# 2022/09/21 -- 2022/09/28 NOTE
## 盧柏璋 Working NOTE
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Original Ourchain Installation NOTE:
https://hackmd.io/Bo8C0LogQfmq_eSuOExr0w?view
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Useful shell command learnt:
1. **top**: call out monitor for checking tasks working on the computer, press "q" to leave the monitor mode on terminal
2. **pgrep bitcoin**: check the label(5 or 4 digit integer Eg:29379) of the task bitcoin that you are running
3. **kill #task label integer#**: shut down the task you are running
4. **make -j 8**: means use multi-thread to work the make command, it would be 8 times faster than the normal make command
5. **gnome-screeshot**: take a screen-shot of the screen
6. **pkill -9 bitcoind**: forcely kill all working bitcoind tasks
7. **bitcoin-cli stop**: stop the bitcoin app

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NOTE: when the following error code occur on the terminal, the possible reason and method to tackel it:
1. Error: Cannot obtain a lock on data directory /home/lab408/.bitcoin/regtest. Bitcoin Core is probably already running.
1.1 ANS: "pkill" all running tasks or kill the bitcoin that is running on the computer and rerun the command :
bitcoind --regtest --daemon
To initiate the new node
2.
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## 0.測試實驗
Purpose of Experiment:
Understand the changes on ourchain when rpc commands input to the terminal, the EXP only focus on the changes to the folder:
**"/home/lab408/Desktop/po-bitcoin-testnode1/ourchain-release/src/relay/regtest"**
Notation: use **data_folder** for abbreviation of the above folder

**Experiment 1:**
Purpose: Understand where do the blockchain data stored

./bitcoind --regtest --datadir=relay --daemon
./bitcoind --regtest --daemon

See the Difference in **data_folder**

**Experiment 2:**
Purpose: when pkill command is used, will the blockchain data still remian?

See the Difference in data_folder
**Experiment 3:**
Purpose: after mining 101 blocks, what would be changed in **data_folder**

See the Difference in data_folder
**Experiment 4:**
Purpose: when the contract is deployed, will elimination of the original contract#my-contract.c# affect the data in **data_folder**

See the Difference in data_folder
## 1.安裝 Install
備註 PS：
1.The Lab 408 Computer use Ubuntu OS so use "sudo" in front of commands
2.沒有Linux環境請使用docker實驗 [參考這裡 here](https://hackmd.io/Bo8C0LogQfmq_eSuOExr0w?both#4%E7%94%A8Use-Docker%E5%BB%BA%E7%BD%AE-Build-OurChain)

**安裝相關依賴套件, Installation of Dependent Packages **

sudo apt-get update
sudo apt-get install build-essential libtool autotools-dev automake pkg-config libssl-dev libevent-dev bsdmainutils    
sudo apt-get install software-properties-common

**若為 Ubuntu Ubuntu 18.04 或更新版本，請執行**

sudo add-apt-repository -y ppa:luke-jr/bitcoincore # for Ubuntu 18.04, 20.04

**接著繼續安裝必要套件**

    sudo apt-get update
    sudo apt-get install libdb4.8-dev libdb4.8++-dev
    sudo apt-get install libboost-system-dev libboost-filesystem-dev libboost-chrono-dev libboost-program-options-dev libboost-test-dev libboost-thread-dev
    sudo apt-get install git vim

##### note: 亦可參考 https://github.com/bitcoin/bitcoin/blob/master/doc/build-unix.md

**下載 Download OurChain code**

git clone -b test_version https://bitbucket.org/lab408/ourchain-release.git

**編譯 Compile OurChain**

    cd ourchain-release/
    ./autogen.sh
    ./configure
    make -j 8 # Or just use make but slower
    sudo make install # 這行是 optional 取決於你是否要把程式加到path 一般來說make完後檔案會在src內
    ldconfig # sudo if needed

**新增 /home/lab408/Desktop/po-bitcoin-testnode1/ourchain-release/src/.bitcoin**

vim /home/lab408/Desktop/po-bitcoin-testnode1/ourchain-release/src/.bitcoin

server=1
rpcuser=test
rpcpassword=test
rpcport=8332
rpcallowip=0.0.0.0/0
datadir=relay # means save block data to the relay folder under src

恭喜你裝完了

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## 2.實驗 Experience

**啟動比特幣回歸測試節點**
--regtest代表回歸測試 在你的電腦上創建一個測試鏈 而非連到當前的主要OurChain(or bitcoin)網路
--因為我把project建立在桌面上而非根目錄下，所以有些指令可能不同

Original version:    bitcoind --regtest --daemon
My project version:  ./bitcoind --regtest --datadir=relay --daemon

**使用bitcoin-cli與你剛剛架設起來的測試OurChain溝通實驗**
在實驗的時候記得加上--regtest
代表你用bitcoin-cli要互動的對象是你創的回歸測試鏈

bitcoin-cli --regtest getblockchaininfo  //取得你剛剛架的回歸測試ourchain的整個區塊鏈資訊

**OurChain挖礦實驗**
在實驗的時候記得加上--regtest
代表你用bitcoin-cli要互動的對象是你創的回歸測試鏈

bitcoin-cli --regtest generate 101  //不同於bitcoin, ourcoin 挖礦使用的不是 generateblock, 而是 generate #number_of_blocks in integer 

bitcoin-cli是bitcoin提供的一個 RPC interface
可以把他想成一個與bitcoin整個鏈互動的街口
透過bitcoin-cli提供的function來與整個bitcoin互動
有了bitcoin-cli你就可以開始你想要的實驗了

bitcoin-cli提供了很多跟ourchain互動的方法
像是剛剛的getblockchaininfo
包含其他像是創建地址、轉錢、挖礦等, 所有比特幣功能

備註：OurChain是基於bitcoin修改來的 所以適用以上功能

[請參考這裡了解所有bitcoin-cli提供的方法, all these supports](https://bitcoin.org/en/developer-reference#bitcoin-core-apis)

恭喜你 到這裡 你應該就有能力寫一個blockchain exploere 或是寫個簡單版本的wallet了
主要就是透過python(或你偏好的語言)找他的rpc-call套件
去訪問bitcoin網路取得你所需要的資料 並顯示在你的網頁上 或 APP上

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## 3.怎麼寫 OurContract
大致上與C一樣，不過有幾個重點需要注意
標頭檔必須加入 Need to include the following header file

#include<ourcontract.h>
必須使用 need to use

int contract_main(int argc,char** argv)
取代原本的to replace int main(int argc,char** argv)，而且不可以使用do not use main()

因為沒有no stdout，所以請勿使用please do not use printf()等等功能，請使用

err_printf
他會輸出在bitcoin執行的資料夾下的it will output to contracts/err

範例：Hello World

#include<ourcontract.h>
#include<stdio.h>
int contract_main(int argc,char** argv)
{
err_printf("Hello World %s\n",argv[0]);
return 0;
}
其餘功能[請參考 Refer to other functions](https://bitbucket.org/lab408/ourchain-release/src/test_version/src/contract/libourcontract.c)

如何在OurChain上執行合約 How to execute：

首先開啟ourchain後，確定自己有足夠多錢支付執行合約的手續費後，使用下面指令來發布合約並執行合約一次後

bitcoin-cli --regtest deploycontract [contract_path]
會獲得合約的名稱[contract_address]

{
"txid" : "[txid]"
"contract address" : "[contract_address]"
}
未來要再次執行合約，使用

bitcoin-cli --regtest callcontract [contract_address] ...
就可以再次執行合約，之後主動或等待他人挖礦後，合約就會自動被ourchain執行
其中上方指令後面所輸入的

[contract_address] ...
將會是int contract_main(int argc,char** argv)的

argv[0] ...

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## 4.用Use Docker建置 Build OurChain
[教學 Instruction](https://hackmd.io/@jKIkT8QLQ4SzITq06RQTvQ/H1108hT9V?type=view)