javascript - 添加新的 Meteor CollectionFS 存储

Question

我一直在使用 CollectionFS 和 GraphicsMagick 来裁剪图像并将其存储在 S3 中。我意识到这些图像对于移动设备来说太大了，现在我想存储缩小的版本。这是我尝试过的。

images = new FS.Collection("images", {
  stores: [
    new Store("images", imageOptions),
    new Store("thumbs", thumbOptions) // added later
  ]
});

thumbs 存储适用于新图像，但缩小旧图像的启动功能则不适用于。

Meteor.startup(function () {
  images.find().forEach(function (fileObj) {
    if (!fileObj.copies.thumbs) {
      var readStream = fileObj.createReadStream('images');
      var writeStream = fileObj.createWriteStream('thumbs');
      gm(readStream)
        .scale(THUMB_DIM, THUMB_DIM)
        .stream()
        .pipe(writeStream);
    }
  });
});

有什么想法吗？是否是由来自 S3 的 readstream 引起的？

Answer 1

似乎您缺少 gm 命令中的第二个参数，该参数应该是原始文件名。我们使用以下迁移脚本在新商店中创建图像的副本:

Migrations.add({
    version: 2,
    name: 'Save old images to new image stores',
    up: function() {
        console.log('Save old images to new image stores');
        Images.find().fetch().forEach(function(image) {
            if (image.copies['32x32'].size === 0) {
                console.log('creating 32x32 image: ' + image.name());
                var readStream = image.createReadStream('original');
                var writeStream = image.createWriteStream('32x32');
                try {
                  gm(readStream, image.name()).resize(32, 32).stream().pipe(writeStream);
                }
                catch (e) {
                  console.log(e);
                }
            }
            if (image.copies['80x80'].size === 0) {
                console.log('creating 80x80 image: ' + image.name());
                var readStream = image.createReadStream('original');
                var writeStream = image.createWriteStream('80x80');
                try {
                  gm(readStream, image.name()).resize(80, 80).stream().pipe(writeStream);
                }
                catch (e) {
                  console.log(e);
                }
            }
        });
    },
    down: function() {
    }
});