Reduce memory allocation, remove some functions in Serializer.

src/ripple/protocol/Serializer.h

@@ -41,6 +41,7 @@ private:
     Blob mData;
 
 public:
+    explicit
     Serializer (int n = 256)
     {
         mData.reserve (n);
@@ -107,7 +108,6 @@ public:
     int addZeros (size_t uBytes);
 
     int addVL (Blob const& vector);
-    int addVL (std::string const& string);
     int addVL (const void* ptr, int len);
 
     // disassemble functions
@@ -232,7 +232,6 @@ public:
     {
         mData.clear ();
     }
-    int removeLastByte ();
     bool chop (int num);
 
     // vector-like functions
@@ -297,17 +296,17 @@ public:
         return h.str ();
     }
 
-    // low-level VL length encode/decode functions
-    static Blob encodeVL (int length);
+    static int decodeLengthLength (int b1);
+    static int decodeVLLength (int b1);
+    static int decodeVLLength (int b1, int b2);
+    static int decodeVLLength (int b1, int b2, int b3);
+private:
     static int lengthVL (int length)
     {
         return length + encodeLengthLength (length);
     }
     static int encodeLengthLength (int length); // length to encode length
-    static int decodeLengthLength (int b1);
-    static int decodeVLLength (int b1);
-    static int decodeVLLength (int b1, int b2);
-    static int decodeVLLength (int b1, int b2, int b3);
+    int addEncoded (int length);
 };
 
 //------------------------------------------------------------------------------

src/ripple/protocol/impl/Serializer.cpp

@@ -278,21 +278,6 @@ bool Serializer::chop (int bytes)
     return true;
 }
 
-int Serializer::removeLastByte ()
-{
-    int size = mData.size () - 1;
-
-    if (size < 0)
-    {
-        assert (false);
-        return -1;
-    }
-
-    int ret = mData[size];
-    mData.resize (size);
-    return ret;
-}
-
 bool Serializer::getRaw (Blob& o, int offset, int length) const
 {
     if ((offset + length) > mData.size ()) return false;
@@ -363,7 +348,7 @@ uint256 Serializer::getPrefixHash (std::uint32_t prefix, const unsigned char* da
 
 int Serializer::addVL (Blob const& vector)
 {
-    int ret = addRaw (encodeVL (vector.size ()));
+    int ret = addEncoded (vector.size ());
     addRaw (vector);
     assert (mData.size () == (ret + vector.size () + encodeLengthLength (vector.size ())));
     return ret;
@@ -371,7 +356,7 @@ int Serializer::addVL (Blob const& vector)
 
 int Serializer::addVL (const void* ptr, int len)
 {
-    int ret = addRaw (encodeVL (len));
+    int ret = addEncoded (len);
 
     if (len)
         addRaw (ptr, len);
@@ -379,16 +364,6 @@ int Serializer::addVL (const void* ptr, int len)
     return ret;
 }
 
-int Serializer::addVL (std::string const& string)
-{
-    int ret = addRaw (string.size ());
-
-    if (!string.empty ())
-        addRaw (string.data (), string.size ());
-
-    return ret;
-}
-
 bool Serializer::getVL (Blob& objectVL, int offset, int& length) const
 {
     int b1;
@@ -470,31 +445,34 @@ bool Serializer::getVLLength (int& length, int offset) const
     return true;
 }
 
-Blob Serializer::encodeVL (int length)
+int Serializer::addEncoded (int length)
 {
-    unsigned char lenBytes[4];
+    std::array<std::uint8_t, 4> bytes;
+    int numBytes = 0;
 
     if (length <= 192)
     {
-        lenBytes[0] = static_cast<unsigned char> (length);
-        return Blob (&lenBytes[0], &lenBytes[1]);
+        bytes[0] = static_cast<unsigned char> (length);
+        numBytes = 1;
     }
     else if (length <= 12480)
     {
         length -= 193;
-        lenBytes[0] = 193 + static_cast<unsigned char> (length >> 8);
-        lenBytes[1] = static_cast<unsigned char> (length & 0xff);
-        return Blob (&lenBytes[0], &lenBytes[2]);
+        bytes[0] = 193 + static_cast<unsigned char> (length >> 8);
+        bytes[1] = static_cast<unsigned char> (length & 0xff);
+        numBytes = 2;
     }
     else if (length <= 918744)
     {
         length -= 12481;
-        lenBytes[0] = 241 + static_cast<unsigned char> (length >> 16);
-        lenBytes[1] = static_cast<unsigned char> ((length >> 8) & 0xff);
-        lenBytes[2] = static_cast<unsigned char> (length & 0xff);
-        return Blob (&lenBytes[0], &lenBytes[3]);
+        bytes[0] = 241 + static_cast<unsigned char> (length >> 16);
+        bytes[1] = static_cast<unsigned char> ((length >> 8) & 0xff);
+        bytes[2] = static_cast<unsigned char> (length & 0xff);
+        numBytes = 3;
     }
     else throw std::overflow_error ("lenlen");
+
+    return addRaw (&bytes[0], numBytes);
 }
 
 int Serializer::encodeLengthLength (int length)

src/ripple/shamap/impl/SHAMapTreeNode.cpp

@@ -79,8 +79,18 @@ SHAMapTreeNode::SHAMapTreeNode (Blob const& rawNode,
 {
     if (format == snfWIRE)
     {
-        Serializer s (rawNode);
-        int type = s.removeLastByte ();
+        if (rawNode.empty ())
+        {
+#ifdef BEAST_DEBUG
+            deprecatedLogs().journal("SHAMapTreeNode").fatal <<
+                "Wire format node is empty";
+            assert (false);
+#endif
+            throw std::runtime_error ("invalid node AW type");
+        }
+
+        Serializer s (rawNode.begin (), rawNode.end () - 1);
+        int type = rawNode.back ();
         int len = s.getLength ();
 
         if ((type < 0) || (type > 4))