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ruby--ruby/ext/objspace/lib/objspace.rb
Jean Boussier fbba6bd4e3 Parse ObjectSpace.dump_all / dump arguments in Ruby to avoid allocation noise
[Feature #17045] ObjectSpace.dump_all should allocate as little as possible in the GC heap

Up until this commit ObjectSpace.dump_all allocates two Hash because of `rb_scan_args`.

It also can allocate a `File` because of `rb_io_get_write_io`.

These allocations are problematic because `dump_all` dumps the Ruby
heap, so it should try modify as little as possible what it is
observing.
2020-09-15 09:18:13 -07:00

87 lines
2.6 KiB
Ruby

# frozen_string_literal: true
require 'objspace.so'
module ObjectSpace
class << self
private :_dump
private :_dump_all
end
module_function
# call-seq:
# ObjectSpace.dump(obj[, output: :string]) # => "{ ... }"
# ObjectSpace.dump(obj, output: :file) # => #<File:/tmp/rubyobj20131125-88733-1xkfmpv.json>
# ObjectSpace.dump(obj, output: :stdout) # => nil
#
# Dump the contents of a ruby object as JSON.
#
# This method is only expected to work with C Ruby.
# This is an experimental method and is subject to change.
# In particular, the function signature and output format are
# not guaranteed to be compatible in future versions of ruby.
def dump(obj, output: :string)
out = case output
when :file, nil
require 'tempfile'
Tempfile.create(%w(rubyobj .json))
when :stdout
STDOUT
when :string
+''
when IO
output
else
raise ArgumentError, "wrong output option: #{output.inspect}"
end
_dump(obj, out)
end
# call-seq:
# ObjectSpace.dump_all([output: :file]) # => #<File:/tmp/rubyheap20131125-88469-laoj3v.json>
# ObjectSpace.dump_all(output: :stdout) # => nil
# ObjectSpace.dump_all(output: :string) # => "{...}\n{...}\n..."
# ObjectSpace.dump_all(output:
# File.open('heap.json','w')) # => #<File:heap.json>
# ObjectSpace.dump_all(output: :string,
# since: 42) # => "{...}\n{...}\n..."
#
# Dump the contents of the ruby heap as JSON.
#
# _since_ must be a non-negative integer or +nil+.
#
# If _since_ is a positive integer, only objects of that generation and
# newer generations are dumped. The current generation can be accessed using
# GC::count.
#
# Objects that were allocated without object allocation tracing enabled
# are ignored. See ::trace_object_allocations for more information and
# examples.
#
# If _since_ is omitted or is +nil+, all objects are dumped.
#
# This method is only expected to work with C Ruby.
# This is an experimental method and is subject to change.
# In particular, the function signature and output format are
# not guaranteed to be compatible in future versions of ruby.
def dump_all(output: :file, full: false, since: nil)
out = case output
when :file, nil
require 'tempfile'
Tempfile.create(%w(rubyheap .json))
when :stdout
STDOUT
when :string
+''
when IO
output
else
raise ArgumentError, "wrong output option: #{output.inspect}"
end
_dump_all(out, full, since)
end
end