source: Evans, Julia. “New Talk: Making Hard Things Easy.” Julia Evans, October 6, 2023. https://jvns.ca/blog/2023/10/06/new-talk--making-hard-things-easy/. How to: Reusable tools: shellcheck Find Good Documentation in that field, for example, HTTP: MDN RFC(rfc9110) Big list to small list, focus on the core: Only learn a few arguments about grep Only know a few fields about the output of dig Understand how computer executed chronologically: SQL Understand the hidden parts: DNS (resolve, library, servers) Communication with each other

tags: Sign Message The starmask has implemented about signing message of APTOS.

tags: Python, High Performance source: Textual Documentation. “Textual - Overhead of Python Asyncio Tasks,” March 8, 2023. https://textual.textualize.io/blog/2023/03/08/overhead-of-python-asyncio-tasks/. Tasks of asyncio from create to run, then shutdown is about: 260K tasks per second.

tags: Nginx One Endpoint for Both WebSocket and Normal Requests,Solana,Solana 101: Create an Escrow dApp I met a lot network issues about connecting to RPC node of Solana, so I’m using a nginx server as a reverse proxy to bypass this problem: location / { # https://serverfault.com/a/923254 try_files /nonexistent @$http_upgrade; } location @ { proxy_pass https://api.testnet.solana.com; proxy_read_timeout 300s; proxy_send_timeout 300s; proxy_set_header Host "api.testnet.solana.com"; } location @websocket { proxy_redirect off; proxy_pass https://api....

tags: Go source: “Wrap and Unwrap Errors in Go (Golang) | Gosamples.Dev.” Accessed October 12, 2022. https://gosamples.dev/wrap-unwrap-errors/. Overview Since Go1.13, there is a new feature about error add to go: Wrap & Unwrap errors. Let’s start from a simple example: package main import ( "errors" "fmt" ) var errRollingInTheDeep = errors.New("rolling in the deep") func doSomeActualJob() error { return errRollingInTheDeep } func someFrameworkCaller() error { // We use fmt.Errorf to wrap error....

tags: DeFi, Blockchain, Uniswap, Uniswap V3 I need derive price from decentralized exchanges, and I have finished some research about Uniswap v3. It’s brand new for me, and after that I want to share some ideas about DeFi, and I think it would be helpful for you to understand Uniswap and some other decentralized exchanges. DeFi from Scratch We exchange stuffs very often, and we can exchange tokens in a centralized exchange....

tags: openssl This problem is caused about the ca certs are different between client and server.

tags: Starcoin Web3 StarTrek,Move When I start learning Move and looking at the stdlib starcoin-framework and starcoin-framework-commons. Then I realized there are must some magic during the block execution in runtime. To roll the world, the runtime should provide some built in types and call some function in the stdlib. How does StarcoinVM Validate Transactions? As a miner, it’s responsible for executing block, it follows: Received some transactions from P2P network: EventHandler of PeerTransactionsMessage....

tags: Starcoin Web3 StarTrek,Account-Model Blockchain Systems We can create an account by wallet like MetaMask or StarMask, but I’m curious about how an account is created on the blockchain system. As a wallet has been embedded in the starcoin node, we can use it to create an account as follow: $ ./target/debug/starcoin -d ~/.starcoin -n dev account create -p my-pass { "ok": { "address": "0x2f1aeb63bd30d8eb841d6a941c5d6df3", "is_default": false, "is_readonly": false, "public_key": "0x91f79bdd9ced49332bf85b751d02339e05aff047c386d0c14b380d8519d2fb4b", "receipt_identifier": "stc1p9udwkcaaxrvwhpqad22pchtd7vy2276p" } } As above we can see our account has been created, and the address is: 0x2f1aeb63bd30d8eb841d6a941c5d6df3....

tags: Merkle tree,Blockchain,Starcoin Web3 StarTrek source: Gao, Zhenhuan, Yuxuan Hu, and Qinfan Wu. “Jellyfish Merkle Tree,” n.d., 12. What is Addressable mean? It means the leaf node in the tree can be found by an address. The address encoded the path to the leaf node, for example, a leaf node in a binary tree, which has 3 level. Its address may be encoded to 010, the corresponding path is: left->right->left:...

tags: Degree, Career I haven’t got a CS degree, it wasn’t a big deal when I was yonger, as I was cheap and many employers could affort, and didn’t care too much about it. But now days, when I’m 30+ years old, and not cheap anymore. The employers who can affort me are much less. And most of them are required a CS degree, so the degree is important to me now....

tags: Learning English,读书笔记 source: Joseph Devlin. How to Speak and Write Correctly, 2007. http://archive.org/details/how_to_speak_and_write_correctly_librivox. I found this book in my Kindle on the subway to work this morning. And remembered that I downloaded it free from the Kindle store years ago. For some reasons, maybe my English was not good enough to read it, I haven’t read it yet. After read a little, I think it’s prefect for me for now....

tags: String,LeetCode101,Stack,Hash Table,Hash Set I have solved this problem years before, LeetCode: 316.Remove Duplicate Letters, but still stuck on it. The key idea is not only about stack, but also required a map to record how many same letters behind current one. Which helps us to decide if drop current letter or not, when the new letter is less than the top of stack, which means smaller in lexicographical order....

tags: Data Structures,Stack source: “Monotonic Stack.” Accessed March 13, 2022. https://liuzhenglaichn.gitbook.io/algorithm/monotonic-stack. A monotonic stack is a stack whose elements are monotonically increasing or descreasing. It’s not only about the order in the stack, it’s also about remove larger/smaller elements before pushing. Monotonically descreasing we need to pop smaller elements from the stack before pushing a new element: vector<int> nums; // fill nums stack<int> st; for (auto i = nums.size() - 1; i >= 0; i--) { while (!...

tags: How to Take Smart Notes,slip-box,PKM source: Part 2: “THE FOUR UNDERLYING PRINCIPLES” from Ahrens, Sönke. How to Take Smart Notes: One Simple Technique to Boost Writing, Learning and Thinking: For Students, Academics and Nonfiction Book Writers. North Charleston, SC: CreateSpace, 2017. Writing Is the Only Thing That Matters Don’t be afraid to writing ideas down and push them public, as there is no private knowledge in the academia area, and there is no such thing as a history of unwritten ideas....

tags: How to Take Smart Notes,slip-box,GTD source: Part 1: “INTRODUCTION” from Ahrens, Sönke. How to Take Smart Notes: One Simple Technique to Boost Writing, Learning and Thinking: For Students, Academics and Nonfiction Book Writers. North Charleston, SC: CreateSpace, 2017. To Keep a Good Structure First, it’s about the flow, and a good structure enables the flow. The flow is: It is the state in which you get so completely immersed in you work that you lose track of time and can just on going as the work becomes effortless....

tags: Career source: “How to Quit like a Boss.” Accessed January 7, 2022. https://jmsbrdy.com/blog/leaving-spring/. HN: https://news.ycombinator.com/item?id=29830296 From the article: Avoid communication failures: your manager should not be surprised by your leaving. Do have regular, clear, frank conversations about your career with your direct manager. Do tell your manager clearly if there’s something you’re looking for in your career which your current role isn’t providing. Don’t withhold concerns or aspirations from your manager....

tags: IRT,读书笔记 source: Yu, Chong Ho. “A Simple Guide to the Item Response Theory ( IRT ) and Rasch Modeling.” Accessed January 6, 2022. https://www.semanticscholar.org/paper/A-Simple-Guide-to-the-Item-Response-Theory-(-IRT-)-Yu/f42efb1bcf38f6650a8b16650e2811e8803cd4ec. IRT is about fitness or simplicity for test. There are two versions of IRT: IRT - three parameters. Rasch modeling - one parameter only. Three parameters: A - discrimination, how effectively this item can discriminate students’s proficient between highly and less. B - difficulty, or the threshold, tells us how easy or how difficult an item is....

tags: Bigdata,Flink,Streaming source: Akidau, Tyler. “Streaming 101: The World beyond Batch.” O’Reilly Media, August 5, 2015. https://www.oreilly.com/radar/the-world-beyond-batch-streaming-101/. Streaming: a type of data processing engine that is designed with infinite data sets in mind. Other common uses of “streaming” that will be avoid in the rest of the post: Unbounded data: A type of ever-growing, essentially infinite data set. Unbounded data processing: An ongoing mode of data processing, applied to the aforementioned type of unbounded data....

tags: Freelance,Microstartup source: https://news.ycombinator.com/item?id=29790964 Comments: Related: “Tell HN: My Microstartups make $500/day while I’m sleeping” (this): https://news.ycombinator.com/item?id=29790964 “AMA: I make $100K+ ARR from my microstartups” (3 months ago): https://news.ycombinator.com/item?id=28561132 “Show HN: I passed up an opportunity to make $200K from my microstartup” (2020): https://twitter.com/1HaKr/status/1301142901510995969 “Show HN: My Indie Hacker goal - Earn $100 a day to keep your desk job away” (2020): https://news.ycombinator.com/item?id=24304674 “Show HN: I made $9000 posting on Hacker News about my microstartup” (2020): https://news....

tags: Learning,Taking Notes,RoamResearch source: https://fortelabs.co/blog/how-to-take-smart-notes/ Luhmann’s slip-box: build second brain context – its network of associations, relationships, and connections to other information. But Luhmann often remarked that he never forced himself to do anything he didn’t feel like doing: “I only do what is easy. I only write when I immediately know how to do it. If I falter for a moment, I put the matter aside and do something else” (Luhmann et al....

Words of To Kill A Mockingbird hostess position ease box interval due front 2.5 0 0 2021-12-24T14:03:09Z Back Noun ˈhəʊstəs həʊˈstɛs a woman who receives or entertains guests Synonyms: party-giver/entertainer/hostess Examples: the perfect dinner-party hostess incurable position ease box interval due front 2.5 0 0 2021-12-24T14:02:18Z Back Adjective ɪnˈkjʊərəb(ə)l (of a sick person or a disease) not able to be cured Synonyms: untreatable/inoperable/irremediable/beyond cure Examples: even when the sick are incurable they are never untreatable incurable diseases Noun ɪnˈkjʊərəb(ə)l...

证书 [译] 写给工程师：关于证书（certificate）和公钥基础设施（PKI）的一切（SmallStep, 2018）

tags: Learning English shape ʃeip be in great/good shape stay/keep in (good) shape 英语表示次数范围 five times a month once two weeks 英语表示尺码 loose /luːs/ 松的 tight /tait/ 紧的 what/how about 提议 What/How about some coffee? What/How about you? 穿衣：try on/take off/put on n.: try on sth I’d like to try on the shoes. pron.: try sth. on I’d like to try them on. think of 认为 sth. 怎么样 What do you think of my new shirt?...

tags: Learning English 副词 adv/adverb 是指在句子中表示行为或状态特征的词，用以修饰动词、形容词、其他副词或全句，表示时间、地点、程度、方式等概念。 副词可分为：时间副词、频率副词、地点副词、方式副词、程度副词、疑问副词、连接副词、关系副词、表顺序的副词以及表完成的副词。 频率副词 always usually often sometimes about 表示大约大约修饰数量。 形容词 adj 形容词后缀 -ful helpful useful thankful 形容词后缀 -ed interested excited 形容词后缀 -ing interesting exciting 动词 verb 情态动词 modal verb. can(could)/may(might)/must/need/to/shall(should)/will(would). 动名词 形式 v.-ing 动词的名词化。 语法：名词 语意：动词 形变规则 特殊 1 -e：去 e 加 ing live -> living give -> giving 特殊 2 短元音 + 一辅音：重复最后一个字母加 ing jog -> jogging swim -> swimming 常规：直接加 ing do -> doing study -> studying 词性 I usually go swimming....

tags: Programming Language Scala 学习资源 Scala Book Scala 这么好的语言为什么不流行 HN：Scala 为什么不流行 Reddit：Scala 为什么不流行 结论：Java 人才更多且成本更低。 Scala 工具 sbt sbt new 无法处理替换过的 SSH 会导致 Auth fail，一个 workaround 就是手动 clone 项目然后： sbt new file:///path/to/template.g8 sbt 国内加速 ~/.sbt/repositories: [repositories] local nexus-aliyun:https://maven.aliyun.com/nexus/content/groups/public nexus-aliyun-ivy:https://maven.aliyun.com/nexus/content/groups/public/, [organization]/[module]/(scala_[scalaVersion]/)(sbt_[sbtVersion]/)[revision]/[type]s/[artifact](-[classifier]).[ext] typesafe: https://repo.typesafe.com/typesafe/ivy-releases/, [organization]/[module]/(scala_[scalaVersion]/)(sbt_[sbtVersion]/)[revision]/[type]s/[artifact](-[classifier]).[ext], bootOnly Unique Scala Rust from Scala Rust 和 Scala 有很多想通的地方，Rust 应该从 Scala 借鉴了很多： 可变量和不可变量 模式匹配 Trait 内置类型 val b: Byte = 1 val x: Int = 1 val l: Long = 1 val s: Short = 1 val d: Double = 2....

tags: 分布式,一致性,Clock Synchronization,Multicast source: https://signalsandthreads.com/clock-synchronization/ Electronic Oscillator: Computer itself to Dervie its Notion of Time Computer’s clock are based on a 1 MHz electronic oscillator circuit, that is oscillating at some frequency, and driving an interrupt. So the operating system can use it to derive its notion of time. It helps computer to keep the time correct. But a bad oscillator could be influenced by the heat of CPU, like compiling Linux kernel, etc....

tags: Translate,Rust,Tokio 原文链接：Understanding Rust futures by going way too deep。 译者注：原文大量的引入了有趣的对话，迫于排版问题这里不进行翻译，必要的对话通过引用块来解释。 深入理解 Rust future 用 Rust future！就是这么简单！直到我们发现并非如此。所以我们先探索简单的部分，然后继续探索困难部分而不是等它慢慢靠近我们。 起步 Choo choo here comes the easy part 🚂💨 我们创建一个新的项目： $ cargo new waytoodeep Created binary (application) `waytoodeep` package 我们需要安装 cargo-edit 如果之前没有安装过的话，接下来就可以直接 cargo add ： $ cargo install cargo-edit Updating crates.io index Downloaded cargo-edit v0.7.0 Downloaded 1 crate (57.6 KB) in 0.47s Ignored package `cargo-edit v0.7.0` is already installed, use --force to override 因为 cargo-edit 很方便，所以你可能已经安装过它。部分读者会感到困惑是因为像 cargo new, cargo build, cargo test, cargo run 等子命令都内置在 cargo 中， 但是 cargo add 没有。...

tags: Memory Model，一致性 FROM 硬件内存模型： threads in the system must agree about a total order for the writes to a single memory location. That is, threads must agree which writes overwrite other writes. This property is called called coherence. 内存一致性的系统都所有线程都必须接受对一个内存地址所有写入的总顺序。换句话说，所有线程必须同意哪些写入可以覆盖另外的一些写入。

tags: Learning English 一些通用的规则： 音标后面的 ː 提示拖长音。 元音 大而圆 音标 中文 发音技巧 常见单词 拼读规则 /​æ​/ 爱 张大嘴发中文的「爱」,发音短促有力。 bag map dad sad a /​e​/ 爱 音同 /​æ​/ 但是嘴形要小一些。 get let pen yes e /​ɔː​/ 哦 嘴巴轮圆了发音，并拖长音 floor door store sport oor,ore,or /​ɔ​/ 哦 /​ɔː​/ 的短音 lot dog hot shop o 扁扁扁 音标 中文 发音技巧 常见单词 拼读规则 /iː​/ 一 相比一嘴要扁一些，稍稍更用力一些 see meet he she ee, e /​i​/ 一 /iː​/ 短音 happy daddy honey 词尾的 y 或 ey /​I​/ 一 用 /​e​/ 的嘴形发 /​i​/ this give it city i /əː​/ 呃 相比中文嘴要扁一些，稍稍更用力一些 work girl dirt sir or, ir /​ə​/ 呃 /əː​/ 的短音 again a father weather 单独的 a 及词尾的 er 需要额外注意的：...

tags: C/C++ source: All about thread-local storage

tags: Translate,Python 原文链接：Python behind the scenes #1: how the CPython VM works。 Python 幕后 #1: CPython 虚拟机如何工作 介绍（Introduction） 你是否曾经好奇过当你运行 Python 代码时 python 做了些什么？ $ python script.py 这篇文章将开启一个系列来尝试解答这个问题。我们将深入 Python 最流行的实现 CPython 的内部。 通过深入 CPython 的内部我们将更深一层的去理解这门编程语言本身。这也是我们这个系列的最主要的目标。 如果你熟悉 Python 并且可以阅读 C 代码，但是对 CPython 源码本身没有太多的经验， 那么你可能非常适合本系列，并且对本系列感兴趣。 什么是 CPython 并且为什么有人想学习它（What CPython is and why anyone would want to study it） 我们首先来说明一些众所周知的事情。CPython 是用 C 编写的 Python 解析器。他是 Python 语言的众多实现 的一种，其他还有诸如 PyPy、Jython、IronPython 等。CPython 的独特之处在于它是 Python 的起源、维护时间最长也是最受欢迎的。...