refactored server to break out into node modules

2025-12-13 14:55:34 +00:00 · 2021-01-29 14:23:37 -06:00
parent 02019ff941
commit 49ebef0202
47 changed files with 1055 additions and 945 deletions
--- a/server/image-utils.js
+++ b/server/image-utils.js
@@ -0,0 +1,113 @@
+const sharp = require('sharp');
+const fetch = require('node-fetch');
+const fs = require('fs').promises;
+const conf = require("./conf.js");
+
+const THUMBNAIL_IMAGE_SIZE = 400;
+const ADDITIONAL_IMAGE_SIZES = [800,1280,1920,2560];
+
+/**
+ * Downloads the image, converts it to JPG, and creates the thumbnail size so that standard dimensions can be taken
+ * @param {string} imageUrl 
+ */
+async function downloadImage(imageUrl){
+
+    let res = await fetch(imageUrl);
+
+    if ( res.status != 200 ){
+        throw(new Error(`download error status=${res.status}`));
+    }
+
+    let buffer = await res.buffer();
+
+    return await processImage(buffer);
+}
+
+async function processImage(buffer){
+    let original = sharp(buffer);
+    let originalBuffer = await original.toFormat("jpg").toBuffer();  
+    let originalMetadata = await original.metadata();
+
+    let thumbnail = await original.resize({ width: THUMBNAIL_IMAGE_SIZE, height: THUMBNAIL_IMAGE_SIZE, fit: 'inside' });
+    let thumbnailBuffer = await thumbnail.toBuffer();
+    let thumbnailMetadata = await sharp(thumbnailBuffer).metadata();
+
+    return {
+        original: {
+            buffer: originalBuffer,
+            width: originalMetadata.width,
+            height: originalMetadata.height
+        },
+        thumbnail: {
+            buffer: thumbnailBuffer,
+            width: thumbnailMetadata.width,
+            height: thumbnailMetadata.height
+        }
+    }
+}
+
+// takes the response from downloadImage, creates ADDITIONAL_IMAGE_SIZE and writes all files to disk
+async function saveImage(userId, pinId, image){
+    let originalImagePath = getImagePath(userId, pinId, 'o');
+    await fs.mkdir(originalImagePath.dir, {recursive: true});
+    await fs.writeFile(originalImagePath.file, image.original.buffer);
+    console.log(`saved original to: ${originalImagePath.file}`);
+
+    let thumbnailImagePath = getImagePath(userId, pinId, '400');
+    await fs.mkdir(thumbnailImagePath.dir, {recursive: true});
+    await fs.writeFile(thumbnailImagePath.file, image.thumbnail.buffer);
+    console.log(`saved thumbnail to: ${thumbnailImagePath.file}`);
+
+    // this will enlarge images if necessary, as the lanczos3 resize algorithm will create better looking enlargements than the browser will
+    for ( let i = 0; i < ADDITIONAL_IMAGE_SIZES.length; ++i ){
+        let size = ADDITIONAL_IMAGE_SIZES[i];
+        
+        let img = await sharp(image.original.buffer);
+        let resizedImg = await img.resize({width: size, height: size, fit: 'inside'})
+        let buf = await resizedImg.toBuffer();
+
+        let imgPath = getImagePath(userId, pinId, size);
+        await fs.mkdir(imgPath.dir, {recursive:true});
+        await fs.writeFile(imgPath.file, buf);
+        console.log(`saved additional size ${size} to: ${imgPath.file}`);
+    }
+}
+
+async function deleteImagesForPin(userId, pinId){
+    console.log("deleting images for userId=" + userId + " pinId=" + pinId);
+    
+    try {
+        await fs.unlink(getImagePath(userId, pinId, 'o').file);
+    } catch (err){
+        console.log("error deleting original: ", err);
+    }
+
+    try {
+    await fs.unlink(getImagePath(userId, pinId, THUMBNAIL_IMAGE_SIZE).file);
+    } catch (err){
+        console.log("error deleting thumbnail: " + err);
+    }
+
+    for ( let s = 0; s < ADDITIONAL_IMAGE_SIZES.length; ++s ){
+        try{
+        await fs.unlink(getImagePath(userId, pinId, ADDITIONAL_IMAGE_SIZES[s]).file);
+        } catch (err){
+            console.log("error deleting additional size " + ADDITIONAL_IMAGE_SIZES[s] + ": ", err);
+        }
+    }
+}
+
+function getImagePath(userId, pinId, size){
+    let paddedId = pinId.toString().padStart(12, '0');
+    let dir =  `${conf.getImagePath()}/${userId}/images/${size}/${paddedId[11]}/${paddedId[10]}/${paddedId[9]}/${paddedId[8]}`;
+    let file = `${dir}/${paddedId}.jpg`;
+    return { dir: dir, file: file};
+}
+
+module.exports = {
+    processImage: processImage,
+    saveImage: saveImage,
+    getImagePath: getImagePath,
+    downloadImage: downloadImage,
+    deleteImagesForPin: deleteImagesForPin
+}