Merge #19088: validation: use std::chrono throughout some validation functions

789e9dd validation: use std::chrono in IsCurrentForFeeEstimation() (fanquake)
47be28c validation: use std::chrono in CChainState::FlushStateToDisk() (fanquake)

Pull request description:

  Probably up for debate as to which type is used for the constants. Personally, swapping these to hours is more readable.

ACKs for top commit:
  MarcoFalke:
    ACK 789e9dd
  jonatack:
    ACK 789e9dd

Tree-SHA512: f4a25cbd00a49a54b7783a1f588be83706dd2a475cecb5c2e8b97b2d4b27c0955a7454d7486f2454e96351c44f233b300c4f4b9ca62fc7336277f10da34dd5c3

Author: MarcoFalke

src/validation.cpp

@@ -71,12 +71,12 @@ static const unsigned int MAX_DISCONNECTED_TX_POOL_SIZE = 20000;
 static const unsigned int BLOCKFILE_CHUNK_SIZE = 0x1000000; // 16 MiB
 /** The pre-allocation chunk size for rev?????.dat files (since 0.8) */
 static const unsigned int UNDOFILE_CHUNK_SIZE = 0x100000; // 1 MiB
-/** Time to wait (in seconds) between writing blocks/block index to disk. */
-static const unsigned int DATABASE_WRITE_INTERVAL = 60 * 60;
-/** Time to wait (in seconds) between flushing chainstate to disk. */
-static const unsigned int DATABASE_FLUSH_INTERVAL = 24 * 60 * 60;
-/** Maximum age of our tip in seconds for us to be considered current for fee estimation */
-static const int64_t MAX_FEE_ESTIMATION_TIP_AGE = 3 * 60 * 60;
+/** Time to wait between writing blocks/block index to disk. */
+static constexpr std::chrono::hours DATABASE_WRITE_INTERVAL{1};
+/** Time to wait between flushing chainstate to disk. */
+static constexpr std::chrono::hours DATABASE_FLUSH_INTERVAL{24};
+/** Maximum age of our tip for us to be considered current for fee estimation */
+static constexpr std::chrono::hours MAX_FEE_ESTIMATION_TIP_AGE{3};
 
 bool CBlockIndexWorkComparator::operator()(const CBlockIndex *pa, const CBlockIndex *pb) const {
     // First sort by most total work, ...
@@ -347,7 +347,7 @@ static bool IsCurrentForFeeEstimation() EXCLUSIVE_LOCKS_REQUIRED(cs_main)
     AssertLockHeld(cs_main);
     if (::ChainstateActive().IsInitialBlockDownload())
         return false;
-    if (::ChainActive().Tip()->GetBlockTime() < (GetTime() - MAX_FEE_ESTIMATION_TIP_AGE))
+    if (::ChainActive().Tip()->GetBlockTime() < count_seconds(GetTime<std::chrono::seconds>() - MAX_FEE_ESTIMATION_TIP_AGE))
         return false;
     if (::ChainActive().Height() < pindexBestHeader->nHeight - 1)
         return false;
@@ -2269,8 +2269,8 @@ bool CChainState::FlushStateToDisk(
 {
     LOCK(cs_main);
     assert(this->CanFlushToDisk());
-    static int64_t nLastWrite = 0;
-    static int64_t nLastFlush = 0;
+    static std::chrono::microseconds nLastWrite{0};
+    static std::chrono::microseconds nLastFlush{0};
     std::set<int> setFilesToPrune;
     bool full_flush_completed = false;
 
@@ -2302,22 +2302,22 @@ bool CChainState::FlushStateToDisk(
                 }
             }
         }
-        int64_t nNow = GetTimeMicros();
+        const auto nNow = GetTime<std::chrono::microseconds>();
         // Avoid writing/flushing immediately after startup.
-        if (nLastWrite == 0) {
+        if (nLastWrite.count() == 0) {
             nLastWrite = nNow;
         }
-        if (nLastFlush == 0) {
+        if (nLastFlush.count() == 0) {
             nLastFlush = nNow;
         }
         // The cache is large and we're within 10% and 10 MiB of the limit, but we have time now (not in the middle of a block processing).
         bool fCacheLarge = mode == FlushStateMode::PERIODIC && cache_state >= CoinsCacheSizeState::LARGE;
         // The cache is over the limit, we have to write now.
         bool fCacheCritical = mode == FlushStateMode::IF_NEEDED && cache_state >= CoinsCacheSizeState::CRITICAL;
         // It's been a while since we wrote the block index to disk. Do this frequently, so we don't need to redownload after a crash.
-        bool fPeriodicWrite = mode == FlushStateMode::PERIODIC && nNow > nLastWrite + (int64_t)DATABASE_WRITE_INTERVAL * 1000000;
+        bool fPeriodicWrite = mode == FlushStateMode::PERIODIC && nNow > nLastWrite + DATABASE_WRITE_INTERVAL;
         // It's been very long since we flushed the cache. Do this infrequently, to optimize cache usage.
-        bool fPeriodicFlush = mode == FlushStateMode::PERIODIC && nNow > nLastFlush + (int64_t)DATABASE_FLUSH_INTERVAL * 1000000;
+        bool fPeriodicFlush = mode == FlushStateMode::PERIODIC && nNow > nLastFlush + DATABASE_FLUSH_INTERVAL;
         // Combine all conditions that result in a full cache flush.
         fDoFullFlush = (mode == FlushStateMode::ALWAYS) || fCacheLarge || fCacheCritical || fPeriodicFlush || fFlushForPrune;
         // Write blocks and block index to disk.