// Copyright (c) 2012 Baidu, Inc. // // Licensed under the Apache License, Version 2.0 (the "License"); // you may not use this file except in compliance with the License. // You may obtain a copy of the License at // // http://www.apache.org/licenses/LICENSE-2.0 // // Unless required by applicable law or agreed to in writing, software // distributed under the License is distributed on an "AS IS" BASIS, // WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. // See the License for the specific language governing permissions and // limitations under the License. // Author: Ge,Jun (gejun@baidu.com) // Date: Thu Nov 22 13:57:56 CST 2012 #include "butil/macros.h" #include "butil/zero_copy_stream_as_streambuf.h" namespace butil { BAIDU_CASSERT(sizeof(std::streambuf::char_type) == sizeof(char), only_support_char); int ZeroCopyStreamAsStreamBuf::overflow(int ch) { if (ch == std::streambuf::traits_type::eof()) { return ch; } void* block = NULL; int size = 0; if (_zero_copy_stream->Next(&block, &size)) { setp((char*)block, (char*)block + size); // if size == 0, this function will call overflow again. return sputc(ch); } else { setp(NULL, NULL); return std::streambuf::traits_type::eof(); } } int ZeroCopyStreamAsStreamBuf::sync() { // data are already in IOBuf. return 0; } ZeroCopyStreamAsStreamBuf::~ZeroCopyStreamAsStreamBuf() { shrink(); } void ZeroCopyStreamAsStreamBuf::shrink() { if (pbase() != NULL) { _zero_copy_stream->BackUp(epptr() - pptr()); setp(NULL, NULL); } } std::streampos ZeroCopyStreamAsStreamBuf::seekoff( std::streamoff off, std::ios_base::seekdir way, std::ios_base::openmode which) { if (off == 0 && way == std::ios_base::cur) { return _zero_copy_stream->ByteCount() - (epptr() - pptr()); } return (std::streampos)(std::streamoff)-1; } } // namespace butil