[backport#15163] Correct units for "-dbcache" and "-prune"

Summary:
6f6514a08090b37b5e8c086015ee4881813ef867 Correct units for "-dbcache" and "-prune" (Hennadii Stepanov)

Pull request description:

  Actually, all `dbcache`-related values in the code are measured in MiB (not in megabytes, MB) or in bytes (e.g., `nTotalCache`).

  See: https://github.com/bitcoin/bitcoin/blob/master/src/txdb.h

  https://github.com/bitcoin/bitcoin/blob/ba8c8b22272ad40fe2de465d7e745532bab48d3b/src/init.cpp#L1405-L1424

  Also, "-prune" is fixed:
  1. The GUI values in GB are translated to the node values in MiB correctly.
  2. The maximum of the "prune" `QSpinBox` is not limited by default value of 99 (GB).

  Fix: #15106

---

Backport of Core [[bitcoin/bitcoin#15163 | PR15163]]

Test Plan:
  ninja all check check-functional

Reviewers: #bitcoin_abc, jasonbcox

Reviewed By: #bitcoin_abc, jasonbcox

Differential Revision: https://reviews.bitcoinabc.org/D7896

src/init.cpp

@@ -430,9 +430,8 @@ void SetupServerArgs() {
         OptionsCategory::OPTIONS);
     gArgs.AddArg(
         "-dbcache=<n>",
-        strprintf(
-            "Set database cache size in megabytes (%d to %d, default: %d)",
-            nMinDbCache, nMaxDbCache, nDefaultDbCache),
+        strprintf("Set database cache size in MiB (%d to %d, default: %d)",
+                  nMinDbCache, nMaxDbCache, nDefaultDbCache),
         ArgsManager::ALLOW_ANY, OptionsCategory::OPTIONS);
     gArgs.AddArg("-debuglogfile=<file>",
                  strprintf("Specify location of debug log file. Relative paths "
@@ -1854,8 +1853,8 @@ bool AppInitParameterInteraction(Config &config) {
                               .translated,
                           MIN_DISK_SPACE_FOR_BLOCK_FILES / 1024 / 1024));
         }
-        LogPrintf("Prune configured to target %uMiB on disk for block and undo "
-                  "files.\n",
+        LogPrintf("Prune configured to target %u MiB on disk for block and "
+                  "undo files.\n",
                   nPruneTarget / 1024 / 1024);
         fPruneMode = true;
     }
@@ -2363,20 +2362,20 @@ bool AppInitMain(Config &config, RPCServer &rpcServer,
     int64_t nMempoolSizeMax =
         gArgs.GetArg("-maxmempool", DEFAULT_MAX_MEMPOOL_SIZE) * 1000000;
     LogPrintf("Cache configuration:\n");
-    LogPrintf("* Using %.1fMiB for block index database\n",
+    LogPrintf("* Using %.1f MiB for block index database\n",
               nBlockTreeDBCache * (1.0 / 1024 / 1024));
     if (gArgs.GetBoolArg("-txindex", DEFAULT_TXINDEX)) {
-        LogPrintf("* Using %.1fMiB for transaction index database\n",
+        LogPrintf("* Using %.1f MiB for transaction index database\n",
                   nTxIndexCache * (1.0 / 1024 / 1024));
     }
     for (BlockFilterType filter_type : g_enabled_filter_types) {
         LogPrintf("* Using %.1f MiB for %s block filter index database\n",
                   filter_index_cache * (1.0 / 1024 / 1024),
                   BlockFilterTypeName(filter_type));
     }
-    LogPrintf("* Using %.1fMiB for chain state database\n",
+    LogPrintf("* Using %.1f MiB for chain state database\n",
               nCoinDBCache * (1.0 / 1024 / 1024));
-    LogPrintf("* Using %.1fMiB for in-memory UTXO set (plus up to %.1fMiB of "
+    LogPrintf("* Using %.1f MiB for in-memory UTXO set (plus up to %.1f MiB of "
               "unused mempool space)\n",
               nCoinCacheUsage * (1.0 / 1024 / 1024),
               nMempoolSizeMax * (1.0 / 1024 / 1024));

src/qt/forms/optionsdialog.ui

@@ -121,7 +121,7 @@
          <item>
           <widget class="QLabel" name="databaseCacheUnitLabel">
            <property name="text">
-            <string>MB</string>
+            <string>MiB</string>
            </property>
            <property name="textFormat">
             <enum>Qt::PlainText</enum>

src/qt/guiconstants.h

@@ -48,4 +48,7 @@ static const int TOOLTIP_WRAP_THRESHOLD = 80;
 #define QAPP_APP_NAME_TESTNET "BitcoinABC-Qt-testnet"
 #define QAPP_APP_NAME_REGTEST "BitcoinABC-Qt-regtest"
 
+/* One gigabyte (GB) in bytes */
+static constexpr uint64_t GB_BYTES{1'000'000'000};
+
 #endif // BITCOIN_QT_GUICONSTANTS_H

src/qt/intro.cpp

@@ -9,6 +9,7 @@
 #include <fs.h>
 #include <interfaces/node.h>
 #include <qt/forms/ui_intro.h>
+#include <qt/guiconstants.h>
 #include <qt/guiutil.h>
 #include <qt/intro.h>
 #include <util/system.h>
@@ -19,7 +20,6 @@
 
 #include <cmath>
 
-static const uint64_t GB_BYTES = 1000000000LL;
 /**
  * Total required space (in GB) depending on user choice (prune, not prune).
  */

src/qt/optionsdialog.cpp

@@ -12,6 +12,7 @@
 #include <interfaces/node.h>
 #include <netbase.h>
 #include <qt/bitcoinunits.h>
+#include <qt/guiconstants.h>
 #include <qt/guiutil.h>
 #include <qt/optionsmodel.h>
 #include <txdb.h>       // for -dbcache defaults
@@ -33,13 +34,6 @@ OptionsDialog::OptionsDialog(QWidget *parent, bool enableWallet)
     /* Main elements init */
     ui->databaseCache->setMinimum(nMinDbCache);
     ui->databaseCache->setMaximum(nMaxDbCache);
-    static const uint64_t GiB = 1024 * 1024 * 1024;
-    static const uint64_t nMinDiskSpace =
-        MIN_DISK_SPACE_FOR_BLOCK_FILES / GiB +
-                (MIN_DISK_SPACE_FOR_BLOCK_FILES % GiB)
-            ? 1
-            : 0;
-    ui->pruneSize->setMinimum(nMinDiskSpace);
     ui->threadsScriptVerif->setMinimum(-GetNumCores());
     ui->threadsScriptVerif->setMaximum(MAX_SCRIPTCHECK_THREADS);
     ui->pruneWarning->setVisible(false);
@@ -178,6 +172,15 @@ void OptionsDialog::setModel(OptionsModel *_model) {
         mapper->toFirst();
 
         updateDefaultProxyNets();
+
+        // Prune values are in GB to be consistent with intro.cpp
+        static constexpr uint64_t nMinDiskSpace =
+            (MIN_DISK_SPACE_FOR_BLOCK_FILES / GB_BYTES) +
+                    (MIN_DISK_SPACE_FOR_BLOCK_FILES % GB_BYTES)
+                ? 1
+                : 0;
+        ui->pruneSize->setRange(nMinDiskSpace,
+                                _model->node().getAssumedBlockchainSize());
     }
 
     /* warn when one of the following settings changes by user action (placed

src/qt/optionsmodel.cpp

@@ -12,6 +12,7 @@
 #include <net.h>
 #include <netbase.h>
 #include <qt/bitcoinunits.h>
+#include <qt/guiconstants.h>
 #include <qt/guiutil.h>
 #include <qt/intro.h>
 #include <txdb.h>       // for -dbcache defaults
@@ -103,10 +104,11 @@ void OptionsModel::Init(bool resetSettings) {
     if (!settings.contains("nPruneSize")) {
         settings.setValue("nPruneSize", 2);
     }
-    // Convert prune size to MB:
-    const uint64_t nPruneSizeMB = settings.value("nPruneSize").toInt() * 1000;
+    // Convert prune size from GB to MiB:
+    const uint64_t nPruneSizeMiB =
+        (settings.value("nPruneSize").toInt() * GB_BYTES) >> 20;
     if (!m_node.softSetArg("-prune", settings.value("bPrune").toBool()
-                                         ? std::to_string(nPruneSizeMB)
+                                         ? std::to_string(nPruneSizeMiB)
                                          : "0")) {
         addOverriddenOption("-prune");
     }

src/validation.h

@@ -229,16 +229,17 @@ static const signed int DEFAULT_CHECKBLOCKS = 6;
 static const unsigned int DEFAULT_CHECKLEVEL = 3;
 
 /**
- * Require that user allocate at least 550MB for block & undo files (blk???.dat
- * and rev???.dat)
+ * Require that user allocate at least 550 MiB for block & undo files
+ * (blk???.dat and rev???.dat)
  * At 1MB per block, 288 blocks = 288MB.
  * Add 15% for Undo data = 331MB
  * Add 20% for Orphan block rate = 397MB
  * We want the low water mark after pruning to be at least 397 MB and since we
  * prune in full block file chunks, we need the high water mark which triggers
  * the prune to be one 128MB block file + added 15% undo data = 147MB greater
- * for a total of 545MB. Setting the target to > than 550MB will make it likely
- * we can respect the target.
+ * for a total of 545MB
+ * Setting the target to >= 550 MiB will make it likely we can respect the
+ * target.
  */
 static const uint64_t MIN_DISK_SPACE_FOR_BLOCK_FILES = 550 * 1024 * 1024;
 

test/functional/feature_pruning.py

@@ -377,7 +377,7 @@ def has_block(index):
         assert not has_block(
             3), "blk00003.dat is still there, should be pruned by now"
 
-        # stop node, start back up with auto-prune at 550MB, make sure still
+        # stop node, start back up with auto-prune at 550 MiB, make sure still
         # runs
         self.stop_node(node_number)
         self.start_node(node_number, extra_args=["-prune=550"])