--- /dev/null Thu Jan 01 00:00:00 1970 +0000
+++ b/searchengine/oss/loc/analysis/inc/public/tinyiterator.h Fri Oct 15 12:09:28 2010 +0530
@@ -0,0 +1,186 @@
+/*
+* Copyright (c) 2010 Nokia Corporation and/or its subsidiary(-ies).
+* All rights reserved.
+* This component and the accompanying materials are made available
+* under the terms of "Eclipse Public License v1.0"
+* which accompanies this distribution, and is available
+* at the URL "http://www.eclipse.org/legal/epl-v10.html".
+*
+* Initial Contributors:
+* Nokia Corporation - initial contribution.
+*
+* Contributors:
+*
+* Description:
+*
+*/
+
+#ifndef TINYITERATOR_H_
+#define TINYITERATOR_H_
+
+#include <exception>
+
+namespace lucene {
+ namespace util {
+ class Reader;
+ }
+}
+namespace analysis {
+
+ /**
+ * This package provides basic
+ */
+ namespace tiny {
+
+ /*
+ *
+ * Meta code for describing the iterator concept used here.
+ * Used to iterate character streams.
+ * Follows closely the STL forward iterator.
+ * Note: Comparisons of form x < y may not work properly.
+ * Note: x - y will not provide distance in characters,
+ * but instead offset distance in the original text.
+ *
+ * Only operators of form ++i is provided. --i is not provided
+ * because complications with utf16 or unicode decomposition/
+ * composition. i++ would lead to innecessary code.
+ *
+
+ concept Iterator {
+
+ // Accessor to the iterator character
+ wchar_t operator*(); // 16 bit unicode
+ OR
+ int operator*(); // 32 bit unicode
+
+ // Next location
+ Iterator& operator++();
+
+ // Returns offset in the original text. Note that one character
+ // may be transformed into a number of characters. This means
+ // that comparisons of form (int)i < (int)j are unreliable and
+ // should not be used. Also lengths i - j are unreliable. With korean
+ // i - j may be produce length 2, but iterating for (;i<j;++i); may
+ // iterate throught e.g. 6 characters. Or, with 32 bit unicode,
+ // length 2 may contain only one character.
+ operator int();
+
+ };
+
+ */
+
+
+ /**
+ * Iterates throught some T that provides array/pointer like interface
+ */
+ template <typename T>
+ struct ArrayIterator {
+ public:
+ inline ArrayIterator(T& array, int i) : array_(&array), i_(i) {}
+ inline ArrayIterator(T& array) : array_(&array), i_(0) {}
+ inline ArrayIterator() : array_(0), i_(0) {}
+
+ inline wchar_t operator*() const { return (*array_)[i_]; };
+ inline ArrayIterator<T>& operator++() { i_++; return *this; };
+ inline operator int() { return i_; }
+ private:
+ T* array_;
+ int i_;
+
+ };
+
+ /**
+ * Iterates from starting position to up to length characters.
+ */
+ template <typename Iterator>
+ struct RangeIterator {
+ public:
+ RangeIterator(Iterator& begin, int length) : i_(begin), left_(length) {}
+ inline int operator*() { return left_ ? *i_: '\0'; }
+ inline RangeIterator& operator++() {
+ if (left_ ) {
+ ++i_; left_--;
+ }
+ return *this;
+ }
+ inline operator int() { return i_; }
+ private:
+ Iterator i_;
+ int left_;
+ };
+
+ /**
+ * Turns iterator into a C++ stream. Allows out<<'c'<<'\0';
+ * kind of syntax to be used with iterators.
+ */
+ template <typename Iterator>
+ struct IteratorOutput {
+ public:
+ IteratorOutput(Iterator i) : i_(i) {}
+ template <typename T>
+ inline IteratorOutput& operator<<(T t) {
+ *i_= t;
+ ++i_;
+ return *this;
+ }
+ private:
+ Iterator i_;
+ };
+
+ /**
+ * CLucene IO support
+ */
+ namespace cl {
+
+ /**
+ * Informs that caller has attempted to read a location
+ * from the reader source, that is no more stored in the
+ * buffer.
+ */
+ class TooOldIndexException : public std::exception {
+ public:
+ const char* what() const;
+ };
+
+ /**
+ * Provides buffer & array like interface to be used with
+ * CLucene readers. If reader r provides access to file X,
+ * and we have buf(r), we can sort of 'random access' file
+ * X with buf[0], buf[X], buf[Z+3] syntaxes. Still, the buffer
+ * is of limited size. There is always the most recent location
+ * L that is read. Trying to access buf[L-SIZE-1] will raise
+ * exception, where SIZE is the buffer size.
+ */
+ template<int SIZE>
+ class ReaderBuffer {
+ public:
+ /** Iterator for iterating the underlying source */
+ typedef ArrayIterator<ReaderBuffer> iterator;
+ /* Constructs buffer for a reader reading some source. */
+ ReaderBuffer(lucene::util::Reader& reader);
+ /** Returns character at location i */
+ wchar_t operator[](int i);
+ /** Returns iterator pointing to location i */
+ inline iterator at(int i);
+ /** Returns iterator pointing to the beginning of character source */
+ inline iterator begin();
+ private:
+ /** Rotating buffer. */
+ wchar_t buf_[SIZE];
+ /** How many characters have been read from reader */
+ int read_;
+ /** Points to the next character to be overwritten in buffer */
+ int cut_;
+ /** Index of oldest character inside the original source */
+ int offset_;
+ /** Reader reading original source */
+ lucene::util::Reader& reader_;
+ };
+
+ }
+
+ }
+
+}
+
+#endif /* TINYITERATOR_H_ */