[libFuzzer] only read MaxLen bytes from every file in the corpus to speedup loading the corpus
llvm-svn: 261267
diff --git a/llvm/lib/Fuzzer/FuzzerIO.cpp b/llvm/lib/Fuzzer/FuzzerIO.cpp
index 5cc589a..6773c60 100644
--- a/llvm/lib/Fuzzer/FuzzerIO.cpp
+++ b/llvm/lib/Fuzzer/FuzzerIO.cpp
@@ -55,12 +55,18 @@
return V;
}
-Unit FileToVector(const std::string &Path) {
+Unit FileToVector(const std::string &Path, size_t MaxSize) {
std::ifstream T(Path);
if (!T) {
Printf("No such directory: %s; exiting\n", Path.c_str());
exit(1);
}
+ if (MaxSize) {
+ Unit Res(MaxSize);
+ T.read(reinterpret_cast<char*>(Res.data()), MaxSize);
+ Res.resize(T.gcount());
+ return Res;
+ }
return Unit((std::istreambuf_iterator<char>(T)),
std::istreambuf_iterator<char>());
}
@@ -84,16 +90,16 @@
}
void ReadDirToVectorOfUnits(const char *Path, std::vector<Unit> *V,
- long *Epoch) {
+ long *Epoch, size_t MaxSize) {
long E = Epoch ? *Epoch : 0;
auto Files = ListFilesInDir(Path, Epoch);
for (size_t i = 0; i < Files.size(); i++) {
auto &X = Files[i];
auto FilePath = DirPlusFile(Path, X);
if (Epoch && GetEpoch(FilePath) < E) continue;
- if ((i % 1000) == 0 && i)
+ if ((i & (i - 1)) == 0 && i >= 1024)
Printf("Loaded %zd/%zd files from %s\n", i, Files.size(), Path);
- V->push_back(FileToVector(FilePath));
+ V->push_back(FileToVector(FilePath, MaxSize));
}
}