strigi/src/streams

streambase.h

00001 /* This file is part of Strigi Desktop Search
00002  *
00003  * Copyright (C) 2006 Jos van den Oever <jos@vandenoever.info>
00004  *
00005  * This library is free software; you can redistribute it and/or
00006  * modify it under the terms of the GNU Library General Public
00007  * License as published by the Free Software Foundation; either
00008  * version 2 of the License, or (at your option) any later version.
00009  *
00010  * This library is distributed in the hope that it will be useful,
00011  * but WITHOUT ANY WARRANTY; without even the implied warranty of
00012  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
00013  * Library General Public License for more details.
00014  *
00015  * You should have received a copy of the GNU Library General Public License
00016  * along with this library; see the file COPYING.LIB.  If not, write to
00017  * the Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor,
00018  * Boston, MA 02110-1301, USA.
00019  */
00020 #ifndef STRIGI_STREAMBASE_H
00021 #define STRIGI_STREAMBASE_H
00022 
00023 #include <stdio.h>
00024 #include <string>
00025 #include <strigi/strigiconfig.h>
00026 
00027 #define INT32MAX 0x7FFFFFFFL
00028 
00029 namespace Strigi {
00030 
00032 enum StreamStatus {
00033     Ok ,
00034     Eof ,
00035     Error 
00036 };
00037 
00038 // java mapping: long=int64, int=int32, byte=uint8_t
00052 class STREAMS_EXPORT StreamBaseBase { //krazy:exclude=dpointer
00053 protected:
00055     int64_t m_size;
00057     int64_t m_position;
00062     std::string m_error;
00064     StreamStatus m_status;
00065 public:
00069     StreamBaseBase() :m_size(-1), m_position(0), m_status(Ok) {}
00073     virtual ~StreamBaseBase() {}
00078     const char* error() const { return m_error.c_str(); }
00082     StreamStatus status() const { return m_status; }
00087     int64_t position() const { return m_position; }
00098     int64_t size() const { return m_size; }
00099 };
00100 
00113 template <class T>
00114 class StreamBase : public StreamBaseBase {
00115 public:
00116     StreamBase() { }
00117     virtual ~StreamBase(){}
00151     virtual int32_t read(const T*& start, int32_t min, int32_t max) = 0;
00165     virtual int64_t skip(int64_t ntoskip);
00191     virtual int64_t reset(int64_t pos) = 0;
00192 };
00193 
00194 
00196 typedef StreamBase<char> InputStream;
00197 
00199 typedef StreamBase<wchar_t> Reader;
00200 
00201 
00202 template <class T>
00203 int64_t
00204 StreamBase<T>::skip(int64_t ntoskip) {
00205     const T* begin;
00206     int32_t nread;
00207     int64_t skipped = 0;
00208     while (ntoskip > 0) {
00209         // make sure we do not overflow uint32_t
00210         int32_t maxstep = (int32_t)((ntoskip > 10000000)
00211                        ?10000000 :ntoskip);
00212         // the default implementation is to simply read the data that we want
00213         // to skip
00214         nread = read(begin, 1, maxstep);
00215         if (nread < -1 ) {
00216             // an error occurred
00217             return nread;
00218         } else if (nread < 1) {
00219             // the end of the stream was encountered
00220             ntoskip = 0;
00221         } else {
00222             skipped += nread;
00223             ntoskip -= nread;
00224         }
00225     }
00226     return skipped;
00227 }
00228 
00229 } // end namespace Strigi
00230 
00231 #endif
strigi/src/streams

streambase.h

strigi/src/streams

KDE Support
