我正在制作缩略图生成器，我正在使用Gearman在上传照片后立即在后台完成工作。我有一个用Node.js编写的工作程序，它基本上进行缩略图处理（对节点使用imagemagick）并将其插入数据库。客户端是用PHP编写的，它基本上发送原始图像的Photo_id和base64编码的字符串。 Node.js工作者获取输入base64编码的图像，并对其进行处理。一切都很好。我发现的问题是，当我通过Node调用Node.js工作时。 PHP第一次，所有3个缩略图（我为每个图像生成3个缩略图）生成，第二次和第三次以及所有3个都生成，但第四次只生成一个缩略图，并且之后无论我打电话给工人多少次，都没有生成缩略图。
我认为问题可能是缓冲区被填满，因为我使用Node.js Buffer将base64字符串转换为Binary，反之亦然。
我在缓冲区变量上使用js delete函数搜索了清除缓冲区的方法，比如将缓冲区变量指向null 。但是，这似乎都没有帮助。缓冲区未被清除或问题根本没有缓冲区。
请仔细阅读代码，并告诉我可能出现的问题。
PHP Gearman客户端
<?php
$client= new GearmanClient();
$client->addServer('127.0.0.1',4731);
print $client->do("infinite", "[\"12246\", \"Base 64 image string in here\"]");
?>
Node.js Gearman客户端
var fs = require('fs');
var db = require('./class.photo.js');
var im = require('imagemagick');
var Gearman = require('node-gearman/lib/gearman.js');
var gearman = new Gearman("127.0.0.1", 4731);
var db = new db();
function initializePic(id,base, req_type, callback) {
console.log("Initializing thumbnail resize on " + id);
var rawbase = base.split(",")[1];
rawbase = rawbase.replace("\n", "");
var buff = new Buffer(rawbase, 'base64');
console.log(buff.length);
var bin = buff.toString('binary');
buff = null;
console.time("image_" + req_type);
imageResize(id, bin, properties[req_type].img_dest_width, properties[req_type].img_dest_height, imageRequestEnum[req_type], function (res) {
if (res) {
console.timeEnd(req_type);
console.timeEnd("image_" + req_type);
}
});
}
function imageResize(id, bin, w, h, s, callback) {
var fileName = id + '_' + w + '_' + h + '_thumb.jpg'
console.log("Initializing resize process with filename " + fileName);
im.resize({
srcData: bin,
// dstPath: fileName,
width: w,
height: h + '\!',
quality: 0.7,
strip: false,
progressive: true,
}, function (err, stdout, stderr) {
if (err)
throw err;
if (stderr)
throw stderr;
var buff = new Buffer(stdout, "binary");
console.log(buff.length);
var b64 = buff.toString('base64');
buff = null;
if (b64) {
b64 = "data:image/jpeg;base64," + b64;
db.insertThumb(id, b64, s, function (res) {
if (res) {
callback(true);
}
});
}
});
}
gearman.connect();
gearman.registerWorker("infinite", function (payload, worker) {
var payload = payload.toString();
var json = JSON.parse(payload);
var id = json[0]; //getting the photo_id from the payload
var base = json[1]; //Getting the base64 image data from the payload
worker.end();
console.time("user_image_small");
initializePic(id,base, "user_image_small");
console.time("user_image_medium");
initializePic(id,base, "user_image_medium");
console.time("profile_photo");
initializePic(id,base, "profile_photo");
});
Node.js控制台响应
Initializing thumbnail resize on 12246
Initializing resize process with filename 12246_50_50_thumb.jpg
Initializing thumbnail resize on 12246
Initializing resize process with filename 12246_90_90_thumb.jpg
Initializing thumbnail resize on 12246
Initializing resize process with filename 12246_245_245_thumb.jpg
profile_photo: 151ms
image_profile_photo: 150ms
user_image_medium: 211ms
image_user_image_medium: 210ms
user_image_small: 218ms
image_user_image_small: 217ms
Initializing thumbnail resize on 12246
Initializing resize process with filename 12246_50_50_thumb.jpg
Initializing thumbnail resize on 12246
Initializing resize process with filename 12246_90_90_thumb.jpg
Initializing thumbnail resize on 12246
Initializing resize process with filename 12246_245_245_thumb.jpg
user_image_small: 98ms
image_user_image_small: 96ms
profile_photo: 142ms
image_profile_photo: 141ms
user_image_medium: 147ms
image_user_image_medium: 145ms
Initializing thumbnail resize on 12246
Initializing resize process with filename 12246_50_50_thumb.jpg
Initializing thumbnail resize on 12246
Initializing resize process with filename 12246_90_90_thumb.jpg
Initializing thumbnail resize on 12246
Initializing resize process with filename 12246_245_245_thumb.jpg
user_image_small: 90ms
image_user_image_small: 89ms
user_image_medium: 141ms
image_user_image_medium: 140ms
profile_photo: 138ms
image_profile_photo: 137ms
Initializing thumbnail resize on 12246
Initializing resize process with filename 12246_50_50_thumb.jpg
Initializing thumbnail resize on 12246
Initializing resize process with filename 12246_90_90_thumb.jpg
Initializing thumbnail resize on 12246
Initializing resize process with filename 12246_245_245_thumb.jpg
user_image_small: 94ms
image_user_image_small: 93ms
Initializing thumbnail resize on 12246
Initializing resize process with filename 12246_50_50_thumb.jpg
Initializing thumbnail resize on 12246
Initializing resize process with filename 12246_90_90_thumb.jpg
Initializing thumbnail resize on 12246
Initializing resize process with filename 12246_245_245_thumb.jpg
Initializing thumbnail resize on 12246
Initializing resize process with filename 12246_50_50_thumb.jpg
Initializing thumbnail resize on 12246
Initializing resize process with filename 12246_90_90_thumb.jpg
Initializing thumbnail resize on 12246
请注意，在最近的几次尝试中，它实际上并没有创建任何缩略图。显示所花费的时间基本上意味着缩略图创建过程已完成。
我不确定问题是什么。寻求帮助。
答案 0 :(得分：1)
经过多次故障排除后，发现问题出在node-mysql包中。使用node.js的mysql包解决了这个问题。查看我的其他question and answer了解更多详情。
答案 1 :(得分：0)
在我看来，问题是你在实际完成工作之前关闭工人。
像
这样的东西gearman.registerWorker("infinite", function (payload, worker) {
var payload = payload.toString();
var json = JSON.parse(payload);
var id = json[0]; //getting the photo_id from the payload
var base = json[1]; //Getting the base64 image data from the payload
// not actually work with your code right now, but you got the idea
Promise.all([
initializePic(id, base, "user_image_small"),
initializePic(id, base, "user_image_medium"),
initializePic(id, base, "profile_photo")
]).then(() => {
// should be called after all processing is done
worker.end();
});
});