67 lines
1.6 KiB
JavaScript
67 lines
1.6 KiB
JavaScript
function createCSVScanner(onRow, cols) {
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let buffer = '';
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return function scanChunk(chunk) {
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buffer += chunk;
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const lines = buffer.split('\n');
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buffer = lines.pop(); // Save incomplete line
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for (const line of lines)
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{
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const fields = [];
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let start = 0;
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let col = 0;
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for (let i = 0; i < line.length; i++) {
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if (line[i] === ',' && col < cols-1) {
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fields.push(line.slice(start, i));
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start = i + 1;
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col++;
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}
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}
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fields.push(line.slice(start, line.length-1));
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onRow(...fields);
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}
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};
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}
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async function DB(url, cols, onRow) {
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const response = await fetch(url);
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if (!response.ok) {
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throw new Error(`HTTP error! status: ${response.status}`);
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}
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const reader = response.body.getReader();
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const decoder = new TextDecoder("utf-8");
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const scanner = createCSVScanner(onRow, cols);
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while (true)
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{
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const { done, value } = await reader.read();
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if (done) break;
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const chunk = decoder.decode(value, { stream: true });
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scanner(chunk);
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}
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}
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/** @import DBTypes from "./types.d.ts" */
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/** @type {DBTypes.Builder} */
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export default function(params)
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{
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return {
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list:{},
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load(){
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let index = 0;
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this.list = {};
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return DB(import.meta.resolve(params.path), params.cols, (...args)=>{
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const [id, data] = params.load(index, ...args);
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id && (this.list[id] = data);
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index++;
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});
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},
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find(id){return this.list[id];},
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save(){},
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};
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} |