add new method: mempool.get_info, and rm redundant relayfee method

Author: SomberNight

docs/protocol-changes.rst

@@ -207,3 +207,10 @@ New methods
 -----------
 
   * :func:`blockchain.transaction.broadcast_package` to broadcast a package of transactions (submitpackage).
+  * :func:`mempool.get_info` to get more detailed and general relayfee info.
+
+Removed methods
+---------------
+
+  * :func:`blockchain.relayfee` is removed. The `minrelaytxfee` field
+    of the new :func:`mempool.get_info` RPC is a direct replacement.

docs/protocol-methods.rst

@@ -253,31 +253,6 @@ Subscribe to receive block headers when a new block is found.
   block headers to acquire a consistent view of the chain state.
 
 
-blockchain.relayfee
-===================
-
-Feerates lower than this are considered zero fee and are not being
-relayed to the bitcoin network by the server.
-This feerate does not guarantee acceptance into the mempool of the server.
-
-**Signature**
-
-  .. function:: blockchain.relayfee()
-
-**Result**
-
-  The feerate in BTC/kvB, as a floating point number.
-
-**Example Results**
-
-::
-
-   1e-05
-
-::
-
-   0.0
-
 blockchain.scripthash.get_balance
 =================================
 
@@ -903,6 +878,42 @@ pool, weighted by transaction size.
    [[59.5, 30324], [40.1, 34305], [35.0, 38459], [29.3, 41270], [27.0, 45167], [24.3, 53512], [22.9, 53488], [21.8, 70279], [20.0, 65328], [18.2, 72180], [18.1, 5254], [18.0, 191579], [16.5, 103640], [15.7, 106715], [15.1, 141776], [14.0, 183261], [13.5, 166496], [11.8, 166050], [11.1, 242436], [9.2, 184043], [7.1, 202137], [5.2, 222011], [4.8, 344788], [4.6, 17101], [4.5, 1696864], [4.1, 598001], [4.0, 32688687], [3.9, 505192], [3.8, 38417], [3.7, 2944970], [3.3, 693364], [3.2, 726373], [3.1, 308878], [3.0, 11884957], [2.6, 996967], [2.3, 822802], [2.2, 9075547], [2.1, 12149801], [2.0, 16387874], [1.4, 873120], [1.3, 3493364], [1.1, 2302460], [1.0, 23204633]]
 
 
+mempool.get_info
+================
+
+Returns details on the active state of the TX memory pool.
+
+**Signature**
+
+  .. function:: mempool.get_info()
+
+**Result**
+
+  A dictionary with the following keys:
+
+    * `mempoolminfee`
+        * Type: floating point number
+        * Value:
+            Dynamic minimum fee rate in BTC/kvB for tx to be accepted given current conditions.
+            The maximum of minrelaytxfee and minimum mempool fee, in BTC/kvB.
+    * `minrelaytxfee`
+        * Type: floating point number
+        * Value: Static operator-configurable minimum relay fee for transactions, in BTC/kvB.
+    * `incrementalrelayfee`
+        * Type: floating point number
+        * Value: Static operator-configurable minimum fee rate increment for mempool limiting or replacement, in BTC/kvB.
+
+**Example Result**
+
+::
+
+  {
+      "mempoolminfee": 0.00001000,
+      "minrelaytxfee": 0.00001000,
+      "incrementalrelayfee": 0.00001000
+  }
+
+
 server.add_peer
 ===============
 

docs/protocol-removed.rst

@@ -323,6 +323,33 @@ bandwidth-intensive request.
     implied starting height will be returned; this may range from zero
     to the coin-specific chunk size.
 
+
+blockchain.relayfee
+===================
+
+Feerates lower than this are considered zero fee and are not being
+relayed to the bitcoin network by the server.
+This feerate does not guarantee acceptance into the mempool of the server.
+
+**Signature**
+
+  .. function:: blockchain.relayfee()
+
+**Result**
+
+  The feerate in BTC/kvB, as a floating point number.
+
+**Example Results**
+
+::
+
+   1e-05
+
+::
+
+   0.0
+
+
 server.version
 ==============