A blockchain simulator for SE 575
Open two terminal windows. In one, run the Simulator build, and in the other run the Frontend installation process, both of which are explained below. Once both are operational, navigate in a web browser to http://localhost:8100.
cd Simulator
./gradlew run
(If both JRE and JDK are installed, gradle may use java from the JRE. Ensure JAVA_HOME is set to path of JDK.)
- Install node.js if it is not already installed. https://nodejs.org/en/download/
npm install -g ioniccd Frontend/ionic-appnpm installionic serve- Website will be hosted on
localhost:8100
In order to carry out general computing and value-moving requirements, including the proof-of-stake algorithm, the blockchain simulator will include a simple smart contract system. The smart contracts will provide functions for simple, proof-of-concept programming structures, and will allow for transferring tokens between accounts.
The smart contract language for this blockchain will be a fairly easily-assembled low-level language that will carry instructions for calculations in the following grammar:
.<label>
<instr>
<instr> <arg>
<instr> <arg> <arg>
<instr> <arg> <arg> <arg>
| Code | Instruction | Argument | Description |
|---|---|---|---|
| 0 | nop | None | No operation. |
| 1 | mov | 'to' memory address, 'from' memory address | Move memory values. |
| 2 | trn | token volume, 'to' account, 'from' account | Transfer tokens from one account to another. |
| 3 | sav | memory address, storage address | Save a value to permanent storage. |
| 4 | lod | memory address, storage address | Load a value from permanent storage. |
| 5 | add | address, value | Add a value to a given memory location. |
| 6 | sub | address, value | Subtract from a given memory location. |
| 7 | mul | address, value | Multiply a given memory location by a value. |
| 8 | jlt | x, y, label | Jump to label if x is less than y. |
| 9 | jgt | x, y, label | Jump to a label if x is greater than y. |
| 10 | jeq | x, y, label | Jump to a label if x is equal to y. |
| 11 | jmp | label | Jump unconditionally to a label. |
| 12 | ret | x | Returns the value in memory address x. |
| 13 | act | None | Creates a new account on the chain. |
| 14 | bal | acct | Retrieve a balance given an account name. |
add 0 1
add 0 1
ret 0
Returns 2.
add 0 10
loop:
add 1 1
jlt 1 0 loop
ret 1
Sets memory index 0 to 10, then adds 1 to memory index 1 repeatedly until it contains 10. Returns the value of memory index 1.