data.cc

// Copyright (C) 2010-2017 Internet Systems Consortium, Inc. ("ISC")
//
// This Source Code Form is subject to the terms of the Mozilla Public
// License, v. 2.0. If a copy of the MPL was not distributed with this
// file, You can obtain one at http://mozilla.org/MPL/2.0/.

#include <config.h>

#include <cc/data.h>

#include <cstring>
#include <cassert>
#include <climits>
#include <list>
#include <map>
#include <cstdio>
#include <iostream>
#include <iomanip>
#include <string>
#include <sstream>
#include <fstream>
#include <cerrno>

#include <boost/lexical_cast.hpp>

#include <cmath>

using namespace std;

namespace {
const char* const WHITESPACE = " \b\f\n\r\t";
} // end anonymous namespace

namespace isc {
namespace data {

std::string
Element::Position::str() const {
    std::ostringstream ss;
    ss << file_ << ":" << line_ << ":" << pos_;
    return (ss.str());
}

std::ostream&
operator<<(std::ostream& out, const Element::Position& pos) {
    out << pos.str();
    return (out);
}

std::string
Element::str() const {
    std::stringstream ss;
    toJSON(ss);
    return (ss.str());
}

std::string
Element::toWire() const {
    std::stringstream ss;
    toJSON(ss);
    return (ss.str());
}

void
Element::toWire(std::ostream& ss) const {
    toJSON(ss);
}

bool
Element::getValue(int64_t&) const {
    return (false);
}

bool
Element::getValue(double&) const {
    return (false);
}

bool
Element::getValue(bool&) const {
    return (false);
}

bool
Element::getValue(std::string&) const {
    return (false);
}

bool
Element::getValue(std::vector<ElementPtr>&) const {
    return (false);
}

bool
Element::getValue(std::map<std::string, ConstElementPtr>&) const {
    return (false);
}

bool
Element::setValue(const long long int) {
    return (false);
}

bool
Element::setValue(const double) {
    return (false);
}

bool
Element::setValue(const bool) {
    return (false);
}

bool
Element::setValue(const std::string&) {
    return (false);
}

bool
Element::setValue(const std::vector<ElementPtr>&) {
    return (false);
}

bool
Element::setValue(const std::map<std::string, ConstElementPtr>&) {
    return (false);
}

ConstElementPtr
Element::get(const int) const {
    throwTypeError("get(int) called on a non-list Element");
}

ElementPtr
Element::getNonConst(const int) const {
    throwTypeError("get(int) called on a non-list Element");
}

void
Element::set(const size_t, ElementPtr) {
    throwTypeError("set(int, element) called on a non-list Element");
}

void
Element::add(ElementPtr) {
    throwTypeError("add() called on a non-list Element");
}

void
Element::remove(const int) {
    throwTypeError("remove(int) called on a non-list Element");
}

size_t
Element::size() const {
    throwTypeError("size() called on a non-list Element");
}

bool
Element::empty() const {
    throwTypeError("empty() called on a non-list Element");
}

ConstElementPtr
Element::get(const std::string&) const {
    throwTypeError("get(string) called on a non-map Element");
}

void
Element::set(const std::string&, ConstElementPtr) {
    throwTypeError("set(name, element) called on a non-map Element");
}

void
Element::remove(const std::string&) {
    throwTypeError("remove(string) called on a non-map Element");
}

bool
Element::contains(const std::string&) const {
    throwTypeError("contains(string) called on a non-map Element");
}

ConstElementPtr
Element::find(const std::string&) const {
    throwTypeError("find(string) called on a non-map Element");
}

bool
Element::find(const std::string&, ConstElementPtr&) const {
    return (false);
}

namespace {
inline void
throwJSONError(const std::string& error, const std::string& file, int line,
               int pos)
{
    std::stringstream ss;
    ss << error << " in " + file + ":" << line << ":" << pos;
    isc_throw(JSONError, ss.str());
}
}

std::ostream&
operator<<(std::ostream& out, const Element& e) {
    return (out << e.str());
}

bool
operator==(const Element& a, const Element& b) {
    return (a.equals(b));
}

bool operator!=(const Element& a, const Element& b) {
    return (!a.equals(b));
};

//
// factory functions
//
ElementPtr
Element::create(const Position& pos) {
    return (ElementPtr(new NullElement(pos)));
}

ElementPtr
Element::create(const long long int i, const Position& pos) {
    return (ElementPtr(new IntElement(static_cast<int64_t>(i), pos)));
}

ElementPtr
Element::create(const int i, const Position& pos) {
    return (create(static_cast<long long int>(i), pos));
};

ElementPtr
Element::create(const long int i, const Position& pos) {
    return (create(static_cast<long long int>(i), pos));
};

ElementPtr
Element::create(const double d, const Position& pos) {
    return (ElementPtr(new DoubleElement(d, pos)));
}

ElementPtr
Element::create(const bool b, const Position& pos) {
    return (ElementPtr(new BoolElement(b, pos)));
}

ElementPtr
Element::create(const std::string& s, const Position& pos) {
    return (ElementPtr(new StringElement(s, pos)));
}

ElementPtr
Element::create(const char *s, const Position& pos) {
    return (create(std::string(s), pos));
}

ElementPtr
Element::createList(const Position& pos) {
    return (ElementPtr(new ListElement(pos)));
}

ElementPtr
Element::createMap(const Position& pos) {
    return (ElementPtr(new MapElement(pos)));
}


//
// helper functions for fromJSON factory
//
namespace {
bool
charIn(const int c, const char* chars) {
    const size_t chars_len = std::strlen(chars);
    for (size_t i = 0; i < chars_len; ++i) {
        if (chars[i] == c) {
            return (true);
        }
    }
    return (false);
}

void
skipChars(std::istream& in, const char* chars, int& line, int& pos) {
    int c = in.peek();
    while (charIn(c, chars) && c != EOF) {
        if (c == '\n') {
            ++line;
            pos = 1;
        } else {
            ++pos;
        }
        in.ignore();
        c = in.peek();
    }
}

// skip on the input stream to one of the characters in chars
// if another character is found this function throws JSONError
// unless that character is specified in the optional may_skip
//
// It returns the found character (as an int value).
int
skipTo(std::istream& in, const std::string& file, int& line,
       int& pos, const char* chars, const char* may_skip="")
{
    int c = in.get();
    ++pos;
    while (c != EOF) {
        if (c == '\n') {
            pos = 1;
            ++line;
        }
        if (charIn(c, may_skip)) {
            c = in.get();
            ++pos;
        } else if (charIn(c, chars)) {
            while (charIn(in.peek(), may_skip)) {
                if (in.peek() == '\n') {
                    pos = 1;
                    ++line;
                } else {
                    ++pos;
                }
                in.ignore();
            }
            return (c);
        } else {
            throwJSONError(std::string("'") + std::string(1, c) + "' read, one of \"" + chars + "\" expected", file, line, pos);
        }
    }
    throwJSONError(std::string("EOF read, one of \"") + chars + "\" expected", file, line, pos);
    return (c); // shouldn't reach here, but some compilers require it
}

// TODO: Should we check for all other official escapes here (and
// error on the rest)?
std::string
strFromStringstream(std::istream& in, const std::string& file,
                    const int line, int& pos) throw (JSONError)
{
    std::stringstream ss;
    int c = in.get();
    ++pos;
    if (c == '"') {
        c = in.get();
        ++pos;
    } else {
        throwJSONError("String expected", file, line, pos);
    }

    while (c != EOF && c != '"') {
        if (c == '\\') {
            // see the spec for allowed escape characters
            switch (in.peek()) {
            case '"':
                c = '"';
                break;
            case '/':
                c = '/';
                break;
            case '\\':
                c = '\\';
                break;
            case 'b':
                c = '\b';
                break;
            case 'f':
                c = '\f';
                break;
            case 'n':
                c = '\n';
                break;
            case 'r':
                c = '\r';
                break;
            case 't':
                c = '\t';
                break;
            default:
                throwJSONError("Bad escape", file, line, pos);
            }
            // drop the escaped char
            in.ignore();
            ++pos;
        }
        ss.put(c);
        c = in.get();
        ++pos;
    }
    if (c == EOF) {
        throwJSONError("Unterminated string", file, line, pos);
    }
    return (ss.str());
}

std::string
wordFromStringstream(std::istream& in, int& pos) {
    std::stringstream ss;
    while (isalpha(in.peek())) {
        ss << (char) in.get();
    }
    pos += ss.str().size();
    return (ss.str());
}

std::string
numberFromStringstream(std::istream& in, int& pos) {
    std::stringstream ss;
    while (isdigit(in.peek()) || in.peek() == '+' || in.peek() == '-' ||
           in.peek() == '.' || in.peek() == 'e' || in.peek() == 'E') {
        ss << (char) in.get();
    }
    pos += ss.str().size();
    return (ss.str());
}

// Should we change from IntElement and DoubleElement to NumberElement
// that can also hold an e value? (and have specific getters if the
// value is larger than an int can handle)
//
ElementPtr
fromStringstreamNumber(std::istream& in, const std::string& file,
                       const int& line, int& pos) {
    // Remember position where the value starts. It will be set in the
    // Position structure of the Element to be created.
    const uint32_t start_pos = pos;
    // This will move the pos to the end of the value.
    const std::string number = numberFromStringstream(in, pos);

    if (number.find_first_of(".eE") < number.size()) {
        try {
            return (Element::create(boost::lexical_cast<double>(number),
                                    Element::Position(file, line, start_pos)));
        } catch (const boost::bad_lexical_cast&) {
            throwJSONError(std::string("Number overflow: ") + number,
                           file, line, start_pos);
        }
    } else {
        try {
            return (Element::create(boost::lexical_cast<int64_t>(number),
                                    Element::Position(file, line, start_pos)));
        } catch (const boost::bad_lexical_cast&) {
            throwJSONError(std::string("Number overflow: ") + number, file,
                           line, start_pos);
        }
    }
    return (ElementPtr());
}

ElementPtr
fromStringstreamBool(std::istream& in, const std::string& file,
                     const int line, int& pos)
{
    // Remember position where the value starts. It will be set in the
    // Position structure of the Element to be created.
    const uint32_t start_pos = pos;
    // This will move the pos to the end of the value.
    const std::string word = wordFromStringstream(in, pos);

    if (word == "true") {
        return (Element::create(true, Element::Position(file, line,
                                                        start_pos)));
    } else if (word == "false") {
        return (Element::create(false, Element::Position(file, line,
                                                         start_pos)));
    } else {
        throwJSONError(std::string("Bad boolean value: ") + word, file,
                       line, start_pos);
    }
    return (ElementPtr());
}

ElementPtr
fromStringstreamNull(std::istream& in, const std::string& file,
                     const int line, int& pos)
{
    // Remember position where the value starts. It will be set in the
    // Position structure of the Element to be created.
    const uint32_t start_pos = pos;
    // This will move the pos to the end of the value.
    const std::string word = wordFromStringstream(in, pos);
    if (word == "null") {
        return (Element::create(Element::Position(file, line, start_pos)));
    } else {
        throwJSONError(std::string("Bad null value: ") + word, file,
                       line, start_pos);
        return (ElementPtr());
    }
}

ElementPtr
fromStringstreamString(std::istream& in, const std::string& file, int& line,
                       int& pos)
{
    // Remember position where the value starts. It will be set in the
    // Position structure of the Element to be created.
    const uint32_t start_pos = pos;
    // This will move the pos to the end of the value.
    const std::string string_value = strFromStringstream(in, file, line, pos);
    return (Element::create(string_value, Element::Position(file, line,
                                                            start_pos)));
}

ElementPtr
fromStringstreamList(std::istream& in, const std::string& file, int& line,
                     int& pos)
{
    int c = 0;
    ElementPtr list = Element::createList(Element::Position(file, line, pos));
    ElementPtr cur_list_element;

    skipChars(in, WHITESPACE, line, pos);
    while (c != EOF && c != ']') {
        if (in.peek() != ']') {
            cur_list_element = Element::fromJSON(in, file, line, pos);
            list->add(cur_list_element);
            c = skipTo(in, file, line, pos, ",]", WHITESPACE);
        } else {
            c = in.get();
            ++pos;
        }
    }
    return (list);
}

ElementPtr
fromStringstreamMap(std::istream& in, const std::string& file, int& line,
                    int& pos)
{
    ElementPtr map = Element::createMap(Element::Position(file, line, pos));
    skipChars(in, WHITESPACE, line, pos);
    int c = in.peek();
    if (c == EOF) {
        throwJSONError(std::string("Unterminated map, <string> or } expected"), file, line, pos);
    } else if (c == '}') {
        // empty map, skip closing curly
        in.ignore();
    } else {
        while (c != EOF && c != '}') {
            std::string key = strFromStringstream(in, file, line, pos);

            skipTo(in, file, line, pos, ":", WHITESPACE);
            // skip the :

            ConstElementPtr value = Element::fromJSON(in, file, line, pos);
            map->set(key, value);

            c = skipTo(in, file, line, pos, ",}", WHITESPACE);
        }
    }
    return (map);
}
} // unnamed namespace

std::string
Element::typeToName(Element::types type) {
    switch (type) {
    case Element::integer:
        return (std::string("integer"));
    case Element::real:
        return (std::string("real"));
    case Element::boolean:
        return (std::string("boolean"));
    case Element::string:
        return (std::string("string"));
    case Element::list:
        return (std::string("list"));
    case Element::map:
        return (std::string("map"));
    case Element::null:
        return (std::string("null"));
    case Element::any:
        return (std::string("any"));
    default:
        return (std::string("unknown"));
    }
}

Element::types
Element::nameToType(const std::string& type_name) {
    if (type_name == "integer") {
        return (Element::integer);
    } else if (type_name == "real") {
        return (Element::real);
    } else if (type_name == "boolean") {
        return (Element::boolean);
    } else if (type_name == "string") {
        return (Element::string);
    } else if (type_name == "list") {
        return (Element::list);
    } else if (type_name == "map") {
        return (Element::map);
    } else if (type_name == "named_set") {
        return (Element::map);
    } else if (type_name == "null") {
        return (Element::null);
    } else if (type_name == "any") {
        return (Element::any);
    } else {
        isc_throw(TypeError, type_name + " is not a valid type name");
    }
}

ElementPtr
Element::fromJSON(std::istream& in, bool preproc) throw(JSONError) {

    int line = 1, pos = 1;
    stringstream filtered;
    if (preproc) {
        preprocess(in, filtered);
    }

    ElementPtr value = fromJSON(preproc ? filtered : in, "<istream>", line, pos);

    return (value);
}

ElementPtr
Element::fromJSON(std::istream& in, const std::string& file_name, bool preproc)
    throw(JSONError)
{
    int line = 1, pos = 1;
    stringstream filtered;
    if (preproc) {
        preprocess(in, filtered);
    }
    return (fromJSON(preproc ? filtered : in, file_name, line, pos));
}

ElementPtr
Element::fromJSON(std::istream& in, const std::string& file, int& line,
                  int& pos) throw(JSONError)
{
    int c = 0;
    ElementPtr element;
    bool el_read = false;
    skipChars(in, WHITESPACE, line, pos);
    while (c != EOF && !el_read) {
        c = in.get();
        pos++;
        switch(c) {
            case '1':
            case '2':
            case '3':
            case '4':
            case '5':
            case '6':
            case '7':
            case '8':
            case '9':
            case '0':
            case '-':
            case '+':
            case '.':
                in.putback(c);
                --pos;
                element = fromStringstreamNumber(in, file, line, pos);
                el_read = true;
                break;
            case 't':
            case 'f':
                in.putback(c);
                --pos;
                element = fromStringstreamBool(in, file, line, pos);
                el_read = true;
                break;
            case 'n':
                in.putback(c);
                --pos;
                element = fromStringstreamNull(in, file, line, pos);
                el_read = true;
                break;
            case '"':
                in.putback('"');
                --pos;
                element = fromStringstreamString(in, file, line, pos);
                el_read = true;
                break;
            case '[':
                element = fromStringstreamList(in, file, line, pos);
                el_read = true;
                break;
            case '{':
                element = fromStringstreamMap(in, file, line, pos);
                el_read = true;
                break;
            case EOF:
                break;
            default:
                throwJSONError(std::string("error: unexpected character ") + std::string(1, c), file, line, pos);
                break;
        }
    }
    if (el_read) {
        return (element);
    } else {
        isc_throw(JSONError, "nothing read");
    }
}

ElementPtr
Element::fromJSON(const std::string& in, bool preproc) {
    std::stringstream ss;
    ss << in;

    int line = 1, pos = 1;
    stringstream filtered;
    if (preproc) {
        preprocess(ss, filtered);
    }
    ElementPtr result(fromJSON(preproc ? filtered : ss, "<string>", line, pos));
    skipChars(ss, WHITESPACE, line, pos);
    // ss must now be at end
    if (ss.peek() != EOF) {
        throwJSONError("Extra data", "<string>", line, pos);
    }
    return result;
}

ElementPtr
Element::fromJSONFile(const std::string& file_name,
                      bool preproc) {
    // zero out the errno to be safe
    errno = 0;

    std::ifstream infile(file_name.c_str(), std::ios::in | std::ios::binary);
    if (!infile.is_open())
    {
        const char* error = strerror(errno);
        isc_throw(InvalidOperation, "failed to read file '" << file_name
                  << "': " << error);
    }

    return (fromJSON(infile, file_name, preproc));
}

// to JSON format

void
IntElement::toJSON(std::ostream& ss) const {
    ss << intValue();
}

void
DoubleElement::toJSON(std::ostream& ss) const {
    ss << doubleValue();
}

void