From 4da93b6ad91dff1de98c3c8dd3674c0544f2958b Mon Sep 17 00:00:00 2001 From: Monty Brandenberg Date: Thu, 21 Jun 2012 19:45:40 -0400 Subject: SH-3177 Add streambuf/iostream adapters to BufferArray object. Initial version that should have enough of the plumbing to produce a working adapter. Memory test is showing 8 bytes held after one of the tests so I'm going to revisit that later. But basic functionality is there going by the unit tests. --- indra/llcorehttp/bufferstream.cpp | 285 ++++++++++++++++++++++++++++++++++++++ 1 file changed, 285 insertions(+) create mode 100644 indra/llcorehttp/bufferstream.cpp (limited to 'indra/llcorehttp/bufferstream.cpp') diff --git a/indra/llcorehttp/bufferstream.cpp b/indra/llcorehttp/bufferstream.cpp new file mode 100644 index 0000000000..6553900eef --- /dev/null +++ b/indra/llcorehttp/bufferstream.cpp @@ -0,0 +1,285 @@ +/** + * @file bufferstream.cpp + * @brief Implements the BufferStream adapter class + * + * $LicenseInfo:firstyear=2012&license=viewerlgpl$ + * Second Life Viewer Source Code + * Copyright (C) 2012, Linden Research, Inc. + * + * This library is free software; you can redistribute it and/or + * modify it under the terms of the GNU Lesser General Public + * License as published by the Free Software Foundation; + * version 2.1 of the License only. + * + * This library is distributed in the hope that it will be useful, + * but WITHOUT ANY WARRANTY; without even the implied warranty of + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU + * Lesser General Public License for more details. + * + * You should have received a copy of the GNU Lesser General Public + * License along with this library; if not, write to the Free Software + * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA + * + * Linden Research, Inc., 945 Battery Street, San Francisco, CA 94111 USA + * $/LicenseInfo$ + */ + +#include "bufferstream.h" + +#include "bufferarray.h" + + +namespace LLCore +{ + +BufferArrayStreamBuf::BufferArrayStreamBuf(BufferArray * array) + : mBufferArray(array), + mReadCurPos(0), + mReadCurBlock(-1), + mReadBegin(NULL), + mReadCur(NULL), + mReadEnd(NULL), + mWriteCurPos(0) +{ + if (array) + { + array->addRef(); + mWriteCurPos = array->mLen; + } +} + + +BufferArrayStreamBuf::~BufferArrayStreamBuf() +{ + if (mBufferArray) + { + mBufferArray->release(); + mBufferArray = NULL; + } +} + + +BufferArrayStreamBuf::int_type BufferArrayStreamBuf::underflow() +{ + if (! mBufferArray) + { + return traits_type::eof(); + } + + if (mReadCur == mReadEnd) + { + // Find the next block with actual data or leave + // mCurBlock/mCur/mEnd unchanged if we're at the end + // of any block chain. + const char * new_begin(NULL), * new_end(NULL); + int new_cur_block(mReadCurBlock + 1); + + while (mBufferArray->getBlockStartEnd(new_cur_block, &new_begin, &new_end)) + { + if (new_begin != new_end) + { + break; + } + ++new_cur_block; + } + if (new_begin == new_end) + { + return traits_type::eof(); + } + + mReadCurBlock = new_cur_block; + mReadBegin = mReadCur = new_begin; + mReadEnd = new_end; + } + + return traits_type::to_int_type(*mReadCur); +} + + +BufferArrayStreamBuf::int_type BufferArrayStreamBuf::uflow() +{ + const int_type ret(underflow()); + + if (traits_type::eof() != ret) + { + ++mReadCur; + ++mReadCurPos; + } + return ret; +} + + +BufferArrayStreamBuf::int_type BufferArrayStreamBuf::pbackfail(int_type ch) +{ + if (! mBufferArray) + { + return traits_type::eof(); + } + + if (mReadCur == mReadBegin) + { + // Find the previous block with actual data or leave + // mCurBlock/mBegin/mCur/mEnd unchanged if we're at the + // beginning of any block chain. + const char * new_begin(NULL), * new_end(NULL); + int new_cur_block(mReadCurBlock - 1); + + while (mBufferArray->getBlockStartEnd(new_cur_block, &new_begin, &new_end)) + { + if (new_begin != new_end) + { + break; + } + --new_cur_block; + } + if (new_begin == new_end) + { + return traits_type::eof(); + } + + mReadCurBlock = new_cur_block; + mReadBegin = new_begin; + mReadEnd = mReadCur = new_end; + } + + if (traits_type::eof() != ch && mReadCur[-1] != ch) + { + return traits_type::eof(); + } + --mReadCurPos; + return traits_type::to_int_type(*--mReadCur); +} + + +std::streamsize BufferArrayStreamBuf::showmanyc() +{ + if (! mBufferArray) + { + return -1; + } + return mBufferArray->mLen - mReadCurPos; +} + + +BufferArrayStreamBuf::int_type BufferArrayStreamBuf::overflow(int c) +{ + if (! mBufferArray || mWriteCurPos > mBufferArray->mLen) + { + return traits_type::eof(); + } + const size_t wrote(mBufferArray->write(mWriteCurPos, &c, 1)); + mWriteCurPos += wrote; + return wrote ? c : traits_type::eof(); +} + + +std::streamsize BufferArrayStreamBuf::xsputn(const char * src, std::streamsize count) +{ + if (! mBufferArray || mWriteCurPos > mBufferArray->mLen) + { + return 0; + } + const size_t wrote(mBufferArray->write(mWriteCurPos, src, count)); + mWriteCurPos += wrote; + return wrote; +} + + +std::streampos BufferArrayStreamBuf::seekoff(std::streamoff off, + std::ios_base::seekdir way, + std::ios_base::openmode which) +{ + std::streampos ret(-1); + + if (! mBufferArray) + { + return ret; + } + + if (std::ios_base::in == which) + { + size_t pos(0); + + switch (way) + { + case std::ios_base::beg: + pos = off; + break; + + case std::ios_base::cur: + pos = mReadCurPos += off; + break; + + case std::ios_base::end: + pos = mBufferArray->mLen - off; + break; + + default: + return ret; + } + + if (pos >= mBufferArray->size()) + { + pos = (std::max)(size_t(0), mBufferArray->size() - 1); + } + size_t ba_offset(0); + int block(mBufferArray->findBlock(pos, &ba_offset)); + if (block < 0) + return ret; + const char * start(NULL), * end(NULL); + if (! mBufferArray->getBlockStartEnd(block, &start, &end)) + return ret; + mReadCurBlock = block; + mReadBegin = start; + mReadCur = start + ba_offset; + mReadEnd = end; + ret = mReadCurPos = pos; + } + else if (std::ios_base::out == which) + { + size_t pos(0); + + switch (way) + { + case std::ios_base::beg: + pos = off; + break; + + case std::ios_base::cur: + pos = mWriteCurPos += off; + break; + + case std::ios_base::end: + pos = mBufferArray->mLen - off; + break; + + default: + return ret; + } + + if (pos < 0) + return ret; + if (pos > mBufferArray->size()) + { + pos = mBufferArray->size(); + } + ret = mWriteCurPos = pos; + } + + return ret; +} + + +BufferArrayStream::BufferArrayStream(BufferArray * ba) + : std::iostream(&mStreamBuf), + mStreamBuf(ba) +{} + + +BufferArrayStream::~BufferArrayStream() +{} + + +} // end namespace LLCore + + -- cgit v1.2.3