D4ParserSax2.h

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// -*- mode: c++; c-basic-offset:4 -*-
 
// This file is part of libdap, A C++ implementation of the OPeNDAP Data
// Access Protocol.
 
// Copyright (c) 2012 OPeNDAP, Inc.
// Author: James Gallagher <jgallagher@opendap.org>
//
// This library is free software; you can redistribute it and/or
// modify it under the terms of the GNU Lesser General Public
// License as published by the Free Software Foundation; either
// version 2.1 of the License, or (at your option) any later version.
//
// This library is distributed in the hope that it will be useful,
// but WITHOUT ANY WARRANTY; without even the implied warranty of
// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
// Lesser General Public License for more details.
//
// You should have received a copy of the GNU Lesser General Public
// License along with this library; if not, write to the Free Software
// Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301  USA
//
// You can contact OPeNDAP, Inc. at PO Box 112, Saunderstown, RI. 02874-0112.
 
#ifndef d4_parser_sax2_h
#define d4_parser_sax2_h
 
#define ATTR 1
 
#include <string.h>
 
#include <iostream>
#include <map>
#include <stack>
#include <string>
 
#include <libxml/parserInternals.h>
 
#define CRLF "\r\n"
#define D4_PARSE_BUFF_SIZE 1048576
 
namespace libdap {
 
class DMR;
class BaseType;
class D4BaseTypeFactory;
class D4Group;
class D4Attributes;
class D4EnumDef;
class D4Dimension;

class D4ParserSax2 {
private:
    enum ParseState {
        parser_start,
 
        inside_dataset,
 
        // inside_group is the state just after parsing the start of a Group
        // element.
        inside_group,
 
        inside_attribute_container,
        inside_attribute,
        inside_attribute_value,
        inside_other_xml_attribute,
 
        inside_enum_def,
        inside_enum_const,
 
        inside_dim_def,
 
        // This covers Byte, ..., Url, Opaque
        inside_simple_type,
 
        // inside_array,
        inside_dim,
        inside_map,
 
        inside_constructor,
 
        // inside_sequence, Removed from merged code jhrg 5/2/14
 
        not_dap4_element,
 
        parser_unknown,
        parser_error,
        parser_fatal_error,
 
        parser_end
    };
    char d_parse_buffer[D4_PARSE_BUFF_SIZE + 1]; // Buff size plus one byte for NULL termination.
 
    xmlSAXHandler d_dmr_sax_parser;
 
    // The results of the parse operation are stored in these fields.
    // This is passed into the parser using the intern() methods.
    DMR *d_dmr; // dump DMR here
    DMR *dmr() const { return d_dmr; }
 
    // These stacks hold the state of the parse as it progresses.
    stack<ParseState> s; // Current parse state
    void push_state(D4ParserSax2::ParseState state) { s.push(state); }
    D4ParserSax2::ParseState get_state() const { return s.top(); }
    void pop_state() { s.pop(); }
    bool empty_state() const { return s.empty(); }
 
    stack<BaseType *> btp_stack; // current variable(s)
    void push_basetype(BaseType *btp) { btp_stack.push(btp); }
    BaseType *top_basetype() const { return btp_stack.top(); }
    void pop_basetype() { btp_stack.pop(); }
    bool empty_basetype() const { return btp_stack.empty(); }
 
    stack<D4Group *> grp_stack; // current groups(s)
    void push_group(D4Group *grp) { grp_stack.push(grp); }
    D4Group *top_group() const { return grp_stack.top(); }
    void pop_group() { grp_stack.pop(); }
    bool empty_group() const { return grp_stack.empty(); }
 
    stack<D4Attributes *> d_attrs_stack; // DAP4 Attributes
    void push_attributes(D4Attributes *attr) { d_attrs_stack.push(attr); }
    D4Attributes *top_attributes() const { return d_attrs_stack.top(); }
    void pop_attributes() { d_attrs_stack.pop(); }
    bool empty_attributes() const { return d_attrs_stack.empty(); }
 
    D4EnumDef *d_enum_def;
    D4EnumDef *enum_def();
    void clear_enum_def() { d_enum_def = 0; }
 
    D4Dimension *d_dim_def;
    D4Dimension *dim_def();
    void clear_dim_def() { d_dim_def = 0; }
 
    // Accumulate stuff inside an 'OtherXML' DAP attribute here
    string other_xml;
 
    // When we're parsing unknown XML, how deeply is it nested? This is used
    // for the OtherXML DAP attributes.
    unsigned int other_xml_depth;
    unsigned int unknown_depth;
 
    // These are used for processing errors.
    string d_error_msg;         // Error message(s), if any.
    xmlParserCtxtPtr d_context; // used for error message line numbers
 
    // These hold temporary values read during the parse.
    string dods_attr_name; // DAP4 attributes, not XML attributes
    string dods_attr_type; // ... not XML ...
    string char_data;      // char data in value elements; null after use
    string root_ns;        // What is the namespace of the root node (Group)
 
    bool d_debug;
    bool debug() const { return d_debug; }
 
    bool d_strict;
 
    class XMLAttribute {
    public:
        string prefix;
        string nsURI;
        string value;
 
        void clone(const XMLAttribute &src) {
            prefix = src.prefix;
            nsURI = src.nsURI;
            value = src.value;
        }
 
        XMLAttribute() : prefix(""), nsURI(""), value("") {}
        XMLAttribute(const string &p, const string &ns, const string &v) : prefix(p), nsURI(ns), value(v) {}
        // 'attributes' as passed from libxml2 is a five element array but this
        // ctor gets the back four elements.
        XMLAttribute(const xmlChar **attributes /*[4]*/) {
            prefix = attributes[0] != 0 ? (const char *)attributes[0] : "";
            nsURI = attributes[1] != 0 ? (const char *)attributes[1] : "";
            value = string((const char *)attributes[2], (const char *)attributes[3]);
        }
        XMLAttribute(const XMLAttribute &rhs) { clone(rhs); }
        ~XMLAttribute() {}
        XMLAttribute &operator=(const XMLAttribute &rhs) {
            if (this == &rhs)
                return *this;
            clone(rhs);
            return *this;
        }
    };
 
    typedef map<string, XMLAttribute> XMLAttrMap;
    XMLAttrMap xml_attrs; // dump XML attributes here
 
    XMLAttrMap::iterator xml_attr_begin() { return xml_attrs.begin(); }
 
    XMLAttrMap::iterator xml_attr_end() { return xml_attrs.end(); }
 
    map<string, string> namespace_table;
 
    void cleanup_parse();

    void transfer_xml_attrs(const xmlChar **attrs, int nb_attributes);
    void transfer_xml_ns(const xmlChar **namespaces, int nb_namespaces);
    bool check_required_attribute(const string &attr);
    bool check_attribute(const string &attr);
    void process_variable_helper(Type t, ParseState s, const xmlChar **attrs, int nb_attributes);
 
    void process_enum_const_helper(const xmlChar **attrs, int nb_attributes);
    void process_enum_def_helper(const xmlChar **attrs, int nb_attributes);
 
    bool process_dimension(const char *name, const xmlChar **attrs, int nb_attrs);
    bool process_dimension_def(const char *name, const xmlChar **attrs, int nb_attrs);
    bool process_map(const char *name, const xmlChar **attrs, int nb_attributes);
    bool process_attribute(const char *name, const xmlChar **attrs, int nb_attributes);
    bool process_variable(const char *name, const xmlChar **attrs, int nb_attributes);
    bool process_group(const char *name, const xmlChar **attrs, int nb_attributes);
    bool process_enum_def(const char *name, const xmlChar **attrs, int nb_attributes);
    bool process_enum_const(const char *name, const xmlChar **attrs, int nb_attributes);
 
    void finish_variable(const char *tag, Type t, const char *expected);
 
    friend class D4ParserSax2Test;
 
public:
    D4ParserSax2()
        : d_dmr(0), d_enum_def(0), d_dim_def(0), other_xml(""), other_xml_depth(0), unknown_depth(0), d_error_msg(""),
          d_context(0), dods_attr_name(""), dods_attr_type(""), char_data(""), root_ns(""), d_debug(false),
          d_strict(true) {
        // xmlSAXHandler ddx_sax_parser;
        memset(&d_dmr_sax_parser, 0, sizeof(xmlSAXHandler));
 
        d_dmr_sax_parser.getEntity = &D4ParserSax2::dmr_get_entity;
        d_dmr_sax_parser.startDocument = &D4ParserSax2::dmr_start_document;
        d_dmr_sax_parser.endDocument = &D4ParserSax2::dmr_end_document;
        d_dmr_sax_parser.characters = &D4ParserSax2::dmr_get_characters;
        d_dmr_sax_parser.ignorableWhitespace = &D4ParserSax2::dmr_ignoreable_whitespace;
        d_dmr_sax_parser.cdataBlock = &D4ParserSax2::dmr_get_cdata;
        d_dmr_sax_parser.warning = &D4ParserSax2::dmr_error;
        d_dmr_sax_parser.error = &D4ParserSax2::dmr_error;
        d_dmr_sax_parser.fatalError = &D4ParserSax2::dmr_fatal_error;
        d_dmr_sax_parser.initialized = XML_SAX2_MAGIC;
        d_dmr_sax_parser.startElementNs = &D4ParserSax2::dmr_start_element;
        d_dmr_sax_parser.endElementNs = &D4ParserSax2::dmr_end_element;
    }
 
    void intern(istream &f, DMR *dest_dmr, bool debug = false);
    // Deprecated - this does not read from a file, it parses text in the string 'document'
    void intern(const string &document, DMR *dest_dmr, bool debug = false);
    void intern(const char *buffer, int size, DMR *dest_dmr, bool debug = false);


    void set_strict(bool s) { d_strict = s; }
    bool get_strict() const { return d_strict; }
 
    static void dmr_start_document(void *parser);
    static void dmr_end_document(void *parser);
 
    static void dmr_start_element(void *parser, const xmlChar *localname, const xmlChar *prefix, const xmlChar *URI,
                                  int nb_namespaces, const xmlChar **namespaces, int nb_attributes, int nb_defaulted,
                                  const xmlChar **attributes);
    static void dmr_end_element(void *parser, const xmlChar *localname, const xmlChar *prefix, const xmlChar *URI);
 
    static void dmr_get_characters(void *parser, const xmlChar *ch, int len);
    static void dmr_ignoreable_whitespace(void *parser, const xmlChar *ch, int len);
    static void dmr_get_cdata(void *parser, const xmlChar *value, int len);
 
    static xmlEntityPtr dmr_get_entity(void *parser, const xmlChar *name);
    static void dmr_fatal_error(void *parser, const char *msg, ...);
    static void dmr_error(void *parser, const char *msg, ...);
};
 
} // namespace libdap
 
#endif // d4_parser_sax2_h