Build sdk initial demo

[alexfreska]

Rough flow:

• query central service that tracks hosts and has contracts with them
• web page will request a set of hosts to use that they can connect to
• web page will open a connect with all of them
• do some uploading

  • encode file with object encoders, for now can write random data as sectors

    • take file stream and run it through encode in 40mb chunks https://github.com/SiaFoundation/renterd/blob/7050587645402b34b0cf70cdc189c4138cbf3c8a/object/slab.go#L91
    • readablestream, take 40mb encode with func, split back erasure coding shards
    • upload shards to 30 hosts, send shards to service
    • shard used to calculate sector root
    • calc sector root with rhp2 merkle https://github.com/SiaFoundation/core/blob/3ffb8d7988b688b2c4ae12f6ec994e3697fd4c7b/rhp/v2/merkle.go#L173

    var shards [][]byte
    object.Encode(data, shards)
    
    for _, shard := range shards {
        sector := (*[rhp2.SectorSize]byte)(&shard)
        root := rhp2.SectorRoot(sector)
    
        root, err := WriteSector(sector)
        if err != nil {
           // handle error
        }
    
        sendToService(root)
    }

  • write sectors

• download
  • opposite, slab reconstruct https://github.com/SiaFoundation/renterd/blob/7050587645402b34b0cf70cdc189c4138cbf3c8a/object/slab.go#L108
• send metadata back to the initial service
• service pins data to contracts, and does repairs etc