This is a second carve-out from #10785.
This introduces a const-correct generic approach for serializing objects using custom serializers (defined separately from the object being serialized), then converts VARINT to use that approach, and then converts chain.h to the new framework (including the new const-correct VARINT macro).
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441@@ -442,6 +442,31 @@ I ReadVarInt(Stream& is)
442 }
443 }
444
445+/** Simple wrapper class to serialize objects using a formatter; used by Using(). */
446+template<typename Formatter, typename T>
447+class Wrapper
448+{
449+protected:
450+ T& m_object;
& reference here and removing it with std::remove_reference below, maybe this could change from T& to T, and typename std::remove_reference<T>::type below could change to T&
This adds the (internal) Wrapper class, and the Using function that uses it. Given
a class F that implements Ser(stream, const object&) and Unser(stream, object&)
functions, this permits writing e.g. READWRITE(Using<F>(object)).
354+ READWRITE(VARINT(obj.nHeight, VarIntMode::NONNEGATIVE_SIGNED));
355+ READWRITE(VARINT(obj.nStatus));
356+ READWRITE(VARINT(obj.nTx));
357+ if (obj.nStatus & (BLOCK_HAVE_DATA | BLOCK_HAVE_UNDO)) READWRITE(VARINT(obj.nFile, VarIntMode::NONNEGATIVE_SIGNED));
358+ if (obj.nStatus & BLOCK_HAVE_DATA) READWRITE(VARINT(obj.nDataPos));
359+ if (obj.nStatus & BLOCK_HAVE_UNDO) READWRITE(VARINT(obj.nUndoPos));
9b66083788581c264a097e26795561cb3eac455d
I know people aren’t fans of macros so this will probably be shut down, but this pattern appears often enough to almost warrant a READWRITEIF(condition, ...). Above cases would be
0READWRITEIF(!(s.GetType() & SER_GETHASH), VARINT(_nVersion, VarIntMode::NONNEGATIVE_SIGNED));
1...
2READWRITEIF(obj.nStatus & (BLOCK_HAVE_DATA | BLOCK_HAVE_UNDO), VARINT(obj.nFile, VarIntMode::NONNEGATIVE_SIGNED));
3READWRITEIF(obj.nStatus & BLOCK_HAVE_DATA, VARINT(obj.nDataPos));
4READWRITEIF(obj.nStatus & BLOCK_HAVE_UNDO, VARINT(obj.nUndoPos));
ACK 9b66083788581c264a097e26795561cb3eac455d (jamesob/ackr/17896.1.sipa.serialization_improvemen)
Built locally, tested starting and stopping bitcoind twice with an existing datadir. These changes are thoroughly tested by functional tests.
0Tested on Linux-4.15.0-47-generic-x86_64-with-Ubuntu-18.04-bionic
1
2Configured with `./configure LDFLAGS=-L/home/james/src/bitcoin/db4/lib/ CPPFLAGS=-I/home/james/src/bitcoin/db4/include/ CXXFLAGS=-std=c++11 -Wthread-safety-analysis -Werror -Wthread-safety-analysis -Werror --enable-wallet --enable-debug --with-daemon CXX=/usr/bin/clang++-4.0 CC=/usr/bin/clang-4.0 --disable-shared --with-pic --enable-benchmark=no --with-bignum=no --enable-module-recovery --disable-jni PYTHONPATH= --disable-shared --with-pic --enable-benchmark=no --with-bignum=no --enable-module-recovery --disable-jni --no-create --no-recursion`
3
4Compiled with `/usr/bin/ccache /usr/bin/clang++-4.0 -std=c++11 -mavx -mavx2 -std=c++11 -Wthread-safety-analysis -Werror -Wthread-safety-analysis -Werror -O0 -g3 -ftrapv -Wstack-protector -fstack-protector-all -msse4 -msha -msse4.1 -msse4.2`
5
6Compiler version: clang version 4.0.1-10 (tags/RELEASE_401/final)