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@@ -28,225 +28,6 @@ namespace master_lexer_internal {
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class State;
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}
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-/// \brief Tokenizer for parsing DNS master files.
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-///
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-/// The \c MasterLexer class provides tokenize interfaces for parsing DNS
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-/// master files. It understands some special rules of master files as
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-/// defined in RFC 1035, such as comments, character escaping, and multi-line
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-/// data, and provides the user application with the actual data in a
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-/// more convenient form such as a std::string object.
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-///
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-/// In order to support the $INCLUDE notation, this class is designed to be
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-/// able to operate on multiple files or input streams in the nested way.
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-/// The \c pushSource() and \c popSource() methods correspond to the push
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-/// and pop operations.
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-///
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-/// While this class is public, it is less likely to be used by normal
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-/// applications; it's mainly expected to be used within this library,
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-/// specifically by the \c MasterLoader class and \c Rdata implementation
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-/// classes.
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-///
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-/// \note The error handling policy of this class is slightly different from
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-/// that of other classes of this library. We generally throw an exception
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-/// for an invalid input, whether it's more likely to be a program error or
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-/// a "user error", which means an invalid input that comes from outside of
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-/// the library. But, this class returns an error code for some certain
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-/// types of user errors instead of throwing an exception. Such cases include
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-/// a syntax error identified by the lexer or a misspelled file name that
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-/// causes a system error at the time of open. This is based on the assumption
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-/// that the main user of this class is a parser of master files, where
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-/// we want to give an option to ignore some non fatal errors and continue
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-/// the parsing. This will be useful if it just performs overall error
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-/// checks on a master file. When the (immediate) caller needs to do explicit
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-/// error handling, exceptions are not that a useful tool for error reporting
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-/// because we cannot separate the normal and error cases anyway, which would
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-/// be one major advantage when we use exceptions. And, exceptions are
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-/// generally more expensive, either when it happens or just by being able
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-/// to handle with \c try and \c catch (depending on the underlying
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-/// implementation of the exception handling). For these reasons, some of
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-/// this class does not throw for an error that would be reported as an
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-/// exception in other classes.
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-class MasterLexer {
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- friend class master_lexer_internal::State;
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-public:
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- /// \brief Exception thrown when we fail to read from the input
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- /// stream or file.
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- struct ReadError : public Unexpected {
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- ReadError(const char* file, size_t line, const char* what) :
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- Unexpected(file, line, what)
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- {}
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- };
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-
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- class Token; // we define it separately for better readability
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-
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- /// \brief Options for getNextToken.
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- ///
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- /// A compound option, indicating multiple options are set, can be
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- /// specified using the logical OR operator (operator|()).
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- enum Options {
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- NONE = 0, ///< No option
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- INITIAL_WS = 1, ///< recognize begin-of-line spaces after an
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- ///< end-of-line
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- QSTRING = 2, ///< recognize quoted string
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- NUMBER = 4 ///< recognize numeric text as integer
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- };
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-
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- /// \brief The constructor.
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- ///
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- /// \throw std::bad_alloc Internal resource allocation fails (rare case).
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- MasterLexer();
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-
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- /// \brief The destructor.
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- ///
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- /// It internally closes any remaining input sources.
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- ~MasterLexer();
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-
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- /// \brief Open a file and make it the current input source of MasterLexer.
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- ///
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- /// The opened file can be explicitly closed by the \c popSource() method;
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- /// if \c popSource() is not called within the lifetime of the
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- /// \c MasterLexer, it will be closed in the destructor.
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- ///
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- /// In the case possible system errors in opening the file (most likely
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- /// because of specifying a non-existent or unreadable file), it returns
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- /// false, and if the optional \c error parameter is non NULL, it will be
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- /// set to a description of the error (any existing content of the string
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- /// will be discarded). If opening the file succeeds, the given
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- /// \c error parameter will be intact.
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- ///
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- /// Note that this method has two styles of error reporting: one by
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- /// returning \c false (and setting \c error optionally) and the other
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- /// by throwing an exception. See the note for the class description
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- /// about the distinction.
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- ///
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- /// \throw InvalidParameter filename is NULL
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- /// \param filename A non NULL string specifying a master file
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- /// \param error If non null, a placeholder to set error description in
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- /// case of failure.
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- ///
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- /// \return true if pushing the file succeeds; false otherwise.
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- bool pushSource(const char* filename, std::string* error = NULL);
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-
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- /// \brief Make the given stream the current input source of MasterLexer.
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- ///
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- /// The caller still holds the ownership of the passed stream; it's the
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- /// caller's responsibility to keep it valid as long as it's used in
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- /// \c MasterLexer or to release any resource for the stream after that.
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- /// The caller can explicitly tell \c MasterLexer to stop using the
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- /// stream by calling the \c popSource() method.
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- ///
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- /// \param input An input stream object that produces textual
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- /// representation of DNS RRs.
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- void pushSource(std::istream& input);
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-
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- /// \brief Stop using the most recently opened input source (file or
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- /// stream).
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- ///
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- /// If it's a file, the previously opened file will be closed internally.
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- /// If it's a stream, \c MasterLexer will simply stop using
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- /// the stream; the caller can assume it will be never used in
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- /// \c MasterLexer thereafter.
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- ///
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- /// This method must not be called when there is no source pushed for
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- /// \c MasterLexer. This method is otherwise exception free.
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- ///
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- /// \throw isc::InvalidOperation Called with no pushed source.
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- void popSource();
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-
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- /// \brief Return the name of the current input source name.
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- ///
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- /// If it's a file, it will be the C string given at the corresponding
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- /// \c pushSource() call, that is, its filename. If it's a stream, it will
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- /// be formatted as \c "stream-%p" where \c %p is hex representation
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- /// of the address of the stream object.
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- ///
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- /// If there is no opened source at the time of the call, this method
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- /// returns an empty string.
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- ///
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- /// \throw std::bad_alloc Resource allocation failed for string
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- /// construction (rare case)
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- ///
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- /// \return A string representation of the current source (see the
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- /// description)
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- std::string getSourceName() const;
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-
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- /// \brief Return the input source line number.
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- ///
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- /// If there is an opened source, the return value will be a non-0
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- /// integer indicating the line number of the current source where
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- /// the \c MasterLexer is currently working. The expected usage of
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- /// this value is to print a helpful error message when parsing fails
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- /// by specifically identifying the position of the error.
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- ///
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- /// If there is no opened source at the time of the call, this method
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- /// returns 0.
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- ///
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- /// \throw None
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- ///
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- /// \return The current line number of the source (see the description)
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- size_t getSourceLine() const;
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-
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- /// \brief Parse and return another token from the input.
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- ///
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- /// It reads a bit of the last opened source and produces another token
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- /// found in it.
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- ///
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- /// This method does not provide the strong exception guarantee. Generally,
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- /// if it throws, the object should not be used any more and should be
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- /// discarded. It was decided all the exceptions thrown from here are
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- /// serious enough that aborting the loading process is the only reasonable
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- /// recovery anyway, so the strong exception guarantee is not needed.
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- ///
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- /// \param options The options can be used to modify the tokenization.
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- /// The method can be made reporting things which are usually ignored
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- /// by this parameter. Multiple options can be passed at once by
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- /// bitwise or (eg. option1 | option 2). See description of available
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- /// options.
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- /// \return Next token found in the input. Note that the token refers to
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- /// some internal data in the lexer. It is valid only until
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- /// getNextToken or ungetToken is called. Also, the token becomes
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- /// invalid when the lexer is destroyed.
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- /// \throw isc::InvalidOperation in case the source is not available. This
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- /// may mean the pushSource() has not been called yet, or that the
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- /// current source has been read past the end.
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- /// \throw ReadError in case there's problem reading from the underlying
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- /// source (eg. I/O error in the file on the disk).
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- /// \throw std::bad_alloc in case allocation of some internal resources
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- /// or the token fail.
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- const Token& getNextToken(Options options = NONE);
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-
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- /// \brief Return the last token back to the lexer.
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- ///
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- /// The method undoes the lasts call to getNextToken(). If you call the
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- /// getNextToken() again with the same options, it'll return the same
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- /// token. If the options are different, it may return a different token,
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- /// but it acts as if the previous getNextToken() was never called.
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- ///
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- /// It is possible to return only one token back in time (you can't call
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- /// ungetToken() twice in a row without calling getNextToken() in between
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- /// successfully).
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- ///
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- /// It does not work after change of source (by pushSource or popSource).
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- ///
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- /// \throw isc::InvalidOperation If called second time in a row or if
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- /// getNextToken() was not called since the last change of the source.
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- void ungetToken();
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-
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-private:
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- struct MasterLexerImpl;
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- MasterLexerImpl* impl_;
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-};
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-
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-/// \brief Operator to combine \c MasterLexer options
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-///
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-/// This is a trivial shortcut so that compound options can be specified
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-/// in an intuitive way.
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-inline MasterLexer::Options
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-operator|(MasterLexer::Options o1, MasterLexer::Options o2) {
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- return (static_cast<MasterLexer::Options>(
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- static_cast<unsigned>(o1) | static_cast<unsigned>(o2)));
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-}
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-
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/// \brief Tokens for \c MasterLexer
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///
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/// This is a simple value-class encapsulating a type of a lexer token and
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@@ -261,7 +42,7 @@ operator|(MasterLexer::Options o1, MasterLexer::Options o2) {
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/// (using the default version of copy constructor and assignment operator),
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/// but it's mainly for internal implementation convenience. Applications will
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/// simply refer to Token object as a reference via the \c MasterLexer class.
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-class MasterLexer::Token {
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+class MasterToken {
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public:
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/// \brief Enumeration for token types
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///
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@@ -318,7 +99,7 @@ public:
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/// \throw InvalidParameter A value type token is specified.
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/// \param type The type of the token. It must indicate a non-value
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/// type (not larger than \c NOVALUE_TYPE_MAX).
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- explicit Token(Type type) : type_(type) {
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+ explicit MasterToken(Type type) : type_(type) {
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if (type > NOVALUE_TYPE_MAX) {
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isc_throw(InvalidParameter, "Token per-type constructor "
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"called with invalid type: " << type);
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@@ -340,7 +121,7 @@ public:
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/// \param str_beg The start address of the string
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/// \param str_len The size of the string in bytes
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/// \param quoted true if it's a quoted string; false otherwise.
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- Token(const char* str_beg, size_t str_len, bool quoted = false) :
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+ MasterToken(const char* str_beg, size_t str_len, bool quoted = false) :
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type_(quoted ? QSTRING : STRING)
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{
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val_.str_region_.beg = str_beg;
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@@ -351,7 +132,7 @@ public:
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///
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/// \brief number An unsigned 32-bit integer corresponding to the token
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/// value.
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- explicit Token(uint32_t number) : type_(NUMBER) {
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+ explicit MasterToken(uint32_t number) : type_(NUMBER) {
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val_.number_ = number;
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}
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@@ -359,7 +140,7 @@ public:
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///
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/// \throw InvalidParameter Invalid error code value is specified.
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/// \brief error_code A pre-defined constant of \c ErrorCode.
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- explicit Token(ErrorCode error_code) : type_(ERROR) {
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+ explicit MasterToken(ErrorCode error_code) : type_(ERROR) {
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if (!(error_code < MAX_ERROR_CODE)) {
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isc_throw(InvalidParameter, "Invalid master lexer error code: "
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<< error_code);
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@@ -476,6 +257,223 @@ private:
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} val_;
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};
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+/// \brief Tokenizer for parsing DNS master files.
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+///
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+/// The \c MasterLexer class provides tokenize interfaces for parsing DNS
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+/// master files. It understands some special rules of master files as
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+/// defined in RFC 1035, such as comments, character escaping, and multi-line
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+/// data, and provides the user application with the actual data in a
|
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+/// more convenient form such as a std::string object.
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+///
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+/// In order to support the $INCLUDE notation, this class is designed to be
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+/// able to operate on multiple files or input streams in the nested way.
|
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|
+/// The \c pushSource() and \c popSource() methods correspond to the push
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+/// and pop operations.
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+///
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+/// While this class is public, it is less likely to be used by normal
|
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+/// applications; it's mainly expected to be used within this library,
|
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+/// specifically by the \c MasterLoader class and \c Rdata implementation
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+/// classes.
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+///
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+/// \note The error handling policy of this class is slightly different from
|
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+/// that of other classes of this library. We generally throw an exception
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+/// for an invalid input, whether it's more likely to be a program error or
|
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+/// a "user error", which means an invalid input that comes from outside of
|
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+/// the library. But, this class returns an error code for some certain
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+/// types of user errors instead of throwing an exception. Such cases include
|
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+/// a syntax error identified by the lexer or a misspelled file name that
|
|
|
+/// causes a system error at the time of open. This is based on the assumption
|
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+/// that the main user of this class is a parser of master files, where
|
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+/// we want to give an option to ignore some non fatal errors and continue
|
|
|
+/// the parsing. This will be useful if it just performs overall error
|
|
|
+/// checks on a master file. When the (immediate) caller needs to do explicit
|
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|
+/// error handling, exceptions are not that a useful tool for error reporting
|
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+/// because we cannot separate the normal and error cases anyway, which would
|
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|
+/// be one major advantage when we use exceptions. And, exceptions are
|
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+/// generally more expensive, either when it happens or just by being able
|
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|
+/// to handle with \c try and \c catch (depending on the underlying
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+/// implementation of the exception handling). For these reasons, some of
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+/// this class does not throw for an error that would be reported as an
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+/// exception in other classes.
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+class MasterLexer {
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+ friend class master_lexer_internal::State;
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+public:
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+ /// \brief Exception thrown when we fail to read from the input
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+ /// stream or file.
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+ struct ReadError : public Unexpected {
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+ ReadError(const char* file, size_t line, const char* what) :
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+ Unexpected(file, line, what)
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+ {}
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+ };
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+
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+ /// \brief Options for getNextToken.
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+ ///
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+ /// A compound option, indicating multiple options are set, can be
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+ /// specified using the logical OR operator (operator|()).
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+ enum Options {
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+ NONE = 0, ///< No option
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+ INITIAL_WS = 1, ///< recognize begin-of-line spaces after an
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+ ///< end-of-line
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+ QSTRING = 2, ///< recognize quoted string
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+ NUMBER = 4 ///< recognize numeric text as integer
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+ };
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+
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+ /// \brief The constructor.
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+ ///
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+ /// \throw std::bad_alloc Internal resource allocation fails (rare case).
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+ MasterLexer();
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+
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+ /// \brief The destructor.
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+ ///
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+ /// It internally closes any remaining input sources.
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+ ~MasterLexer();
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+
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+ /// \brief Open a file and make it the current input source of MasterLexer.
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+ ///
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+ /// The opened file can be explicitly closed by the \c popSource() method;
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+ /// if \c popSource() is not called within the lifetime of the
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+ /// \c MasterLexer, it will be closed in the destructor.
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+ ///
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+ /// In the case possible system errors in opening the file (most likely
|
|
|
+ /// because of specifying a non-existent or unreadable file), it returns
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+ /// false, and if the optional \c error parameter is non NULL, it will be
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|
|
+ /// set to a description of the error (any existing content of the string
|
|
|
+ /// will be discarded). If opening the file succeeds, the given
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+ /// \c error parameter will be intact.
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+ ///
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+ /// Note that this method has two styles of error reporting: one by
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|
+ /// returning \c false (and setting \c error optionally) and the other
|
|
|
+ /// by throwing an exception. See the note for the class description
|
|
|
+ /// about the distinction.
|
|
|
+ ///
|
|
|
+ /// \throw InvalidParameter filename is NULL
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|
|
+ /// \param filename A non NULL string specifying a master file
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|
|
+ /// \param error If non null, a placeholder to set error description in
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+ /// case of failure.
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+ ///
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+ /// \return true if pushing the file succeeds; false otherwise.
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+ bool pushSource(const char* filename, std::string* error = NULL);
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+
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+ /// \brief Make the given stream the current input source of MasterLexer.
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+ ///
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+ /// The caller still holds the ownership of the passed stream; it's the
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+ /// caller's responsibility to keep it valid as long as it's used in
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+ /// \c MasterLexer or to release any resource for the stream after that.
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+ /// The caller can explicitly tell \c MasterLexer to stop using the
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+ /// stream by calling the \c popSource() method.
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+ ///
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+ /// \param input An input stream object that produces textual
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+ /// representation of DNS RRs.
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+ void pushSource(std::istream& input);
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+
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+ /// \brief Stop using the most recently opened input source (file or
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+ /// stream).
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+ ///
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+ /// If it's a file, the previously opened file will be closed internally.
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+ /// If it's a stream, \c MasterLexer will simply stop using
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+ /// the stream; the caller can assume it will be never used in
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+ /// \c MasterLexer thereafter.
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+ ///
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+ /// This method must not be called when there is no source pushed for
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+ /// \c MasterLexer. This method is otherwise exception free.
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+ ///
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+ /// \throw isc::InvalidOperation Called with no pushed source.
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+ void popSource();
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+
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+ /// \brief Return the name of the current input source name.
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+ ///
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+ /// If it's a file, it will be the C string given at the corresponding
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+ /// \c pushSource() call, that is, its filename. If it's a stream, it will
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+ /// be formatted as \c "stream-%p" where \c %p is hex representation
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+ /// of the address of the stream object.
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+ ///
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+ /// If there is no opened source at the time of the call, this method
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+ /// returns an empty string.
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+ ///
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+ /// \throw std::bad_alloc Resource allocation failed for string
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+ /// construction (rare case)
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+ ///
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+ /// \return A string representation of the current source (see the
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+ /// description)
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+ std::string getSourceName() const;
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+
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+ /// \brief Return the input source line number.
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+ ///
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+ /// If there is an opened source, the return value will be a non-0
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+ /// integer indicating the line number of the current source where
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+ /// the \c MasterLexer is currently working. The expected usage of
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+ /// this value is to print a helpful error message when parsing fails
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+ /// by specifically identifying the position of the error.
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+ ///
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+ /// If there is no opened source at the time of the call, this method
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+ /// returns 0.
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|
+ ///
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+ /// \throw None
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|
+ ///
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+ /// \return The current line number of the source (see the description)
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|
|
+ size_t getSourceLine() const;
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+
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+ /// \brief Parse and return another token from the input.
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+ ///
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+ /// It reads a bit of the last opened source and produces another token
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+ /// found in it.
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|
+ ///
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|
+ /// This method does not provide the strong exception guarantee. Generally,
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|
+ /// if it throws, the object should not be used any more and should be
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|
+ /// discarded. It was decided all the exceptions thrown from here are
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|
+ /// serious enough that aborting the loading process is the only reasonable
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|
+ /// recovery anyway, so the strong exception guarantee is not needed.
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|
+ ///
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|
+ /// \param options The options can be used to modify the tokenization.
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|
+ /// The method can be made reporting things which are usually ignored
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|
+ /// by this parameter. Multiple options can be passed at once by
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|
+ /// bitwise or (eg. option1 | option 2). See description of available
|
|
|
+ /// options.
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|
|
+ /// \return Next token found in the input. Note that the token refers to
|
|
|
+ /// some internal data in the lexer. It is valid only until
|
|
|
+ /// getNextToken or ungetToken is called. Also, the token becomes
|
|
|
+ /// invalid when the lexer is destroyed.
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|
|
+ /// \throw isc::InvalidOperation in case the source is not available. This
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|
|
+ /// may mean the pushSource() has not been called yet, or that the
|
|
|
+ /// current source has been read past the end.
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|
|
+ /// \throw ReadError in case there's problem reading from the underlying
|
|
|
+ /// source (eg. I/O error in the file on the disk).
|
|
|
+ /// \throw std::bad_alloc in case allocation of some internal resources
|
|
|
+ /// or the token fail.
|
|
|
+ const MasterToken& getNextToken(Options options = NONE);
|
|
|
+
|
|
|
+ /// \brief Return the last token back to the lexer.
|
|
|
+ ///
|
|
|
+ /// The method undoes the lasts call to getNextToken(). If you call the
|
|
|
+ /// getNextToken() again with the same options, it'll return the same
|
|
|
+ /// token. If the options are different, it may return a different token,
|
|
|
+ /// but it acts as if the previous getNextToken() was never called.
|
|
|
+ ///
|
|
|
+ /// It is possible to return only one token back in time (you can't call
|
|
|
+ /// ungetToken() twice in a row without calling getNextToken() in between
|
|
|
+ /// successfully).
|
|
|
+ ///
|
|
|
+ /// It does not work after change of source (by pushSource or popSource).
|
|
|
+ ///
|
|
|
+ /// \throw isc::InvalidOperation If called second time in a row or if
|
|
|
+ /// getNextToken() was not called since the last change of the source.
|
|
|
+ void ungetToken();
|
|
|
+
|
|
|
+private:
|
|
|
+ struct MasterLexerImpl;
|
|
|
+ MasterLexerImpl* impl_;
|
|
|
+};
|
|
|
+
|
|
|
+/// \brief Operator to combine \c MasterLexer options
|
|
|
+///
|
|
|
+/// This is a trivial shortcut so that compound options can be specified
|
|
|
+/// in an intuitive way.
|
|
|
+inline MasterLexer::Options
|
|
|
+operator|(MasterLexer::Options o1, MasterLexer::Options o2) {
|
|
|
+ return (static_cast<MasterLexer::Options>(
|
|
|
+ static_cast<unsigned>(o1) | static_cast<unsigned>(o2)));
|
|
|
+}
|
|
|
+
|
|
|
} // namespace dns
|
|
|
} // namespace isc
|
|
|
#endif // MASTER_LEXER_H
|
JINMEI Tatuya