Write `get-file` and commands to get the list of blocks from another node

Description

This closes #1 (closed) by providing an API that allows to get a file with just its hash

Detailed list of changes

• add get_file, get_blocks_info_from and other things related to managing the filesystem
• add new commands to nu API
• remove DragoonBehaviour as it was not useful
• add two new tests for get_file and change the already existing test to use the new API

Note

The get_file is still very rough, the error management needs to be handled better to take into a lot more cases of failure

tests/message_exchange_block_per_block.nu

@@ -67,39 +67,39 @@ try {
     let block_hashes = $encode_res.1 | from json  #! This is a string not a list, need to convert
     let file_hash = $encode_res.0
 
-    print $"The file got cut into blocks, block hashes are: ($block_hashes)"
+    print $"The file got cut into blocks, block hashes are"
+    print $block_hashes
     print $"The hash of the file is: ($file_hash)"
 
-    print "\nNode 0 starts providing the blocks"
-    for $hash in $block_hashes {
-        print $"Node 0 starts providing the block with hash ($hash)"
-        app start-provide --node $SWARM.0.ip_port $hash
-    }
-    print "Node 0 finished announcing which blocks it provides\n"
+    print "\nNode 0 starts providing the file"
+    app start-provide --node $SWARM.0.ip_port $file_hash
 
-    print "Node 1 starts searching for the providers with the hashes of the blocks"
-    mut providers = []
-    for $hash in $block_hashes {
-        print $"Node 1 searching for the provider of the block with hash ($hash)"
-        $providers = ($providers | append (app get-providers --node $SWARM.1.ip_port $hash | get 0))
-    }
-    print "Node 1 finished searching for the providers\n"
+    print "Node 1 starts searching for the providers with the file hash"
+    let providers = app get-providers --node $SWARM.1.ip_port $file_hash | get 0
     print $"The providers are:"
     print $providers
 
+    print "\nNode 1 asks node 0 to provide the list of blocks it has for the file"
+    let received_block_list = app get-blocks-info-from --node $SWARM.1.ip_port $providers $file_hash | from json
+    print $"The blocks node 0 has are:"
+    print $received_block_list
+
+    print "\nComparing to the actual block list"
+    assert equal ($block_hashes |sort) ($received_block_list |sort)
+
     print "Creating the directory to receive the files"
     mkdir $output_dir
 
     print "\nNode 1 asks for the blocks to node 0"
-    for $i in 0..<($block_hashes | length) {
-        let $hash = $block_hashes | get $i
+    for $i in 0..<($received_block_list | length) {
+        let $hash = $received_block_list | get $i
         print $"Getting block ($hash)"
-        app get-block-from --node $SWARM.1.ip_port ($providers | get $i) $file_hash ($hash) | save $"($output_dir)/($hash)"
+        app get-block-from --node $SWARM.1.ip_port ($providers | get $i) $file_hash ($hash) | get 1 | save $"($output_dir)/($hash)"
     }
     print "Finished getting all the blocks\n"
     
     print "Node 1 reconstructs the file with the blocks"
-    app decode-blocks --node $SWARM.1.ip_port $output_dir $block_hashes $res_filename
+    app decode-blocks --node $SWARM.1.ip_port $output_dir $received_block_list $res_filename
 
     print "Killing the swarm"
     swarm kill --no-shell