wallet: Remove confusing double return value ret+success

Also, remove redundant comments

Author: MarcoFalke

src/wallet/bdb.cpp

@@ -809,10 +809,8 @@ bool BerkeleyBatch::ReadKey(CDataStream& key, CDataStream& value)
     if (!pdb)
         return false;
 
-    // Key
     SafeDbt datKey(key.data(), key.size());
 
-    // Read
     SafeDbt datValue;
     int ret = pdb->get(activeTxn, datKey, datValue, 0);
     if (ret == 0 && datValue.get_data() != nullptr) {
@@ -829,13 +827,10 @@ bool BerkeleyBatch::WriteKey(CDataStream& key, CDataStream& value, bool overwrit
     if (fReadOnly)
         assert(!"Write called on database in read-only mode");
 
-    // Key
     SafeDbt datKey(key.data(), key.size());
 
-    // Value
     SafeDbt datValue(value.data(), value.size());
 
-    // Write
     int ret = pdb->put(activeTxn, datKey, datValue, (overwrite ? 0 : DB_NOOVERWRITE));
     return (ret == 0);
 }
@@ -847,10 +842,8 @@ bool BerkeleyBatch::EraseKey(CDataStream& key)
     if (fReadOnly)
         assert(!"Erase called on database in read-only mode");
 
-    // Key
     SafeDbt datKey(key.data(), key.size());
 
-    // Erase
     int ret = pdb->del(activeTxn, datKey, 0);
     return (ret == 0 || ret == DB_NOTFOUND);
 }
@@ -860,10 +853,8 @@ bool BerkeleyBatch::HasKey(CDataStream& key)
     if (!pdb)
         return false;
 
-    // Key
     SafeDbt datKey(key.data(), key.size());
 
-    // Exists
     int ret = pdb->exists(activeTxn, datKey, 0);
     return ret == 0;
 }

src/wallet/bdb.h

@@ -223,64 +223,51 @@ class BerkeleyBatch
     template <typename K, typename T>
     bool Read(const K& key, T& value)
     {
-        // Key
         CDataStream ssKey(SER_DISK, CLIENT_VERSION);
         ssKey.reserve(1000);
         ssKey << key;
 
         CDataStream ssValue(SER_DISK, CLIENT_VERSION);
-        bool success = false;
-        bool ret = ReadKey(ssKey, ssValue);
-        if (ret) {
-            // Unserialize value
-            try {
-                ssValue >> value;
-                success = true;
-            } catch (const std::exception&) {
-                // In this case success remains 'false'
-            }
+        if (!ReadKey(ssKey, ssValue)) return false;
+        try {
+            ssValue >> value;
+            return true;
+        } catch (const std::exception&) {
+            return false;
         }
-        return ret && success;
     }
 
     template <typename K, typename T>
     bool Write(const K& key, const T& value, bool fOverwrite = true)
     {
-        // Key
         CDataStream ssKey(SER_DISK, CLIENT_VERSION);
         ssKey.reserve(1000);
         ssKey << key;
 
-        // Value
         CDataStream ssValue(SER_DISK, CLIENT_VERSION);
         ssValue.reserve(10000);
         ssValue << value;
 
-        // Write
         return WriteKey(ssKey, ssValue, fOverwrite);
     }
 
     template <typename K>
     bool Erase(const K& key)
     {
-        // Key
         CDataStream ssKey(SER_DISK, CLIENT_VERSION);
         ssKey.reserve(1000);
         ssKey << key;
 
-        // Erase
         return EraseKey(ssKey);
     }
 
     template <typename K>
     bool Exists(const K& key)
     {
-        // Key
         CDataStream ssKey(SER_DISK, CLIENT_VERSION);
         ssKey.reserve(1000);
         ssKey << key;
 
-        // Exists
         return HasKey(ssKey);
     }