Remove Stream

Summary:
Switch existing code to gen::byLine.  Also fix namespaces in
folly/experimental/(symbolizer|exception_tracer).

Test Plan:
fbconfig -r folly && fbmake runtests_opt, ran non-test folly
binaries by hand, fbgs for other uses (there aren't any)

Reviewed By: tjackson@fb.com

FB internal diff: D629576

folly/experimental/Gen-inl.h

@@ -247,9 +247,9 @@ template<class Value,
          class Gen,
          class Handler>
 typename std::enable_if<
-  IsCompatibleSignature<Handler, bool(Value)>::value>::type
+  IsCompatibleSignature<Handler, bool(Value)>::value, bool>::type
 operator|(const GenImpl<Value, Gen>& gen, Handler&& handler) {
-  gen.self().apply(std::forward<Handler>(handler));
+  return gen.self().apply(std::forward<Handler>(handler));
 }
 
 /**

folly/experimental/exception_tracer/ExceptionTracer.cpp

@@ -36,9 +36,10 @@ GetExceptionStackTraceStackType getExceptionStackTraceStackFn;
 
 }  // namespace
 
-using namespace ::facebook::symbolizer;
+using namespace ::folly::symbolizer;
 using namespace __cxxabiv1;
 
+namespace folly {
 namespace exception_tracer {
 
 std::ostream& operator<<(std::ostream& out, const ExceptionInfo& info) {
@@ -198,4 +199,5 @@ void installHandlers() {
 }
 
 }  // namespace exception_tracer
+}  // namespace folly
 

folly/experimental/exception_tracer/ExceptionTracer.h

@@ -23,6 +23,7 @@
 #include <vector>
 #include <iostream>
 
+namespace folly {
 namespace exception_tracer {
 
 struct ExceptionInfo {
@@ -47,6 +48,7 @@ std::vector<ExceptionInfo> getCurrentExceptions();
 void installHandlers();
 
 }  // namespace exception_tracer
+}  // namespace folly
 
 #endif /* FOLLY_EXPERIMENTAL_EXCEPTION_TRACER_EXCEPTIONTRACER_H_ */
 

folly/experimental/exception_tracer/ExceptionTracerLib.cpp

@@ -173,7 +173,7 @@ namespace {
 struct Initializer {
   Initializer() {
     try {
-      exception_tracer::installHandlers();
+      ::folly::exception_tracer::installHandlers();
     } catch (...) {
     }
   }

folly/experimental/exception_tracer/ExceptionTracerTest.cpp

@@ -25,7 +25,7 @@ void bar() {
 
 void dumpExceptions(const char* prefix) {
   std::cerr << "--- " << prefix << "\n";
-  auto exceptions = exception_tracer::getCurrentExceptions();
+  auto exceptions = ::folly::exception_tracer::getCurrentExceptions();
   for (auto& exc : exceptions) {
     std::cerr << exc << "\n";
   }

folly/experimental/io/HugePages.cpp

@@ -38,7 +38,10 @@
 #include "folly/Range.h"
 #include "folly/ScopeGuard.h"
 #include "folly/String.h"
-#include "folly/experimental/io/Stream.h"
+
+#include "folly/experimental/Gen.h"
+#include "folly/experimental/FileGen.h"
+#include "folly/experimental/StringGen.h"
 
 namespace folly {
 
@@ -48,15 +51,23 @@ namespace {
 size_t getDefaultHugePageSize() {
   // We need to parse /proc/meminfo
   static const boost::regex regex(R"!(Hugepagesize:\s*(\d+)\s*kB)!");
+  size_t pageSize = 0;
   boost::cmatch match;
-  for (auto& byteLine : byLine("/proc/meminfo")) {
-    StringPiece line(byteLine);
+
+  bool error = gen::byLine("/proc/meminfo") | gen::eachAs<StringPiece>() |
+    [&] (StringPiece line) -> bool {
       if (boost::regex_match(line.begin(), line.end(), match, regex)) {
         StringPiece numStr(line.begin() + match.position(1), match.length(1));
-      return to<size_t>(numStr) * 1024;  // in KiB
-    }
+        pageSize = to<size_t>(numStr) * 1024;  // in KiB
+        return false;  // stop
       }
+      return true;
+    };
+
+  if (error) {
     throw std::runtime_error("Can't find default huge page size");
+  }
+  return pageSize;
 }
 
 // Get raw huge page sizes (without mount points, they'll be filled later)
@@ -124,8 +135,9 @@ HugePageSizeVec getHugePageSizes() {
   // Read and parse /proc/mounts
   std::vector<StringPiece> parts;
   std::vector<StringPiece> options;
-  for (auto& byteLine : byLine("/proc/mounts")) {
-    StringPiece line(byteLine);
+
+  gen::byLine("/proc/mounts") | gen::eachAs<StringPiece>() |
+    [&](StringPiece line) {
       parts.clear();
       split(" ", line, parts);
       // device path fstype options uid gid
@@ -133,7 +145,7 @@ HugePageSizeVec getHugePageSizes() {
         throw std::runtime_error("Invalid /proc/mounts line");
       }
       if (parts[2] != "hugetlbfs") {
-      continue;  // we only care about hugetlbfs
+        return;  // we only care about hugetlbfs
       }
 
       options.clear();
@@ -164,7 +176,7 @@ HugePageSizeVec getHugePageSizes() {
         pos->mountPoint = fs::canonical(fs::path(parts[1].begin(),
                                                  parts[1].end()));
       }
-  }
+    };
 
   return sizeVec;
 }

folly/experimental/symbolizer/Dwarf.cpp

@@ -21,7 +21,7 @@
 
 #include <dwarf.h>
 
-namespace facebook {
+namespace folly {
 namespace symbolizer {
 
 Dwarf::Dwarf(const ElfFile* elf) : elf_(elf) {
@@ -815,5 +815,5 @@ bool Dwarf::LineNumberVM::findAddress(uintptr_t target, Path& file,
 }
 
 }  // namespace symbolizer
-}  // namespace facebook
+}  // namespace folly
 

folly/experimental/symbolizer/Dwarf.h

@@ -24,7 +24,7 @@
 #include "folly/experimental/symbolizer/Elf.h"
 #include "folly/Range.h"
 
-namespace facebook {
+namespace folly {
 namespace symbolizer {
 
 /**
@@ -270,7 +270,7 @@ inline std::ostream& operator<<(std::ostream& out, const Dwarf::Path& path) {
 }
 
 }  // namespace symbolizer
-}  // namespace facebook
+}  // namespace folly
 
 #endif /* FOLLY_EXPERIMENTAL_SYMBOLIZER_DWARF_H_ */
 

folly/experimental/symbolizer/Elf-inl.h

@@ -19,7 +19,7 @@
 # error This file must be included from Elf.h
 #endif
 
-namespace facebook {
+namespace folly {
 namespace symbolizer {
 
 template <class Fn>
@@ -61,5 +61,5 @@ const char* ElfFile::iterateStrings(const ElfW(Shdr)& stringTable, Fn fn)
 
 
 }  // namespace symbolizer
-}  // namespace facebook
+}  // namespace folly
 

folly/experimental/symbolizer/Elf.cpp

@@ -29,7 +29,7 @@
 
 #include "folly/Conv.h"
 
-namespace facebook {
+namespace folly {
 namespace symbolizer {
 
 ElfFile::ElfFile()
@@ -287,5 +287,5 @@ const char* ElfFile::getSymbolName(Symbol symbol) const {
 }
 
 }  // namespace symbolizer
-}  // namespace facebook
+}  // namespace folly
 

folly/experimental/symbolizer/Elf.h

@@ -30,7 +30,7 @@
 #include "folly/Range.h"
 #include "folly/Conv.h"
 
-namespace facebook {
+namespace folly {
 namespace symbolizer {
 
 /**
@@ -151,7 +151,7 @@ inline void enforce(bool v, Args... args) {
 }
 
 }  // namespace symbolizer
-}  // namespace facebook
+}  // namespace folly
 
 #include "folly/experimental/symbolizer/Elf-inl.h"
 

folly/experimental/symbolizer/ElfUtil.cpp

@@ -22,8 +22,8 @@
 #include <gflags/gflags.h>
 #include <glog/logging.h>
 
-using namespace facebook;
-using namespace facebook::symbolizer;
+using namespace folly;
+using namespace folly::symbolizer;
 
 int main(int argc, char *argv[]) {
   google::ParseCommandLineFlags(&argc, &argv, true);

folly/experimental/symbolizer/Symbolizer.cpp

@@ -18,26 +18,28 @@
 #include "folly/experimental/symbolizer/Symbolizer.h"
 
 #include <boost/regex.hpp>
+#include <glog/logging.h>
 
 #include "folly/experimental/symbolizer/Elf.h"
 #include "folly/experimental/symbolizer/Dwarf.h"
-#include "glog/logging.h"
 #include "folly/Range.h"
 #include "folly/FBString.h"
 #include "folly/String.h"
-#include "folly/experimental/io/Stream.h"
+#include "folly/experimental/Gen.h"
+#include "folly/experimental/FileGen.h"
+#include "folly/experimental/StringGen.h"
 
-namespace facebook {
+namespace folly {
 namespace symbolizer {
 
 namespace {
-folly::StringPiece sp(const boost::csub_match& m) {
-  return folly::StringPiece(m.first, m.second);
+StringPiece sp(const boost::csub_match& m) {
+  return StringPiece(m.first, m.second);
 }
 
-uint64_t fromHex(folly::StringPiece s) {
+uint64_t fromHex(StringPiece s) {
   // Make a copy; we need a null-terminated string for strtoull
-  folly::fbstring str(s.data(), s.size());
+  fbstring str(s.data(), s.size());
   const char* p = str.c_str();
   char* end;
   uint64_t val = strtoull(p, &end, 16);
@@ -53,7 +55,7 @@ struct MappedFile {
 
 }  // namespace
 
-bool Symbolizer::symbolize(uintptr_t address, folly::StringPiece& symbolName,
+bool Symbolizer::symbolize(uintptr_t address, StringPiece& symbolName,
                            Dwarf::LocationInfo& location) {
   symbolName.clear();
   location = Dwarf::LocationInfo();
@@ -75,27 +77,27 @@ bool Symbolizer::symbolize(uintptr_t address, folly::StringPiece& symbolName,
   boost::cmatch match;
 
   MappedFile foundFile;
-  bool found = false;
-  for (auto& byteLine : folly::byLine("/proc/self/maps")) {
-    folly::StringPiece line(byteLine);
+  bool error = gen::byLine("/proc/self/maps") | gen::eachAs<StringPiece>() |
+    [&] (StringPiece line) -> bool {
       CHECK(boost::regex_match(line.begin(), line.end(), match, mapLineRegex));
       uint64_t begin = fromHex(sp(match[1]));
       uint64_t end = fromHex(sp(match[2]));
       uint64_t fileOffset = fromHex(sp(match[3]));
       if (fileOffset != 0) {
-      continue;  // main mapping starts at 0
+        return true;  // main mapping starts at 0
       }
 
       if (begin <= address && address < end) {
-      found = true;
         foundFile.begin = begin;
         foundFile.end = end;
         foundFile.name.assign(match[4].first, match[4].second);
-      break;
-    }
+        return false;
       }
 
-  if (!found) {
+      return true;
+    };
+
+  if (error) {
     return false;
   }
 
@@ -128,14 +130,14 @@ ElfFile& Symbolizer::getFile(const std::string& name) {
 }
 
 void Symbolizer::write(std::ostream& out, uintptr_t address,
-                       folly::StringPiece symbolName,
+                       StringPiece symbolName,
                        const Dwarf::LocationInfo& location) {
   char buf[20];
   sprintf(buf, "%#18jx", address);
   out << "    @ " << buf;
 
   if (!symbolName.empty()) {
-    out << " " << folly::demangle(symbolName.toString().c_str());
+    out << " " << demangle(symbolName.toString().c_str());
 
     std::string file;
     if (location.hasFileAndLine) {
@@ -158,4 +160,4 @@ void Symbolizer::write(std::ostream& out, uintptr_t address,
 }
 
 }  // namespace symbolizer
-}  // namespace facebook
+}  // namespace folly

folly/experimental/symbolizer/Symbolizer.h

@@ -26,7 +26,7 @@
 #include "folly/experimental/symbolizer/Elf.h"
 #include "folly/experimental/symbolizer/Dwarf.h"
 
-namespace facebook {
+namespace folly {
 namespace symbolizer {
 
 /**
@@ -55,7 +55,7 @@ class Symbolizer {
 };
 
 }  // namespace symbolizer
-}  // namespace facebook
+}  // namespace folly
 
 #endif /* FOLLY_EXPERIMENTAL_SYMBOLIZER_SYMBOLIZER_H_ */
 

folly/experimental/symbolizer/SymbolizerTest.cpp

@@ -18,16 +18,15 @@
 
 #include "folly/experimental/symbolizer/Symbolizer.h"
 
-#include "common/init/Init.h"
-#include "glog/logging.h"
+#include <glog/logging.h>
 
-using namespace facebook;
-using namespace facebook::symbolizer;
+using namespace folly;
+using namespace folly::symbolizer;
 
 int main(int argc, char *argv[]) {
-  facebook::initFacebook(&argc, &argv);
+  google::InitGoogleLogging(argv[0]);
   Symbolizer s;
-  folly::StringPiece name;
+  StringPiece name;
   Dwarf::LocationInfo location;
   CHECK(s.symbolize(reinterpret_cast<uintptr_t>(main), name, location));
   LOG(INFO) << name << " " << location.file << " " << location.line << " ("

folly/experimental/test/GenTest.cpp

@@ -619,7 +619,7 @@ TEST(StringGen, EmptySplit) {
   {
     auto pieces = split(",,", ',') | take(1) | collect;
     EXPECT_EQ(1, pieces.size());
-    EXPECT_EQ("", pieces[1]);
+    EXPECT_EQ("", pieces[0]);
   }
 }
 

folly/test/SubprocessTest.cpp

@@ -20,7 +20,9 @@
 #include <gtest/gtest.h>
 
 #include "folly/Format.h"
-#include "folly/experimental/io/Stream.h"
+#include "folly/experimental/Gen.h"
+#include "folly/experimental/FileGen.h"
+#include "folly/experimental/StringGen.h"
 
 using namespace folly;
 
@@ -57,12 +59,12 @@ TEST(SimpleSubprocessTest, ShellExitsWithError) {
 TEST(PopenSubprocessTest, PopenRead) {
   Subprocess proc("ls /", Subprocess::pipeStdout());
   int found = 0;
-  for (auto bline : byLine(proc.stdout())) {
-    StringPiece line(bline);
+  gen::byLine(proc.stdout()) | gen::eachAs<StringPiece>() |
+    [&] (StringPiece line) {
       if (line == "etc" || line == "bin" || line == "usr") {
         ++found;
       }
-  }
+    };
   EXPECT_EQ(3, found);
   proc.waitChecked();
 }