The Tor Browser: comparison ipc/chromium/src/base/stl

--1:000000000000
+:4bb0d2bbee42
+// Copyright (c) 2006-2008 The Chromium Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+// STL utility functions.  Usually, these replace built-in, but slow(!),
+// STL functions with more efficient versions.
+#ifndef BASE_STL_UTIL_INL_H_
+#define BASE_STL_UTIL_INL_H_
+#include <string.h>  // for memcpy
+#include <functional>
+#include <set>
+#include <string>
+#include <vector>
+#include <cassert>
+// Clear internal memory of an STL object.
+// STL clear()/reserve(0) does not always free internal memory allocated
+// This function uses swap/destructor to ensure the internal memory is freed.
+template<class T> void STLClearObject(T* obj) {
+T tmp;
+tmp.swap(*obj);
+obj->reserve(0);  // this is because sometimes "T tmp" allocates objects with
+// memory (arena implementation?).  use reserve()
+// to clear() even if it doesn't always work
+}
+// Reduce memory usage on behalf of object if it is using more than
+// "bytes" bytes of space.  By default, we clear objects over 1MB.
+template <class T> inline void STLClearIfBig(T* obj, size_t limit = 1<<20) {
+if (obj->capacity() >= limit) {
+STLClearObject(obj);
+} else {
+obj->clear();
+}
+}
+// Reserve space for STL object.
+// STL's reserve() will always copy.
+// This function avoid the copy if we already have capacity
+template<class T> void STLReserveIfNeeded(T* obj, int new_size) {
+if (obj->capacity() < new_size)   // increase capacity
+obj->reserve(new_size);
+else if (obj->size() > new_size)  // reduce size
+obj->resize(new_size);
+}
+// STLDeleteContainerPointers()
+//  For a range within a container of pointers, calls delete
+//  (non-array version) on these pointers.
+// NOTE: for these three functions, we could just implement a DeleteObject
+// functor and then call for_each() on the range and functor, but this
+// requires us to pull in all of algorithm.h, which seems expensive.
+// For hash_[multi]set, it is important that this deletes behind the iterator
+// because the hash_set may call the hash function on the iterator when it is
+// advanced, which could result in the hash function trying to deference a
+// stale pointer.
+template <class ForwardIterator>
+void STLDeleteContainerPointers(ForwardIterator begin,
+ForwardIterator end) {
+while (begin != end) {
+ForwardIterator temp = begin;
+++begin;
+delete *temp;
+}
+}
+// STLDeleteContainerPairPointers()
+//  For a range within a container of pairs, calls delete
+//  (non-array version) on BOTH items in the pairs.
+// NOTE: Like STLDeleteContainerPointers, it is important that this deletes
+// behind the iterator because if both the key and value are deleted, the
+// container may call the hash function on the iterator when it is advanced,
+// which could result in the hash function trying to dereference a stale
+// pointer.
+template <class ForwardIterator>
+void STLDeleteContainerPairPointers(ForwardIterator begin,
+ForwardIterator end) {
+while (begin != end) {
+ForwardIterator temp = begin;
+++begin;
+delete temp->first;
+delete temp->second;
+}
+}
+// STLDeleteContainerPairFirstPointers()
+//  For a range within a container of pairs, calls delete (non-array version)
+//  on the FIRST item in the pairs.
+// NOTE: Like STLDeleteContainerPointers, deleting behind the iterator.
+template <class ForwardIterator>
+void STLDeleteContainerPairFirstPointers(ForwardIterator begin,
+ForwardIterator end) {
+while (begin != end) {
+ForwardIterator temp = begin;
+++begin;
+delete temp->first;
+}
+}
+// STLDeleteContainerPairSecondPointers()
+//  For a range within a container of pairs, calls delete
+//  (non-array version) on the SECOND item in the pairs.
+template <class ForwardIterator>
+void STLDeleteContainerPairSecondPointers(ForwardIterator begin,
+ForwardIterator end) {
+while (begin != end) {
+delete begin->second;
+++begin;
+}
+}
+template<typename T>
+inline void STLAssignToVector(std::vector<T>* vec,
+const T* ptr,
+size_t n) {
+vec->resize(n);
+memcpy(&vec->front(), ptr, n*sizeof(T));
+}
+/***** Hack to allow faster assignment to a vector *****/
+// This routine speeds up an assignment of 32 bytes to a vector from
+// about 250 cycles per assignment to about 140 cycles.
+//
+// Usage:
+//      STLAssignToVectorChar(&vec, ptr, size);
+//      STLAssignToString(&str, ptr, size);
+inline void STLAssignToVectorChar(std::vector<char>* vec,
+const char* ptr,
+size_t n) {
+STLAssignToVector(vec, ptr, n);
+}
+inline void STLAssignToString(std::string* str, const char* ptr, size_t n) {
+str->resize(n);
+memcpy(&*str->begin(), ptr, n);
+}
+// To treat a possibly-empty vector as an array, use these functions.
+// If you know the array will never be empty, you can use &*v.begin()
+// directly, but that is allowed to dump core if v is empty.  This
+// function is the most efficient code that will work, taking into
+// account how our STL is actually implemented.  THIS IS NON-PORTABLE
+// CODE, so call us instead of repeating the nonportable code
+// everywhere.  If our STL implementation changes, we will need to
+// change this as well.
+template<typename T>
+inline T* vector_as_array(std::vector<T>* v) {
+# ifdef NDEBUG
+return &*v->begin();
+# else
+return v->empty() ? NULL : &*v->begin();
+# endif
+}
+template<typename T>
+inline const T* vector_as_array(const std::vector<T>* v) {
+# ifdef NDEBUG
+return &*v->begin();
+# else
+return v->empty() ? NULL : &*v->begin();
+# endif
+}
+// Return a mutable char* pointing to a string's internal buffer,
+// which may not be null-terminated. Writing through this pointer will
+// modify the string.
+//
+// string_as_array(&str)[i] is valid for 0 <= i < str.size() until the
+// next call to a string method that invalidates iterators.
+//
+// As of 2006-04, there is no standard-blessed way of getting a
+// mutable reference to a string's internal buffer. However, issue 530
+// (http://www.open-std.org/JTC1/SC22/WG21/docs/lwg-active.html#530)
+// proposes this as the method. According to Matt Austern, this should
+// already work on all current implementations.
+inline char* string_as_array(std::string* str) {
+// DO NOT USE const_cast<char*>(str->data())! See the unittest for why.
+return str->empty() ? NULL : &*str->begin();
+}
+// These are methods that test two hash maps/sets for equality.  These exist
+// because the == operator in the STL can return false when the maps/sets
+// contain identical elements.  This is because it compares the internal hash
+// tables which may be different if the order of insertions and deletions
+// differed.
+template <class HashSet>
+inline bool
+HashSetEquality(const HashSet& set_a,
+const HashSet& set_b) {
+if (set_a.size() != set_b.size()) return false;
+for (typename HashSet::const_iterator i = set_a.begin();
+i != set_a.end();
+++i) {
+if (set_b.find(*i) == set_b.end())
+return false;
+}
+return true;
+}
+template <class HashMap>
+inline bool
+HashMapEquality(const HashMap& map_a,
+const HashMap& map_b) {
+if (map_a.size() != map_b.size()) return false;
+for (typename HashMap::const_iterator i = map_a.begin();
+i != map_a.end(); ++i) {
+typename HashMap::const_iterator j = map_b.find(i->first);
+if (j == map_b.end()) return false;
+if (i->second != j->second) return false;
+}
+return true;
+}
+// The following functions are useful for cleaning up STL containers
+// whose elements point to allocated memory.
+// STLDeleteElements() deletes all the elements in an STL container and clears
+// the container.  This function is suitable for use with a vector, set,
+// hash_set, or any other STL container which defines sensible begin(), end(),
+// and clear() methods.
+//
+// If container is NULL, this function is a no-op.
+//
+// As an alternative to calling STLDeleteElements() directly, consider
+// STLElementDeleter (defined below), which ensures that your container's
+// elements are deleted when the STLElementDeleter goes out of scope.
+template <class T>
+void STLDeleteElements(T *container) {
+if (!container) return;
+STLDeleteContainerPointers(container->begin(), container->end());
+container->clear();
+}
+// Given an STL container consisting of (key, value) pairs, STLDeleteValues
+// deletes all the "value" components and clears the container.  Does nothing
+// in the case it's given a NULL pointer.
+template <class T>
+void STLDeleteValues(T *v) {
+if (!v) return;
+for (typename T::iterator i = v->begin(); i != v->end(); ++i) {
+delete i->second;
+}
+v->clear();
+}
+// The following classes provide a convenient way to delete all elements or
+// values from STL containers when they goes out of scope.  This greatly
+// simplifies code that creates temporary objects and has multiple return
+// statements.  Example:
+//
+// vector<MyProto *> tmp_proto;
+// STLElementDeleter<vector<MyProto *> > d(&tmp_proto);
+// if (...) return false;
+// ...
+// return success;
+// Given a pointer to an STL container this class will delete all the element
+// pointers when it goes out of scope.
+template<class STLContainer> class STLElementDeleter {
+public:
+STLElementDeleter(STLContainer *ptr) : container_ptr_(ptr) {}
+~STLElementDeleter() { STLDeleteElements(container_ptr_); }
+private:
+STLContainer *container_ptr_;
+};
+// Given a pointer to an STL container this class will delete all the value
+// pointers when it goes out of scope.
+template<class STLContainer> class STLValueDeleter {
+public:
+STLValueDeleter(STLContainer *ptr) : container_ptr_(ptr) {}
+~STLValueDeleter() { STLDeleteValues(container_ptr_); }
+private:
+STLContainer *container_ptr_;
+};
+// Forward declare some callback classes in callback.h for STLBinaryFunction
+template <class R, class T1, class T2>
+class ResultCallback2;
+// STLBinaryFunction is a wrapper for the ResultCallback2 class in callback.h
+// It provides an operator () method instead of a Run method, so it may be
+// passed to STL functions in <algorithm>.
+//
+// The client should create callback with NewPermanentCallback, and should
+// delete callback after it is done using the STLBinaryFunction.
+template <class Result, class Arg1, class Arg2>
+class STLBinaryFunction : public std::binary_function<Arg1, Arg2, Result> {
+public:
+typedef ResultCallback2<Result, Arg1, Arg2> Callback;
+STLBinaryFunction(Callback* callback)
+: callback_(callback) {
+assert(callback_);
+}
+Result operator() (Arg1 arg1, Arg2 arg2) {
+return callback_->Run(arg1, arg2);
+}
+private:
+Callback* callback_;
+};
+// STLBinaryPredicate is a specialized version of STLBinaryFunction, where the
+// return type is bool and both arguments have type Arg.  It can be used
+// wherever STL requires a StrictWeakOrdering, such as in sort() or
+// lower_bound().
+//
+// templated typedefs are not supported, so instead we use inheritance.
+template <class Arg>
+class STLBinaryPredicate : public STLBinaryFunction<bool, Arg, Arg> {
+public:
+typedef typename STLBinaryPredicate<Arg>::Callback Callback;
+STLBinaryPredicate(Callback* callback)
+: STLBinaryFunction<bool, Arg, Arg>(callback) {
+}
+};
+// Functors that compose arbitrary unary and binary functions with a
+// function that "projects" one of the members of a pair.
+// Specifically, if p1 and p2, respectively, are the functions that
+// map a pair to its first and second, respectively, members, the
+// table below summarizes the functions that can be constructed:
+//
+// * UnaryOperate1st<pair>(f) returns the function x -> f(p1(x))
+// * UnaryOperate2nd<pair>(f) returns the function x -> f(p2(x))
+// * BinaryOperate1st<pair>(f) returns the function (x,y) -> f(p1(x),p1(y))
+// * BinaryOperate2nd<pair>(f) returns the function (x,y) -> f(p2(x),p2(y))
+//
+// A typical usage for these functions would be when iterating over
+// the contents of an STL map. For other sample usage, see the unittest.
+template<typename Pair, typename UnaryOp>
+class UnaryOperateOnFirst
+: public std::unary_function<Pair, typename UnaryOp::result_type> {
+public:
+UnaryOperateOnFirst() {
+}
+UnaryOperateOnFirst(const UnaryOp& f) : f_(f) {
+}
+typename UnaryOp::result_type operator()(const Pair& p) const {
+return f_(p.first);
+}
+private:
+UnaryOp f_;
+};
+template<typename Pair, typename UnaryOp>
+UnaryOperateOnFirst<Pair, UnaryOp> UnaryOperate1st(const UnaryOp& f) {
+return UnaryOperateOnFirst<Pair, UnaryOp>(f);
+}
+template<typename Pair, typename UnaryOp>
+class UnaryOperateOnSecond
+: public std::unary_function<Pair, typename UnaryOp::result_type> {
+public:
+UnaryOperateOnSecond() {
+}
+UnaryOperateOnSecond(const UnaryOp& f) : f_(f) {
+}
+typename UnaryOp::result_type operator()(const Pair& p) const {
+return f_(p.second);
+}
+private:
+UnaryOp f_;
+};
+template<typename Pair, typename UnaryOp>
+UnaryOperateOnSecond<Pair, UnaryOp> UnaryOperate2nd(const UnaryOp& f) {
+return UnaryOperateOnSecond<Pair, UnaryOp>(f);
+}
+template<typename Pair, typename BinaryOp>
+class BinaryOperateOnFirst
+: public std::binary_function<Pair, Pair, typename BinaryOp::result_type> {
+public:
+BinaryOperateOnFirst() {
+}
+BinaryOperateOnFirst(const BinaryOp& f) : f_(f) {
+}
+typename BinaryOp::result_type operator()(const Pair& p1,
+const Pair& p2) const {
+return f_(p1.first, p2.first);
+}
+private:
+BinaryOp f_;
+};
+template<typename Pair, typename BinaryOp>
+BinaryOperateOnFirst<Pair, BinaryOp> BinaryOperate1st(const BinaryOp& f) {
+return BinaryOperateOnFirst<Pair, BinaryOp>(f);
+}
+template<typename Pair, typename BinaryOp>
+class BinaryOperateOnSecond
+: public std::binary_function<Pair, Pair, typename BinaryOp::result_type> {
+public:
+BinaryOperateOnSecond() {
+}
+BinaryOperateOnSecond(const BinaryOp& f) : f_(f) {
+}
+typename BinaryOp::result_type operator()(const Pair& p1,
+const Pair& p2) const {
+return f_(p1.second, p2.second);
+}
+private:
+BinaryOp f_;
+};
+template<typename Pair, typename BinaryOp>
+BinaryOperateOnSecond<Pair, BinaryOp> BinaryOperate2nd(const BinaryOp& f) {
+return BinaryOperateOnSecond<Pair, BinaryOp>(f);
+}
+// Translates a set into a vector.
+template<typename T>
+std::vector<T> SetToVector(const std::set<T>& values) {
+std::vector<T> result;
+result.reserve(values.size());
+result.insert(result.begin(), values.begin(), values.end());
+return result;
+}
+#endif  // BASE_STL_UTIL_INL_H_

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comparison: ipc/chromium/src/base/stl_util-inl.h

ipc/chromium/src/base/stl_util-inl.h