================
@@ -499,11 +652,78 @@ struct _LIBCPP_TEMPLATE_VIS __format_to_n_buffer final
_LIBCPP_HIDE_FROM_ABI auto __make_output_iterator() { return
this->__output_.__make_output_iterator(); }
_LIBCPP_HIDE_FROM_ABI format_to_n_result<_OutIt> __result() && {
- this->__output_.__flush();
+ this->__output_.__flush(0);
return {std::move(this->__writer_).__out_it(), this->__size_};
}
};
+// ***** ***** ***** LLVM-20 classes ***** ***** *****
+
+// A dynamically growing buffer.
+template <__fmt_char_type _CharT>
+class _LIBCPP_TEMPLATE_VIS __allocating_buffer : public
__output_buffer<_CharT> {
+public:
+ __allocating_buffer(const __allocating_buffer&) = delete;
+ __allocating_buffer& operator=(const __allocating_buffer&) = delete;
+
+ [[nodiscard]] _LIBCPP_HIDE_FROM_ABI __allocating_buffer()
+ : __output_buffer<_CharT>{__buffer_, __buffer_size_, __prepare_write} {}
+
+ _LIBCPP_HIDE_FROM_ABI ~__allocating_buffer() {
+ if (__ptr_ != __buffer_) {
+ ranges::destroy_n(__ptr_, this->__size());
+ allocator_traits<_Alloc>::deallocate(__alloc_, __ptr_,
this->__capacity());
+ }
+ }
+
+ [[nodiscard]] _LIBCPP_HIDE_FROM_ABI basic_string_view<_CharT> __view() {
return {__ptr_, this->__size()}; }
+
+private:
+ // At the moment the allocator is hard-code. There might be reasons to have
+ // an allocator trait in the future. This ensures forward compatibility.
+ using _Alloc = allocator<_CharT>;
+ _LIBCPP_NO_UNIQUE_ADDRESS _Alloc __alloc_;
+
+ // Since allocating is expensive the class has a small internal buffer. When
+ // its capacity is exceeded a dynamic buffer will be allocated.
+ static constexpr size_t __buffer_size_ = 256;
+ _CharT __buffer_[__buffer_size_];
+ _CharT* __ptr_{__buffer_};
+
+ _LIBCPP_HIDE_FROM_ABI void __grow_buffer(size_t __capacity) {
+ if (__capacity < __buffer_size_)
+ return;
+
+ _LIBCPP_ASSERT_INTERNAL(__capacity > this->__capacity(), "the buffer must
grow");
+ auto __result = std::__allocate_at_least(__alloc_, __capacity);
+ auto __guard = std::__make_exception_guard([&] {
+ allocator_traits<_Alloc>::deallocate(__alloc_, __result.ptr,
__result.count);
+ });
+ // This shouldn't throw, but just to be safe. Note that at -O1 this
+ // guard is optimized away so there is no runtime overhead.
+ new (__result.ptr) _CharT[__result.count];
+ std::copy_n(__ptr_, this->__size(), __result.ptr);
+ __guard.__complete();
+ if (__ptr_ != __buffer_) {
+ ranges::destroy_n(__ptr_, this->__capacity());
+ allocator_traits<_Alloc>::deallocate(__alloc_, __ptr_,
this->__capacity());
+ }
----------------
ldionne wrote:
```suggestion
auto __guard = std::__make_exception_guard([&] {
allocator_traits<_Alloc>::deallocate(__alloc_, __result.ptr,
__result.count);
});
// This shouldn't throw, but just to be safe. Note that at -O1 this
// guard is optimized away so there is no runtime overhead.
std::__uninitialized_allocator_relocate(__alloc_, __ptr_, __ptr_ +
this->__size(), __result.ptr);
__guard.__complete();
if (__ptr_ != __buffer_) {
allocator_traits<_Alloc>::deallocate(__alloc_, __ptr_,
this->__capacity());
}
```
https://github.com/llvm/llvm-project/pull/101817
_______________________________________________
llvm-branch-commits mailing list
llvm-branch-commits@lists.llvm.org
https://lists.llvm.org/cgi-bin/mailman/listinfo/llvm-branch-commits
