view contrib/fuzz/fuzzutil.cc @ 39318:c03c5f528e9b

perf: use storage API for resolving manifest node

lookup() isn't part of the storage API. And this code shouldn't
be accessing manifestlog._revlog directly for the modern code base.
So let's port it to the modern API.

Note that the previous code was busted for cases where we needed
to call lookup() because lookup() isn't exposed by manifestrevlog
any more.

This change is strictly BC breaking because we no longer support
resolving partial nodes. But it is a perf* command and I don't
think we should flag the change as such.

Differential Revision: https://phab.mercurial-scm.org/D4390

#include "fuzzutil.h"

#include <cstring>
#include <utility>

contrib::optional<two_inputs> SplitInputs(const uint8_t *Data, size_t Size)
{
	if (!Size) {
		return contrib::nullopt;
	}
	// figure out a random point in [0, Size] to split our input.
	size_t left_size = (Data[0] / 255.0) * (Size - 1);

	// Copy inputs to new allocations so if bdiff over-reads
	// AddressSanitizer can detect it.
	std::unique_ptr<char[]> left(new char[left_size]);
	std::memcpy(left.get(), Data + 1, left_size);
	// right starts at the next byte after left ends
	size_t right_size = Size - (left_size + 1);
	std::unique_ptr<char[]> right(new char[right_size]);
	std::memcpy(right.get(), Data + 1 + left_size, right_size);
	LOG(2) << "inputs are  " << left_size << " and " << right_size
	       << " bytes" << std::endl;
	two_inputs result = {std::move(right), right_size, std::move(left),
	                     left_size};
	return result;
}