Matt Corallo c632fffc3d Avoid calling libsecp serialization fns when calculating length ... When writing out libsecp256k1 objects during serialization in a TLV, we potentially calculate the TLV length twice before performing the actual serialization (once when calculating the total TLV-stream length and once when calculating the length of the secp256k1-object-containing TLV). Because the lengths of secp256k1 objects is a constant, we'd ideally like LLVM to entirely optimize out those calls and simply know the expected length. However, without cross-language LTO, there is no way for LLVM to verify that there are no side-effects of the calls to libsecp256k1, leaving LLVM with no way to optimize them out. This commit adds a new method to `Writeable` which returns the length of an object once serialized. It is implemented by default using `LengthCalculatingWriter` (which LLVM generally optimizes out for Rust objects) and overrides it for libsecp256k1 objects. As of this commit, on an Intel 2687W v3, the serialization benchmarks take: test routing::network_graph::benches::read_network_graph ... bench: 2,035,402,164 ns/iter (+/- 1,855,357) test routing::network_graph::benches::write_network_graph ... bench: 308,235,267 ns/iter (+/- 140,202)		2021-06-01 15:47:01 +00:00
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src	Avoid calling libsecp serialization fns when calculating length	2021-06-01 15:47:01 +00:00
Cargo.toml	Bump versions to 0.0.14, lightning-invoice 0.5	2021-05-01 00:43:15 +00:00