content - p2p - Compact Block messages

- Start adding `blocktxn`, `cmpctblock`, `getblocktxn`, and `sendcmpct`
messages
  - blocktxn and getblocktxn description and format added
  - Placeholders for cmpctblock and sendcmpct

_autocrossref.yaml

@@ -20,7 +20,11 @@ bitcoin QR codes: URI QR code
 bitcoinj:
 '`block` message': block message
 '`block` messages': block message
+'`blocktxn` message': blocktxn message
+'`blocktxn` messages': blocktxn message
 certificate chain:
+'`cmpctblock` message': cmpctblock message
+'`cmpctblock` messages': cmpctblock message
 DER:
 DER format: der
 DER-formatted: der
@@ -57,6 +61,8 @@ fiat:
 '`filterload` messages': filterload message
 '`getblocks` message': getblocks message
 '`getblocks` messages': getblocks message
+'`getblocktxn` message': getblocktxn message
+'`getblocktxn` messages': getblocktxn message
 '`getdata` message': getdata message
 '`getdata` messages': getdata message
 '`getheaders` message': getheaders message
@@ -172,6 +178,8 @@ RPC:
 RPCs: rpc
 '`script`': DO NOT AUTOCROSSREF
 secp256k1:
+'`sendcmpct` message': sendcmpct message
+'`sendcmpct` messages': sendcmpct message
 '`spork` message': spork message
 '`spork` messages': spork message
 '`ssc` message': ssc message

_includes/devdoc/ref_p2p_networking.md

@@ -203,6 +203,42 @@ different reasons:
 
 {% endautocrossref %}
 
+#### Blocktxn
+{% include helpers/subhead-links.md %}
+
+{% autocrossref %}
+
+*Added in protocol version 70209 of Dash Core.*
+
+The `blocktxn` message sends requested block transactions to a node which
+previously requested them with a `getblocktxn` message.
+
+| Bytes    | Name                 | Data Type            | Encoding | Description|
+|----------|----------------------|----------------------|----------|------|
+| 32       | blockhash            | Binary blob          | The output from a double-SHA256 of the block header, as used elsewhere | The blockhash of the block which the transactions being provided are in
+| 1 or 3   | transactions_length  | CompactSize          | As used to encode array lengths elsewhere | The number of transactions provided
+| variable | transactions         | List of transactions | As encoded in `tx` messages in response to `getdata MSG_TX` | The transactions provided
+
+The following annotated hexdump shows a `blocktxn` message.  (The
+message header has been omitted.)
+
+{% highlight text %}
+**ADD HEXDUMP HERE**
+{% endhighlight %}
+
+{% endautocrossref %}
+
+#### CmpctBlock
+{% include helpers/subhead-links.md %}
+
+{% autocrossref %}
+
+The `cmpctblock` message transmits a single serialized compact block.
+
+**ADD DESCRIPTION, FORMAT, AND HEXDUMP**
+
+{% endautocrossref %}
+
 #### GetBlocks
 {% include helpers/subhead-links.md %}
 
@@ -255,6 +291,31 @@ d39f608a7775b537729884d4e6633bb2
 
 {% endautocrossref %}
 
+#### GetBlockTxn
+{% include helpers/subhead-links.md %}
+
+{% autocrossref %}
+
+*Added in protocol version 70209 of Dash Core.*
+
+The `getblocktxn` message requests a `blocktxn` message for any transactions
+that it has not seen after a compact block is received.
+
+| Bytes    | Name            | Data Type            | Encoding | Description|
+|----------|-----------------|----------------------|----------|------|
+| 32       | blockhash       | Binary blob          | The output from a double-SHA256 of the block header, as used elsewhere | The blockhash of the block which the transactions being requested are in
+| 1 or 3   | indexes_length  | CompactSize          | As used to encode array lengths elsewhere | The number of transactions requested
+| (1 or 3) * `indexes_length` | indexes         | List of CompactSizes | Differentially encoded | The indexes of the transactions being requested in the block
+
+The following annotated hexdump shows a `getblocktxn` message.  (The
+message header has been omitted.)
+
+{% highlight text %}
+**ADD HEXDUMP HERE**
+{% endhighlight %}
+
+{% endautocrossref %}
+
 #### GetData
 {% include helpers/subhead-links.md %}
 
@@ -1290,6 +1351,23 @@ header has been omitted.)
 
 {% endautocrossref %}
 
+#### SendCmpct
+{% include helpers/subhead-links.md %}
+
+{% autocrossref %}
+
+The `sendcmpct` message tells the receiving peer to send new block
+announcements using a `cmpctblock` message rather than an `inv` message.
+
+<!--
+There is no payload in a `sendheaders` message.  See the [message header
+section][section message header] for an example of a message without a payload.
+-->
+
+**ADD FORMAT AND HEXDUMP**
+
+{% endautocrossref %}
+
 #### SendHeaders
 {% include helpers/subhead-links.md %}
 
@@ -1303,7 +1381,6 @@ section][section message header] for an example of a message without a payload.
 
 {% endautocrossref %}
 
-
 #### Spork
 {% include helpers/subhead-links.md %}
 

_includes/references.md

@@ -206,6 +206,8 @@ http://opensource.org/licenses/MIT.
 [addr message]: /en/developer-reference#addr "The P2P network message which relays IP addresses and port numbers of active nodes to other nodes and clients, allowing decentralized peer discovery."
 [alert message]: /en/developer-reference#alert "The P2P network message which sends alerts in case of major software problems."
 [block message]: /en/developer-reference#block "The P2P network message which sends a serialized block"
+[blocktxn message]: /en/developer-reference#blocktxn "The P2P network message which sends a list of requested transactions from a compact block"
+[cmpctblock message]: /en/developer-reference#cmpctblock "The P2P network message which sends a serialized compact block"
 [dsa message]: /en/developer-reference#dsa "A P2P network message used to join a mixing pool"
 [dsc message]: /en/developer-reference#dsc "A P2P network message used to indicates a PrivateSend mixing session is complete"
 [dsf message]: /en/developer-reference#dsf "A P2P network message sent as the final mixing transaction in a session asking users to sign the final mixing TX messages"
@@ -221,6 +223,7 @@ http://opensource.org/licenses/MIT.
 [filterload message]: /en/developer-reference#filterclear "A P2P protocol message used to send a filter to a remote peer, requesting that they only send transactions which match the filter."
 [getaddr message]: /en/developer-reference#getaddr "A P2P protool message used to request an addr message containing connection information for other nodes"
 [getblocks message]: /en/developer-reference#getblocks "A P2P protocol message used to request an inv message containing a range of block header hashes"
+[getblocktxn message]: /en/developer-reference#getblocktxn "A P2P protocol message used to request transactions from a compact block"
 [getdata message]: /en/developer-reference#getdata "A P2P protocol message used to request one or more transactions, blocks, or merkle blocks"
 [getheaders message]: /en/developer-reference#getheaders "A P2P protocol message used to request a range of block headers"
 [getsporks message]: /en/developer-reference#getsporks "A P2P network message used to request the status of sporks"
@@ -241,6 +244,7 @@ http://opensource.org/licenses/MIT.
 [ping message]: /en/developer-reference#ping "A P2P network message used to see if the remote host is still connected"
 [pong message]: /en/developer-reference#pong "A P2P network message used to reply to a P2P network ping message"
 [reject message]: /en/developer-reference#reject "A P2P network message used to indicate a previously-received message was rejected for some reason"
+[sendcmpct message]: /en/developer-reference#sendcmpct "A P2P network message used to request new blocks be announced as compact blocks"
 [sendheaders message]: /en/developer-reference#sendheaders "A P2P network message used to request new blocks be announced through headers messages rather than inv messages"
 [spork message]: /en/developer-reference#spork "A P2P network message used to send the activation status of a spork"
 [ssc message]: /en/developer-reference#ssc "A P2P network message used to track the sync status of masternode objects ()"