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# frozen_string_literal: true
require 'fast_spec_helper'
RSpec.describe Gitlab::Memory::Jemalloc do
let(:outdir) { Dir.mktmpdir }
after do
FileUtils.rm_f(outdir)
end
context 'when jemalloc is loaded' do
let(:fiddle_func) { instance_double(::Fiddle::Function) }
context 'with JSON format' do
let(:format) { :json }
let(:output) { '{"a": 24}' }
before do
stub_stats_call(output, 'J')
end
describe '.stats' do
it 'returns stats JSON' do
expect(described_class.stats(format: format)).to eq(output)
end
end
describe '.dump_stats' do
it 'writes stats JSON file' do
described_class.dump_stats(path: outdir, format: format)
file = Dir.entries(outdir).find { |e| e.match(/jemalloc_stats\.#{$$}\.\d+\.json$/) }
expect(file).not_to be_nil
expect(File.read(File.join(outdir, file))).to eq(output)
end
end
end
context 'with text format' do
let(:format) { :text }
let(:output) { 'stats' }
before do
stub_stats_call(output)
end
describe '.stats' do
it 'returns a text report' do
expect(described_class.stats(format: format)).to eq(output)
end
end
describe '.dump_stats' do
it 'writes stats text file' do
described_class.dump_stats(path: outdir, format: format)
file = Dir.entries(outdir).find { |e| e.match(/jemalloc_stats\.#{$$}\.\d+\.txt$/) }
expect(file).not_to be_nil
expect(File.read(File.join(outdir, file))).to eq(output)
end
end
end
context 'with unsupported format' do
let(:format) { 'unsupported' }
describe '.stats' do
it 'raises an error' do
expect do
described_class.stats(format: format)
end.to raise_error(/format must be one of/)
end
end
describe '.dump_stats' do
it 'raises an error' do
expect do
described_class.dump_stats(path: outdir, format: format)
end.to raise_error(/format must be one of/)
end
end
end
end
context 'when jemalloc is not loaded' do
before do
expect(::Fiddle::Handle).to receive(:sym).and_raise(Fiddle::DLError)
end
describe '.stats' do
it 'returns nil' do
expect(described_class.stats).to be_nil
end
end
describe '.dump_stats' do
it 'does nothing' do
stub_env('LD_PRELOAD', nil)
described_class.dump_stats(path: outdir)
expect(Dir.empty?(outdir)).to be(true)
end
end
end
def stub_stats_call(output, expected_options = '')
# Stub function pointer to stats call.
func_pointer = Fiddle::Pointer.new(0xd34db33f)
expect(::Fiddle::Handle).to receive(:sym).with('malloc_stats_print').and_return(func_pointer)
# Stub actual function call.
expect(::Fiddle::Function).to receive(:new)
.with(func_pointer, anything, anything)
.and_return(fiddle_func)
expect(fiddle_func).to receive(:call).with(anything, nil, expected_options) do |callback, _, options|
callback.call(nil, output)
end
end
end
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