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author | EuAndreh <eu@euandre.org> | 2020-02-24 02:26:34 -0300 |
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committer | EuAndreh <eu@euandre.org> | 2020-02-24 02:26:34 -0300 |
commit | a9f1ed883ead6fe3c9d52c93d9de2059e96a1524 (patch) | |
tree | 2bf666e6c72fc98ad16a5accbef346b29344c63a /_drafts | |
parent | WIP Database Internals review (diff) | |
download | euandre.org-a9f1ed883ead6fe3c9d52c93d9de2059e96a1524.tar.gz euandre.org-a9f1ed883ead6fe3c9d52c93d9de2059e96a1524.tar.xz |
Move draft posts to _drafts
Diffstat (limited to '_drafts')
-rw-r--r-- | _drafts/2020-02-11-on-webassembly-killing-javascript.md | 205 | ||||
-rw-r--r-- | _drafts/2020-02-20-book-review-database-internals.md | 24 | ||||
-rw-r--r-- | _drafts/2020-03-30-data-formats-a-comparison.md | 10 |
3 files changed, 239 insertions, 0 deletions
diff --git a/_drafts/2020-02-11-on-webassembly-killing-javascript.md b/_drafts/2020-02-11-on-webassembly-killing-javascript.md new file mode 100644 index 0000000..998c176 --- /dev/null +++ b/_drafts/2020-02-11-on-webassembly-killing-javascript.md @@ -0,0 +1,205 @@ +--- +title: On WebAssembly killing JavaScript +date: 2020-02-11 +layout: post +lang: en +ref: on-webassembly-killing-javascript +--- +When discussing WebAssembly (WASM), I often see people portraiting it too much +as a JavaScript replacement, but I think this framing misses the point of some +of the aspects on how WASM can be a great tool: being a portability oportunity, +which means increasing the reach to code. + +If you think of WASM strictly as a optimization of JavaScript, that's where +you'll end up: WASM is the same as JavaScript, but faster. + +But there's a more interesting aspect (to me) of it: portability. That means you +can now write multiplatforme code that runs everywhere. I mean, everywhere, even +in the browser. Let's imagine how you could write SQLite and mke it run on the Web. + +# SQLite + +If I were to create, say, SQLite today, I would consider adding web support for +it. SQLite already is available almost everywhere[^1]. This is due to it having +very so few dependencies, + +Imagine having writing SQLite today + +There are also other legimate uses of WASM, such as WASI and etc. + +Here's how I would start writing an application that could run on any POSIX +system and, on top of that, could run on the browser: + +``` +// api.h + +extern void platformDependentPersistInt(int); +extern int platformDependentRetrieveInt(); + + +// api-posix.c + +/* POSIX implementation of "api.h" interface to be used in non-web contexts */ + +#include <stdio.h> + +void platformDependentPersistInt(int n) { + FILE* fp = fopen("/tmp/persisted.txt", "w+"); + fprintf(fp, "%d", n); + fclose(fp); +} + +int platformDependentRetrieveInt() { + FILE* fp = fopen("/tmp/persisted.txt", "r"); + int persisted = fgetc(fp); + return persisted; +} + + +// api-wasm.js + +/* WASM implementation of "api.h" interface to be used in web contexts */ + +export const platformDependentPersistInt = (n) => + localStorage.setItem("persisted", n.toString()); + +export const platformDependentRetrieveInt = () => + parseInt(localStorage.getItem("persisted")); + + +// add.h + +int add(int a, int b); +void persistInt(int n); +int retrieveInt(); + + +// add.c + +#include "api.h" + +int add(int a, int b) { + return a * a + b; +} + +void persistInt(int n) { + platformDependentPersistInt(n); +} + +int retrieveInt() { + return platformDependentRetrieveInt(); +} +``` + +``` +// main.c + +#include <stdio.h> +#include "add.h" + +int main() { + int added = add(4, 5); + printf("Adding 4 and 5: %d\n", added); + + persistInt(6); + int persisted = retrieveInt(); + printf("Persisted number: %c\n", persisted); + return 0; +} + + +// index.html + +<script type="module"> + import * as api from "./api-wasm.js"; + + WebAssembly + .instantiateStreaming(fetch("add.wasm"), { env: api }) + .then(({instance: {exports}}) => { + const added = exports.add(4, 5); + console.log("Adding 4 and 5:", added); + + exports.persistInt(6); + const persisted = exports.retrieveInt(); + console.log("Persisted number:", persisted); + }); +</script> +``` + +In order to +``` +// server.py + +#!/usr/bin/env python +import SimpleHTTPServer +import SocketServer + +PORT = 8001 + +class Handler(SimpleHTTPServer.SimpleHTTPRequestHandler): + pass + +Handler.extensions_map['.wasm'] = 'application/wasm' + +httpd = SocketServer.TCPServer(("", PORT), Handler) + +print "serving at port", PORT +httpd.serve_forever() +``` + +Dependency graph: +api-posix.c api-wasm.js +api.h +add.h +add.c +main.c index.html + +Compiling and running the POSIX code: +```shell +$ clang -o add main.c add.c api-posix.c +$ ./add +Adding 4 and 5: 21 +Persisted number: 6 +``` + +Compiling and running the WASM +```shell +$ clang \ + --target=wasm32 \ + -nostdlib \ + -Wl,--no-entry \ + -Wl,--export-all \ + -Wl,--allow-undefined \ + -o add.wasm \ + add.c +$ ./server.py +``` + +After opening the browser, the console shows: +``` +Adding 4 and 5: 21 +Persisted number: 6 +``` + +Rust, C, Zig + +No Emscripten, no GC, no runtime + +Emscripten 11KB + +# Limitations + +"System call" cost in WebAssembly. + +WASM is very new, no flush guarantees. + +Confusing dependency tree + +AFAICT you can't package WASM with JavaScript. + + +[^1]: [Platforms supported by SQLite are](https://sqlite.org/features.html): + "Android, *BSD, iOS, Linux, Mac, Solaris, VxWorks, and Windows (Win32, + WinCE, WinRT) are supported out of the box. Easy to port to other systems". + +https://sqlite.org/selfcontained.html diff --git a/_drafts/2020-02-20-book-review-database-internals.md b/_drafts/2020-02-20-book-review-database-internals.md new file mode 100644 index 0000000..8cac601 --- /dev/null +++ b/_drafts/2020-02-20-book-review-database-internals.md @@ -0,0 +1,24 @@ +--- +title: Book review - "Database Internals" +date: 2020-02-20 +layout: post +lang: en +ref: book-review-database-internals +--- +I'm now reading the "Database Internals" book, by Alex Petrov. I'm liking it a +lot, and I have a similar feeling at the end of each chapter of when I was +reading "Designing Data-Intensive Applications": each chapter has some +references to other books, articles and resources, and I feel like I should go +and reach all of them to have a deeper understanding of the subject. + +It gives just enough historical background in the text itself to show that the +author does have knowledge in this area. + +# Chapter 1: Introduction and Overview + +The covering of basic vocabulary (column vs wide-column) is very good and +straightforward, and the fundamental trade-offs are shown very clearly, like +in-memory and disk-based storage, primary-keys and offset lookups, etc. + +Finishing this chapter I was happy with it's content and looking forward for a +more in-depth tour of many of the concepts presented here. diff --git a/_drafts/2020-03-30-data-formats-a-comparison.md b/_drafts/2020-03-30-data-formats-a-comparison.md new file mode 100644 index 0000000..9df7db5 --- /dev/null +++ b/_drafts/2020-03-30-data-formats-a-comparison.md @@ -0,0 +1,10 @@ +--- +title: Data formats - a comparison +date: 2020-03-30 +layout: post +lang: en +ref: data-formats-a-comparison +--- +Avro, EDN, etc. (The Language of the system) + +Look at column store data formats too? Parquet, ORC, etc. (Database Internals book) |