Move some static functions out of wallet.h/cpp

This commit just moves a few function declarations and updates callers.
Function bodies are moved in two followup MOVEONLY commits.

This change is desirable because wallet.h/cpp are monolithic and hard to
navigate, so pulling things out and grouping together pieces of related
functionality should improve the organization.

Another proximate motivation is the wallet process separation work in
https://github.com/bitcoin/bitcoin/pull/10973, where (at least initially)
parameter parsing and fee estimation are still done in the main process rather
than the wallet process, and having functions that run in different processes
scrambled up throughout wallet.cpp is unnecessarily confusing.

13 files changed, 117 insertions, 50 deletions

diff --git a/src/Makefile.am b/src/Makefile.am
index f7abab482e..dea656869d 100644
--- a/src/Makefile.am
+++ b/src/Makefile.am
@@ -162,6 +162,8 @@ BITCOIN_CORE_H = \
   wallet/crypter.h \
   wallet/db.h \
   wallet/feebumper.h \
+  wallet/fees.h \
+  wallet/init.h \
   wallet/rpcwallet.h \
   wallet/wallet.h \
   wallet/walletdb.h \
@@ -239,6 +241,8 @@ libbitcoin_wallet_a_SOURCES = \
   wallet/crypter.cpp \
   wallet/db.cpp \
   wallet/feebumper.cpp \
+  wallet/fees.cpp \
+  wallet/init.cpp \
   wallet/rpcdump.cpp \
   wallet/rpcwallet.cpp \
   wallet/wallet.cpp \
diff --git a/src/init.cpp b/src/init.cpp
index d79c2967b9..c6ddefbfc9 100644
--- a/src/init.cpp
+++ b/src/init.cpp
@@ -43,6 +43,7 @@
 #include "utilmoneystr.h"
 #include "validationinterface.h"
 #ifdef ENABLE_WALLET
+#include "wallet/init.h"
 #include "wallet/wallet.h"
 #endif
 #include "warnings.h"
@@ -420,7 +421,7 @@ std::string HelpMessage(HelpMessageMode mode)
     strUsage += HelpMessageOpt("-maxuploadtarget=<n>", strprintf(_("Tries to keep outbound traffic under the given target (in MiB per 24h), 0 = no limit (default: %d)"), DEFAULT_MAX_UPLOAD_TARGET));
 
 #ifdef ENABLE_WALLET
-    strUsage += CWallet::GetWalletHelpString(showDebug);
+    strUsage += GetWalletHelpString(showDebug);
 #endif
 
 #if ENABLE_ZMQ
@@ -1035,7 +1036,7 @@ bool AppInitParameterInteraction()
         if (!ParseMoney(gArgs.GetArg("-minrelaytxfee", ""), n)) {
             return InitError(AmountErrMsg("minrelaytxfee", gArgs.GetArg("-minrelaytxfee", "")));
         }
-        // High fee check is done afterward in CWallet::ParameterInteraction()
+        // High fee check is done afterward in WalletParameterInteraction()
         ::minRelayTxFee = CFeeRate(n);
     } else if (incrementalRelayFee > ::minRelayTxFee) {
         // Allow only setting incrementalRelayFee to control both
@@ -1068,7 +1069,7 @@ bool AppInitParameterInteraction()
     nBytesPerSigOp = gArgs.GetArg("-bytespersigop", nBytesPerSigOp);
 
 #ifdef ENABLE_WALLET
-    if (!CWallet::ParameterInteraction())
+    if (!WalletParameterInteraction())
         return false;
 #endif
 
@@ -1245,7 +1246,7 @@ bool AppInitMain(boost::thread_group& threadGroup, CScheduler& scheduler)
 
     // ********************************************************* Step 5: verify wallet database integrity
 #ifdef ENABLE_WALLET
-    if (!CWallet::Verify())
+    if (!WalletVerify())
         return false;
 #endif
     // ********************************************************* Step 6: network initialization
@@ -1566,7 +1567,7 @@ bool AppInitMain(boost::thread_group& threadGroup, CScheduler& scheduler)
 
     // ********************************************************* Step 8: load wallet
 #ifdef ENABLE_WALLET
-    if (!CWallet::InitLoadWallet())
+    if (!InitLoadWallet())
         return false;
 #else
     LogPrintf("No wallet support compiled in!\n");
diff --git a/src/qt/coincontroldialog.cpp b/src/qt/coincontroldialog.cpp
index f3ee0fbe39..562c361799 100644
--- a/src/qt/coincontroldialog.cpp
+++ b/src/qt/coincontroldialog.cpp
@@ -18,6 +18,7 @@
 #include "policy/fees.h"
 #include "policy/policy.h"
 #include "validation.h" // For mempool
+#include "wallet/fees.h"
 #include "wallet/wallet.h"
 
 #include <QApplication>
@@ -510,7 +511,7 @@ void CoinControlDialog::updateLabels(WalletModel *model, QDialog* dialog)
                 nBytes -= 34;
 
         // Fee
-        nPayFee = CWallet::GetMinimumFee(nBytes, *coinControl, ::mempool, ::feeEstimator, nullptr /* FeeCalculation */);
+        nPayFee = GetMinimumFee(nBytes, *coinControl, ::mempool, ::feeEstimator, nullptr /* FeeCalculation */);
 
         if (nPayAmount > 0)
         {
diff --git a/src/qt/optionsdialog.cpp b/src/qt/optionsdialog.cpp
index b80b6541dd..6f2f2f37c6 100644
--- a/src/qt/optionsdialog.cpp
+++ b/src/qt/optionsdialog.cpp
@@ -17,10 +17,6 @@
 #include "netbase.h"
 #include "txdb.h" // for -dbcache defaults
 
-#ifdef ENABLE_WALLET
-#include "wallet/wallet.h" // for CWallet::GetRequiredFee()
-#endif
-
 #include <QDataWidgetMapper>
 #include <QDir>
 #include <QIntValidator>
diff --git a/src/qt/sendcoinsdialog.cpp b/src/qt/sendcoinsdialog.cpp
index a01886c3ea..625e435742 100644
--- a/src/qt/sendcoinsdialog.cpp
+++ b/src/qt/sendcoinsdialog.cpp
@@ -22,7 +22,7 @@
 #include "ui_interface.h"
 #include "txmempool.h"
 #include "policy/fees.h"
-#include "wallet/wallet.h"
+#include "wallet/fees.h"
 
 #include <QFontMetrics>
 #include <QMessageBox>
@@ -185,7 +185,7 @@ void SendCoinsDialog::setModel(WalletModel *_model)
         connect(ui->checkBoxMinimumFee, SIGNAL(stateChanged(int)), this, SLOT(coinControlUpdateLabels()));
         connect(ui->optInRBF, SIGNAL(stateChanged(int)), this, SLOT(updateSmartFeeLabel()));
         connect(ui->optInRBF, SIGNAL(stateChanged(int)), this, SLOT(coinControlUpdateLabels()));
-        ui->customFee->setSingleStep(CWallet::GetRequiredFee(1000));
+        ui->customFee->setSingleStep(GetRequiredFee(1000));
         updateFeeSectionControls();
         updateMinFeeLabel();
         updateSmartFeeLabel();
@@ -610,7 +610,7 @@ void SendCoinsDialog::on_buttonMinimizeFee_clicked()
 void SendCoinsDialog::setMinimumFee()
 {
     ui->radioCustomPerKilobyte->setChecked(true);
-    ui->customFee->setValue(CWallet::GetRequiredFee(1000));
+    ui->customFee->setValue(GetRequiredFee(1000));
 }
 
 void SendCoinsDialog::updateFeeSectionControls()
@@ -643,7 +643,7 @@ void SendCoinsDialog::updateMinFeeLabel()
 {
     if (model && model->getOptionsModel())
         ui->checkBoxMinimumFee->setText(tr("Pay only the required fee of %1").arg(
-            BitcoinUnits::formatWithUnit(model->getOptionsModel()->getDisplayUnit(), CWallet::GetRequiredFee(1000)) + "/kB")
+            BitcoinUnits::formatWithUnit(model->getOptionsModel()->getDisplayUnit(), GetRequiredFee(1000)) + "/kB")
         );
 }
 
@@ -668,7 +668,7 @@ void SendCoinsDialog::updateSmartFeeLabel()
     updateCoinControlState(coin_control);
     coin_control.m_feerate.reset(); // Explicitly use only fee estimation rate for smart fee labels
     FeeCalculation feeCalc;
-    CFeeRate feeRate = CFeeRate(CWallet::GetMinimumFee(1000, coin_control, ::mempool, ::feeEstimator, &feeCalc));
+    CFeeRate feeRate = CFeeRate(GetMinimumFee(1000, coin_control, ::mempool, ::feeEstimator, &feeCalc));
 
     ui->labelSmartFee->setText(BitcoinUnits::formatWithUnit(model->getOptionsModel()->getDisplayUnit(), feeRate.GetFeePerK()) + "/kB");
 
diff --git a/src/wallet/feebumper.cpp b/src/wallet/feebumper.cpp
index c1ea2b6290..285b0099c2 100644
--- a/src/wallet/feebumper.cpp
+++ b/src/wallet/feebumper.cpp
@@ -5,6 +5,7 @@
 #include "consensus/validation.h"
 #include "wallet/coincontrol.h"
 #include "wallet/feebumper.h"
+#include "wallet/fees.h"
 #include "wallet/wallet.h"
 #include "policy/fees.h"
 #include "policy/policy.h"
@@ -156,7 +157,7 @@ CFeeBumper::CFeeBumper(const CWallet *pWallet, const uint256 txidIn, const CCoin
             currentResult = BumpFeeResult::INVALID_PARAMETER;
             return;
         }
-        CAmount requiredFee = CWallet::GetRequiredFee(maxNewTxSize);
+        CAmount requiredFee = GetRequiredFee(maxNewTxSize);
         if (totalFee < requiredFee) {
             vErrors.push_back(strprintf("Insufficient totalFee (cannot be less than required fee %s)",
                                                                 FormatMoney(requiredFee)));
@@ -166,7 +167,7 @@ CFeeBumper::CFeeBumper(const CWallet *pWallet, const uint256 txidIn, const CCoin
         nNewFee = totalFee;
         nNewFeeRate = CFeeRate(totalFee, maxNewTxSize);
     } else {
-        nNewFee = CWallet::GetMinimumFee(maxNewTxSize, coin_control, mempool, ::feeEstimator, nullptr /* FeeCalculation */);
+        nNewFee = GetMinimumFee(maxNewTxSize, coin_control, mempool, ::feeEstimator, nullptr /* FeeCalculation */);
         nNewFeeRate = CFeeRate(nNewFee, maxNewTxSize);
 
         // New fee rate must be at least old rate + minimum incremental relay rate
diff --git a/src/wallet/fees.cpp b/src/wallet/fees.cpp
new file mode 100644
index 0000000000..3a9e68354d
--- /dev/null
+++ b/src/wallet/fees.cpp
@@ -0,0 +1,13 @@
+// Copyright (c) 2009-2010 Satoshi Nakamoto
+// Copyright (c) 2009-2017 The Bitcoin Core developers
+// Distributed under the MIT software license, see the accompanying
+// file COPYING or http://www.opensource.org/licenses/mit-license.php.
+
+#include "wallet/fees.h"
+
+#include "policy/policy.h"
+#include "txmempool.h"
+#include "util.h"
+#include "validation.h"
+#include "wallet/coincontrol.h"
+#include "wallet/wallet.h"
diff --git a/src/wallet/fees.h b/src/wallet/fees.h
new file mode 100644
index 0000000000..7b8a7dc868
--- /dev/null
+++ b/src/wallet/fees.h
@@ -0,0 +1,34 @@
+// Copyright (c) 2009-2010 Satoshi Nakamoto
+// Copyright (c) 2009-2017 The Bitcoin Core developers
+// Distributed under the MIT software license, see the accompanying
+// file COPYING or http://www.opensource.org/licenses/mit-license.php.
+
+#ifndef BITCOIN_WALLET_FEES_H
+#define BITCOIN_WALLET_FEES_H
+
+#include "amount.h"
+
+class CBlockPolicyEstimator;
+class CCoinControl;
+class CFeeRate;
+class CTxMemPool;
+struct FeeCalculation;
+
+/**
+ * Return the minimum required fee taking into account the
+ * floating relay fee and user set minimum transaction fee
+ */
+CAmount GetRequiredFee(unsigned int nTxBytes);
+
+/**
+ * Estimate the minimum fee considering user set parameters
+ * and the required fee
+ */
+CAmount GetMinimumFee(unsigned int nTxBytes, const CCoinControl& coin_control, const CTxMemPool& pool, const CBlockPolicyEstimator& estimator, FeeCalculation *feeCalc);
+
+/**
+ * Return the maximum feerate for discarding change.
+ */
+CFeeRate GetDiscardRate(const CBlockPolicyEstimator& estimator);
+
+#endif // BITCOIN_WALLET_FEES_H
diff --git a/src/wallet/init.cpp b/src/wallet/init.cpp
new file mode 100644
index 0000000000..0946678926
--- /dev/null
+++ b/src/wallet/init.cpp
@@ -0,0 +1,12 @@
+// Copyright (c) 2009-2010 Satoshi Nakamoto
+// Copyright (c) 2009-2017 The Bitcoin Core developers
+// Distributed under the MIT software license, see the accompanying
+// file COPYING or http://www.opensource.org/licenses/mit-license.php.
+
+#include "wallet/init.h"
+
+#include "net.h"
+#include "util.h"
+#include "utilmoneystr.h"
+#include "validation.h"
+#include "wallet/wallet.h"
diff --git a/src/wallet/init.h b/src/wallet/init.h
new file mode 100644
index 0000000000..fa2251506d
--- /dev/null
+++ b/src/wallet/init.h
@@ -0,0 +1,25 @@
+// Copyright (c) 2009-2010 Satoshi Nakamoto
+// Copyright (c) 2009-2017 The Bitcoin Core developers
+// Distributed under the MIT software license, see the accompanying
+// file COPYING or http://www.opensource.org/licenses/mit-license.php.
+
+#ifndef BITCOIN_WALLET_INIT_H
+#define BITCOIN_WALLET_INIT_H
+
+#include <string>
+
+//! Return the wallets help message.
+std::string GetWalletHelpString(bool showDebug);
+
+//! Wallets parameter interaction
+bool WalletParameterInteraction();
+
+//! Responsible for reading and validating the -wallet arguments and verifying the wallet database.
+//  This function will perform salvage on the wallet if requested, as long as only one wallet is
+//  being loaded (CWallet::ParameterInteraction forbids -salvagewallet, -zapwallettxes or -upgradewallet with multiwallet).
+bool WalletVerify();
+
+//! Load wallet databases.
+bool InitLoadWallet();
+
+#endif // BITCOIN_WALLET_INIT_H
diff --git a/src/wallet/rpcwallet.cpp b/src/wallet/rpcwallet.cpp
index a6176c3485..30b8c8260a 100644
--- a/src/wallet/rpcwallet.cpp
+++ b/src/wallet/rpcwallet.cpp
@@ -8,7 +8,6 @@
 #include "chain.h"
 #include "consensus/validation.h"
 #include "core_io.h"
-#include "init.h"
 #include "httpserver.h"
 #include "validation.h"
 #include "net.h"
@@ -27,6 +26,8 @@
 #include "wallet/wallet.h"
 #include "wallet/walletdb.h"
 
+#include <init.h>  // For StartShutdown
+
 #include <stdint.h>
 
 #include <univalue.h>
diff --git a/src/wallet/wallet.cpp b/src/wallet/wallet.cpp
index 599e74149c..a9b6152751 100644
--- a/src/wallet/wallet.cpp
+++ b/src/wallet/wallet.cpp
@@ -30,6 +30,7 @@
 #include "util.h"
 #include "ui_interface.h"
 #include "utilmoneystr.h"
+#include "wallet/fees.h"
 
 #include <assert.h>
 
@@ -494,7 +495,7 @@ void CWallet::Flush(bool shutdown)
     dbw->Flush(shutdown);
 }
 
-bool CWallet::Verify()
+bool WalletVerify()
 {
     if (gArgs.GetBoolArg("-disablewallet", DEFAULT_DISABLE_WALLET))
         return true;
@@ -2599,7 +2600,7 @@ bool CWallet::FundTransaction(CMutableTransaction& tx, CAmount& nFeeRet, int& nC
     return true;
 }
 
-static CFeeRate GetDiscardRate(const CBlockPolicyEstimator& estimator)
+CFeeRate GetDiscardRate(const CBlockPolicyEstimator& estimator)
 {
     unsigned int highest_target = estimator.HighestTargetTracked(FeeEstimateHorizon::LONG_HALFLIFE);
     CFeeRate discard_rate = estimator.estimateSmartFee(highest_target, nullptr /* FeeCalculation */, false /* conservative */);
@@ -3031,12 +3032,12 @@ bool CWallet::AddAccountingEntry(const CAccountingEntry& acentry, CWalletDB *pwa
     return true;
 }
 
-CAmount CWallet::GetRequiredFee(unsigned int nTxBytes)
+CAmount GetRequiredFee(unsigned int nTxBytes)
 {
-    return std::max(minTxFee.GetFee(nTxBytes), ::minRelayTxFee.GetFee(nTxBytes));
+    return std::max(CWallet::minTxFee.GetFee(nTxBytes), ::minRelayTxFee.GetFee(nTxBytes));
 }
 
-CAmount CWallet::GetMinimumFee(unsigned int nTxBytes, const CCoinControl& coin_control, const CTxMemPool& pool, const CBlockPolicyEstimator& estimator, FeeCalculation *feeCalc)
+CAmount GetMinimumFee(unsigned int nTxBytes, const CCoinControl& coin_control, const CTxMemPool& pool, const CBlockPolicyEstimator& estimator, FeeCalculation *feeCalc)
 {
     /* User control of how to calculate fee uses the following parameter precedence:
        1. coin_control.m_feerate
@@ -3068,7 +3069,7 @@ CAmount CWallet::GetMinimumFee(unsigned int nTxBytes, const CCoinControl& coin_c
         fee_needed = estimator.estimateSmartFee(target, feeCalc, conservative_estimate).GetFee(nTxBytes);
         if (fee_needed == 0) {
             // if we don't have enough data for estimateSmartFee, then use fallbackFee
-            fee_needed = fallbackFee.GetFee(nTxBytes);
+            fee_needed = CWallet::fallbackFee.GetFee(nTxBytes);
             if (feeCalc) feeCalc->reason = FeeReason::FALLBACK;
         }
         // Obey mempool min fee when using smart fee estimation
@@ -3888,7 +3889,7 @@ std::vector<std::string> CWallet::GetDestValues(const std::string& prefix) const
     return values;
 }
 
-std::string CWallet::GetWalletHelpString(bool showDebug)
+std::string GetWalletHelpString(bool showDebug)
 {
     std::string strUsage = HelpMessageGroup(_("Wallet options:"));
     strUsage += HelpMessageOpt("-disablewallet", _("Do not load the wallet and disable wallet RPC calls"));
@@ -4121,7 +4122,7 @@ CWallet* CWallet::CreateWalletFromFile(const std::string walletFile)
     return walletInstance;
 }
 
-bool CWallet::InitLoadWallet()
+bool InitLoadWallet()
 {
     if (gArgs.GetBoolArg("-disablewallet", DEFAULT_DISABLE_WALLET)) {
         LogPrintf("Wallet disabled!\n");
@@ -4129,7 +4130,7 @@ bool CWallet::InitLoadWallet()
     }
 
     for (const std::string& walletFile : gArgs.GetArgs("-wallet")) {
-        CWallet * const pwallet = CreateWalletFromFile(walletFile);
+        CWallet * const pwallet = CWallet::CreateWalletFromFile(walletFile);
         if (!pwallet) {
             return false;
         }
@@ -4153,7 +4154,7 @@ void CWallet::postInitProcess(CScheduler& scheduler)
     }
 }
 
-bool CWallet::ParameterInteraction()
+bool WalletParameterInteraction()
 {
     gArgs.SoftSetArg("-wallet", DEFAULT_WALLET_DAT);
     const bool is_multiwallet = gArgs.GetArgs("-wallet").size() > 1;
diff --git a/src/wallet/wallet.h b/src/wallet/wallet.h
index f97a99d82a..bceeb12fbb 100644
--- a/src/wallet/wallet.h
+++ b/src/wallet/wallet.h
@@ -960,16 +960,6 @@ public:
     static CFeeRate minTxFee;
     static CFeeRate fallbackFee;
     static CFeeRate m_discard_rate;
-    /**
-     * Estimate the minimum fee considering user set parameters
-     * and the required fee
-     */
-    static CAmount GetMinimumFee(unsigned int nTxBytes, const CCoinControl& coin_control, const CTxMemPool& pool, const CBlockPolicyEstimator& estimator, FeeCalculation *feeCalc);
-    /**
-     * Return the minimum required fee taking into account the
-     * floating relay fee and user set minimum transaction fee
-     */
-    static CAmount GetRequiredFee(unsigned int nTxBytes);
 
     bool NewKeyPool();
     size_t KeypoolCountExternalKeys();
@@ -1060,11 +1050,6 @@ public:
     //! Flush wallet (bitdb flush)
     void Flush(bool shutdown=false);
 
-    //! Responsible for reading and validating the -wallet arguments and verifying the wallet database.
-    //  This function will perform salvage on the wallet if requested, as long as only one wallet is
-    //  being loaded (CWallet::ParameterInteraction forbids -salvagewallet, -zapwallettxes or -upgradewallet with multiwallet).
-    static bool Verify();
-    
     /** 
      * Address book entry changed.
      * @note called with lock cs_wallet held.
@@ -1101,12 +1086,8 @@ public:
     /** Mark a transaction as replaced by another transaction (e.g., BIP 125). */
     bool MarkReplaced(const uint256& originalHash, const uint256& newHash);
 
-    /* Returns the wallets help message */
-    static std::string GetWalletHelpString(bool showDebug);
-
     /* Initializes the wallet, returns a new CWallet instance or a null pointer in case of an error */
     static CWallet* CreateWalletFromFile(const std::string walletFile);
-    static bool InitLoadWallet();
 
     /**
      * Wallet post-init setup
@@ -1114,9 +1095,6 @@ public:
      */
     void postInitProcess(CScheduler& scheduler);
 
-    /* Wallets parameter interaction */
-    static bool ParameterInteraction();
-
     bool BackupWallet(const std::string& strDest);
 
     /* Set the HD chain model (chain child index counters) */