我一直在Node.js中编写一个应用程序，用于在MongoDB的GridFS文件系统中存储图像。
我通过应用程序上传了图片，图片似乎存储正确：
$ mongofiles -v -d speaker-karaoke get howard-basement-100x115.jpg
Tue Jul 17 12:14:16 creating new connection to:127.0.0.1
Tue Jul 17 12:14:16 BackgroundJob starting: ConnectBG
Tue Jul 17 12:14:16 connected connection!
connected to: 127.0.0.1
done write to: howard-basement-100x115.jpg
这抓住了MongoDB中的.jpg并且我能够打开它没问题，所以看起来我上传的内容正确存储。
但是，在我正在运行的应用程序中，当我尝试读取同一个文件时，我得到：
12:15:44 web.1 | started with pid 89621
12:15:45 web.1 | Connecting to mongodb://localhost/speaker-karaoke
12:15:45 web.1 | Speaker Karaoke express app started on 5000
12:15:48 web.1 | DEBUG: Get review thumbnail for 5005b7550333650000000001
12:15:48 web.1 |
12:15:48 web.1 | node.js:201
12:15:48 web.1 | throw e; // process.nextTick error, or 'error' event on first tick
12:15:48 web.1 | ^
12:15:48 web.1 | Error: Illegal chunk format
12:15:48 web.1 | at Error (unknown source)
12:15:48 web.1 | at new <anonymous> (/Users/hlship/workspaces/github/speaker-karaoke/node_modules/mongodb/lib/mongodb/gridfs/chunk.js:43:11)
12:15:48 web.1 | at /Users/hlship/workspaces/github/speaker-karaoke/node_modules/mongodb/lib/mongodb/gridfs/gridstore.js:488:24
12:15:48 web.1 | at Cursor.nextObject (/Users/hlship/workspaces/github/speaker-karaoke/node_modules/mongoose/node_modules/mongodb/lib/mongodb/cursor.js:462:5)
12:15:48 web.1 | at [object Object].<anonymous> (/Users/hlship/workspaces/github/speaker-karaoke/node_modules/mongoose/node_modules/mongodb/lib/mongodb/cursor.js:456:12)
12:15:48 web.1 | at [object Object].g (events.js:156:14)
12:15:48 web.1 | at [object Object].emit (events.js:88:20)
12:15:48 web.1 | at Db._callHandler (/Users/hlship/workspaces/github/speaker-karaoke/node_modules/mongoose/node_modules/mongodb/lib/mongodb/db.js:1290:25)
12:15:48 web.1 | at /Users/hlship/workspaces/github/speaker-karaoke/node_modules/mongoose/node_modules/mongodb/lib/mongodb/connection/server.js:329:30
12:15:48 web.1 | at [object Object].parseBody (/Users/hlship/workspaces/github/speaker-karaoke/node_modules/mongoose/node_modules/mongodb/lib/mongodb/responses/mongo_reply.js:118:5)
12:15:48 web.1 | process terminated
12:15:48 system | sending SIGTERM to all processes
使用此代码（CoffeeScript，for Express）：
app.get "/images/review-thumbnail/:id", (req, res) ->
id = req.params.id
util.debug "Get review thumbnail for #{id}"
store = new GridStore mongoose.connection.db, new ObjectID(id), null, "r"
store.open (err, file) ->
throw err if err
util.debug "Store open for #{id}, type = #{file.contentType}"
# TODO: Scale the image before sending it!
res.header "Content-Type", file.contentType
store.stream(true).pipe res
所以它似乎没有成为传递给store.open（）的回调。
当你知道id而不是文件名时打开GridFS文件是否有问题？
顺便说一句：
$ npm ls
speaker-karaoki@0.0.1 /Users/hlship/workspaces/github/speaker-karaoke
├─┬ blueimp-file-upload-node@1.0.2 extraneous
│ ├── formidable@1.0.11
│ ├── imagemagick@0.1.2
│ └── node-static@0.6.0
├── coffee-script@1.3.3
├─┬ connect-assets@2.1.9
│ ├── connect-file-cache@0.2.4
│ ├── mime@1.2.2
│ ├─┬ snockets@1.3.4
│ │ ├── coffee-script@1.3.3
│ │ ├── dep-graph@1.0.1
│ │ └── uglify-js@1.0.7
│ └── underscore@1.1.7
├─┬ express@2.5.9
│ ├─┬ connect@1.9.1
│ │ └── formidable@1.0.11
│ ├── mime@1.2.4
│ ├── mkdirp@0.3.0
│ └── qs@0.4.2
├─┬ jade@0.26.0
│ ├── commander@0.5.2
│ └── mkdirp@0.3.0
├─┬ mongodb@1.0.2
│ └── bson@0.0.6
├─┬ mongoose@2.7.0
│ ├── hooks@0.2.1
│ └─┬ mongodb@1.0.2
│ └── bson@0.0.6
├─┬ passport@0.1.10
│ └── pkginfo@0.2.3
├─┬ passport-twitter@0.1.3
│ ├─┬ passport-oauth@0.1.9
│ │ ├── oauth@0.9.7
│ │ └── passport@0.1.11
│ └── pkginfo@0.2.3
├── sass@0.5.0
└── underscore@1.3.3
这是失败的功能：
var Chunk = exports.Chunk = function(file, mongoObject) {
if(!(this instanceof Chunk)) return new Chunk(file, mongoObject);
this.file = file;
var self = this;
var mongoObjectFinal = mongoObject == null ? {} : mongoObject;
this.objectId = mongoObjectFinal._id == null ? new ObjectID() : mongoObjectFinal._id;
this.chunkNumber = mongoObjectFinal.n == null ? 0 : mongoObjectFinal.n;
this.data = new Binary();
if(mongoObjectFinal.data == null) {
} else if(typeof mongoObjectFinal.data == "string") {
var buffer = new Buffer(mongoObjectFinal.data.length);
buffer.write(mongoObjectFinal.data, 'binary', 0);
this.data = new Binary(buffer);
} else if(Array.isArray(mongoObjectFinal.data)) {
var buffer = new Buffer(mongoObjectFinal.data.length);
buffer.write(mongoObjectFinal.data.join(''), 'binary', 0);
this.data = new Binary(buffer);
} else if(mongoObjectFinal.data instanceof Binary || Object.prototype.toString.call(mongoObjectFinal.data) == "[object Binary]") {
this.data = mongoObjectFinal.data;
} else if(Buffer.isBuffer(mongoObjectFinal.data)) {
} else {
throw Error("Illegal chunk format");
}
// Update position
this.internalPosition = 0;
};
解决方案
在此处更新解决方案，因为它在下面的评论中无法正确呈现。
问题在于重复; mongodb和bson有两份，即使版本相同。
幸运的是，mongoose将它需要的mongodb导出为属性mongo，所以我能够从我的package.json中删除显式的mongodb并更改：
mongo = require "mongodb"
mongoose = require "mongoose"
为：
mongoose = require "mongoose"
mongo = mongoose.mongo
事情看起来很好;我仍然认为模块系统需要一种受制裁的方式来访问依赖项依赖项（对于dep不够周到以暴露其deps的情况）。
答案 0 :(得分：2)
很确定它是mongodb模块的重复副本（相同版本）;删除node_modules和nmp install似乎修复了它。