Question

我正在编写一个应用程序，它从CouchDB文档中提取附件，将其写入磁盘，对其进行操作，然后将生成的文档存储回CouchDB。第一部分运作出色。获取附件没有问题，将其写入磁盘并进行操作。

要复制下面的错误，您需要以下内容：

在某处运行或访问一个CouchDB服务器。
名为演示文稿的数据库
所述数据库中的文件。
为演示文稿
所述目录中的PNG。
节点模块
- FS
- 路径
- 默
- 水珠
- TXN

更改_workdir的位置以匹配您创建目录的位置。

将程序保存为uploadPNG.js。使用此命令运行

./uploadPNG.js --id directoryName。

它应该通过并将所有文件添加到与目录具有相同ID的CouchDB文档中。以下代码实际上是拉文档。它只是不添加附件，我不知道为什么。以下是运行程序时产生的错误。

任何人都可以像我认为的那样帮助我实现这项工作吗？

错误

{ [Error: CouchDB error: {"error":"unknown_error","reason":"function_clause"}]
  statusCode: 500,
  error: 'unknown_error',
  reason: 'function_clause' }

Error: CouchDB error: {"error":"unknown_error","reason":"function_clause"}
    at /Users/digilord/projects/superslick/couch_worker/node_modules/txn/lib/lib.js:59:18
    at Request._callback (/Users/digilord/projects/superslick/couch_worker/node_modules/txn/lib/lib.js:125:12)
    at Request.self.callback (/Users/digilord/projects/superslick/couch_worker/node_modules/txn/node_modules/request/index.js:142:22)
    at Request.EventEmitter.emit (events.js:98:17)
    at Request.<anonymous> (/Users/digilord/projects/superslick/couch_worker/node_modules/txn/node_modules/request/index.js:856:14)
    at Request.EventEmitter.emit (events.js:117:20)
    at IncomingMessage.<anonymous> (/Users/digilord/projects/superslick/couch_worker/node_modules/txn/node_modules/request/index.js:808:12)
    at IncomingMessage.EventEmitter.emit (events.js:117:20)
    at _stream_readable.js:895:16
    at process._tickCallback (node.js:415:13)

uploadPNG.js

#!/usr/bin/env node
var fs = require('fs'),
    path = require('path'),
    mime = require('mime'),
    glob = require("glob");

var txn = require('txn').defaults({"timestamps":true, "couch":"http://localhost:5984"});
var presentations_txn = txn.defaults({"db":"presentations", "delay":1000, "timeout":30000});


var argv = require('optimist')
    .usage('Usage: $0 --id [Document ID]')
    .demand(['id'])
    .argv;

var _doc_id = argv.id;

var _workdir = path.join(path.resolve('/Volumes/ramdisk'), 'work');
var _docdir = path.join(_workdir, _doc_id);

var _doc = null

var addAttachments = function(doc, to_txn){
    console.log(doc);
    console.log('Initial document fetched for: ', doc._id);
    console.log('Ready to push files to CouchDB for: ', _doc_id);

    var _globPattern = _docdir + '/*.png';
    var _pngs = glob.sync(_globPattern);
    // console.log('PNGs: ', _pngs);

    _pngs.forEach(function(_file){
        var _filecontents = fs.readFileSync(_file);
        var _mime_type = mime.lookup(_file);
        var _filename = _file.split('/').pop();

        console.log("Processing Attachment: ", _filename)
        if(typeof doc._attachments[_filename] == 'object'){
            doc._attachments[_filename].content_type = _mime_type;
            doc._attachments[_filename].body = _filecontents;
        } else {
            doc._attachments[_filename] = {};
            doc._attachments[_filename].content_type = _mime_type;
            doc._attachments[_filename].body = _filecontents;
        }
        // uploadAttachment(_file, _docdir, _doc_id)
    });
    doc.processed = true;
    to_txn()
}

presentations_txn({"id": _doc_id}, addAttachments, function(error, newData) {
  if(!error)
    return console.log("Processed " + _doc_id + " to state: " + newData.processed);

  // These errors can be sent by Txn.
  if(error.timeout)
    return console.log("Gave up after MANY conflicts");
  if(error.conflict)
    return console.log("addAttachments never completed. Troubleshoot and try again");

  console.log(error);
  throw error; // Unknown error
});

Answer 1

我认为您需要对附件体进行base64编码。另外，我认为附件内容存储在.data下，而不是.body。

doc._attachments[_filename].content_type = _mime_type;
doc._attachments[_filename].data = _filecontents.toString('base64');

在Node.js问题中使用TXN将附件上载到CouchDB

错误

uploadPNG.js

1 个答案: