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qpdf/libqpdf/QPDF_Name.cc

121 lines
3.4 KiB
C++

#include <qpdf/QPDF_Name.hh>
#include <qpdf/JSON_writer.hh>
#include <qpdf/QUtil.hh>
QPDF_Name::QPDF_Name(std::string const& name) :
QPDFValue(::ot_name, "name"),
name(name)
{
}
std::shared_ptr<QPDFObject>
QPDF_Name::create(std::string const& name)
{
return do_create(new QPDF_Name(name));
}
std::shared_ptr<QPDFObject>
QPDF_Name::copy(bool shallow)
{
return create(name);
}
std::string
QPDF_Name::normalizeName(std::string const& name)
{
if (name.empty()) {
return name;
}
std::string result;
result += name.at(0);
for (size_t i = 1; i < name.length(); ++i) {
char ch = name.at(i);
// Don't use locale/ctype here; follow PDF spec guidelines.
if (ch == '\0') {
// QPDFTokenizer embeds a null character to encode an invalid #.
result += "#";
} else if (
ch < 33 || ch == '#' || ch == '/' || ch == '(' || ch == ')' || ch == '{' || ch == '}' ||
ch == '<' || ch == '>' || ch == '[' || ch == ']' || ch == '%' || ch > 126) {
result += QUtil::hex_encode_char(ch);
} else {
result += ch;
}
}
return result;
}
std::string
QPDF_Name::unparse()
{
return normalizeName(this->name);
}
std::pair<bool, bool>
QPDF_Name::analyzeJSONEncoding(const std::string& name)
{
int tail = 0; // Number of continuation characters expected.
bool tail2 = false; // Potential overlong 3 octet utf-8.
bool tail3 = false; // potential overlong 4 octet
bool needs_escaping = false;
for (auto const& it: name) {
auto c = static_cast<unsigned char>(it);
if (tail) {
if ((c & 0xc0) != 0x80) {
return {false, false};
}
if (tail2) {
if ((c & 0xe0) == 0x80) {
return {false, false};
}
tail2 = false;
} else if (tail3) {
if ((c & 0xf0) == 0x80) {
return {false, false};
}
tail3 = false;
}
tail--;
} else if (c < 0x80) {
if (!needs_escaping) {
needs_escaping = !((c > 34 && c != '\\') || c == ' ' || c == 33);
}
} else if ((c & 0xe0) == 0xc0) {
if ((c & 0xfe) == 0xc0) {
return {false, false};
}
tail = 1;
} else if ((c & 0xf0) == 0xe0) {
tail2 = (c == 0xe0);
tail = 2;
} else if ((c & 0xf8) == 0xf0) {
tail3 = (c == 0xf0);
tail = 3;
} else {
return {false, false};
}
}
return {tail == 0, !needs_escaping};
}
void
QPDF_Name::writeJSON(int json_version, JSON::Writer& p)
{
// For performance reasons this code is duplicated in QPDF_Dictionary::writeJSON. When updating
// this method make sure QPDF_Dictionary is also update.
if (json_version == 1) {
p << "\"" << JSON::Writer::encode_string(normalizeName(name)) << "\"";
} else {
if (auto res = analyzeJSONEncoding(name); res.first) {
if (res.second) {
p << "\"" << name << "\"";
} else {
p << "\"" << JSON::Writer::encode_string(name) << "\"";
}
} else {
p << "\"n:" << JSON::Writer::encode_string(normalizeName(name)) << "\"";
}
}
}