Use a .dat folder to resume links and RC2 API (#476, #484)

[joehand]

General Changes

• Uses .dat folder to resume links in the given directory (share & download)
  • Resuming a share only adds new files not in archive
  • Does not support updated files
• Keep download connections open for both live & static (no option to close).
• Updates tests
• Use leveldb

API Changes

• Updates API to use proposed RC2 version (see usage.txt)
• Removes most options
• Add --list option
• Rename --static to --snapshot
• Make live default

Output Changes

• Update wording around dat link:
  
• Tell user when a Dat is resumed
• Show download/share folder

[mafintosh]

@joehand "Does not support updated files" - I need to fix this right?

[mafintosh]

Why is there no flag to exit on content downloaded? That sounds very useful when scripting stuff.

[mafintosh]

I actually like a separate cmd that fetches and exits more than a flag now that i think about it.

[joehand]

"Does not support updated files" - I need to fix this right?

@mafintosh ya, we need to store the mtimes in hyperdrive for this. Once we have that, will be straightforward for me to check.

Why is there no flag to exit on content downloaded? That sounds very useful when scripting stuff.

Oh ya, didn't think about that use. I can add it.

[joehand]

I actually like a separate cmd that fetches and exits more than a flag now that i think about it.

Ya I think that'd make sense - but do we want to support both of those? dat checkout <link>?

We could change dat get <link> to something more specific too. dat join <link>? Not sure what describes it properly (downloading, connecting, and remaining connected).

[mafintosh]

@joehand what about this?

• dat share <link-or-folder> (similar to git clone / pull / push in terms or arguments). this shares the dat and keeps downloading/uploading data.
• dat get <link-or-folder> is just for downloading. it'll fetch the data and exit. if you dat get <folder> it'll fetch updates and exit
• dat <link-or-folder> is just a shortcut to share.

(for now share will require the 2nd destination argument as you describe above when using dat <link> but we can make the optional in the future like we've discussed)

[mafintosh]

mkdirp is missing from devdeps

[joehand]

• dat share (similar to git clone / pull / push in terms or arguments). this shares the dat and keeps downloading/uploading data.
• dat get is just for downloading. it'll fetch the data and exit. if you dat get it'll fetch updates and exit
• dat is just a shortcut to share.

dat <link/folder> is good and like the idea. But dat share <link/folder> will be super counter-intuitive for downloads. Though I guess if we have dat get <link> then thats the easier option.

[mafintosh]

@joehand if its easy to add again could you make it store the previously used port in level? like we did before.

[mafintosh]

Tests are green. I'm happy. I think we should merge this into master and use it for a bit and see how it feels. @joehand before potentially merging this could you squash the commits?

[okdistribute]

Yeah I'm down for merging and in the next week getting some direct feedback and see where the pain points and bugs are

[okdistribute]

why not dat <directory> [link] ?

[joehand]

why not dat <directory> [link]?

@Karissa a few reasons we went with dat [link] <dir>:

1. It's now dat <source> <destination> for both commands, keeping option to make destination optional in the future without breaking. Source will always be required.
2. dat 4f36c088e9687ddf53d36f785ab84c65f4d24d8c4161950519b96a57d65ae08a joe/downloads will be much easier to share/copy command or change download directories.

[joehand]

@maxogden updated with your output suggestions.

I'll smush commits and merge tomorrow (CC: @mafintosh, @Karissa).

[mafintosh]

@joehand 🎉 LGTM 🎉