add Cursor::peekBytes()

[folly.git] / folly / Subprocess.cpp

diff --git a/folly/Subprocess.cpp b/folly/Subprocess.cpp
index 2a1c3bce686d4280615aea4f8bdefdcd7b21f62d..8190c47063b64737b1a277ba579caab20b5cf3ae 100644 (file)
--- a/folly/Subprocess.cpp
+++ b/folly/Subprocess.cpp
@@ -1,5 +1,5 @@
 /*
- * Copyright 2015 Facebook, Inc.
+ * Copyright 2016 Facebook, Inc.
  *
  * Licensed under the Apache License, Version 2.0 (the "License");
  * you may not use this file except in compliance with the License.
@@ -42,8 +42,7 @@
 #include <folly/ScopeGuard.h>
 #include <folly/String.h>
 #include <folly/io/Cursor.h>
-
-extern char** environ;
+#include <folly/portability/Environment.h>
 
 constexpr int kExecFailure = 127;
 constexpr int kChildFailure = 126;
@@ -211,8 +210,7 @@ struct ChildErrorInfo {
   int errnoValue;
 };
 
-FOLLY_NORETURN void childError(int errFd, int errCode, int errnoValue);
-void childError(int errFd, int errCode, int errnoValue) {
+[[noreturn]] void childError(int errFd, int errCode, int errnoValue) {
   ChildErrorInfo info = {errCode, errnoValue};
   // Write the error information over the pipe to our parent process.
   // We can't really do anything else if this write call fails.
@@ -481,7 +479,9 @@ int Subprocess::prepareChild(const Options& options,
 #if __linux__
   // Opt to receive signal on parent death, if requested
   if (options.parentDeathSignal_ != 0) {
-    if (prctl(PR_SET_PDEATHSIG, options.parentDeathSignal_, 0, 0, 0) == -1) {
+    const auto parentDeathSignal =
+        static_cast<unsigned long>(options.parentDeathSignal_);
+    if (prctl(PR_SET_PDEATHSIG, parentDeathSignal, 0, 0, 0) == -1) {
       return errno;
     }
   }
@@ -606,21 +606,23 @@ pid_t Subprocess::pid() const {
 
 namespace {
 
-std::pair<const uint8_t*, size_t> queueFront(const IOBufQueue& queue) {
+ByteRange queueFront(const IOBufQueue& queue) {
   auto* p = queue.front();
-  if (!p) return std::make_pair(nullptr, 0);
-  return io::Cursor(p).peek();
+  if (!p) {
+    return ByteRange{};
+  }
+  return io::Cursor(p).peekBytes();
 }
 
 // fd write
 bool handleWrite(int fd, IOBufQueue& queue) {
   for (;;) {
-    auto p = queueFront(queue);
-    if (p.second == 0) {
+    auto b = queueFront(queue);
+    if (b.empty()) {
       return true;  // EOF
     }
 
-    ssize_t n = writeNoInt(fd, p.first, p.second);
+    ssize_t n = writeNoInt(fd, b.data(), b.size());
     if (n == -1 && errno == EAGAIN) {
       return false;
     }