provide missing SetBlobProperties function and add missing properties to GetBlobProperties

[schreibe72]

Add following properties to GetBlobProperties:

• Cache-Control
• Cache-Language

Add function SetBlobProperties to set ContentSettings like:

• Content-MD5
• Content-Language
• Content-Encoding
• Content-Type
• Cache-Control

Add Test for SetBlobProperties.

[msftclas]

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[ahmetb]

@schreibe72 thank you for your pull request, please ping me once you signed the CLA and I'll review.

[schreibe72]

@ahmetalpbalkan I have signed the CLA and send via DocuSign.

[ahmetb]

@schreibe72 I guess there is a processing delay in that case, we can come back to that later. I'll leave some comments now.

[ahmetb]

Maybe call this BlobHeaders? (more about this below)

[ahmetb]

It looks like Set Blob Properties and Get Blob Properties (+List Blobs) work a bit weird as in "Set" accepts x-ms-* headers and "Get/List" return XML fields named properly.

Therefore it appears like using the same struct both on response deserialization path from 'Get/List' and as headers in 'Set' is going to be a bit challenging.

[ahmetb]

@schreibe72 just got this crazy idea. What if we annotate this ContentSetting struct (or better: BlobHeaders or struct) with BOTH "xml" and "header" tags?

This way:

1. we can embed this struct into type BlobPropertiesResponse and thanks to xml tag, it will deserialize just fine
2. For SetBlobProperties, func headersFromStruct(v interface{}) (map[..], error) will do the job and read from "header" field tag.
3. For GetBlobProperties we write a new method called func structFromHeaders(map[string]string, v interface{}) error which looks at the "header" field tag and deserializes the headers in the response of Get Blob Properties into our struct and just return it! This way we don't have to populate its fields manually?

[ahmetb]

@schreibe72 thanks for making the changes. I think we should somehow embed BlobHeaders struct into BlobProperties struct and have some deserializer that does map-->struct. I feel like it might be a lot of work whereas this patch is probably solving your problem. What do you think?

[schreibe72]

i would split this in to two pull requests. One is for the new function setBlobProperties, the other for refactoring getBlobProperties.
The deserializer is a bit more tricky, because there are not only string types. The other thing is, that if we change the struct BlobProperties some depending code might break.

[ahmetb]

@schreibe72 fair point. Thanks.