bb530efa18 Disallow extended encoding for non-witness transactions (Pieter Wuille)
Pull request description:
BIP144 specifies that transactions without witness should use the legacy encoding, which is currently not enforced.
This rule was present in the original SegWit implementation (https://github.com/bitcoin/bitcoin/pull/8149), but was subsequently dropped (https://github.com/bitcoin/bitcoin/pull/8589).
As all hashes, txids, and weights are always computed over a reserialized version of a transaction, it is mostly harmless to permit extended encoding for non-segwit transactions, but I'd rather strictly follow the BIP.
ACKs for commit bb530e:
instagibbs:
utACK bb530efa18
stevenroose:
utACK bb530efa18
Tree-SHA512: 1aeccd6a555f43784fefb076ce2e8ad2f5ba7be49840544a50050d0390f82373f87201bf56cf8bb30841b4f9cd893b382261a080da875d4e11ab7051f8640dbe
This makes the above constructor explicit. The rationale is that this conversion has very significant performance effects. Making it explicit makes it easier to reason about these performance trade-offs, and helps identify possible functions that need a CMutableTransaction version.
This adds a READWRITEAS(type, obj) macro which serializes obj as if it
were casted to (const type&) when const, and to (type&) when non-const.
This makes it usable in serialization code that uses a single
implementation for both serialization and deserializing, which doesn't
know the constness of the object involved.
9ad6746ccd Use static_cast instead of C-style casts for non-fundamental types (practicalswift)
Pull request description:
A C-style cast is equivalent to try casting in the following order:
1. `const_cast(...)`
2. `static_cast(...)`
3. `const_cast(static_cast(...))`
4. `reinterpret_cast(...)`
5. `const_cast(reinterpret_cast(...))`
By using `static_cast<T>(...)` explicitly we avoid the possibility of an unintentional and dangerous `reinterpret_cast`. Furthermore `static_cast<T>(...)` allows for easier grepping of casts.
For a more thorough discussion, see ["ES.49: If you must use a cast, use a named cast"](https://isocpp.github.io/CppCoreGuidelines/CppCoreGuidelines#es49-if-you-must-use-a-cast-use-a-named-cast) in the C++ Core Guidelines (Stroustrup & Sutter).
Tree-SHA512: bd6349b7ea157da93a47b8cf238932af5dff84731374ccfd69b9f732fabdad1f9b1cdfca67497040f14eaa85346391404f4c0495e22c467f26ca883cd2de4d3c
A C-style cast is equivalent to try casting in the following order:
1. const_cast(...)
2. static_cast(...)
3. const_cast(static_cast(...))
4. reinterpret_cast(...)
5. const_cast(reinterpret_cast(...))
By using static_cast<T>(...) explicitly we avoid the possibility
of an unintentional and dangerous reinterpret_cast. Furthermore
static_cast<T>(...) allows for easier grepping of casts.
37495e0d8 Reorder C{,Mutable}Transaction for better packing (Jeremy Rubin)
Pull request description:
These commits revise the layout of a few key classes to eliminate padding, eliminating useless memory overhead.
-This reduces CTransaction from 96 bytes to 88 bytes
Tree-SHA512: 91d1fec363edebbb1f1a5b98142c767511e99d3be857148a76e31cc512c9ab3d153083fa6b46b6407974d3b88de984b436c33e8606fbb2b273d74c825195aa17
0aadc11fd Avoid dereference-of-casted-pointer (Pieter Wuille)
Pull request description:
And prefer a static_cast to the intended reference type.
Tree-SHA512: e83b20023a4dca6029b46f7040a8a6fd54e1b42112ec0c87c3c3b567ed641de97a9e2335b57a2efb075491f641e5b977bc226a474276bea0c3c3c71d8d6ac54d
Some people keep thinking that MAX_BLOCK_BASE_SIZE is a separate
size limit from the weight limit when it fact it is superfluous,
and used in early tests before the witness data has been
validated or just to compute worst case sizes. The size checks
that use it would not behave any differently consensus wise
if they were eliminated completely.
Its correct value is not independently settable but is a function
of the weight limit and weight formula.
This patch just eliminates it and uses the scale factor as
required to compute the worse case constants.
It also moves the weight factor out of primitives into consensus,
which is a more logical place for it.
Remove the nType and nVersion as parameters to all serialization methods
and functions. There is only one place where it's read and has an impact
(in CAddress), and even there it does not impact any of the recursively
invoked serializers.
Instead, the few places that need nType or nVersion are changed to read
it directly from the stream object, through GetType() and GetVersion()
methods which are added to all stream classes.
Given that in default GetSerializeSize implementations created by
ADD_SERIALIZE_METHODS we're already using CSizeComputer(), get rid
of the specialized GetSerializeSize methods everywhere, and just use
CSizeComputer. This removes a lot of code which isn't actually used
anywhere.
For CCompactSize and CVarInt this actually removes a more efficient
size computing algorithm, which is brought back in a later commit.
