ManualExecutor: add clear method

[folly.git] / folly / small_vector.h

diff --git a/folly/small_vector.h b/folly/small_vector.h
index b03eec05f3a3281ba3b73b05dba18d86300dab2b..827cf687230ae1319e0d81ac4673eed26a253839 100644 (file)
--- a/folly/small_vector.h
+++ b/folly/small_vector.h
@@ -1,5 +1,5 @@
 /*
- * Copyright 2014 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.
@@ -20,10 +20,8 @@
  *
  * @author Jordan DeLong <delong.j@fb.com>
  */
-#ifndef FOLLY_SMALL_VECTOR_H_
-#define FOLLY_SMALL_VECTOR_H_
 
-#include <folly/Portability.h>
+#pragma once
 
 #include <stdexcept>
 #include <cstdlib>
@@ -44,11 +42,14 @@
 #include <boost/mpl/empty.hpp>
 #include <boost/mpl/size.hpp>
 #include <boost/mpl/count.hpp>
-#include <boost/mpl/max.hpp>
 
+#include <folly/FormatTraits.h>
 #include <folly/Malloc.h>
+#include <folly/Portability.h>
+#include <folly/portability/Constexpr.h>
+#include <folly/portability/Malloc.h>
 
-#if defined(__GNUC__) && FOLLY_X64
+#if defined(__GNUC__) && (FOLLY_X64 || FOLLY_PPC64)
 # include <folly/SmallLocks.h>
 # define FB_PACK_ATTR FOLLY_PACK_ATTR
 # define FB_PACK_PUSH FOLLY_PACK_PUSH
@@ -59,16 +60,6 @@
 # define FB_PACK_POP
 #endif
 
-#if FOLLY_HAVE_MALLOC_SIZE
-  extern "C" std::size_t malloc_size(const void*);
-# if !FOLLY_HAVE_MALLOC_USABLE_SIZE
-#  define malloc_usable_size malloc_size
-# endif
-# ifndef malloc_usable_size
-#  define malloc_usable_size malloc_size
-# endif
-#endif
-
 // Ignore shadowing warnings within this file, so includers can use -Wshadow.
 #pragma GCC diagnostic push
 #pragma GCC diagnostic ignored "-Wshadow"
@@ -364,10 +355,8 @@ class small_vector
    * into our value_type*, we will inline more than they asked.)
    */
   enum {
-    MaxInline = boost::mpl::max<
-                  boost::mpl::int_<sizeof(Value*) / sizeof(Value)>,
-                  boost::mpl::int_<RequestedMaxInline>
-                >::type::value
+    MaxInline =
+        constexpr_max(sizeof(Value*) / sizeof(Value), RequestedMaxInline),
   };
 
 public:
@@ -382,7 +371,7 @@ public:
   typedef std::reverse_iterator<iterator>       reverse_iterator;
   typedef std::reverse_iterator<const_iterator> const_reverse_iterator;
 
-  explicit small_vector() {}
+  explicit small_vector() = default;
 
   small_vector(small_vector const& o) {
     auto n = o.size();
@@ -658,6 +647,17 @@ public:
     emplaceBack(std::forward<Args>(args)...);
   }
 
+  void emplace_back(const value_type& t) {
+    push_back(t);
+  }
+  void emplace_back(value_type& t) {
+    push_back(t);
+  }
+
+  void emplace_back(value_type&& t) {
+    push_back(std::move(t));
+  }
+
   void push_back(value_type&& t) {
     if (capacity() == size()) {
       makeSize(std::max(size_type(2), 3 * size() / 2), &t, size());
@@ -668,9 +668,17 @@ public:
   }
 
   void push_back(value_type const& t) {
-    // Make a copy and forward to the rvalue value_type&& overload
-    // above.
-    push_back(value_type(t));
+    // TODO: we'd like to make use of makeSize (it can be optimized better,
+    // because it manipulates the internals)
+    // unfortunately the current implementation only supports moving from
+    // a supplied rvalue, and doing an extra move just to reuse it is a perf
+    // net loss
+    if (size() == capacity()) {// && isInside(&t)) {
+      value_type tmp(t);
+      emplaceBack(std::move(tmp));
+    } else {
+      emplaceBack(t);
+    }
   }
 
   void pop_back() {
@@ -809,13 +817,6 @@ private:
     this->setSize(size() + 1);
   }
 
-  /*
-   * Special case of emplaceBack for rvalue
-   */
-  void emplaceBack(value_type&& t) {
-    push_back(std::move(t));
-  }
-
   static iterator unconst(const_iterator it) {
     return const_cast<iterator>(it);
   }
@@ -871,7 +872,7 @@ private:
       // With iterators that only allow a single pass, we can't really
       // do anything sane here.
       while (first != last) {
-        push_back(*first++);
+        emplace_back(*first++);
       }
       return;
     }
@@ -1046,7 +1047,7 @@ private:
     }
   } FB_PACK_ATTR;
 
-#if FOLLY_X64
+#if (FOLLY_X64 || FOLLY_PPC64)
   typedef unsigned char InlineStorageType[sizeof(value_type) * MaxInline];
 #else
   typedef typename std::aligned_storage<
@@ -1129,7 +1130,17 @@ void swap(small_vector<T,MaxInline,A,B,C>& a,
 
 //////////////////////////////////////////////////////////////////////
 
-}
+namespace detail {
+
+// Format support.
+template <class T, size_t M, class A, class B, class C>
+struct IndexableTraits<small_vector<T, M, A, B, C>>
+  : public IndexableTraitsSeq<small_vector<T, M, A, B, C>> {
+};
+
+}  // namespace detail
+
+}  // namespace folly
 
 #pragma GCC diagnostic pop
 
@@ -1138,5 +1149,3 @@ void swap(small_vector<T,MaxInline,A,B,C>& a,
 # undef FB_PACK_PUSH
 # undef FB_PACK_POP
 #endif
-
-#endif