Javascript 是否需要清除Node.js中的缓冲区？如果是，如何进行？如果没有，这里的问题是什么？

我正在制作一个缩略图生成器，我用它在照片上传后立即在后台完成这项工作。我在Node.js中编写了一个worker，它基本上执行缩略图处理（用于Node）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编码字符串。js工作者获取输入的base64编码图像，并对其进行处理。一切正常。我发现的问题是，当我通过调用Node.js worker时。PHP第一次生成所有3个缩略图（我为每个图像生成3个缩略图），第二次和第三次也生成所有3个缩略图，但第四次只生成一个缩略图，之后无论我调用worker多少次，都不会生成缩略图

我认为问题可能是缓冲区被填满了，因为我正在使用Node.js Buffer将base64字符串转换为二进制，反之亦然

我寻找清除缓冲区的方法，比如将缓冲区变量指向null，对缓冲区变量使用js

delete

函数。但是，所有这些似乎都无济于事。要么缓冲区未被清除，要么根本不是缓冲区的问题

请通读代码，并让我知道问题可能是什么

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\"]");
?>

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

注意，在最近几次尝试中，它实际上并没有创建任何缩略图。显示所用时间基本上意味着缩略图创建过程已完成

---

我不确定问题可能是什么。正在寻求帮助。

在我看来，问题是您在实际完成工作之前关闭了工人

差不多

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();
    });
});

---

经过多次故障排除，发现问题出在软件包上。使用node.js包解决了这个问题。查看我的另一个以了解更多详细信息。

如果我没有错，worker.end（）只允许PHP Gearman客户端停止等待响应。我一开始就需要它，因为我不希望PHP端等待响应。而且我一直在尝试这个方法，我发现即使没有考虑Gearman，我在一个循环中多次调用Node.js脚本中的

initializeepic

函数，或者一个接一个，它也只处理4到5次。我无法准确指出问题所在。