From 6ecc367b9fa9cbcee9a55dea5a3ff662716ace4b Mon Sep 17 00:00:00 2001 From: Matthew Wilber Date: Thu, 19 Sep 2002 02:59:59 +0000 Subject: [PATCH] initial check in git-svn-id: file:///srv/svn/repos/haiku/trunk/current@1084 a95241bf-73f2-0310-859d-f6bbb57e9c96 --- .../tgatranslator/StreamBuffer.cpp | 186 ++++++++++++++++++ 1 file changed, 186 insertions(+) create mode 100644 src/add-ons/translators/tgatranslator/StreamBuffer.cpp diff --git a/src/add-ons/translators/tgatranslator/StreamBuffer.cpp b/src/add-ons/translators/tgatranslator/StreamBuffer.cpp new file mode 100644 index 0000000000..80cad4cad7 --- /dev/null +++ b/src/add-ons/translators/tgatranslator/StreamBuffer.cpp @@ -0,0 +1,186 @@ +/*****************************************************************************/ +// StreamBuffer +// StreamBuffer.cpp +// +// The description goes here. +// +// +// Copyright (c) 2002 OpenBeOS Project +// +// Permission is hereby granted, free of charge, to any person obtaining a +// copy of this software and associated documentation files (the "Software"), +// to deal in the Software without restriction, including without limitation +// the rights to use, copy, modify, merge, publish, distribute, sublicense, +// and/or sell copies of the Software, and to permit persons to whom the +// Software is furnished to do so, subject to the following conditions: +// +// The above copyright notice and this permission notice shall be included +// in all copies or substantial portions of the Software. +// +// 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 AND NONINFRINGEMENT. IN NO EVENT SHALL +// THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER +// LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING +// FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER +// DEALINGS IN THE SOFTWARE. +/*****************************************************************************/ + +#include "StreamBuffer.h" + +#define min(x,y) (((x) < (y)) ? (x) : (y)) +#define max(x,y) (((x) > (y)) ? (x) : (y)) + +// --------------------------------------------------------------- +// Constructor +// +// Initializes the StreamBuffer to read from pstream, buffering +// nbuffersize bytes of data at a time. Note that if nbuffersize +// is smaller than MIN_BUFFER_SIZE, MIN_BUFFER_SIZE is used +// as the buffer size. +// +// Preconditions: +// +// Parameters: pstream, the stream to be buffered +// +// nbuffersize, number of bytes to be read from +// pstream at a time +// +// Postconditions: +// +// Returns: +// --------------------------------------------------------------- +StreamBuffer::StreamBuffer(BPositionIO *pstream, size_t nbuffersize) +{ + m_pStream = pstream; + m_pBuffer = NULL; + m_nBufferSize = 0; + m_nLen = 0; + m_nPos = 0; + + if (!pstream) + return; + + m_nBufferSize = max(nbuffersize, MIN_BUFFER_SIZE); + m_pBuffer = new uint8[m_nBufferSize]; + if (m_pBuffer) + ReadStream(); + // Fill the buffer with data so that + // object is prepared for first call to + // Read() +} + +// --------------------------------------------------------------- +// Destructor +// +// Destroys data allocated for this object +// +// Preconditions: +// +// Parameters: +// +// Postconditions: +// +// Returns: +// --------------------------------------------------------------- +StreamBuffer::~StreamBuffer() +{ + m_nBufferSize = 0; + m_nLen = 0; + m_nPos = 0; + m_pStream = NULL; + + delete[] m_pBuffer; + m_pBuffer = NULL; +} + +// --------------------------------------------------------------- +// InitCheck +// +// Determines whether the constructor failed or not +// +// Preconditions: +// +// Parameters: +// +// Postconditions: +// +// Returns: B_OK if object has been initialized successfully, +// B_ERROR if not +// --------------------------------------------------------------- +status_t StreamBuffer::InitCheck() +{ + if (m_pStream && m_pBuffer) + return B_OK; + else + return B_ERROR; +} + +// --------------------------------------------------------------- +// Read +// +// Copies up to nbytes of data from the stream into pinto +// +// Preconditions: ReadStream() must be called once before this +// function is called (the constructor does this) +// +// Parameters: pinto, the buffer to be copied to +// +// nbytes, the maximum number of bytes to copy +// +// Postconditions: +// +// Returns: the number of bytes successfully read or an +// error code returned by BPositionIO::Read() +// --------------------------------------------------------------- +ssize_t StreamBuffer::Read(uint8 *pinto, size_t nbytes) +{ + ssize_t result = B_ERROR; + size_t rd1 = 0, rd2 = 0; + + rd1 = min(nbytes, m_nLen - m_nPos); + memcpy(pinto, m_pBuffer + m_nPos, rd1); + m_nPos += rd1; + + if (rd1 < nbytes) { + pinto += rd1; + result = ReadStream(); + if (result > 0) { + rd2 = min(nbytes - rd1, m_nLen); + memcpy(pinto, m_pBuffer, rd2); + m_nPos += rd2; + } else + // return error code or zero + return result; + } + + return rd1 + rd2; +} + +// --------------------------------------------------------------- +// ReadStream +// +// Fills the stream buffer with data read in from the stream +// +// Preconditions: m_pBuffer must be allocated and m_nBufferSize +// must be valid +// +// Parameters: +// +// Postconditions: +// +// Returns: the number of bytes successfully read or an +// error code returned by BPositionIO::Read() +// --------------------------------------------------------------- +ssize_t StreamBuffer::ReadStream() +{ + ssize_t rd; + rd = m_pStream->Read(m_pBuffer, m_nBufferSize); + if (rd >= 0) { + m_nLen = rd; + m_nPos = 0; + } + return rd; +} + +