##// END OF EJS Templates
revlog: add a small cache of unfiltered chunk...
revlog: add a small cache of unfiltered chunk This can provides a massive boost to the reading of multiple revision and the computation of a valid delta chain. This greatly help operation like `hg log --patch`, delta computation (helping pull/unbundle), linkrev adjustment (helping copy tracing). A first round of benchmark for `hg log --patch --limit 1000` shows improvement in the 10-20% range on "small" repository like pypy or mercurial and large improvements (about 33%) for more complex ones like netbeans and mozilla's. These speeds up are consistent with the improvement to `hg pull` (from a server sending poor deltas) I saw benchmarking this last year. Further benchmark will be run during the freeze. I added some configuration in the experimental space to be able to further test the effect of various tuning for now. This feature should fit well in the "usage/resource profile" configuration that we should land next cycle. When it does not provides a benefit the overhead of the cache seem to be around 2%, a small price for the big improvement. In addition I believe we could shave most of this overhead with a more efficent lru implementation.

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bdiff.cc
39 lines | 969 B | text/x-c | CppLexer
/*
* bdiff.cc - fuzzer harness for bdiff.c
*
* Copyright 2018, Google Inc.
*
* This software may be used and distributed according to the terms of
* the GNU General Public License, incorporated herein by reference.
*/
#include <memory>
#include <stdlib.h>
#include "FuzzedDataProvider.h"
extern "C" {
#include "bdiff.h"
extern "C" int LLVMFuzzerInitialize(int *argc, char ***argv)
{
return 0;
}
int LLVMFuzzerTestOneInput(const uint8_t *Data, size_t Size)
{
FuzzedDataProvider provider(Data, Size);
std::string left = provider.ConsumeRandomLengthString(Size);
std::string right = provider.ConsumeRemainingBytesAsString();
struct bdiff_line *a, *b;
int an = bdiff_splitlines(left.c_str(), left.size(), &a);
int bn = bdiff_splitlines(right.c_str(), right.size(), &b);
struct bdiff_hunk l;
bdiff_diff(a, an, b, bn, &l);
free(a);
free(b);
bdiff_freehunks(l.next);
return 0; // Non-zero return values are reserved for future use.
}
} // extern "C"