Nodejs bluebird 承诺在处理图像时失败
Nodejs bluebird promise fails while processing image
//Created a promise for each image size.
var promises = sizes.map(function (size) {
return new Promise(function (resolve, reject) {
var destinationDir = fileUtil.getAbsolutePathOfImage(destinationPath);
fileUtil.createDirectoryIfNotExists(destinationDir);
destinationDir += size.src;
fileUtil.createDirectoryIfNotExists(destinationDir);
//Resize the image.
//console.log('imagefile : ' + JSON.stringify(imageFile));
//console.log('destinationDir: ' + JSON.stringify(destinationDir));
//Called an imageUtil resize method to perform resize.
imageUtil.resize(imageFile, destinationDir, size).then(data => {
var fileName = destinationPath + size.src + '/' + data;
resolve(imageUtil.createImageData(fileName, size.height, size.width));
}).catch(err => {
console.error(err);
return reject(err);
});
});
});
Promise.all(promises)
.then(savedImages => {
console.log('saved Images are: ' + JSON.stringify(savedImages));
return res.status(200).json(savedImages);
}).catch(err => {
console.log('i am here' + JSON.stringify(err.message));
return res.status(400).json(JSON.stringify(err.message));
});
---------------------Resize method of imageutil---------------
var Promise = require('bluebird'),
gm = require('gm'),
path = require('path'),
fs = require('fs');
Promise.promisifyAll(gm.prototype);
module.exports = {
resize(imageFile, destinationPath, size){
if (!imageFile || !destinationPath || !size) {
return;
}
return new Promise(function (resolve, reject) {
// If we just passed callback directly, errors would be fatal
var fileName = fileUtil.getFileName(imageFile);
//console.log('sourceFile : ' + JSON.stringify(imageFile));
//console.log('saveDirectory : ' + JSON.stringify(destinationPath));
//console.log('fileName is :' + fileName);
//Create a write stream.
var writeStream = fs.createWriteStream(destinationPath + '/' + fileName);
//console.log('Saving at location: ' + writeStream.path);
gm(imageFile)
.resize(size.width, size.height, '^')
.gravity('Center')
.crop(size.width, size.height)
.writeAsync(writeStream.path, function (err) {
if (err) {
var error = 'Error while creating image of resolution : ' + size.width + 'x' + size.height + '.';
console.error(JSON.stringify(error));
return reject(new Error(error));
}
});
resolve(fileName);
});
}
};
*似乎一切正常,它创建了四个损坏的图像文件,后来给我错误,但请求已成功处理。我的图像处理的控制台输出如下:
saved Images are: [{"src":"/uploads/300/fhjXFLgqq59F91uFK_2h8GiS.jpg","height":"200","width":"300"},{"src":"/uploads/120/fhjXFLgqq59F91uFK_2h8GiS.jpg","height":"120","width":"120"},{"src":"/uploads/48/fhjXFLgqq59F91uFK_2h8GiS.jpg","height":"48","width":"48"}]
POST /api/upload/image/ 200 51.790 毫秒 - 241
"Error while creating image of resolution : 120x120."
"Error while creating image of resolution : 48x48."
"Error while creating image of resolution : 300x200."*
由于您已经在使用 promisifyAll
,因此您不需要(和 should not)使用 Promise
构造函数。 write<em>Async</em>
已经 returns 一个承诺 - 如果你不传递回调,因为这是 Bluebird 能够传递的要求回调本身在正确的位置。
你应该使用
module.exports = {
resize(imageFile, destinationPath, size){
if (!imageFile || !destinationPath || !size) {
return Promise.reject(new Error("missing arguments"));
}
var fileName = fileUtil.getFileName(imageFile);
//console.log('sourceFile : ' + JSON.stringify(imageFile));
//console.log('saveDirectory : ' + JSON.stringify(destinationPath));
//console.log('fileName is :' + fileName);
//Create a write stream.
var writeStream = fs.createWriteStream(destinationPath + '/' + fileName);
//console.log('Saving at location: ' + writeStream.path);
var promise = gm(imageFile)
.resize(size.width, size.height, '^')
.gravity('Center')
.crop(size.width, size.height)
.writeAsync(writeStream.path);
return promise.then(function() {
return filename;
}, function (err) {
var error = 'Error while creating image of resolution : ' + size.width + 'x' + size.height + '.';
console.error(error, err);
throw new Error(error);
});
}
};
同样,您不应该在对 resize
的调用中使用 Promise
构造函数反模式 - 它已经 returns 一个承诺:
var promises = sizes.map(function (size) {
var destinationDir = fileUtil.getAbsolutePathOfImage(destinationPath);
fileUtil.createDirectoryIfNotExists(destinationDir);
destinationDir += size.src;
fileUtil.createDirectoryIfNotExists(destinationDir);
//Resize the image.
//console.log('imagefile : ' + JSON.stringify(imageFile));
//console.log('destinationDir: ' + JSON.stringify(destinationDir));
return imageUtil.resize(imageFile, destinationDir, size)
//^^^^^^
.then(data => {
var fileName = destinationPath + size.src + '/' + data;
return imageUtil.createImageData(fileName, size.height, size.width));
}, err => {
console.error(err);
throw err;
});
});
//Created a promise for each image size.
var promises = sizes.map(function (size) {
return new Promise(function (resolve, reject) {
var destinationDir = fileUtil.getAbsolutePathOfImage(destinationPath);
fileUtil.createDirectoryIfNotExists(destinationDir);
destinationDir += size.src;
fileUtil.createDirectoryIfNotExists(destinationDir);
//Resize the image.
//console.log('imagefile : ' + JSON.stringify(imageFile));
//console.log('destinationDir: ' + JSON.stringify(destinationDir));
//Called an imageUtil resize method to perform resize.
imageUtil.resize(imageFile, destinationDir, size).then(data => {
var fileName = destinationPath + size.src + '/' + data;
resolve(imageUtil.createImageData(fileName, size.height, size.width));
}).catch(err => {
console.error(err);
return reject(err);
});
});
});
Promise.all(promises)
.then(savedImages => {
console.log('saved Images are: ' + JSON.stringify(savedImages));
return res.status(200).json(savedImages);
}).catch(err => {
console.log('i am here' + JSON.stringify(err.message));
return res.status(400).json(JSON.stringify(err.message));
});
---------------------Resize method of imageutil---------------
var Promise = require('bluebird'),
gm = require('gm'),
path = require('path'),
fs = require('fs');
Promise.promisifyAll(gm.prototype);
module.exports = {
resize(imageFile, destinationPath, size){
if (!imageFile || !destinationPath || !size) {
return;
}
return new Promise(function (resolve, reject) {
// If we just passed callback directly, errors would be fatal
var fileName = fileUtil.getFileName(imageFile);
//console.log('sourceFile : ' + JSON.stringify(imageFile));
//console.log('saveDirectory : ' + JSON.stringify(destinationPath));
//console.log('fileName is :' + fileName);
//Create a write stream.
var writeStream = fs.createWriteStream(destinationPath + '/' + fileName);
//console.log('Saving at location: ' + writeStream.path);
gm(imageFile)
.resize(size.width, size.height, '^')
.gravity('Center')
.crop(size.width, size.height)
.writeAsync(writeStream.path, function (err) {
if (err) {
var error = 'Error while creating image of resolution : ' + size.width + 'x' + size.height + '.';
console.error(JSON.stringify(error));
return reject(new Error(error));
}
});
resolve(fileName);
});
}
};
*似乎一切正常,它创建了四个损坏的图像文件,后来给我错误,但请求已成功处理。我的图像处理的控制台输出如下:
saved Images are: [{"src":"/uploads/300/fhjXFLgqq59F91uFK_2h8GiS.jpg","height":"200","width":"300"},{"src":"/uploads/120/fhjXFLgqq59F91uFK_2h8GiS.jpg","height":"120","width":"120"},{"src":"/uploads/48/fhjXFLgqq59F91uFK_2h8GiS.jpg","height":"48","width":"48"}]
POST /api/upload/image/ 200 51.790 毫秒 - 241 "Error while creating image of resolution : 120x120." "Error while creating image of resolution : 48x48." "Error while creating image of resolution : 300x200."*
由于您已经在使用 promisifyAll
,因此您不需要(和 should not)使用 Promise
构造函数。 write<em>Async</em>
已经 returns 一个承诺 - 如果你不传递回调,因为这是 Bluebird 能够传递的要求回调本身在正确的位置。
你应该使用
module.exports = {
resize(imageFile, destinationPath, size){
if (!imageFile || !destinationPath || !size) {
return Promise.reject(new Error("missing arguments"));
}
var fileName = fileUtil.getFileName(imageFile);
//console.log('sourceFile : ' + JSON.stringify(imageFile));
//console.log('saveDirectory : ' + JSON.stringify(destinationPath));
//console.log('fileName is :' + fileName);
//Create a write stream.
var writeStream = fs.createWriteStream(destinationPath + '/' + fileName);
//console.log('Saving at location: ' + writeStream.path);
var promise = gm(imageFile)
.resize(size.width, size.height, '^')
.gravity('Center')
.crop(size.width, size.height)
.writeAsync(writeStream.path);
return promise.then(function() {
return filename;
}, function (err) {
var error = 'Error while creating image of resolution : ' + size.width + 'x' + size.height + '.';
console.error(error, err);
throw new Error(error);
});
}
};
同样,您不应该在对 resize
的调用中使用 Promise
构造函数反模式 - 它已经 returns 一个承诺:
var promises = sizes.map(function (size) {
var destinationDir = fileUtil.getAbsolutePathOfImage(destinationPath);
fileUtil.createDirectoryIfNotExists(destinationDir);
destinationDir += size.src;
fileUtil.createDirectoryIfNotExists(destinationDir);
//Resize the image.
//console.log('imagefile : ' + JSON.stringify(imageFile));
//console.log('destinationDir: ' + JSON.stringify(destinationDir));
return imageUtil.resize(imageFile, destinationDir, size)
//^^^^^^
.then(data => {
var fileName = destinationPath + size.src + '/' + data;
return imageUtil.createImageData(fileName, size.height, size.width));
}, err => {
console.error(err);
throw err;
});
});