Aegisub/aegisub/libaegisub/common/charset_ucd.cpp

108 lines
2.9 KiB
C++

// Copyright (c) 2010, Amar Takhar <verm@aegisub.org>
//
// Permission to use, copy, modify, and distribute this software for any
// purpose with or without fee is hereby granted, provided that the above
// copyright notice and this permission notice appear in all copies.
//
// THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
// WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
// MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
// ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
// WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
// ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
// OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
/// @file charset_ucd.cpp
/// @brief Character set detection using Universalchardet
/// @ingroup libaegisub
#include "charset_ucd.h"
#include "libaegisub/io.h"
#include "libaegisub/scoped_ptr.h"
#include "../../universalchardet/nsCharSetProber.h"
namespace agi {
namespace charset {
UCDetect::UCDetect(const std::string &file)
: nsUniversalDetector(NS_FILTER_ALL)
{
{
agi::scoped_ptr<std::ifstream> fp(io::Open(file, true));
// If it's over 100 MB it's either binary or big enough that we won't
// be able to do anything useful with it anyway
fp->seekg(0, std::ios::end);
if (fp->tellg() > 100 * 1024 * 1024) {
list.emplace_back(1.f, "binary");
return;
}
fp->seekg(0, std::ios::beg);
std::streamsize binaryish = 0;
std::streamsize bytes = 0;
while (!mDone && *fp) {
char buf[4096];
fp->read(buf, sizeof(buf));
std::streamsize read = fp->gcount();
HandleData(buf, (PRUint32)read);
// A dumb heuristic to detect binary files
if (!mDone) {
bytes += read;
for (std::streamsize i = 0; i < read; ++i) {
if ((unsigned char)buf[i] < 32 && (buf[i] != '\r' && buf[i] != '\n' && buf[i] != '\t'))
++binaryish;
}
if (binaryish > bytes / 8) {
list.emplace_back(1.f, "binary");
return;
}
}
}
}
DataEnd();
if (mDetectedCharset)
list.emplace_back(1.f, mDetectedCharset);
else {
switch (mInputState) {
case eHighbyte: {
for (PRInt32 i=0; i<NUM_OF_CHARSET_PROBERS; i++) {
if (!mCharSetProbers[i]) continue;
float conf = mCharSetProbers[i]->GetConfidence();
if (conf > 0.01f)
list.emplace_back(conf, mCharSetProbers[i]->GetCharSetName());
}
break;
}
case ePureAscii:
list.emplace_back(1.f, "US-ASCII");
break;
default:
throw UnknownCharset("Unknown character set.");
}
if (list.empty() && (mInputState == eHighbyte))
throw UnknownCharset("Unknown character set.");
typedef std::pair<float, std::string> const& result;
sort(begin(list), end(list), [](result lft, result rgt) { return lft.first > rgt.first; });
}
}
std::string UCDetect::Single() const {
return list.front().second;
}
} // namespace util
} // namespace agi