Merge #16042: test: Bump MAX_NODES to 12

fa47330397 test: Speed up cache creation (MarcoFalke)
fa6ad7a5ec test: Bump MAX_NODES to 12 (MarcoFalke)

Pull request description:

  When testing a combination of settings that affect the datadir (e.g. prune, blockfilter, ...) we may need a lot of datadirs.
  Bump the maximum number of nodes proactively from 8 to 12, so that caches get populated with 12 node dirs, as opposed to 8.

  Also, add an assert that the list of deterministic keys is exactly the number of max nodes (and not more than that.

  Also, create the cache faster.

ACKs for commit fa4733:
  laanwj:
    utACK fa473303972b7dad600d949dc9b303d8136cb7e7

Tree-SHA512: 9803c765ed52d344102f5a3bce57b05d88a7429dcb05ed66ed6c881fda8d87c2834d02d21b95fe9f39c0efe3b8527e13cf94f006588cde22e8c2cd50b2d517a6

3 files changed, 42 insertions, 51 deletions

diff --git a/test/functional/test_framework/test_framework.py b/test/functional/test_framework/test_framework.py
index 2187bf5f5f..aa674f9ebe 100755
--- a/test/functional/test_framework/test_framework.py
+++ b/test/functional/test_framework/test_framework.py
@@ -29,7 +29,6 @@ from .util import (
     disconnect_nodes,
     get_datadir_path,
     initialize_datadir,
-    p2p_port,
     sync_blocks,
     sync_mempools,
 )
@@ -468,35 +467,23 @@ class BitcoinTestFramework(metaclass=BitcoinTestMetaClass):
     def _initialize_chain(self):
         """Initialize a pre-mined blockchain for use by the test.
 
-        Create a cache of a 199-block-long chain (with wallet) for MAX_NODES
+        Create a cache of a 199-block-long chain
         Afterward, create num_nodes copies from the cache."""
 
+        CACHE_NODE_ID = 0  # Use node 0 to create the cache for all other nodes
+        cache_node_dir = get_datadir_path(self.options.cachedir, CACHE_NODE_ID)
         assert self.num_nodes <= MAX_NODES
-        create_cache = False
-        for i in range(MAX_NODES):
-            if not os.path.isdir(get_datadir_path(self.options.cachedir, i)):
-                create_cache = True
-                break
-
-        if create_cache:
-            self.log.debug("Creating data directories from cached datadir")
-
-            # find and delete old cache directories if any exist
-            for i in range(MAX_NODES):
-                if os.path.isdir(get_datadir_path(self.options.cachedir, i)):
-                    shutil.rmtree(get_datadir_path(self.options.cachedir, i))
-
-            # Create cache directories, run bitcoinds:
-            for i in range(MAX_NODES):
-                datadir = initialize_datadir(self.options.cachedir, i)
-                args = [self.options.bitcoind, "-datadir=" + datadir, '-disablewallet']
-                if i > 0:
-                    args.append("-connect=127.0.0.1:" + str(p2p_port(0)))
-                self.nodes.append(TestNode(
-                    i,
-                    get_datadir_path(self.options.cachedir, i),
+
+        if not os.path.isdir(cache_node_dir):
+            self.log.debug("Creating cache directory {}".format(cache_node_dir))
+
+            initialize_datadir(self.options.cachedir, CACHE_NODE_ID)
+            self.nodes.append(
+                TestNode(
+                    CACHE_NODE_ID,
+                    cache_node_dir,
                     extra_conf=["bind=127.0.0.1"],
-                    extra_args=[],
+                    extra_args=['-disablewallet'],
                     rpchost=None,
                     timewait=self.rpc_timeout,
                     bitcoind=self.options.bitcoind,
@@ -504,12 +491,10 @@ class BitcoinTestFramework(metaclass=BitcoinTestMetaClass):
                     coverage_dir=None,
                     cwd=self.options.tmpdir,
                 ))
-                self.nodes[i].args = args
-                self.start_node(i)
+            self.start_node(CACHE_NODE_ID)
 
             # Wait for RPC connections to be ready
-            for node in self.nodes:
-                node.wait_for_rpc_connection()
+            self.nodes[CACHE_NODE_ID].wait_for_rpc_connection()
 
             # Create a 199-block-long chain; each of the 4 first nodes
             # gets 25 mature blocks and 25 immature.
@@ -518,29 +503,29 @@ class BitcoinTestFramework(metaclass=BitcoinTestMetaClass):
             # This is needed so that we are out of IBD when the test starts,
             # see the tip age check in IsInitialBlockDownload().
             for i in range(8):
-                self.nodes[0].generatetoaddress(25 if i != 7 else 24, self.nodes[i % 4].get_deterministic_priv_key().address)
-            self.sync_blocks()
+                self.nodes[CACHE_NODE_ID].generatetoaddress(
+                    nblocks=25 if i != 7 else 24,
+                    address=TestNode.PRIV_KEYS[i % 4].address,
+                )
 
-            for n in self.nodes:
-                assert_equal(n.getblockchaininfo()["blocks"], 199)
+            assert_equal(self.nodes[CACHE_NODE_ID].getblockchaininfo()["blocks"], 199)
 
-            # Shut them down, and clean up cache directories:
+            # Shut it down, and clean up cache directories:
             self.stop_nodes()
             self.nodes = []
 
-            def cache_path(n, *paths):
-                return os.path.join(get_datadir_path(self.options.cachedir, n), "regtest", *paths)
+            def cache_path(*paths):
+                return os.path.join(cache_node_dir, "regtest", *paths)
 
-            for i in range(MAX_NODES):
-                os.rmdir(cache_path(i, 'wallets'))  # Remove empty wallets dir
-                for entry in os.listdir(cache_path(i)):
-                    if entry not in ['chainstate', 'blocks']:
-                        os.remove(cache_path(i, entry))
+            os.rmdir(cache_path('wallets'))  # Remove empty wallets dir
+            for entry in os.listdir(cache_path()):
+                if entry not in ['chainstate', 'blocks']:  # Only keep chainstate and blocks folder
+                    os.remove(cache_path(entry))
 
         for i in range(self.num_nodes):
-            from_dir = get_datadir_path(self.options.cachedir, i)
+            self.log.debug("Copy cache directory {} to node {}".format(cache_node_dir, i))
             to_dir = get_datadir_path(self.options.tmpdir, i)
-            shutil.copytree(from_dir, to_dir)
+            shutil.copytree(cache_node_dir, to_dir)
             initialize_datadir(self.options.tmpdir, i)  # Overwrite port/rpcport in bitcoin.conf
 
     def _initialize_chain_clean(self):
diff --git a/test/functional/test_framework/test_node.py b/test/functional/test_framework/test_node.py
index b9d1082ddc..3311377090 100755
--- a/test/functional/test_framework/test_node.py
+++ b/test/functional/test_framework/test_node.py
@@ -23,6 +23,7 @@ import sys
 
 from .authproxy import JSONRPCException
 from .util import (
+    MAX_NODES,
     append_config,
     delete_cookie_file,
     get_rpc_proxy,
@@ -110,10 +111,8 @@ class TestNode():
 
         self.p2ps = []
 
-    def get_deterministic_priv_key(self):
-        """Return a deterministic priv key in base58, that only depends on the node's index"""
-        AddressKeyPair = collections.namedtuple('AddressKeyPair', ['address', 'key'])
-        PRIV_KEYS = [
+    AddressKeyPair = collections.namedtuple('AddressKeyPair', ['address', 'key'])
+    PRIV_KEYS = [
             # address , privkey
             AddressKeyPair('mjTkW3DjgyZck4KbiRusZsqTgaYTxdSz6z', 'cVpF924EspNh8KjYsfhgY96mmxvT6DgdWiTYMtMjuM74hJaU5psW'),
             AddressKeyPair('msX6jQXvxiNhx3Q62PKeLPrhrqZQdSimTg', 'cUxsWyKyZ9MAQTaAhUQWJmBbSvHMwSmuv59KgxQV7oZQU3PXN3KE'),
@@ -124,8 +123,15 @@ class TestNode():
             AddressKeyPair('myzuPxRwsf3vvGzEuzPfK9Nf2RfwauwYe6', 'cQMpDLJwA8DBe9NcQbdoSb1BhmFxVjWD5gRyrLZCtpuF9Zi3a9RK'),
             AddressKeyPair('mumwTaMtbxEPUswmLBBN3vM9oGRtGBrys8', 'cSXmRKXVcoouhNNVpcNKFfxsTsToY5pvB9DVsFksF1ENunTzRKsy'),
             AddressKeyPair('mpV7aGShMkJCZgbW7F6iZgrvuPHjZjH9qg', 'cSoXt6tm3pqy43UMabY6eUTmR3eSUYFtB2iNQDGgb3VUnRsQys2k'),
-        ]
-        return PRIV_KEYS[self.index]
+            AddressKeyPair('mq4fBNdckGtvY2mijd9am7DRsbRB4KjUkf', 'cN55daf1HotwBAgAKWVgDcoppmUNDtQSfb7XLutTLeAgVc3u8hik'),
+            AddressKeyPair('mpFAHDjX7KregM3rVotdXzQmkbwtbQEnZ6', 'cT7qK7g1wkYEMvKowd2ZrX1E5f6JQ7TM246UfqbCiyF7kZhorpX3'),
+            AddressKeyPair('mzRe8QZMfGi58KyWCse2exxEFry2sfF2Y7', 'cPiRWE8KMjTRxH1MWkPerhfoHFn5iHPWVK5aPqjW8NxmdwenFinJ'),
+    ]
+
+    def get_deterministic_priv_key(self):
+        """Return a deterministic priv key in base58, that only depends on the node's index"""
+        assert len(self.PRIV_KEYS) == MAX_NODES
+        return self.PRIV_KEYS[self.index]
 
     def get_mem_rss_kilobytes(self):
         """Get the memory usage (RSS) per `ps`.
diff --git a/test/functional/test_framework/util.py b/test/functional/test_framework/util.py
index 0583b42388..26215083fb 100644
--- a/test/functional/test_framework/util.py
+++ b/test/functional/test_framework/util.py
@@ -228,7 +228,7 @@ def wait_until(predicate, *, attempts=float('inf'), timeout=float('inf'), lock=N
 ############################################
 
 # The maximum number of nodes a single test can spawn
-MAX_NODES = 8
+MAX_NODES = 12
 # Don't assign rpc or p2p ports lower than this
 PORT_MIN = 11000
 # The number of ports to "reserve" for p2p and rpc, each