peerplays-fc/src/io/json.cpp

839 lines
25 KiB
C++

#include <fc/io/json.hpp>
#include <fc/exception/exception.hpp>
#include <fc/io/iostream.hpp>
#include <fc/io/buffered_iostream.hpp>
#include <fc/io/fstream.hpp>
#include <fc/io/sstream.hpp>
#include <fc/log/logger.hpp>
//#include <utfcpp/utf8.h>
#include <iostream>
#include <fstream>
#include <sstream>
#include <boost/filesystem/fstream.hpp>
namespace fc
{
// forward declarations of provided functions
template<typename T, json::parse_type parser_type> variant variant_from_stream( T& in );
template<typename T> char parseEscape( T& in );
template<typename T> fc::string stringFromStream( T& in );
template<typename T> bool skip_white_space( T& in );
template<typename T> fc::string stringFromToken( T& in );
template<typename T, json::parse_type parser_type> variant_object objectFromStream( T& in );
template<typename T, json::parse_type parser_type> variants arrayFromStream( T& in );
template<typename T, json::parse_type parser_type> variant number_from_stream( T& in );
template<typename T> variant token_from_stream( T& in );
void escape_string( const string& str, ostream& os );
template<typename T> void to_stream( T& os, const variants& a, json::output_formatting format );
template<typename T> void to_stream( T& os, const variant_object& o, json::output_formatting format );
template<typename T> void to_stream( T& os, const variant& v, json::output_formatting format );
fc::string pretty_print( const fc::string& v, uint8_t indent );
}
#include <fc/io/json_relaxed.hpp>
namespace fc
{
template<typename T>
char parseEscape( T& in )
{
if( in.peek() == '\\' )
{
try {
in.get();
switch( in.peek() )
{
case 't':
in.get();
return '\t';
case 'n':
in.get();
return '\n';
case 'r':
in.get();
return '\r';
case '\\':
in.get();
return '\\';
default:
return in.get();
}
} FC_RETHROW_EXCEPTIONS( info, "Stream ended with '\\'" );
}
FC_THROW_EXCEPTION( parse_error_exception, "Expected '\\'" );
}
template<typename T>
bool skip_white_space( T& in )
{
bool skipped = false;
while( true )
{
switch( in.peek() )
{
case ' ':
case '\t':
case '\n':
case '\r':
skipped = true;
in.get();
break;
default:
return skipped;
}
}
}
template<typename T>
fc::string stringFromStream( T& in )
{
fc::stringstream token;
try
{
char c = in.peek();
if( c != '"' )
FC_THROW_EXCEPTION( parse_error_exception,
"Expected '\"' but read '${char}'",
("char", string(&c, (&c) + 1) ) );
in.get();
while( true )
{
switch( c = in.peek() )
{
case '\\':
token << parseEscape( in );
break;
case 0x04:
FC_THROW_EXCEPTION( parse_error_exception, "EOF before closing '\"' in string '${token}'",
("token", token.str() ) );
case '"':
in.get();
return token.str();
default:
token << c;
in.get();
}
}
FC_THROW_EXCEPTION( parse_error_exception, "EOF before closing '\"' in string '${token}'",
("token", token.str() ) );
} FC_RETHROW_EXCEPTIONS( warn, "while parsing token '${token}'",
("token", token.str() ) );
}
template<typename T>
fc::string stringFromToken( T& in )
{
fc::stringstream token;
try
{
char c = in.peek();
while( true )
{
switch( c = in.peek() )
{
case '\\':
token << parseEscape( in );
break;
case '\t':
case ' ':
case '\0':
case '\n':
in.get();
return token.str();
default:
if( isalnum( c ) || c == '_' || c == '-' || c == '.' || c == ':' || c == '/' )
{
token << c;
in.get();
}
else return token.str();
}
}
return token.str();
}
catch( const fc::eof_exception& eof )
{
return token.str();
}
catch (const std::ios_base::failure&)
{
return token.str();
}
FC_RETHROW_EXCEPTIONS( warn, "while parsing token '${token}'",
("token", token.str() ) );
}
template<typename T, json::parse_type parser_type>
variant_object objectFromStream( T& in )
{
mutable_variant_object obj;
try
{
char c = in.peek();
if( c != '{' )
FC_THROW_EXCEPTION( parse_error_exception,
"Expected '{', but read '${char}'",
("char",string(&c, &c + 1)) );
in.get();
skip_white_space(in);
while( in.peek() != '}' )
{
if( in.peek() == ',' )
{
in.get();
continue;
}
if( skip_white_space(in) ) continue;
string key = stringFromStream( in );
skip_white_space(in);
if( in.peek() != ':' )
{
FC_THROW_EXCEPTION( parse_error_exception, "Expected ':' after key \"${key}\"",
("key", key) );
}
in.get();
auto val = variant_from_stream<T, parser_type>( in );
obj(std::move(key),std::move(val));
skip_white_space(in);
}
if( in.peek() == '}' )
{
in.get();
return obj;
}
FC_THROW_EXCEPTION( parse_error_exception, "Expected '}' after ${variant}", ("variant", obj ) );
}
catch( const fc::eof_exception& e )
{
FC_THROW_EXCEPTION( parse_error_exception, "Unexpected EOF: ${e}", ("e", e.to_detail_string() ) );
}
catch( const std::ios_base::failure& e )
{
FC_THROW_EXCEPTION( parse_error_exception, "Unexpected EOF: ${e}", ("e", e.what() ) );
} FC_RETHROW_EXCEPTIONS( warn, "Error parsing object" );
}
template<typename T, json::parse_type parser_type>
variants arrayFromStream( T& in )
{
variants ar;
try
{
if( in.peek() != '[' )
FC_THROW_EXCEPTION( parse_error_exception, "Expected '['" );
in.get();
skip_white_space(in);
while( in.peek() != ']' )
{
if( in.peek() == ',' )
{
in.get();
continue;
}
if( skip_white_space(in) ) continue;
ar.push_back( variant_from_stream<T, parser_type>(in) );
skip_white_space(in);
}
if( in.peek() != ']' )
FC_THROW_EXCEPTION( parse_error_exception, "Expected ']' after parsing ${variant}",
("variant", ar) );
in.get();
} FC_RETHROW_EXCEPTIONS( warn, "Attempting to parse array ${array}",
("array", ar ) );
return ar;
}
template<typename T, json::parse_type parser_type>
variant number_from_stream( T& in )
{
fc::stringstream ss;
bool dot = false;
bool neg = false;
if( in.peek() == '-')
{
neg = true;
ss.put( in.get() );
}
bool done = false;
try
{
char c;
while((c = in.peek()) && !done)
{
switch( c )
{
case '.':
if (dot)
FC_THROW_EXCEPTION(parse_error_exception, "Can't parse a number with two decimal places");
dot = true;
case '0':
case '1':
case '2':
case '3':
case '4':
case '5':
case '6':
case '7':
case '8':
case '9':
ss.put( in.get() );
break;
default:
if( isalnum( c ) )
{
return ss.str() + stringFromToken( in );
}
done = true;
break;
}
}
}
catch (fc::eof_exception&)
{
}
catch (const std::ios_base::failure&)
{
}
fc::string str = ss.str();
if (str == "-." || str == ".") // check the obviously wrong things we could have encountered
FC_THROW_EXCEPTION(parse_error_exception, "Can't parse token \"${token}\" as a JSON numeric constant", ("token", str));
if( dot )
return parser_type == json::legacy_parser_with_string_doubles ? variant(str) : variant(to_double(str));
if( neg )
return to_int64(str);
return to_uint64(str);
}
template<typename T>
variant token_from_stream( T& in )
{
std::stringstream ss;
ss.exceptions( std::ifstream::badbit );
bool received_eof = false;
bool done = false;
try
{
char c;
while((c = in.peek()) && !done)
{
switch( c )
{
case 'n':
case 'u':
case 'l':
case 't':
case 'r':
case 'e':
case 'f':
case 'a':
case 's':
ss.put( in.get() );
break;
default:
done = true;
break;
}
}
}
catch (fc::eof_exception&)
{
received_eof = true;
}
catch (const std::ios_base::failure&)
{
received_eof = true;
}
// we can get here either by processing a delimiter as in "null,"
// an EOF like "null<EOF>", or an invalid token like "nullZ"
fc::string str = ss.str();
if( str == "null" )
return variant();
if( str == "true" )
return true;
if( str == "false" )
return false;
else
{
if (received_eof)
{
if (str.empty())
FC_THROW_EXCEPTION( parse_error_exception, "Unexpected EOF" );
else
return str;
}
else
{
// if we've reached this point, we've either seen a partial
// token ("tru<EOF>") or something our simple parser couldn't
// make out ("falfe")
// A strict JSON parser would signal this as an error, but we
// will just treat the malformed token as an un-quoted string.
return str + stringFromToken(in);;
}
}
}
template<typename T, json::parse_type parser_type>
variant variant_from_stream( T& in )
{
skip_white_space(in);
variant var;
while( signed char c = in.peek() )
{
switch( c )
{
case ' ':
case '\t':
case '\n':
case '\r':
in.get();
continue;
case '"':
return stringFromStream( in );
case '{':
return objectFromStream<T, parser_type>( in );
case '[':
return arrayFromStream<T, parser_type>( in );
case '-':
case '.':
case '0':
case '1':
case '2':
case '3':
case '4':
case '5':
case '6':
case '7':
case '8':
case '9':
return number_from_stream<T, parser_type>( in );
// null, true, false, or 'warning' / string
case 'n':
case 't':
case 'f':
return token_from_stream( in );
case 0x04: // ^D end of transmission
case EOF:
case 0:
FC_THROW_EXCEPTION( eof_exception, "unexpected end of file" );
default:
FC_THROW_EXCEPTION( parse_error_exception, "Unexpected char '${c}' in \"${s}\"",
("c", c)("s", stringFromToken(in)) );
}
}
return variant();
}
/** the purpose of this check is to verify that we will not get a stack overflow in the recursive descent parser */
void check_string_depth( const string& utf8_str )
{
int32_t open_object = 0;
int32_t open_array = 0;
for( auto c : utf8_str )
{
switch( c )
{
case '{': open_object++; break;
case '}': open_object--; break;
case '[': open_array++; break;
case ']': open_array--; break;
default: break;
}
FC_ASSERT( open_object < 100 && open_array < 100, "object graph too deep", ("object depth",open_object)("array depth", open_array) );
}
}
variant json::from_string( const std::string& utf8_str, parse_type ptype )
{ try {
check_string_depth( utf8_str );
fc::stringstream in( utf8_str );
//in.exceptions( std::ifstream::eofbit );
switch( ptype )
{
case legacy_parser:
return variant_from_stream<fc::stringstream, legacy_parser>( in );
case legacy_parser_with_string_doubles:
return variant_from_stream<fc::stringstream, legacy_parser_with_string_doubles>( in );
case strict_parser:
return json_relaxed::variant_from_stream<fc::stringstream, true>( in );
case relaxed_parser:
return json_relaxed::variant_from_stream<fc::stringstream, false>( in );
default:
FC_ASSERT( false, "Unknown JSON parser type {ptype}", ("ptype", ptype) );
}
} FC_RETHROW_EXCEPTIONS( warn, "", ("str",utf8_str) ) }
variants json::variants_from_string( const std::string& utf8_str, parse_type ptype )
{ try {
check_string_depth( utf8_str );
variants result;
fc::stringstream in( utf8_str );
//in.exceptions( std::ifstream::eofbit );
try {
while( true )
{
// result.push_back( variant_from_stream( in ));
result.push_back(json_relaxed::variant_from_stream<fc::stringstream, false>( in ));
}
} catch ( const fc::eof_exception& ){}
return result;
} FC_RETHROW_EXCEPTIONS( warn, "", ("str",utf8_str) ) }
/*
void toUTF8( const char str, ostream& os )
{
// validate str == valid utf8
utf8::replace_invalid( &str, &str + 1, ostream_iterator<char>(os) );
}
void toUTF8( const wchar_t c, ostream& os )
{
utf8::utf16to8( &c, (&c)+1, ostream_iterator<char>(os) );
}
*/
/**
* Convert '\t', '\a', '\n', '\\' and '"' to "\t\a\n\\\""
*
* All other characters are printed as UTF8.
*/
void escape_string( const string& str, ostream& os )
{
os << '"';
for( auto itr = str.begin(); itr != str.end(); ++itr )
{
switch( *itr )
{
case '\t':
os << "\\t";
break;
case '\n':
os << "\\n";
break;
case '\\':
os << "\\\\";
break;
case '\r':
os << "\\r";
break;
case '\a':
os << "\\a";
break;
case '\"':
os << "\\\"";
break;
default:
os << *itr;
//toUTF8( *itr, os );
}
}
os << '"';
}
ostream& json::to_stream( ostream& out, const fc::string& str )
{
escape_string( str, out );
return out;
}
template<typename T>
void to_stream( T& os, const variants& a, json::output_formatting format )
{
os << '[';
auto itr = a.begin();
while( itr != a.end() )
{
to_stream( os, *itr, format );
++itr;
if( itr != a.end() )
os << ',';
}
os << ']';
}
template<typename T>
void to_stream( T& os, const variant_object& o, json::output_formatting format )
{
os << '{';
auto itr = o.begin();
while( itr != o.end() )
{
escape_string( itr->key(), os );
os << ':';
to_stream( os, itr->value(), format );
++itr;
if( itr != o.end() )
os << ',';
}
os << '}';
}
template<typename T>
void to_stream( T& os, const variant& v, json::output_formatting format )
{
switch( v.get_type() )
{
case variant::null_type:
os << "null";
return;
case variant::int64_type:
{
int64_t i = v.as_int64();
if( format == json::stringify_large_ints_and_doubles &&
i > 0xffffffff )
os << '"'<<v.as_string()<<'"';
else
os << i;
return;
}
case variant::uint64_type:
{
uint64_t i = v.as_uint64();
if( format == json::stringify_large_ints_and_doubles &&
i > 0xffffffff )
os << '"'<<v.as_string()<<'"';
else
os << i;
return;
}
case variant::double_type:
if (format == json::stringify_large_ints_and_doubles)
os << '"'<<v.as_string()<<'"';
else
os << v.as_string();
return;
case variant::bool_type:
os << v.as_string();
return;
case variant::string_type:
escape_string( v.get_string(), os );
return;
case variant::blob_type:
escape_string( v.as_string(), os );
return;
case variant::array_type:
{
const variants& a = v.get_array();
to_stream( os, a, format );
return;
}
case variant::object_type:
{
const variant_object& o = v.get_object();
to_stream(os, o, format );
return;
}
}
}
fc::string json::to_string( const variant& v, output_formatting format /* = stringify_large_ints_and_doubles */ )
{
fc::stringstream ss;
fc::to_stream( ss, v, format );
return ss.str();
}
fc::string pretty_print( const fc::string& v, uint8_t indent ) {
int level = 0;
fc::stringstream ss;
bool first = false;
bool quote = false;
bool escape = false;
for( uint32_t i = 0; i < v.size(); ++i ) {
switch( v[i] ) {
case '\\':
if( !escape ) {
if( quote )
escape = true;
} else { escape = false; }
ss<<v[i];
break;
case ':':
if( !quote ) {
ss<<": ";
} else {
ss<<':';
}
break;
case '"':
if( first ) {
ss<<'\n';
for( int i = 0; i < level*indent; ++i ) ss<<' ';
first = false;
}
if( !escape ) {
quote = !quote;
}
escape = false;
ss<<'"';
break;
case '{':
case '[':
ss<<v[i];
if( !quote ) {
++level;
first = true;
}else {
escape = false;
}
break;
case '}':
case ']':
if( !quote ) {
if( v[i-1] != '[' && v[i-1] != '{' ) {
ss<<'\n';
}
--level;
if( !first ) {
for( int i = 0; i < level*indent; ++i ) ss<<' ';
}
first = false;
ss<<v[i];
break;
} else {
escape = false;
ss<<v[i];
}
break;
case ',':
if( !quote ) {
ss<<',';
first = true;
} else {
escape = false;
ss<<',';
}
break;
case 'n':
//If we're in quotes and see a \n, just print it literally but unset the escape flag.
if( quote && escape )
escape = false;
//No break; fall through to default case
default:
if( first ) {
ss<<'\n';
for( int i = 0; i < level*indent; ++i ) ss<<' ';
first = false;
}
ss << v[i];
}
}
return ss.str();
}
fc::string json::to_pretty_string( const variant& v, output_formatting format /* = stringify_large_ints_and_doubles */ )
{
return pretty_print(to_string(v, format), 2);
}
void json::save_to_file( const variant& v, const fc::path& fi, bool pretty, output_formatting format /* = stringify_large_ints_and_doubles */ )
{
if( pretty )
{
auto str = json::to_pretty_string( v, format );
fc::ofstream o(fi);
o.write( str.c_str(), str.size() );
}
else
{
fc::ofstream o(fi);
fc::to_stream( o, v, format );
}
}
variant json::from_file( const fc::path& p, parse_type ptype )
{
//auto tmp = std::make_shared<fc::ifstream>( p, ifstream::binary );
//auto tmp = std::make_shared<std::ifstream>( p.generic_string().c_str(), std::ios::binary );
//buffered_istream bi( tmp );
boost::filesystem::ifstream bi( p, std::ios::binary );
switch( ptype )
{
case legacy_parser:
return variant_from_stream<boost::filesystem::ifstream, legacy_parser>( bi );
case legacy_parser_with_string_doubles:
return variant_from_stream<boost::filesystem::ifstream, legacy_parser_with_string_doubles>( bi );
case strict_parser:
return json_relaxed::variant_from_stream<boost::filesystem::ifstream, true>( bi );
case relaxed_parser:
return json_relaxed::variant_from_stream<boost::filesystem::ifstream, false>( bi );
default:
FC_ASSERT( false, "Unknown JSON parser type {ptype}", ("ptype", ptype) );
}
}
variant json::from_stream( buffered_istream& in, parse_type ptype )
{
switch( ptype )
{
case legacy_parser:
return variant_from_stream<fc::buffered_istream, legacy_parser>( in );
case legacy_parser_with_string_doubles:
return variant_from_stream<fc::buffered_istream, legacy_parser_with_string_doubles>( in );
case strict_parser:
return json_relaxed::variant_from_stream<buffered_istream, true>( in );
case relaxed_parser:
return json_relaxed::variant_from_stream<buffered_istream, false>( in );
default:
FC_ASSERT( false, "Unknown JSON parser type {ptype}", ("ptype", ptype) );
}
}
ostream& json::to_stream( ostream& out, const variant& v, output_formatting format /* = stringify_large_ints_and_doubles */ )
{
fc::to_stream( out, v, format );
return out;
}
ostream& json::to_stream( ostream& out, const variants& v, output_formatting format /* = stringify_large_ints_and_doubles */ )
{
fc::to_stream( out, v, format );
return out;
}
ostream& json::to_stream( ostream& out, const variant_object& v, output_formatting format /* = stringify_large_ints_and_doubles */ )
{
fc::to_stream( out, v, format );
return out;
}
bool json::is_valid( const std::string& utf8_str, parse_type ptype )
{
if( utf8_str.size() == 0 ) return false;
fc::stringstream in( utf8_str );
switch( ptype )
{
case legacy_parser:
variant_from_stream<fc::stringstream, legacy_parser>( in );
break;
case legacy_parser_with_string_doubles:
variant_from_stream<fc::stringstream, legacy_parser_with_string_doubles>( in );
break;
case strict_parser:
json_relaxed::variant_from_stream<fc::stringstream, true>( in );
break;
case relaxed_parser:
json_relaxed::variant_from_stream<fc::stringstream, false>( in );
break;
default:
FC_ASSERT( false, "Unknown JSON parser type {ptype}", ("ptype", ptype) );
}
try { in.peek(); } catch ( const eof_exception& e ) { return true; }
return false;
}
} // fc