:no_foreign_keys]
fks = foreign_key_list(table)
# If dropping a column, if there is a foreign key with that
# column, don't include it when building a copy of the table.
if ocp = opts[:old_columns_proc]
fks.delete_if{|c| ocp.call(c[:columns].dup) != c[:columns]}
end
# Skip any foreign key columns where a constraint for those
# foreign keys is being dropped.
if sfkc = opts[:skip_foreign_key_columns]
fks.delete_if{|c| c[:columns] == sfkc}
end
constraints.concat(fks.each{|h| h[:type] = :foreign_key})
end
def_columns_str = (def_columns.map{|c| column_definition_sql(c)} + constraints.map{|c| constraint_definition_sql(c)}).join(', ')
new_columns = old_columns.dup
opts[:new_columns_proc].call(new_columns) if opts[:new_columns_proc]
qt = quote_schema_table(table)
bt = quote_identifier(backup_table_name(qt))
a = [
"ALTER TABLE #{qt} RENAME TO #{bt}",
"CREATE TABLE #{qt}(#{def_columns_str})",
"INSERT INTO #{qt}(#{dataset.send(:identifier_list, new_columns)}) SELECT #{dataset.send(:identifier_list, old_columns)} FROM #{bt}",
"DROP TABLE #{bt}"
]
indexes(table).each do |name, h|
if (h[:columns].map{|x| x.to_s} - new_columns).empty?
a << alter_table_sql(table, h.merge(:op=>:add_index, :name=>name))
end
end
a
end
# SQLite folds unquoted identifiers to lowercase, so it shouldn't need to upcase identifiers on input.
def identifier_input_method_default
nil
end
# SQLite folds unquoted identifiers to lowercase, so it shouldn't need to upcase identifiers on output.
def identifier_output_method_default
nil
end
# Does the reverse of on_delete_clause, eg. converts strings like +'SET NULL'+
# to symbols +:set_null+.
def on_delete_sql_to_sym str
case str
when 'RESTRICT'
:restrict
when 'CASCADE'
:cascade
when 'SET NULL'
:set_null
when 'SET DEFAULT'
:set_default
when 'NO ACTION'
:no_action
end
end
# Parse the output of the table_info pragma
def parse_pragma(table_name, opts)
metadata_dataset.with_sql("PRAGMA table_info(?)", input_identifier_meth(opts[:dataset]).call(table_name)).map do |row|
row.delete(:cid)
row[:allow_null] = row.delete(:notnull).to_i == 0
row[:default] = row.delete(:dflt_value)
row[:primary_key] = row.delete(:pk).to_i > 0
row[:default] = nil if blank_object?(row[:default]) || row[:default] == 'NULL'
row[:db_type] = row.delete(:type)
row[:type] = schema_column_type(row[:db_type])
row
end
end
# SQLite treats integer primary keys as autoincrementing (alias of rowid).
def schema_autoincrementing_primary_key?(schema)
super && schema[:db_type].downcase == 'integer'
end
# SQLite supports schema parsing using the table_info PRAGMA, so
# parse the output of that into the format Sequel expects.
def schema_parse_table(table_name, opts)
m = output_identifier_meth(opts[:dataset])
parse_pragma(table_name, opts).map do |row|
[m.call(row.delete(:name)), row]
end
end
# Backbone of the tables and views support.
def tables_and_views(filter, opts)
m = output_identifier_meth
metadata_dataset.from(:sqlite_master).server(opts[:server]).filter(filter).map{|r| m.call(r[:name])}
end
# SQLite only supports AUTOINCREMENT on integer columns, not
# bigint columns, so use integer instead of bigint for those
# columns.
def type_literal_generic_bignum(column)
column[:auto_increment] ? :integer : super
end
end
# Instance methods for datasets that connect to an SQLite database
module DatasetMethods
include Dataset::Replace
SELECT_CLAUSE_METHODS = Dataset.clause_methods(:select, %w'select distinct columns from join where group having compounds order limit')
CONSTANT_MAP = {:CURRENT_DATE=>"date(CURRENT_TIMESTAMP, 'localtime')".freeze, :CURRENT_TIMESTAMP=>"datetime(CURRENT_TIMESTAMP, 'localtime')".freeze, :CURRENT_TIME=>"time(CURRENT_TIMESTAMP, 'localtime')".freeze}
EMULATED_FUNCTION_MAP = {:char_length=>'length'.freeze}
EXTRACT_MAP = {:year=>"'%Y'", :month=>"'%m'", :day=>"'%d'", :hour=>"'%H'", :minute=>"'%M'", :second=>"'%f'"}
NOT_SPACE = Dataset::NOT_SPACE
COMMA = Dataset::COMMA
PAREN_CLOSE = Dataset::PAREN_CLOSE
AS = Dataset::AS
APOS = Dataset::APOS
EXTRACT_OPEN = "CAST(strftime(".freeze
EXTRACT_CLOSE = ') AS '.freeze
NUMERIC = 'NUMERIC'.freeze
INTEGER = 'INTEGER'.freeze
BACKTICK = '`'.freeze
BACKTICK_RE = /`/.freeze
DOUBLE_BACKTICK = '``'.freeze
BLOB_START = "X'".freeze
HSTAR = "H*".freeze
DATE_OPEN = "date(".freeze
DATETIME_OPEN = "datetime(".freeze
def cast_sql_append(sql, expr, type)
if type == Time or type == DateTime
sql << DATETIME_OPEN
literal_append(sql, expr)
sql << PAREN_CLOSE
elsif type == Date
sql << DATE_OPEN
literal_append(sql, expr)
sql << PAREN_CLOSE
else
super
end
end
# SQLite doesn't support a NOT LIKE b, you need to use NOT (a LIKE b).
# It doesn't support xor or the extract function natively, so those have to be emulated.
def complex_expression_sql_append(sql, op, args)
case op
when :"NOT LIKE", :"NOT ILIKE"
sql << NOT_SPACE
complex_expression_sql_append(sql, (op == :"NOT ILIKE" ? :ILIKE : :LIKE), args)
when :^
sql << complex_expression_arg_pairs(args) do |a, b|
a = literal(a)
b = literal(b)
"((~(#{a} & #{b})) & (#{a} | #{b}))"
end
when :extract
part = args.at(0)
raise(Sequel::Error, "unsupported extract argument: #{part.inspect}") unless format = EXTRACT_MAP[part]
sql << EXTRACT_OPEN << format << COMMA
literal_append(sql, args.at(1))
sql << EXTRACT_CLOSE << (part == :second ? NUMERIC : INTEGER) << PAREN_CLOSE
else
super
end
end
# SQLite has CURRENT_TIMESTAMP and related constants in UTC instead
# of in localtime, so convert those constants to local time.
def constant_sql_append(sql, constant)
if c = CONSTANT_MAP[constant]
sql << c
else
super
end
end
# SQLite performs a TRUNCATE style DELETE if no filter is specified.
# Since we want to always return the count of records, add a condition
# that is always true and then delete.
def delete
@opts[:where] ? super : where(1=>1).delete
end
# Return an array of strings specifying a query explanation for a SELECT of the
# current dataset. Currently, the options are ignore, but it accepts options
# to be compatible with other adapters.
def explain(opts=nil)
# Load the PrettyTable class, needed for explain output
Sequel.extension(:_pretty_table) unless defined?(Sequel::PrettyTable)
ds = db.send(:metadata_dataset).clone(:sql=>"EXPLAIN #{select_sql}")
rows = ds.all
Sequel::PrettyTable.string(rows, ds.columns)
end
# HAVING requires GROUP BY on SQLite
def having(*cond)
raise(InvalidOperation, "Can only specify a HAVING clause on a grouped dataset") unless @opts[:group]
super
end
# SQLite uses the nonstandard ` (backtick) for quoting identifiers.
def quoted_identifier_append(sql, c)
sql << BACKTICK << c.to_s.gsub(BACKTICK_RE, DOUBLE_BACKTICK) << BACKTICK
end
# When a qualified column is selected on SQLite and the qualifier
# is a subselect, the column name used is the full qualified name
# (including the qualifier) instead of just the column name. To
# get correct column names, you must use an alias.
def select(*cols)
if ((f = @opts[:from]) && f.any?{|t| t.is_a?(Dataset) || (t.is_a?(SQL::AliasedExpression) && t.expression.is_a?(Dataset))}) || ((j = @opts[:join]) && j.any?{|t| t.table.is_a?(Dataset)})
super(*cols.map{|c| alias_qualified_column(c)})
else
super
end
end
# SQLite does not support INTERSECT ALL or EXCEPT ALL
def supports_intersect_except_all?
false
end
# SQLite does not support IS TRUE
def supports_is_true?
false
end
# SQLite does not support multiple columns for the IN/NOT IN operators
def supports_multiple_column_in?
false
end
# SQLite supports timezones in literal timestamps, since it stores them
# as text. But using timezones in timestamps breaks SQLite datetime
# functions, so we allow the user to override the default per database.
def supports_timestamp_timezones?
db.use_timestamp_timezones?
end
# SQLite cannot use WHERE 't'.
def supports_where_true?
false
end
private
# SQLite uses string literals instead of identifiers in AS clauses.
def as_sql_append(sql, aliaz)
aliaz = aliaz.value if aliaz.is_a?(SQL::Identifier)
sql << AS
literal_append(sql, aliaz.to_s)
end
# If col is a qualified column, alias it to the same as the column name
def alias_qualified_column(col)
case col
when Symbol
t, c, a = split_symbol(col)
if t && !a
alias_qualified_column(SQL::QualifiedIdentifier.new(t, c))
else
col
end
when SQL::QualifiedIdentifier
SQL::AliasedExpression.new(col, col.column)
else
col
end
end
# SQL fragment specifying a list of identifiers
def identifier_list(columns)
columns.map{|i| quote_identifier(i)}.join(COMMA)
end
# SQLite uses a preceding X for hex escaping strings
def literal_blob_append(sql, v)
sql << BLOB_START << v.unpack(HSTAR).first << APOS
end
# Respect the database integer_booleans setting, using 0 or 'f'.
def literal_false
@db.integer_booleans ? '0' : "'f'"
end
# Respect the database integer_booleans setting, using 1 or 't'.
def literal_true
@db.integer_booleans ? '1' : "'t'"
end
# SQLite does not support the SQL WITH clause
def select_clause_methods
SELECT_CLAUSE_METHODS
end
# SQLite does not support FOR UPDATE, but silently ignore it
# instead of raising an error for compatibility with other
# databases.
def select_lock_sql(sql)
super unless @opts[:lock] == :update
end
# SQLite treats a DELETE with no WHERE clause as a TRUNCATE
def _truncate_sql(table)
"DELETE FROM #{table}"
end
end
end
end
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