Class: Wasval::Executor

Inherits:
Object
  • Object
show all
Defined in:
lib/wasval/executor.rb

Constant Summary collapse

STDOUT_BUFFER_SIZE =

10 MB

10 * 1024 * 1024
STDERR_BUFFER_SIZE =

1 MB

1 * 1024 * 1024
WASM_PATH = 
ENV["WASVAL_RUBY_WASM_PATH"]
CWASM_PATH = 
ENV["WASVAL_RUBY_CWASM_PATH"]

Instance Method Summary collapse

Constructor Details

#initialize ⇒ Executor

Returns a new instance of Executor.



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# File 'lib/wasval/executor.rb', line 12

def initialize
  @engine = Wasmtime::Engine.new(epoch_interruption: true)

  if WASM_PATH
    @mod = Wasmtime::Module.from_file(@engine, WASM_PATH)
  elsif CWASM_PATH
    @mod = Wasmtime::Module.deserialize_file(@engine, CWASM_PATH)
  else
    raise ArgumentError.new "Please specify 'WASVAL_RUBY_WASM_PATH' or 'WASVAL_RUBY_CWASM_PATH' env"
  end
end

Instance Method Details

#execute(code:, timeout:, memory_limit:) ⇒ Object 



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# File 'lib/wasval/executor.rb', line 24

def execute(code:, timeout:, memory_limit:)
  if code.nil? || code.strip.empty?
    return Result.new(
      status: :sandbox_error,
      output: "",
      stderr: "",
      error_message: "code must not be nil or empty"
    )
  end

  stdout_buf = +""
  stderr_buf = +""

  wasi_config = Wasmtime::WasiConfig.new
    .set_argv(["ruby", "-"])
    .set_stdin_string(wrapped_code(code))
    .set_stdout_buffer(stdout_buf, STDOUT_BUFFER_SIZE)
    .set_stderr_buffer(stderr_buf, STDERR_BUFFER_SIZE)

  store = Wasmtime::Store.new(@engine,
    wasi_p1_config: wasi_config,
    limits: { memory_size: memory_limit * 1024 * 1024 }
  )
  store.set_epoch_deadline(timeout)

  linker = Wasmtime::Linker.new(@engine)
  Wasmtime::WASI::P1.add_to_linker_sync(linker)

  @engine.start_epoch_interval(1000)

  begin
    linker.instantiate(store, @mod).invoke("_start")
    classify_output(stdout_buf, stderr_buf, store)
  rescue Wasmtime::WasiExit
    classify_output(stdout_buf, stderr_buf, store)
  rescue Wasmtime::Trap => e
    if e.code == :interrupt
      Result.new(status: :timeout, output: stdout_buf, stderr: "", error_message: "execution timed out")
    elsif store.linear_memory_limit_hit?
      Result.new(status: :memory_limit, output: stdout_buf, stderr: "", error_message: "memory limit exceeded")
    else
      Result.new(status: :sandbox_error, output: stdout_buf, stderr: stderr_buf, error_message: e.message)
    end
  rescue Wasmtime::Error => e
    if store.linear_memory_limit_hit?
      Result.new(status: :memory_limit, output: stdout_buf, stderr: "", error_message: "memory limit exceeded")
    else
      Result.new(status: :sandbox_error, output: stdout_buf, stderr: stderr_buf, error_message: e.message)
    end
  rescue => e
    Result.new(status: :sandbox_error, output: stdout_buf, stderr: stderr_buf, error_message: e.message)
  end
end