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Diffstat (limited to 'Source/cmUVStreambuf.h')
| -rw-r--r-- | Source/cmUVStreambuf.h | 219 |
1 files changed, 219 insertions, 0 deletions
diff --git a/Source/cmUVStreambuf.h b/Source/cmUVStreambuf.h new file mode 100644 index 000000000..873352b1a --- /dev/null +++ b/Source/cmUVStreambuf.h @@ -0,0 +1,219 @@ +/* Distributed under the OSI-approved BSD 3-Clause License. See accompanying + file Copyright.txt or https://cmake.org/licensing for details. */ +#ifndef cmUVStreambuf_h +#define cmUVStreambuf_h + +#include "cmUVHandlePtr.h" + +#include "cm_uv.h" + +#include <algorithm> +#include <cstring> +#include <streambuf> +#include <vector> + +/* + * This file is based on example code from: + * + * http://www.voidcn.com/article/p-vjnlygmc-gy.html + * + * The example code was distributed under the following license: + * + * Copyright 2007 Edd Dawson. + * Distributed under the Boost Software License, Version 1.0. + * + * Boost Software License - Version 1.0 - August 17th, 2003 + * + * Permission is hereby granted, free of charge, to any person or organization + * obtaining a copy of the software and accompanying documentation covered by + * this license (the "Software") to use, reproduce, display, distribute, + * execute, and transmit the Software, and to prepare derivative works of the + * Software, and to permit third-parties to whom the Software is furnished to + * do so, all subject to the following: + * + * The copyright notices in the Software and this entire statement, including + * the above license grant, this restriction and the following disclaimer, + * must be included in all copies of the Software, in whole or in part, and + * all derivative works of the Software, unless such copies or derivative + * works are solely in the form of machine-executable object code generated by + * a source language processor. + * + * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR + * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, + * FITNESS FOR A PARTICULAR PURPOSE, TITLE AND NON-INFRINGEMENT. IN NO EVENT + * SHALL THE COPYRIGHT HOLDERS OR ANYONE DISTRIBUTING THE SOFTWARE BE LIABLE + * FOR ANY DAMAGES OR OTHER LIABILITY, WHETHER IN CONTRACT, TORT OR OTHERWISE, + * ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER + * DEALINGS IN THE SOFTWARE. + */ + +template <typename CharT, typename Traits = std::char_traits<CharT>> +class cmBasicUVStreambuf : public std::basic_streambuf<CharT, Traits> +{ +public: + cmBasicUVStreambuf(std::size_t bufSize = 256, std::size_t putBack = 8); + ~cmBasicUVStreambuf() override; + + bool is_open() const; + + cmBasicUVStreambuf* open(uv_stream_t* stream); + + cmBasicUVStreambuf* close(); + +protected: + typename cmBasicUVStreambuf::int_type underflow() override; + std::streamsize showmanyc() override; + + // FIXME: Add write support + +private: + uv_stream_t* Stream = nullptr; + void* OldStreamData = nullptr; + const std::size_t PutBack = 0; + std::vector<CharT> InputBuffer; + bool EndOfFile = false; + + void StreamReadStartStop(); + + void StreamRead(ssize_t nread); + void HandleAlloc(uv_buf_t* buf); +}; + +template <typename CharT, typename Traits> +cmBasicUVStreambuf<CharT, Traits>::cmBasicUVStreambuf(std::size_t bufSize, + std::size_t putBack) + : PutBack(std::max<std::size_t>(putBack, 1)) + , InputBuffer(std::max<std::size_t>(this->PutBack, bufSize) + this->PutBack) +{ + this->close(); +} + +template <typename CharT, typename Traits> +cmBasicUVStreambuf<CharT, Traits>::~cmBasicUVStreambuf() +{ + this->close(); +} + +template <typename CharT, typename Traits> +bool cmBasicUVStreambuf<CharT, Traits>::is_open() const +{ + return this->Stream != nullptr; +} + +template <typename CharT, typename Traits> +cmBasicUVStreambuf<CharT, Traits>* cmBasicUVStreambuf<CharT, Traits>::open( + uv_stream_t* stream) +{ + this->close(); + this->Stream = stream; + this->EndOfFile = false; + if (this->Stream) { + this->OldStreamData = this->Stream->data; + this->Stream->data = this; + } + this->StreamReadStartStop(); + return this; +} + +template <typename CharT, typename Traits> +cmBasicUVStreambuf<CharT, Traits>* cmBasicUVStreambuf<CharT, Traits>::close() +{ + if (this->Stream) { + uv_read_stop(this->Stream); + this->Stream->data = this->OldStreamData; + } + this->Stream = nullptr; + CharT* readEnd = this->InputBuffer.data() + this->InputBuffer.size(); + this->setg(readEnd, readEnd, readEnd); + return this; +} + +template <typename CharT, typename Traits> +typename cmBasicUVStreambuf<CharT, Traits>::int_type +cmBasicUVStreambuf<CharT, Traits>::underflow() +{ + if (!this->is_open()) { + return Traits::eof(); + } + + if (this->gptr() < this->egptr()) { + return Traits::to_int_type(*this->gptr()); + } + + this->StreamReadStartStop(); + while (this->in_avail() == 0) { + uv_run(this->Stream->loop, UV_RUN_ONCE); + } + if (this->in_avail() == -1) { + return Traits::eof(); + } + return Traits::to_int_type(*this->gptr()); +} + +template <typename CharT, typename Traits> +std::streamsize cmBasicUVStreambuf<CharT, Traits>::showmanyc() +{ + if (!this->is_open() || this->EndOfFile) { + return -1; + } + return 0; +} + +template <typename CharT, typename Traits> +void cmBasicUVStreambuf<CharT, Traits>::StreamReadStartStop() +{ + if (this->Stream) { + uv_read_stop(this->Stream); + if (this->gptr() >= this->egptr()) { + uv_read_start( + this->Stream, + [](uv_handle_t* handle, size_t /* unused */, uv_buf_t* buf) { + auto streambuf = + static_cast<cmBasicUVStreambuf<CharT, Traits>*>(handle->data); + streambuf->HandleAlloc(buf); + }, + [](uv_stream_t* stream2, ssize_t nread, const uv_buf_t* /* unused */) { + auto streambuf = + static_cast<cmBasicUVStreambuf<CharT, Traits>*>(stream2->data); + streambuf->StreamRead(nread); + }); + } + } +} + +template <typename CharT, typename Traits> +void cmBasicUVStreambuf<CharT, Traits>::HandleAlloc(uv_buf_t* buf) +{ + auto size = this->egptr() - this->gptr(); + std::memmove(this->InputBuffer.data(), this->gptr(), + this->egptr() - this->gptr()); + this->setg(this->InputBuffer.data(), this->InputBuffer.data(), + this->InputBuffer.data() + size); + buf->base = this->egptr(); +#ifdef _WIN32 +# define BUF_LEN_TYPE ULONG +#else +# define BUF_LEN_TYPE size_t +#endif + buf->len = BUF_LEN_TYPE( + (this->InputBuffer.data() + this->InputBuffer.size() - this->egptr()) * + sizeof(CharT)); +#undef BUF_LEN_TYPE +} + +template <typename CharT, typename Traits> +void cmBasicUVStreambuf<CharT, Traits>::StreamRead(ssize_t nread) +{ + if (nread > 0) { + this->setg(this->eback(), this->gptr(), + this->egptr() + nread / sizeof(CharT)); + uv_read_stop(this->Stream); + } else if (nread < 0 /*|| nread == UV_EOF*/) { + this->EndOfFile = true; + uv_read_stop(this->Stream); + } +} + +using cmUVStreambuf = cmBasicUVStreambuf<char>; + +#endif |