The man command, short for manual, displays the setup instructions (what you are reading now) for the courseware. To view the instructions for the current exercise, use the e option. If you are using an IDE, you can also open up the setup instructions (README.md) file or the current exercises instructions (src/test/resources/README.md) file in your workspace.
// display the setup instructions
man [e] > ... > initial-state > man
// display the instructions for the current exercise
man [e] > ... > initial-state > man eAs part of each exercise, we use the run command to bootstrap the main class. This command starts the application for the current exercise that we interact with and verify our solution.
man [e] > ...> initial-state > runNavigation through the courseware is possibile with a few sbt commands. Also, tests are provided to confirm our solution is accurate. It is important to note that the tests make some assumptions about the code, in particular, naming and scope; please adjust your source accordingly. Following are the available navigation commands:
// show the current exercise
man [e] > ... > initial-state > showExerciseId
[INFO] Currently at exercise_000_initial_state
// move to the next exercise
man [e] > ... > ... > nextExercise
[INFO] Moved to ...
// move to the previous exercise
man [e] > ... > ... > prevExercise
[INFO] Moved to exercise_000_initial_state
// save the current state of an exercise for later retrieval and study
man [e] > ... > initial-state > saveState
[INFO] State for exercise exercise_000_initial_state saved successfully
// List previously saved states
man [e] > ... > ... > savedStates
[INFO] Saved exercise states are available for the following exercise(s):
exercise_000_initial_state
...
// Restore a previously saved exercise state
man [e] > ... > initial-state > restoreState exercise_000_initial_state
[INFO] Exercise exercise_000_initial_state restoredTo clean your current exercise, use the clean command from your sbt session. Clean deletes all generated files in the target directory.
man [e] > ... > initial-state > cleanTo compile your current exercise, use the compile command from your sbt session. This command compiles the source in the src/main/scala directory.
man [e] > ... > initial-state > compileTo reload sbt, use the reload command from your sbt session. This command reloads the build definitions, build.sbt, project/.scala and project/.sbt files. Reloading is a requirement if you change the build definition files.
man [e] > ... > initial-state > reloadTo test your current exercise, use the test command from your sbt session. Test compiles and runs all tests for the current exercise. Automated tests are your safeguard and validate whether or not you have completed the exercise successfully and are ready to move on.
man [e] > ... > initial-state > test| Name | Order Cars completed in milliseconds |
|---|---|
| 0 ms run | 1 375 ms |
| 16 ms run | 15 484 ms |
| 14 ms run | 13 439 ms |
| 12 ms run | 11 426 ms |
| 14 ms tail run | 14 140 ms |
| 10 ms 2 asyncs run | 10 072 ms |
Question: Why does the list include two install-upgrades-stage-maps? Does this mean the 16 ms run is actually the 18 ms run? Look in the UpgradeShop class. Do you see more than one map operator? Are all the map operators run for each ordered car?
Answer: The installUpgrades flow includes to map operators (one for DX upgrade and another for Sport upgrade). The map operators don't run for each car, the cars are balanced for the three types of upgrades (DX, Sport and Standard), so each map operator runs for 1/3 of the cars. It continues to be a 16 ms run because for each car only one map operator runs.
Question: Can you determine how long the UpgradeShop balance and UpgradeShop merge took?
Answer: balance took 1µs and merge took 723ns.
Question: What class and method contain the install-engine-stage-iterableSource operator?
Answer: EngineShop class, shipments source uses an iterator that continually produces shipments.
| Name | Order Cars completed per sec (stream throughput) |
|---|---|
| 16 ms run | 65 |
| 12 ms run | 88 |
| 10 ms 2 asyncs run | 100 |