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// Copyright (c) 2005-2018 Jay Berkenbilt
//
// This file is part of qpdf.
//
// Licensed under the Apache License, Version 2.0 (the "License");
// you may not use this file except in compliance with the License.
// You may obtain a copy of the License at
//
// http://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS IS" BASIS,
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
// See the License for the specific language governing permissions and
// limitations under the License.
//
// Versions of qpdf prior to version 7 were released under the terms
// of version 2.0 of the Artistic License. At your option, you may
// continue to consider qpdf to be licensed under those terms. Please
// see the manual for additional information.
#ifndef __QPDFTOKENIZER_HH__
#define __QPDFTOKENIZER_HH__
#include <qpdf/DLL.h>
#include <qpdf/InputSource.hh>
#include <qpdf/PointerHolder.hh>
#include <string>
#include <stdio.h>
class QPDFTokenizer
{
public:
// Token type tt_eof is only returned of allowEOF() is called on
// the tokenizer. tt_eof was introduced in QPDF version 4.1.
// tt_space and tt_comment were added in QPDF version 8.
enum token_type_e
{
tt_bad,
tt_array_close,
tt_array_open,
tt_brace_close,
tt_brace_open,
tt_dict_close,
tt_dict_open,
tt_integer,
tt_name,
tt_real,
tt_string,
tt_null,
tt_bool,
tt_word,
tt_eof,
tt_space,
tt_comment,
};
class Token
{
public:
Token() : type(tt_bad) {}
Token(token_type_e type, std::string const& value) :
type(type),
value(value)
{
}
Token(token_type_e type, std::string const& value,
std::string raw_value, std::string error_message) :
type(type),
value(value),
raw_value(raw_value),
error_message(error_message)
{
}
token_type_e getType() const
{
return this->type;
}
std::string const& getValue() const
{
return this->value;
}
std::string const& getRawValue() const
{
return this->raw_value;
}
std::string const& getErrorMessage() const
{
return this->error_message;
}
bool operator==(Token const& rhs)
{
// Ignore fields other than type and value
return ((this->type != tt_bad) &&
(this->type == rhs.type) &&
(this->value == rhs.value));
}
private:
token_type_e type;
std::string value;
std::string raw_value;
std::string error_message;
};
QPDF_DLL
QPDFTokenizer();
// PDF files with version < 1.2 allowed the pound character
// anywhere in a name. Starting with version 1.2, the pound
// character was allowed only when followed by two hexadecimal
// digits. This method should be called when parsing a PDF file
// whose version is older than 1.2.
QPDF_DLL
void allowPoundAnywhereInName();
// If called, treat EOF as a separate token type instead of an
// error. This was introduced in QPDF 4.1 to facilitate
// tokenizing content streams.
QPDF_DLL
void allowEOF();
// If called, readToken will return "ignorable" tokens for space
// and comments. This was added in QPDF 8.
QPDF_DLL
void includeIgnorable();
// Mode of operation:
// Keep presenting characters and calling getToken() until
// getToken() returns true. When it does, be sure to check
// unread_ch and to unread ch if it is true.
// It these are called when a token is available, an exception
// will be thrown.
QPDF_DLL
void presentCharacter(char ch);
QPDF_DLL
void presentEOF();
// If a token is available, return true and initialize token with
// the token, unread_char with whether or not we have to unread
// the last character, and if unread_char, ch with the character
// to unread.
QPDF_DLL
bool getToken(Token& token, bool& unread_char, char& ch);
// This function returns true of the current character is between
// tokens (i.e., white space that is not part of a string) or is
// part of a comment. A tokenizing filter can call this to
// determine whether to output the character.
QPDF_DLL
bool betweenTokens();
// Read a token from an input source. Context describes the
// context in which the token is being read and is used in the
// exception thrown if there is an error.
QPDF_DLL
Token readToken(PointerHolder<InputSource> input,
std::string const& context,
bool allow_bad = false,
size_t max_len = 0);
private:
void reset();
void resolveLiteral();
bool isSpace(char);
// Lexer state
enum { st_top, st_in_space, st_in_comment, st_in_string, st_lt, st_gt,
st_literal, st_in_hexstring, st_token_ready } state;
bool pound_special_in_name;
bool allow_eof;
bool include_ignorable;
// Current token accumulation
token_type_e type;
std::string val;
std::string raw_val;
std::string error_message;
bool unread_char;
char char_to_unread;
// State for strings
int string_depth;
bool string_ignoring_newline;
char bs_num_register[4];
bool last_char_was_bs;
};
#endif // __QPDFTOKENIZER_HH__
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