upstream/mercurial-mirror Files · contrib/fuzz/fuzzutil.h

wireprotoframing: buffer emitted data to reduce frame count...

wireprotoframing: buffer emitted data to reduce frame count An upcoming commit introduces a wire protocol command that can emit hundreds of thousands of small objects. Without a buffering layer, we would emit a single, small frame for every object. Performance profiling revealed this to be a source of significant overhead for both client and server. This commit introduces a very crude buffering layer so that we emit fewer, bigger frames in such a scenario. This code will likely get rewritten in the future to be part of the streams API, as we'll need a similar strategy for compressing data. I don't want to think about it too much at the moment though. server before: user 32.500+0.000 sys 1.160+0.000 after: user 20.230+0.010 sys 0.180+0.000 client before: user 133.400+0.000 sys 93.120+0.000 after: user 68.370+0.000 sys 32.950+0.000 This appears to indicate we have significant overhead in the frame processing code on both client and server. It might be worth profiling that at some point... Differential Revision: https://phab.mercurial-scm.org/D4473

Augie Fackler - - Load All Authors

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      #ifndef CONTRIB_FUZZ_FUZZUTIL_H

      #define CONTRIB_FUZZ_FUZZUTIL_H

      #include <iostream>

      #include <memory>

      #include <stdint.h>

      /* Try and use std::optional, but failing that assume we'll have a

       * workable https://abseil.io/ install on the include path to get

       * their backport of std::optional. */

      #ifdef __has_include

      #if __has_include(<optional>) && __cplusplus >= 201703L

      #include <optional>

      #define CONTRIB_FUZZ_HAVE_STD_OPTIONAL

      #endif

      #endif

      #ifdef CONTRIB_FUZZ_HAVE_STD_OPTIONAL

      namespace contrib

      {

      using std::nullopt;

      using std::optional;

      } /* namespace contrib */

      #else

      #include "third_party/absl/types/optional.h"

      namespace contrib

      {

      using absl::nullopt;

      using absl::optional;

      } /* namespace contrib */

      #endif

      /* set DEBUG to 1 for a few debugging prints, or 2 for a lot */

      #define DEBUG 0

      #define LOG(level)                                                             \

      	if (level <= DEBUG)                                                    \

      	std::cout

      struct two_inputs {

      	std::unique_ptr<char[]> right;

      	size_t right_size;

      	std::unique_ptr<char[]> left;

      	size_t left_size;

      };

      /* Split a non-zero-length input into two inputs. */

      contrib::optional<two_inputs> SplitInputs(const uint8_t *Data, size_t Size);

      #endif /* CONTRIB_FUZZ_FUZZUTIL_H */

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				#ifndef CONTRIB_FUZZ_FUZZUTIL_H
				#define CONTRIB_FUZZ_FUZZUTIL_H
				#include <iostream>
				#include <memory>
				#include <stdint.h>

				/* Try and use std::optional, but failing that assume we'll have a
				* workable https://abseil.io/ install on the include path to get
				* their backport of std::optional. */
				#ifdef __has_include
				#if __has_include(<optional>) && __cplusplus >= 201703L
				#include <optional>
				#define CONTRIB_FUZZ_HAVE_STD_OPTIONAL
				#endif
				#endif
				#ifdef CONTRIB_FUZZ_HAVE_STD_OPTIONAL
				namespace contrib
				{
				using std::nullopt;
				using std::optional;
				} /* namespace contrib */
				#else
				#include "third_party/absl/types/optional.h"
				namespace contrib
				{
				using absl::nullopt;
				using absl::optional;
				} /* namespace contrib */
				#endif

				/* set DEBUG to 1 for a few debugging prints, or 2 for a lot */
				#define DEBUG 0
				#define LOG(level) \
				if (level <= DEBUG) \
				std::cout

				struct two_inputs {
				std::unique_ptr<char[]> right;
				size_t right_size;
				std::unique_ptr<char[]> left;
				size_t left_size;
				};

				/* Split a non-zero-length input into two inputs. */
				contrib::optional<two_inputs> SplitInputs(const uint8_t *Data, size_t Size);

				#endif /* CONTRIB_FUZZ_FUZZUTIL_H */