I was trying to encode and decode HTTP responses. to deal with the body I created a custom ReadCloser with its own UnmarshalBinary and MarshalBinary methods. The gob output was inconsistent with the output of the UnmarshalBinary
I also created a sample repo to demonstrate the same - https://github.com/slayerjain/gob-decode-issue.
I've also created an issue on the golang repo - https://github.com/golang/go/issues/51645
Thanks to a user on Reddit I found the solution. The problem is that in the UnmarshalBinary method I need to create a copy of the byte array. Else it'll be populated with other data since it's a pointer.
ref: https://www.reddit.com/r/golang/comments/tddjdd/gob_is_appending_gibberish_to_my_object/
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I am using URLSession 'uploadTask from file'
func uploadTask(with request: URLRequest, fromFile fileURL: URL) -> URLSessionUploadTask
Almost everything works fine, but now our server needs an extra param as 'uploadKey' to be passed as content disposition along with fileName.
This can be done by generating multipart request with content disposition added as we normally do.
I want to add it while using 'uploadTask from file' to avoid memory pressure. Please suggest how to do it.
From reading the question, I suspect that you're subtly misunderstanding what upload tasks do (and unfortunately, Apple's documentation needs some serious improvement in this area, which doesn't help matters). These tasks don't upload a file in the same way that a web browser would if you chose a file in an upload form. Rather, they use the file as the body of an upload request. I think they default to providing a sane Content-Type based on the filename, though I'm not certain, but they do not send data in form encoding.
So assuming I'm fully understanding the question, your options are either:
Keep using multipart encoding. Optionally write the multipart body into a file rather than keeping it in memory, and use the upload task to provide the body from that file instead of from an NSData object.
Upload the file you're trying to send, unencoded, as the entirety of the upload body, and provide whatever additional parameters you need to provide in the form of GET parameters in the URL itself.
Use some other encoding like JSON or protocol buffers.
Either way, the server code will determine which of these approaches is supported. If you can modify the server code, then I would recommend the second approach. It is slightly more efficient than the first approach, much more efficient than JSON, and easier to implement than any of the other approaches.
I'd like to write a Codec plugin to enable LogStash to decode a binary data format.
The official documentation for writing a Codec shows that I need to define a decode method that accepts a single parameter: a variable called data.
I'm new to both LogStash and Ruby. Having worked mostly with statically typed languages, I'm unsure how to learn more about the data variable. I assume that it's analogous to an InputStream-type object, allowing me to read data as it becomes available, but I'm not sure.
Questions:
What type is the data object? What methods does it have?
How do Ruby developers typically go about investigating variables like this? I'm not sure I see a way to figure it out without writing a skeleton plugin and dumping a string representation of data to STDOUT.
Thanks!
The documentation for writing an input plugin hints at this. From the run() method section:
data = $stdin.sysread(16384)
#codec.decode(data) do |event|
decorate(event)
event.set("host", #host) if !event.include?("host")
queue << event
end
The data variable is a Ruby String, which is being used as a buffer of arbitrary bytes. I have verified this by creating a skeleton plugin and inspecting the value at runtime.
This seems to be cause for caution: the bytes provided to your codec's decode method are not guaranteed to be a complete event.
In particular I'm trying to successfully return a payment object to the bitcoin client,
this line of code:
required bytes serialized_payment_details = 4;
in the PaymentRequest message of .proto is required but I don't know how to generate the serialised payment details or even what it means to be honest?
Thanks in advance for any help :)
all that does is declare that field 4 should hold a blob - a sequence of raw data. No meaning, translation or intent is provided for that, so all processing must be done externally to protocol buffers. As for how to serialize it: that comes down to bitcoin and whatever bitcoin library / tools you are using.
The answer was:
serialized_payment_details = PaymentDetailsObject.SerializeToString()
I have serialized an object in YAML and send it to a remote worker.
The worker doesent have the object definition so i get a YAML::Object.
How can i access the field inside it?
A text field seems like that base64 encoded, how can i decode that? (no, decode64 not works).
you can pass the object as something "known between both sides" (like an openstruct or hash) or give the description to the client.
It would be interesting to have a serialization format that also serialized the class and its methods...I'll have to think about that one...
try c["bar"]
you can also see all the provided keys using c.keys
I need to include the content-length of a image /png file posted in an upload to a webservice.
But how do I calculate the content-length to include in the header?
Thanks.
I am submitting it using rest-client.
The webservice for the upload is Postful: and the documentation has been unclear: http://www.postful.com/developer/guide#uploading_attachments
Because I am writing the payload and headers, seems like I need to input that value.
I am also looking at postalmethods which says that the content-length is the user input:
http://postalmethods.com/method/2009-02-26/UploadFile
The files themselves are .PNG. I am going to attach them to a model using Paperclip, so will have a filepath from that.
The file that I need the content-length to post is stored as an attachment using paperclip, so the specific code generating problems is:
File.size(#postalcard.postalimage.url)
Well, you know how you're reading and posting the data, presumably - so you know how much data you're sending. That's the content length. If you're just sending it directly in binary as the body of the post, it's just the length of the file. If you're base-64 encoding it, then the content length will be the ((file length + 2) / 3) * 4. If it's going in a SOAP envelope etc, you'll need to take account of that.
One way of doing this for complicated situations is to build the entire post body in memory first, set the content length, and then just copy from memory directly to the post body.
Well, you can use File.size(filepath) but it's unlikely that you'll need to - most libraries for making HTTP requests should do that automatically - which library are you using? (Or, what kind of webservice is it?)