Merge pull request #928 from jessopb/xformFileOnServe

implements querystring image transformation

package.json

@@ -46,6 +46,7 @@
     "express-http-context": "^1.2.0",
     "generate-password": "^1.4.1",
     "get-video-dimensions": "^1.0.0",
+    "gm": "^1.23.1",
     "helmet": "^3.15.0",
     "image-size": "^0.6.3",
     "inquirer": "^5.2.0",

server/controllers/assets/utils/getClaimIdAndServeAsset.js

@@ -15,9 +15,20 @@ const BLOCKED_CLAIM = 'BLOCKED_CLAIM';
 const NO_FILE = 'NO_FILE';
 const CONTENT_UNAVAILABLE = 'CONTENT_UNAVAILABLE';
 
-const { publishing: { serveOnlyApproved, approvedChannels } } = require('@config/siteConfig');
+const {
+  publishing: { serveOnlyApproved, approvedChannels },
+} = require('@config/siteConfig');
 
-const getClaimIdAndServeAsset = (channelName, channelClaimId, claimName, claimId, originalUrl, ip, res, headers) => {
+const getClaimIdAndServeAsset = (
+  channelName,
+  channelClaimId,
+  claimName,
+  claimId,
+  originalUrl,
+  ip,
+  res,
+  headers
+) => {
   getClaimId(channelName, channelClaimId, claimName, claimId)
     .then(fullClaimId => {
       claimId = fullClaimId;
@@ -39,19 +50,27 @@ const getClaimIdAndServeAsset = (channelName, channelClaimId, claimName, claimId
     .then(claim => {
       let claimDataValues = claim.dataValues;
 
-      if (serveOnlyApproved && !isApprovedChannel({ longId: claimDataValues.publisher_id || claimDataValues.certificateId }, approvedChannels)) {
+      if (
+        serveOnlyApproved &&
+        !isApprovedChannel(
+          { longId: claimDataValues.publisher_id || claimDataValues.certificateId },
+          approvedChannels
+        )
+      ) {
         throw new Error(CONTENT_UNAVAILABLE);
       }
 
-      let outpoint = claimDataValues.outpoint || `${claimDataValues.transaction_hash_id}:${claimDataValues.vout}`;
+      let outpoint =
+        claimDataValues.outpoint ||
+        `${claimDataValues.transaction_hash_id}:${claimDataValues.vout}`;
       logger.debug('Outpoint:', outpoint);
       return db.Blocked.isNotBlocked(outpoint).then(() => {
         // If content was found, is approved, and not blocked - log a view.
         if (headers && headers['user-agent'] && /LBRY/.test(headers['user-agent']) === false) {
           db.Views.create({
-            time       : Date.now(),
-            isChannel  : false,
-            claimId    : claimDataValues.claim_id || claimDataValues.claimId,
+            time: Date.now(),
+            isChannel: false,
+            claimId: claimDataValues.claim_id || claimDataValues.claimId,
             publisherId: claimDataValues.publisher_id || claimDataValues.certificateId,
             ip,
           });
@@ -70,7 +89,7 @@ const getClaimIdAndServeAsset = (channelName, channelClaimId, claimName, claimId
       if (!fileRecord) {
         throw NO_FILE;
       }
-      serveFile(fileRecord.dataValues, res);
+      serveFile(fileRecord.dataValues, res, originalUrl);
     })
     .catch(error => {
       if (error === NO_CLAIM) {
@@ -98,7 +117,8 @@ const getClaimIdAndServeAsset = (channelName, channelClaimId, claimName, claimId
         logger.debug('claim was blocked');
         return res.status(451).json({
           success: false,
-          message: 'In response to a complaint we received under the US Digital Millennium Copyright Act, we have blocked access to this content from our applications. For more details, see https://lbry.io/faq/dmca',
+          message:
+            'In response to a complaint we received under the US Digital Millennium Copyright Act, we have blocked access to this content from our applications. For more details, see https://lbry.io/faq/dmca',
         });
       }
       if (error === NO_FILE) {

server/controllers/assets/utils/serveFile.js

@@ -1,19 +1,46 @@
 const logger = require('winston');
+const transformImage = require('./transformImage');
+const serveFile = async ({ filePath, fileType }, res, originalUrl) => {
+  const queryObject = {};
+  // TODO: replace quick/dirty try catch with better practice
+  try {
+    originalUrl
+      .split('?')[1]
+      .split('&')
+      .map(pair => {
+        if (pair.includes('=')) {
+          let parr = pair.split('=');
+          queryObject[parr[0]] = parr[1];
+        } else queryObject[pair] = true;
+      });
+  } catch (e) {}
 
-const serveFile = ({ filePath, fileType }, res) => {
   if (!fileType) {
     logger.error(`no fileType provided for ${filePath}`);
   }
+
+  let mediaType = fileType ? fileType.substr(0, fileType.indexOf('/')) : '';
+  const transform =
+    mediaType === 'image' && queryObject.hasOwnProperty('h') && queryObject.hasOwnProperty('w');
+
   const sendFileOptions = {
     headers: {
-      'X-Content-Type-Options'      : 'nosniff',
-      'Content-Type'                : fileType,
-      'Access-Control-Allow-Origin' : '*',
+      'X-Content-Type-Options': 'nosniff',
+      'Content-Type': fileType,
+      'Access-Control-Allow-Origin': '*',
       'Access-Control-Allow-Headers': 'Origin, X-Requested-With, Content-Type, Accept',
     },
   };
   logger.debug(`fileOptions for ${filePath}:`, sendFileOptions);
+  if (transform) {
+    logger.debug(`transforming and sending file`);
+
+    let xformed = await transformImage(filePath, queryObject);
+    res.status(200).set(sendFileOptions.headers);
+    res.end(xformed, 'binary');
+  } else {
     res.status(200).sendFile(filePath, sendFileOptions);
+  }
 };
 
 module.exports = serveFile;

server/controllers/assets/utils/transformImage.js

@@ -0,0 +1,76 @@
+const gm = require('gm');
+const logger = require('winston');
+const imageMagick = gm.subClass({ imageMagick: true });
+const { getImageHeightAndWidth } = require('../../../utils/imageProcessing');
+
+module.exports = function transformImage(path, queryObj) {
+  return new Promise((resolve, reject) => {
+    let { h: cHeight = null } = queryObj;
+    let { w: cWidth = null } = queryObj;
+    let { t: transform = null } = queryObj;
+    let { x: xOrigin = null } = queryObj;
+    let { y: yOrigin = null } = queryObj;
+    let oHeight,
+      oWidth = null;
+    try {
+      getImageHeightAndWidth(path).then(hwarr => {
+        oHeight = hwarr[0];
+        oWidth = hwarr[1];
+        // conditional logic here
+        if (transform === 'crop') {
+          resolve(_cropCenter(path, cWidth, cHeight, oWidth, oHeight));
+        } else if (transform === 'stretch') {
+          imageMagick(path)
+            .resize(cWidth, cHeight, '!')
+            .toBuffer(null, (err, buf) => {
+              resolve(buf);
+            });
+        } else {
+          // resize scaled
+          imageMagick(path)
+            .resize(cWidth, cHeight)
+            .toBuffer(null, (err, buf) => {
+              resolve(buf);
+            });
+        }
+      });
+    } catch (e) {
+      logger.error(e);
+      reject(e);
+    }
+  });
+};
+
+function _cropCenter(path, cropWidth, cropHeight, originalWidth, originalHeight) {
+  let oAspect = originalWidth / originalHeight;
+  let cAspect = cropWidth / cropHeight;
+  let resizeX,
+    resizeY,
+    xpoint,
+    ypoint = null;
+
+  if (oAspect >= cAspect) {
+    // if crop is narrower aspect than original
+    resizeY = cropHeight;
+    xpoint = (oAspect * cropHeight) / 2 - cropWidth / 2;
+    ypoint = 0;
+  } else {
+    // if crop is wider aspect than original
+    resizeX = cropWidth;
+    xpoint = 0;
+    ypoint = cropWidth / oAspect / 2 - cropHeight / 2;
+  }
+  return new Promise((resolve, reject) => {
+    try {
+      imageMagick(path)
+        .resize(resizeX, resizeY)
+        .crop(cropWidth, cropHeight, xpoint, ypoint)
+        .toBuffer(null, (err, buf) => {
+          resolve(buf);
+        });
+    } catch (e) {
+      logger.error(e);
+      reject(e);
+    }
+  });
+}