[wallet] Add comments for doxygen

Author: MarcoFalke

src/wallet/wallet.cpp

@@ -1842,6 +1842,7 @@ bool CWallet::CreateTransaction(const vector<CRecipient>& vecSend, CWalletTx& wt
         LOCK2(cs_main, cs_wallet);
         {
             nFeeRet = 0;
+            // Start with no fee and loop until there is enough fee
             while (true)
             {
                 txNew.vin.clear();

src/wallet/wallet.h

@@ -451,6 +451,11 @@ class CWalletKey
 class CWallet : public CCryptoKeyStore, public CValidationInterface
 {
 private:
+    /**
+     * Select a set of coins such that nValueRet >= nTargetValue and at least
+     * all coins from coinControl are selected; Never select unconfirmed coins
+     * if they are not ours
+     */
     bool SelectCoins(const CAmount& nTargetValue, std::set<std::pair<const CWalletTx*,unsigned int> >& setCoinsRet, CAmount& nValueRet, const CCoinControl *coinControl = NULL) const;
 
     CWalletDB *pwalletdbEncryption;
@@ -552,9 +557,12 @@ class CWallet : public CCryptoKeyStore, public CValidationInterface
      * populate vCoins with vector of available COutputs.
      */
     void AvailableCoins(std::vector<COutput>& vCoins, bool fOnlyConfirmed=true, const CCoinControl *coinControl = NULL, bool fIncludeZeroValue=false) const;
+
     /**
-     * Select coins until nTargetValue is reached. Return the actual value
-     * and the corresponding coin set.
+     * Shuffle and select coins until nTargetValue is reached while avoiding
+     * small change; This method is stochastic for some inputs and upon
+     * completion the coin set and corresponding actual target value is
+     * assembled
      */
     bool SelectCoinsMinConf(const CAmount& nTargetValue, int nConfMine, int nConfTheirs, std::vector<COutput> vCoins, std::set<std::pair<const CWalletTx*,unsigned int> >& setCoinsRet, CAmount& nValueRet) const;
 
@@ -638,7 +646,17 @@ class CWallet : public CCryptoKeyStore, public CValidationInterface
     CAmount GetWatchOnlyBalance() const;
     CAmount GetUnconfirmedWatchOnlyBalance() const;
     CAmount GetImmatureWatchOnlyBalance() const;
+
+    /**
+     * Insert additional inputs into the transaction by
+     * calling CreateTransaction();
+     */
     bool FundTransaction(CMutableTransaction& tx, CAmount& nFeeRet, int& nChangePosRet, std::string& strFailReason, bool includeWatching);
+
+    /**
+     * Create a new transaction paying the recipients with a set of coins
+     * selected by SelectCoins(); Also create the change output, when needed
+     */
     bool CreateTransaction(const std::vector<CRecipient>& vecSend, CWalletTx& wtxNew, CReserveKey& reservekey, CAmount& nFeeRet, int& nChangePosRet,
                            std::string& strFailReason, const CCoinControl *coinControl = NULL, bool sign = true);
     bool CommitTransaction(CWalletTx& wtxNew, CReserveKey& reservekey);