Merge bitcoin/bitcoin#32748: fees: fix noisy flushing log

02b5f6078d65c3a2f9ba8b30474d8201516c5c4b fees: make flushes log debug only (ismaelsadeeq)

Pull request description:

  This is a simple PR that updates the flushing log to use debug-level logging under the estimatefee category. It also ensures the log consistently includes only the full file path.
  The motivation behind this is that the "Flushed fee estimates to fee_estimates.dat." logs can become noisy; it's done after one hour, so hiding it in the debug estimatefee category seems reasonable.

  ---
  I left the logs when the file is not found as info because that should only occur when you start a fresh node, change datadir, or explicitly delete the file

ACKs for top commit:
  achow101:
    ACK 02b5f6078d65c3a2f9ba8b30474d8201516c5c4b
  furszy:
    utACK 02b5f6078d65c3a2f9ba8b30474d8201516c5c4b
  l0rinc:
    Lightly tested ACK 02b5f6078d65c3a2f9ba8b30474d8201516c5c4b
  sipa:
    utACK 02b5f6078d65c3a2f9ba8b30474d8201516c5c4b

Tree-SHA512: 3e4b822caa23db9b30f1bb8990b36f35dcfcd82dbfb27c319463447da1df988eded84c47d5319ad637c822bdd04f0a727a176da3632c40d786332b6a5aaa6d89

src/policy/fees/block_policy_estimator.cpp

@@ -972,7 +972,7 @@ void CBlockPolicyEstimator::FlushFeeEstimates()
         LogWarning("Failed to close fee estimates file %s: %s. Continuing anyway.", fs::PathToString(m_estimation_filepath), SysErrorString(errno));
         return;
     }
-    LogInfo("Flushed fee estimates to %s.", fs::PathToString(m_estimation_filepath.filename()));
+    LogDebug(BCLog::ESTIMATEFEE, "Flushed fee estimates to %s.", fs::PathToString(m_estimation_filepath));
 }
 
 bool CBlockPolicyEstimator::Write(AutoFile& fileout) const

test/functional/feature_fee_estimation.py

@@ -332,7 +332,8 @@ class EstimateFeeTest(BitcoinTestFramework):
 
         # Verify if the string "Flushed fee estimates to fee_estimates.dat." is present in the debug log file.
         # If present, it indicates that fee estimates have been successfully flushed to disk.
-        with self.nodes[0].assert_debug_log(expected_msgs=["Flushed fee estimates to fee_estimates.dat."], timeout=1):
+        expected_messages = [f"Flushed fee estimates to {fee_dat}."]
+        with self.nodes[0].assert_debug_log(expected_msgs=expected_messages, timeout=1):
             # Mock the scheduler for an hour to flush fee estimates to fee_estimates.dat
             self.nodes[0].mockscheduler(SECONDS_PER_HOUR)
 
@@ -342,7 +343,7 @@ class EstimateFeeTest(BitcoinTestFramework):
         # Verify that the estimates remain the same if there are no blocks in the flush interval
         block_hash_before = self.nodes[0].getbestblockhash()
         fee_dat_initial_content = open(fee_dat, "rb").read()
-        with self.nodes[0].assert_debug_log(expected_msgs=["Flushed fee estimates to fee_estimates.dat."], timeout=1):
+        with self.nodes[0].assert_debug_log(expected_msgs=expected_messages, timeout=1):
             # Mock the scheduler for an hour to flush fee estimates to fee_estimates.dat
             self.nodes[0].mockscheduler(SECONDS_PER_HOUR)
 
@@ -358,7 +359,7 @@ class EstimateFeeTest(BitcoinTestFramework):
         assert_equal(fee_dat_current_content, fee_dat_initial_content)
 
         # Verify that the estimates are not the same if new blocks were produced in the flush interval
-        with self.nodes[0].assert_debug_log(expected_msgs=["Flushed fee estimates to fee_estimates.dat."], timeout=1):
+        with self.nodes[0].assert_debug_log(expected_msgs=expected_messages, timeout=1):
             # Mock the scheduler for an hour to flush fee estimates to fee_estimates.dat
             self.generate(self.nodes[0], 5, sync_fun=self.no_op)
             self.nodes[0].mockscheduler(SECONDS_PER_HOUR)