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Don't use QString and family when parsing OBJ file
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@10110111
10110111 committed Mar 5, 2024
1 parent b3134d8 commit 7362d36
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Showing 2 changed files with 86 additions and 139 deletions.
212 changes: 81 additions & 131 deletions src/core/StelOBJ.cpp
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Original file line number Diff line number Diff line change
Expand Up @@ -35,6 +35,38 @@

Q_LOGGING_CATEGORY(stelOBJ,"stel.OBJ")

namespace
{
// Split line by spaces without allocating memory, including allocation for storing
// the result (we assume that the output vector has a reasonable amount of space reserved)
void splitBySpacesWithoutEmptyParts(const QByteArray& line, std::vector<std::string_view>& splits)
{
splits.clear();
int startPos = 0;
for(int n = 0; n < line.size(); ++n)
{
if(line[n] != ' ') continue;
const int currStartPos = startPos;
startPos = n + 1;
if(n == currStartPos) continue; // skip empty entry
splits.emplace_back(line.data() + currStartPos, n - currStartPos);
}
// store last entry if it's not empty
const int n = line.size();
if(n == startPos) return;
splits.emplace_back(line.data() + startPos, n - startPos);
}

QDebug& operator<<(QDebug& dbg, std::vector<std::string_view> const& strings)
{
dbg << "{";
for(const auto& str : strings)
dbg << QString(QByteArray(str.data(), str.size()));
dbg << "}";
return dbg;
}
}

StelOBJ::StelOBJ()
: m_isLoaded(false)
{
Expand Down Expand Up @@ -97,7 +129,7 @@ bool StelOBJ::load(const QString& filename, const VertexOrder vertexOrder, const
}

//macro to test out different ways of comparison and their performance
#define CMD_CMP(a) (QLatin1String(a)==cmd)
#define CMD_CMP(a) (std::string_view(a)==cmd)

//macro to increase a list by size one and return a reference to the last element
//used instead of append() to avoid memory copies
Expand All @@ -122,21 +154,9 @@ bool StelOBJ::parseBool(const ParseParams &params, bool &out, int paramsStart)
return true;
}

bool StelOBJ::parseInt(const QStringView& str, int& out)
bool StelOBJ::parseInt(const std::string_view& str, int& out)
{
// We'll do the allocationless equivalent of QString::toLocal8Bit(). The buffer will contain
// non-terminated Latin1 version of the contents of the input QString.
char buf[64];
// There can't be too many chars in a number; if there are, just fail
if (str.size() - 1 > int(sizeof buf))
{
qCCritical(stelOBJ) << "Error parsing int: too long number found:" << str;
return false;
}
for(int n = 0; n < str.size(); ++n)
buf[n] = str[n].toLatin1();
const auto res = std::from_chars(buf, buf + str.size(), out);
return res.ec == std::errc{};
return std::from_chars(str.data(), str.data() + str.size(), out).ec == std::errc{};
}

bool StelOBJ::parseInt(const ParseParams &params, int &out, int paramsStart)
Expand Down Expand Up @@ -167,7 +187,7 @@ bool StelOBJ::parseString(const ParseParams &params, QString &out, int paramsSta
qCWarning(stelOBJ)<<"Additional parameters ignored in statement"<<params;
}

out = params.at(paramsStart).toString();
out = QString(QByteArray(params[paramsStart].data(), params[paramsStart].size()));
return true;
}

Expand All @@ -188,20 +208,8 @@ bool StelOBJ::parseFloat(const ParseParams &params, float &out, int paramsStart)
qCWarning(stelOBJ)<<"Additional parameters ignored in statement"<<params;
}

const auto& xQStr = params[paramsStart+0];
// We'll do the allocationless equivalent of QString::toLocal8Bit(). The buffer will contain
// non-terminated Latin1 version of the contents of the input QString.
char string[1024]; // There can't be too many chars in a number; if there are, just fail

if (xQStr.size() - 1 > int(sizeof string))
{
qCCritical(stelOBJ) << "Error parsing float: too long number found:" << params;
return false;
}

for(int n = 0; n < xQStr.size(); ++n)
string[n] = xQStr[n].toLatin1();
const auto res = std::from_chars(string, string + xQStr.size(), out);
const auto& str = params[paramsStart];
const auto res = std::from_chars(str.data(), str.data() + str.size(), out);
return res.ec == std::errc{};
}

Expand All @@ -214,36 +222,18 @@ bool StelOBJ::parseVec3(const ParseParams& params, T &out, int paramsStart)
return false;
}

const auto& xQStr = params[paramsStart+0];
const auto& yQStr = params[paramsStart+1];
const auto& zQStr = params[paramsStart+2];

// We'll do the allocationless equivalent of QString::toLocal8Bit(). The buffer will contain
// non-terminated Latin1 version of the contents of each of the component QStrings.
char string[1024]; // There can't be too many chars in a number; if there are, just fail

if (xQStr.size() - 1 > int(sizeof string) ||
yQStr.size() - 1 > int(sizeof string) ||
zQStr.size() - 1 > int(sizeof string))
{
qCCritical(stelOBJ) << "Error parsing Vec3: too long number found:" << params;
return false;
}
const auto& xStr = params[paramsStart+0];
const auto& yStr = params[paramsStart+1];
const auto& zStr = params[paramsStart+2];

for(int n = 0; n < xQStr.size(); ++n)
string[n] = xQStr[n].toLatin1();
std::from_chars_result res;
res = std::from_chars(string, string + xQStr.size(), out[0]);
res = std::from_chars(xStr.data(), xStr.data() + xStr.size(), out[0]);
if (res.ec != std::errc{}) goto error;

for(int n = 0; n < yQStr.size(); ++n)
string[n] = yQStr[n].toLatin1();
res = std::from_chars(string, string + yQStr.size(), out[1]);
res = std::from_chars(yStr.data(), yStr.data() + yStr.size(), out[1]);
if (res.ec != std::errc{}) goto error;

for(int n = 0; n < zQStr.size(); ++n)
string[n] = zQStr[n].toLatin1();
res = std::from_chars(string, string + zQStr.size(), out[2]);
res = std::from_chars(zStr.data(), zStr.data() + zStr.size(), out[2]);
if (res.ec != std::errc{}) goto error;

return true;
Expand All @@ -262,29 +252,14 @@ bool StelOBJ::parseVec2(const ParseParams& params,T &out, int paramsStart)
return false;
}

const auto& xQStr = params[paramsStart+0];
const auto& yQStr = params[paramsStart+1];
const auto& xStr = params[paramsStart+0];
const auto& yStr = params[paramsStart+1];

// We'll do the allocationless equivalent of QString::toLocal8Bit(). The buffer will contain
// non-terminated Latin1 version of the contents of each of the component QStrings.
char string[1024]; // There can't be too many chars in a number; if there are, just fail

if (xQStr.size() - 1 > int(sizeof string) ||
yQStr.size() - 1 > int(sizeof string))
{
qCCritical(stelOBJ) << "Error parsing Vec2: too long number found:" << params;
return false;
}

for(int n = 0; n < xQStr.size(); ++n)
string[n] = xQStr[n].toLatin1();
std::from_chars_result res;
res = std::from_chars(string, string + xQStr.size(), out[0]);
res = std::from_chars(xStr.data(), xStr.data() + xStr.size(), out[0]);
if (res.ec != std::errc{}) goto error;

for(int n = 0; n < yQStr.size(); ++n)
string[n] = yQStr[n].toLatin1();
res = std::from_chars(string, string + yQStr.size(), out[1]);
res = std::from_chars(yStr.data(), yStr.data() + yStr.size(), out[1]);
if (res.ec != std::errc{}) goto error;

return true;
Expand Down Expand Up @@ -388,11 +363,11 @@ bool StelOBJ::parseFace(const ParseParams& params, const V3Vec& posList, const V

// Find all slashes without allocating memory, including allocation for storing
// the result (we assume that the output vector has a reasonable amount of space reserved)
const auto findSlashes = [](const QStringView& line, std::vector<int>& slashes)
const auto findSlashes = [](const std::string_view& line, std::vector<int>& slashes)
{
slashes.clear();
for(int n = 0; n < line.size(); ++n)
if(line[n] == QLatin1Char('/'))
for(unsigned n = 0; n < line.size(); ++n)
if(line[n] == '/')
slashes.push_back(n);
};

Expand All @@ -414,28 +389,28 @@ bool StelOBJ::parseFace(const ParseParams& params, const V3Vec& posList, const V
break;
case 1: //single slash, vert/tex
CHK_MODE(2)
CHK_OK(ok = parseInt(vertStr.mid(0, slashes[0]), posIdx));
CHK_OK(ok = parseInt(vertStr.substr(0, slashes[0]), posIdx));
FIX_REL(posIdx, posList)
CHK_OK(ok = parseInt(vertStr.mid(slashes[0] + 1, vertStr.size() - (slashes[0] + 1)), texIdx));
CHK_OK(ok = parseInt(vertStr.substr(slashes[0] + 1, vertStr.size() - (slashes[0] + 1)), texIdx));
FIX_REL(texIdx, texList)
break;
case 2: //2 slashes, either v/t/n or v//n
if(slashes[1]-slashes[0] != 1)
{
CHK_MODE(3)
CHK_OK(ok = parseInt(vertStr.mid(0, slashes[0]), posIdx));
CHK_OK(ok = parseInt(vertStr.substr(0, slashes[0]), posIdx));
FIX_REL(posIdx, posList)
CHK_OK(ok = parseInt(vertStr.mid(slashes[0] + 1, slashes[1] - (slashes[0] + 1)), texIdx));
CHK_OK(ok = parseInt(vertStr.substr(slashes[0] + 1, slashes[1] - (slashes[0] + 1)), texIdx));
FIX_REL(texIdx, texList)
CHK_OK(ok = parseInt(vertStr.mid(slashes[1] + 1, vertStr.size() - (slashes[1] + 1)), normIdx));
CHK_OK(ok = parseInt(vertStr.substr(slashes[1] + 1, vertStr.size() - (slashes[1] + 1)), normIdx));
FIX_REL(normIdx, normList)
}
else
{
CHK_MODE(4)
CHK_OK(ok = parseInt(vertStr.mid(0, slashes[0]), posIdx));
CHK_OK(ok = parseInt(vertStr.substr(0, slashes[0]), posIdx));
FIX_REL(posIdx, posList)
CHK_OK(ok = parseInt(vertStr.mid(slashes[1] + 1, vertStr.size() - (slashes[1] + 1)), normIdx));
CHK_OK(ok = parseInt(vertStr.substr(slashes[1] + 1, vertStr.size() - (slashes[1] + 1)), normIdx));
FIX_REL(normIdx, normList)
}
break;
Expand Down Expand Up @@ -511,30 +486,25 @@ StelOBJ::MaterialList StelOBJ::Material::loadFromFile(const QString &filename)
return list;
}

QTextStream stream(&file);
Material* curMaterial = Q_NULLPTR;
int lineNr = 0;
// some exporters give d and Tr, and some give contradicting interpretations. Track a warning with these.
bool dHasBeenGiven = false;
bool trHasBeenGiven = false;

while(!stream.atEnd())
ParseParams splits;
while(!file.atEnd())
{
++lineNr;
bool ok = true;
//make sure only spaces are the separator
QString line = stream.readLine().simplified();
//split line by space
#if (QT_VERSION>=QT_VERSION_CHECK(6,0,0))
ParseParams splits = ParseParam(line).split(' ', Qt::SkipEmptyParts);
#elif (QT_VERSION>=QT_VERSION_CHECK(5,15,0))
ParseParams splits = line.splitRef(' ', Qt::SkipEmptyParts);
#else
ParseParams splits = line.splitRef(' ', QString::SkipEmptyParts);
#endif
if(!splits.isEmpty())
const QByteArray line = file.readLine().simplified();

splitBySpacesWithoutEmptyParts(line, splits);

if(!splits.empty())
{
const ParseParam& cmd = splits.at(0);
const ParseParam& cmd = splits[0];

//macro to make sure a material is currently active
#define CHECK_MTL() if(!curMaterial) { ok = false; qCCritical(stelOBJ)<<"Encountered material statement without active material"; }
Expand Down Expand Up @@ -711,20 +681,20 @@ StelOBJ::MaterialList StelOBJ::Material::loadFromFile(const QString &filename)
curMaterial->illum = static_cast<Illum>(tmp);
}
}
else if(!cmd.startsWith(QChar('#')))
else if(!cmd.empty() && cmd[0] !='#')
{
CHECK_MTL()
if(ok)
{
//unknown command, add to additional params
//we need to convert to actual string instances to store them
QStringList list;
for(int i = 1; i<splits.size();++i)
for(unsigned i = 1; i<splits.size();++i)
{
list.append(splits.at(i).toString());
list.append(QString(QByteArray(splits[i].data(), splits[i].size())));
}

curMaterial->additionalParams.insert(cmd.toString(),list);
curMaterial->additionalParams.insert(QString(QByteArray(cmd.data(), cmd.size())), list);
//qCWarning(stelOBJ)<<"Unknown MTL statement:"<<line;
}
}
Expand All @@ -746,11 +716,7 @@ bool StelOBJ::Material::parseBool(const QStringList &params, bool &out)
ParseParams pp(params.size());
for(int i = 0; i< params.size();++i)
{
#if (QT_VERSION>=QT_VERSION_CHECK(6,0,0))
pp[i] = params.at(i);
#else
pp[i] = QStringRef(&params.at(i));
#endif
pp[i] = params[i].toStdString();
}
return StelOBJ::parseBool(pp,out,0);
}
Expand All @@ -760,11 +726,7 @@ bool StelOBJ::Material::parseFloat(const QStringList &params, float &out)
ParseParams pp(params.size());
for(int i = 0; i< params.size();++i)
{
#if (QT_VERSION>=QT_VERSION_CHECK(6,0,0))
pp[i] = params.at(i);
#else
pp[i] = ParseParam(&params.at(i));
#endif
pp[i] = params[i].toStdString();
}
return StelOBJ::parseFloat(pp,out,0);
}
Expand All @@ -774,11 +736,7 @@ bool StelOBJ::Material::parseVec2d(const QStringList &params, Vec2d &out)
ParseParams pp(params.size());
for(int i = 0; i< params.size();++i)
{
#if (QT_VERSION>=QT_VERSION_CHECK(6,0,0))
pp[i] = params.at(i);
#else
pp[i] = ParseParam(&params.at(i));
#endif
pp[i] = params[i].toStdString();
}
return StelOBJ::parseVec2(pp,out,0);
}
Expand Down Expand Up @@ -813,7 +771,6 @@ bool StelOBJ::load(QIODevice& device, const QString &basePath, const VertexOrder

QElapsedTimer timer;
timer.start();
QTextStream stream(&device);

bool smoothGroupWarned = false;
bool vertexWWarned = false;
Expand All @@ -828,28 +785,21 @@ bool StelOBJ::load(QIODevice& device, const QString &basePath, const VertexOrder

VertexCache vertCache;
CurrentParserState state = CurrentParserState();
static const QChar separator(' ');

int lineNr=0;

ParseParams splits;
//read file line by line
while(!stream.atEnd())
while(!device.atEnd())
{
++lineNr;
//ignore front/back whitespace
QString line = stream.readLine().trimmed();

//split line by whitespace
#if (QT_VERSION>=QT_VERSION_CHECK(6,0,0))
ParseParams splits = ParseParam(line).split(separator, Qt::SkipEmptyParts);
#elif (QT_VERSION>=QT_VERSION_CHECK(5,15,0))
ParseParams splits = line.splitRef(separator, Qt::SkipEmptyParts);
#else
ParseParams splits = line.splitRef(separator, QString::SkipEmptyParts);
#endif
if(!splits.isEmpty())
const QByteArray line = device.readLine().trimmed();
splitBySpacesWithoutEmptyParts(line, splits);

if(!splits.empty())
{
const ParseParam& cmd = splits.at(0);
const ParseParam& cmd = splits[0];

bool ok = true;

Expand Down Expand Up @@ -1022,7 +972,7 @@ bool StelOBJ::load(QIODevice& device, const QString &basePath, const VertexOrder
smoothGroupWarned = true;
}
}
else if(!cmd.startsWith('#'))
else if(!cmd.empty() && cmd[0] !='#')
{
//unknown command, warn
qCWarning(stelOBJ)<<"Unknown OBJ statement:"<<line;
Expand Down
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