This repository contains the starter code for project 1 (15-440, Fall 2022). It also contains the tests that we will use to grade your implementation, and two simple echo server/client (srunner and crunner, respectively) programs that you might find useful for your own testing purposes.

If at any point you have any trouble with building, installing, or testing your code, the article titled How to Write Go Code is a great resource for understanding how Go workspaces are built and organized. You might also find the documentation for the go command to be helpful. As always, feel free to post your questions on Edstem.

This project was designed for and tested on AFS cluster machines, though you may choose to write and build your code locally as well.

Part A

Testing your code using srunner & crunner

To make testing your server a bit easier we have provided two simple echo server/client programs called srunner and crunner. If you look at the source code for the two programs, you’ll notice that they import the github.com/cmu440/lsp package (in other words, they compile against the current state of your LSP implementation). We believe you will find these programs useful in the early stages of development when your client and server implementations are largely incomplete.

To compile, build, and run these programs, use the go run command from inside the directory storing the file.

go run srunner.go

The srunner and crunner programs may be customized using command line flags. For more information, specify the -h flag at the command line. For example,

$ go run srunner.go -h
Usage of bin/srunner:
  -elim=5: epoch limit
  -ems=2000: epoch duration (ms)
  -port=9999: port number
  -rdrop=0: network read drop percent
  -v=false: show srunner logs
  -wdrop=0: network write drop percent
  -wsize=1: window
  -maxUnackMessages=1: maximum unacknowledged messages allowed
  -maxBackoff: maximum interval epoch

We have also provided pre-compiled executables for you to use called srunner_sols and crunner_sols. These binaries were compiled against our reference LSP implementation, so you might find them useful in the early stages of the development process (for example, if you wanted to test your client implementation but haven’t finished implementing the server yet, etc.). Separate binaries are provided for each OS in the bin/ folder.

As an example, to start an echo server on port 6060 on an AFS cluster machine, execute the following command:

<path_to_p1>/bin/linux/srunner_sols -port=6060

Running the tests

To test your submission, we will execute the following command from inside the p1/src/github.com/cmu440/lsp directory for each of the tests (where TestName is the name of one of the 61 test cases, such as TestBasic6 or TestWindow1):

go test -run=TestName

Note that we will execute each test individually using the -run flag and by specifying a regular expression identifying the name of the test to run. To ensure that previous tests don’t affect the outcome of later tests, we recommend executing the tests individually (or in small batches, such as go test -run=TestBasic which will execute all tests beginning with TestBasic) as opposed to all together using go test.

On some tests, we will also check your code for race conditions using Go’s race detector:

go test -race -run=TestName

We have also provided Gradescope test scripts mocks in sh/. When you are inside the p1/src/github.com/cmu440/lsp directory and execute corresponding script, you can have a rough sense of what your score should be like on Gradescope.

Submitting to Gradescope

As with project 0, we will be using Gradescope to grade your submissions for this project. We will run some—but not all—of the tests with the race detector enabled.

Please remove all your print statements before making the submission. The autograder may not work properly with print statements.

To submit your code to Gradescope, create a lsp.zip file containing your LSP implementation as follows:

cd p1/src/github.com/cmu440/
zip -r lsp.zip lsp/

Keep in mind the submission limits and partner guidelines described in the handout.

Part B

Importing the bitcoin package

In order to use the starter code we provide in the hash.go and message.go files, use the following import statement:

import "github.com/cmu440/bitcoin"

Once you do this, you should be able to make use of the bitcoin package as follows:

hash := bitcoin.Hash("thom yorke", 19970521)

msg := bitcoin.NewRequest("jonny greenwood", 200, 71010)

Compiling the client, miner & server programs

To compile the client, miner, and server programs, use the go install command as follows:

# Compile the client, miner, and server programs. The resulting binaries
# will be located in the $GOPATH/bin directory.
go install github.com/cmu440/bitcoin/client
go install github.com/cmu440/bitcoin/miner
go install github.com/cmu440/bitcoin/server

# Start the server, specifying the port to listen on.
$HOME/go/bin/server 6060

# Start a miner, specifying the server's host:port.
$HOME/go/bin/miner localhost:6060

# Start the client, specifying the server's host:port, the message
# "bradfitz", and max nonce 9999.
$HOME/go/bin/client localhost:6060 bradfitz 9999

Note that you will need to use the os.Args variable in your code to access the user-specified command line arguments.

Run Sanity Tests

We have provided basic tests for your miner and client implementations. Note that passing them does not indicate that your implementation is correct, nor does it mean your code will earn full scores on Gradescope. Extra tests are encouraged before you submit your code.

To sanity tests, you need to ensure you have compiled version of client, miner and server in $HOME/go/bin. Then you need to move ctest and mtest into $HOME/go/bin as follows:

cp <path_to_p1>/bin/{YOUR-OS}/ctest $HOME/go/bin/
cp <path_to_p1>/bin/{YOUR-OS}/mtest $HOME/go/bin/

You can then run ctest and mtest (without any parameters) in $HOME/go/bin/ as follows:


Submitting to Gradescope

Please remove all your print statements before making the submission. The autograder may not work properly with print statements.

On gradescope, all three programs (client, miner, and server) use YOUR lsp implementation, provided in the lsp/ folder of your submitted zip file.

To submit your code to Gradescope, create a cmu440.zip file containing your part A and part B implementation as follows:

cd p1/src/github.com/
zip -r cmu440.zip cmu440/


Reading the API Documentation

Before you begin the project, you should read and understand all of the starter code we provide. To make this experience a little less traumatic (we know, it's a lot :P), you can read the documentation in a browser:

  1. Install godoc globally, by running the following command outside the src/github.com/cmu440 directory:
go install golang.org/x/tools/cmd/godoc@latest
  1. Start a godoc server by running the following command inside the src/github.com/cmu440 directory:
godoc -http=:6060
  1. While the server is running, navigate to localhost:6060/pkg/github.com/cmu440 in a browser.

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