Aegisub/aegisub/text_file_reader.cpp

342 lines
8.5 KiB
C++

// Copyright (c) 2005, Rodrigo Braz Monteiro
// All rights reserved.
//
// Redistribution and use in source and binary forms, with or without
// modification, are permitted provided that the following conditions are met:
//
// * Redistributions of source code must retain the above copyright notice,
// this list of conditions and the following disclaimer.
// * Redistributions in binary form must reproduce the above copyright notice,
// this list of conditions and the following disclaimer in the documentation
// and/or other materials provided with the distribution.
// * Neither the name of the Aegisub Group nor the names of its contributors
// may be used to endorse or promote products derived from this software
// without specific prior written permission.
//
// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
// AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
// IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
// ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE
// LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
// CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
// SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
// INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
// CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
// ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
// POSSIBILITY OF SUCH DAMAGE.
//
// -----------------------------------------------------------------------------
//
// AEGISUB
//
// Website: http://aegisub.cellosoft.com
// Contact: mailto:zeratul@cellosoft.com
//
///////////
// Headers
#include <fstream>
#include <algorithm>
#include <string>
#include "text_file_reader.h"
#ifdef __WINDOWS__
#define AUTODETECT_CHARSET
#include "charset_detect.h"
#endif
///////////////
// Constructor
TextFileReader::TextFileReader(wxString _filename,wxString enc,bool _trim) {
// Setup
open = false;
customConv = false;
trim = _trim;
filename = _filename;
// Open file
Open();
// Set encoding
encoding = enc;
if (encoding.IsEmpty()) encoding = GetEncoding(filename);
SetEncodingConfiguration();
}
//////////////
// Destructor
TextFileReader::~TextFileReader() {
Close();
// Clean up conversion
if (customConv) delete conv;
}
///////////////////////////
// Determine file encoding
wxString TextFileReader::GetEncoding(const wxString _filename) {
// Prepare
using namespace std;
unsigned char b[4];
for (int i=0;i<4;i++) b[i] = 0;
// Read four bytes from file
#ifdef TEXT_READER_USE_STDIO
// TODO: maybe make this use posix-style fopen() api's instead as well?
HANDLE ifile = CreateFile(
_filename.c_str(), // filename
FILE_READ_DATA, // access mode
FILE_SHARE_READ, // share mode
0, // security descriptor
OPEN_EXISTING, // creation disposition
FILE_FLAG_SEQUENTIAL_SCAN, // flags
0); // template file
if (ifile == INVALID_HANDLE_VALUE) {
return _T("unknown");
}
DWORD numread;
if (!ReadFile(ifile, (char*)b, 4, &numread, 0)) {
// Unable to open
return _T("unknown");
}
if (numread < 4) {
// File too short to decide, assume local
return _T("Local");
}
CloseHandle(ifile);
#else
ifstream ifile;
ifile.open(wxFNCONV(_filename));
if (!ifile.is_open()) {
return _T("unknown");
}
ifile.read((char*)b,4);
ifile.close();
#endif
// Try to get the byte order mark from them
if (b[0] == 0xEF && b[1] == 0xBB && b[2] == 0xBF) return _T("UTF-8");
else if (b[0] == 0xFF && b[1] == 0xFE && b[2] == 0x00 && b[3] == 0x00) return _T("UTF-32LE");
else if (b[0] == 0x00 && b[1] == 0x00 && b[2] == 0xFE && b[3] == 0xFF) return _T("UTF-32BE");
else if (b[0] == 0xFF && b[1] == 0xFE) return _T("UTF-16LE");
else if (b[0] == 0xFE && b[1] == 0xFF) return _T("UTF-16BE");
else if (b[0] == 0x2B && b[1] == 0x2F && b[2] == 0x76) return _T("UTF-7");
// Try to guess UTF-16
else if (b[0] == 0x00 && b[2] == 0x00) return _T("UTF-16BE");
else if (b[1] == 0x00 && b[3] == 0x00) return _T("UTF-16LE");
// If any of the first four bytes are under 0x20 (the first printable character),
// except for 9-13 range, assume binary
for (int i=0;i<4;i++) {
if (b[i] < 9 || (b[i] > 13 && b[i] < 32)) return _T("binary");
}
#ifdef AUTODETECT_CHARSET
// Use universalchardet library to detect charset
CharSetDetect det;
return det.GetEncoding(_filename);
#else
// Fall back to local
return _T("Local");
#endif
}
//////////////////////////////
// Set encoding configuration
void TextFileReader::SetEncodingConfiguration() {
// Set encoding configuration
swap = false;
Is16 = false;
customConv = false;
conv = NULL;
if (encoding == _T("UTF-8")) {
conv = new wxMBConvUTF8;
customConv = true;
}
else if (encoding == _T("UTF-16LE")) {
Is16 = true;
}
else if (encoding == _T("UTF-16BE")) {
Is16 = true;
swap = true;
}
else if (encoding == _T("UTF-7")) {
conv = new wxCSConv(encoding);
customConv = true;
}
else if (encoding == _T("Local")) {
conv = wxConvCurrent;
}
else {
conv = new wxCSConv(encoding);
customConv = true;
}
}
//////////////////////////
// Reads a line from file
wxString TextFileReader::ReadLineFromFile() {
Open();
wxString wxbuffer;
size_t bufAlloc = 1024;
wxbuffer.Alloc(bufAlloc);
#ifdef TEXT_READER_USE_STDIO
char buffer[512];
buffer[0] = 0;
#else
std::string buffer = "";
#endif
// Read UTF-16 line from file
if (Is16) {
char charbuffer[3];
charbuffer[2] = 0;
wchar_t ch = 0;
size_t len = 0;
#ifdef TEXT_READER_USE_STDIO
while (ch != L'\n' && !feof(file)) {
// Read two chars from file
fread(charbuffer, 2, 1, file);
#else
while (ch != L'\n' && !file.eof()) {
// Read two chars from file
file.read(charbuffer,2);
#endif
// Swap bytes for big endian
if (swap) {
register char aux = charbuffer[0];
charbuffer[0] = charbuffer[1];
charbuffer[1] = aux;
}
// Convert two chars into a widechar and append to string
ch = *((wchar_t*)charbuffer);
if (len >= bufAlloc - 1) {
bufAlloc *= 2;
wxbuffer.Alloc(bufAlloc);
}
wxbuffer += ch;
len++;
}
}
// Read ASCII/UTF-8 line from file
else {
#ifdef TEXT_READER_USE_STDIO
while (1) {
buffer[511] = '\1';
if (fgets(buffer, 512, file)) {
// read succeeded
// FIXME, this might break on incomplete multibyte characters
wxString linepart(buffer, *conv);
wxbuffer += linepart;
if (buffer[511] == '\1' || buffer[510] == '\n') {
// our sentinel \1 wasn't overwritten, meaning an EOL was found
break;
}
// otherwise the sentinel \1 was overwritten (presumably with \0), so just loop on
}
else {
// hit EOF
break;
}
}
#else
getline(file,buffer);
wxbuffer = wxString(buffer.c_str(),*conv);
#endif
}
// Remove line breaks
//wxbuffer.Replace(_T("\r"),_T("\0"));
//wxbuffer.Replace(_T("\n"),_T("\0"));
size_t len=wxbuffer.Length();
for (size_t i=0;i<len;i++) {
if (wxbuffer[i] == _T('\r') || wxbuffer[i] == _T('\n')) wxbuffer[i] = _T(' ');
}
// Remove BOM
if (wxbuffer.Length() > 0 && wxbuffer[0] == 0xFEFF) {
wxbuffer = wxbuffer.Mid(1);
}
// Trim
if (trim) {
wxbuffer.Trim(true);
wxbuffer.Trim(false);
}
return wxbuffer;
}
/////////////
// Open file
void TextFileReader::Open() {
if (open) return;
#ifdef TEXT_READER_USE_STDIO
// binary mode, because ascii mode is never to be trusted
file = _tfopen(filename.c_str(), _T("rb"));
if (file == 0) {
throw _T("Failed opening file for reading.");
}
#else
file.open(wxFNCONV(filename),std::ios::in | std::ios::binary);
if (!file.is_open()) {
throw _T("Failed opening file for reading.");
}
#endif
open = true;
}
//////////////
// Close file
void TextFileReader::Close() {
if (!open) return;
#ifdef TEXT_READER_USE_STDIO
fclose(file);
#else
file.close();
#endif
open = false;
}
//////////////////////////////////
// Checks if there's more to read
bool TextFileReader::HasMoreLines() {
#ifdef TEXT_READER_USE_STDIO
if (encoding == _T("binary")) return false;
return !feof(file);
#else
return (!file.eof());
#endif
}
////////////////////////////////
// Ensure that charset is valid
void TextFileReader::EnsureValid(wxString enc) {
if (enc == _T("unknown") || enc == _T("UTF-32BE") || enc == _T("UTF-32LE")) {
wxString error = _T("Character set ");
error += enc;
error += _T(" is not supported.");
throw error;
}
}
///////////////////////////
// Get encoding being used
wxString TextFileReader::GetCurrentEncoding() {
return encoding;
}