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comparison markdown_converter/markdown_to_html_wasm.js @ 154:bdcc610eeed8

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[Markdown Converter][GuiZe] Added markdown coverter in C and wasm rule sets. Needs further view on this as I haven't taken a look. Written by Claude.
author June Park <parkjune1995@gmail.com>
date Mon, 12 Jan 2026 09:11:58 -0800
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153:790930d9bb90 154:bdcc610eeed8
1 /**
2 * Markdown to HTML Converter - WASM FFI Wrapper
3 * Loads the C implementation via WebAssembly and provides JavaScript API
4 *
5 * Build the WASM with: bazel build //markdown_converter:markdown_to_html_wasm
6 */
7
8 class MarkdownConverterWasm {
9 constructor() {
10 this.wasm = undefined;
11 this.ready = false;
12 }
13
14 /**
15 * Initialize the WASM module
16 * @param {string} wasmPath - Path to the .wasm file
17 * @returns {Promise<void>}
18 */
19 async init(wasmPath = '/markdown_to_html_wasm.wasm') {
20 if (this.ready) return;
21
22 try {
23 this.wasm = await WebAssembly.instantiateStreaming(fetch(wasmPath), {
24 env: {}
25 });
26 this.ready = true;
27 } catch (err) {
28 console.error('Failed to load markdown WASM module:', err);
29 throw err;
30 }
31 }
32
33 /**
34 * Write string to WASM memory
35 * @private
36 */
37 _writeString(str) {
38 const encoder = new TextEncoder();
39 const bytes = encoder.encode(str + '\0');
40 const ptr = this.wasm.instance.exports.malloc(bytes.length);
41 const memory = new Uint8Array(this.wasm.instance.exports.memory.buffer);
42 memory.set(bytes, ptr);
43 return ptr;
44 }
45
46 /**
47 * Read string from WASM memory
48 * @private
49 */
50 _readString(ptr) {
51 const memory = new Uint8Array(this.wasm.instance.exports.memory.buffer);
52 let end = ptr;
53 while (memory[end] !== 0) end++;
54 const bytes = memory.slice(ptr, end);
55 const decoder = new TextDecoder();
56 return decoder.decode(bytes);
57 }
58
59 /**
60 * Reset the WASM heap (call between conversions to reclaim memory)
61 */
62 resetHeap() {
63 if (this.ready) {
64 this.wasm.instance.exports.heap_reset();
65 }
66 }
67
68 /**
69 * Convert markdown string to HTML string using WASM
70 * @param {string} markdown - The markdown text to convert
71 * @returns {string} The converted HTML
72 */
73 convert(markdown) {
74 if (!this.ready) {
75 throw new Error('WASM module not initialized. Call init() first.');
76 }
77
78 // Reset heap before each conversion to reclaim memory
79 this.resetHeap();
80
81 // Write markdown to WASM memory
82 const inputPtr = this._writeString(markdown);
83
84 // Call the C function
85 const outputPtr = this.wasm.instance.exports.markdown_to_html(inputPtr);
86
87 // Read the result
88 const html = this._readString(outputPtr);
89
90 return html;
91 }
92
93 /**
94 * Convert markdown to DOM elements (compatible with original API)
95 * @param {string} markdown - The markdown text to convert
96 * @returns {Array<HTMLElement>} Array of DOM elements
97 */
98 convertToElements(markdown) {
99 const html = this.convert(markdown);
100 const template = document.createElement('template');
101 template.innerHTML = html;
102 return Array.from(template.content.children);
103 }
104 }
105
106 // Singleton instance
107 const markdownWasm = new MarkdownConverterWasm();
108
109 /**
110 * Convert markdown to DOM elements (WASM version)
111 * Compatible with original markdownConverter() API
112 * @param {string} value - Markdown string
113 * @returns {Promise<Array<HTMLElement>>} Array of DOM elements
114 */
115 async function markdownConverterWasm(value) {
116 if (!markdownWasm.ready) {
117 await markdownWasm.init();
118 }
119 return markdownWasm.convertToElements(value);
120 }
121
122 /**
123 * Render markdown to a container element (WASM version)
124 * Compatible with original renderMarkdown() API
125 * @param {HTMLElement} container - Container element
126 * @param {string} markdown - Markdown string
127 */
128 async function renderMarkdownWasm(container, markdown) {
129 if (!markdownWasm.ready) {
130 await markdownWasm.init();
131 }
132 container.innerHTML = markdownWasm.convert(markdown);
133 }
134
135 // Export for use in other files
136 if (typeof module !== 'undefined' && module.exports) {
137 module.exports = {
138 MarkdownConverterWasm,
139 markdownWasm,
140 markdownConverterWasm,
141 renderMarkdownWasm
142 };
143 }