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/**
* @file unicode.cpp
* Detects, read and writes characters in the proper format.
*
* @author Ben Gardner
* @license GPL v2+
*/
#include "unicode.h"
using namespace std;
//! See if all characters are ASCII (0-127)
static bool is_ascii(const vector<UINT8> &data, size_t &non_ascii_cnt, size_t &zero_cnt);
//! Convert the array of bytes into an array of ints
static bool decode_bytes(const vector<UINT8> &in_data, deque<int> &out_data);
/**
* Decode UTF-8 sequences from in_data and put the chars in out_data.
* If there are any decoding errors, then return false.
*/
static bool decode_utf8(const vector<UINT8> &in_data, deque<int> &out_data);
/**
* Extract 2 bytes from the stream and increment idx by 2
*
* @param in byte vector with input data
* @param idx index points to working position in vector
*/
static int get_word(const vector<UINT8> &in_data, size_t &idx, bool be);
/**
* Decode a UTF-16 sequence.
* Sets enc based on the BOM.
* Must have the BOM as the first two bytes.
*/
static bool decode_utf16(const vector<UINT8> &in_data, deque<int> &out_data, char_encoding_e &enc);
/**
* Looks for the BOM of UTF-16 BE/LE and UTF-8.
* If found, set enc and return true.
* Sets enc to char_encoding_e::e_ASCII and returns false if not found.
*/
static bool decode_bom(const vector<UINT8> &in_data, char_encoding_e &enc);
//! Write for ASCII and BYTE encoding
static void write_byte(int ch);
//! Writes a single character to a file using UTF-8 encoding
static void write_utf8(int ch);
static void write_utf16(int ch, bool be);
static bool is_ascii(const vector<UINT8> &data, size_t &non_ascii_cnt, size_t &zero_cnt)
{
non_ascii_cnt = 0;
zero_cnt = 0;
for (unsigned char value : data)
{
if (value & 0x80)
{
non_ascii_cnt++;
}
if (!value)
{
zero_cnt++;
}
}
return((non_ascii_cnt + zero_cnt) == 0);
}
static bool decode_bytes(const vector<UINT8> &in_data, deque<int> &out_data)
{
out_data.resize(in_data.size());
for (size_t idx = 0; idx < in_data.size(); idx++)
{
out_data[idx] = in_data[idx];
}
return(true);
}
void encode_utf8(int ch, vector<UINT8> &res)
{
if (ch < 0)
{
// illegal code - do not store
}
else if (ch < 0x80)
{
// 0xxxxxxx
res.push_back(ch);
}
else if (ch < 0x0800)
{
// 110xxxxx 10xxxxxx
res.push_back(0xC0 | (ch >> 6));
res.push_back(0x80 | (ch & 0x3f));
}
else if (ch < 0x10000)
{
// 1110xxxx 10xxxxxx 10xxxxxx
res.push_back(0xE0 | (ch >> 12));
res.push_back(0x80 | ((ch >> 6) & 0x3f));
res.push_back(0x80 | (ch & 0x3f));
}
else if (ch < 0x200000)
{
// 11110xxx 10xxxxxx 10xxxxxx 10xxxxxx
res.push_back(0xF0 | (ch >> 18));
res.push_back(0x80 | ((ch >> 12) & 0x3f));
res.push_back(0x80 | ((ch >> 6) & 0x3f));
res.push_back(0x80 | (ch & 0x3f));
}
else if (ch < 0x4000000)
{
// 111110xx 10xxxxxx 10xxxxxx 10xxxxxx 10xxxxxx
res.push_back(0xF8 | (ch >> 24));
res.push_back(0x80 | ((ch >> 18) & 0x3f));
res.push_back(0x80 | ((ch >> 12) & 0x3f));
res.push_back(0x80 | ((ch >> 6) & 0x3f));
res.push_back(0x80 | (ch & 0x3f));
}
else // (ch <= 0x7fffffff)
{
// 1111110x 10xxxxxx 10xxxxxx 10xxxxxx 10xxxxxx 10xxxxxx
res.push_back(0xFC | (ch >> 30));
res.push_back(0x80 | ((ch >> 24) & 0x3f));
res.push_back(0x80 | ((ch >> 18) & 0x3f));
res.push_back(0x80 | ((ch >> 12) & 0x3f));
res.push_back(0x80 | ((ch >> 6) & 0x3f));
res.push_back(0x80 | (ch & 0x3f));
}
} // encode_utf8
static bool decode_utf8(const vector<UINT8> &in_data, deque<int> &out_data)
{
size_t idx = 0;
int cnt;
out_data.clear();
// check for UTF-8 BOM silliness and skip
if (in_data.size() >= 3)
{
if ( (in_data[0] == 0xef)
&& (in_data[1] == 0xbb)
&& (in_data[2] == 0xbf))
{
idx = 3; // skip it
}
}
while (idx < in_data.size())
{
int ch = in_data[idx++];
if (ch < 0x80) // 1-byte sequence
{
out_data.push_back(ch);
continue;
}
else if ((ch & 0xE0) == 0xC0) // 2-byte sequence
{
ch &= 0x1F;
cnt = 1;
}
else if ((ch & 0xF0) == 0xE0) // 3-byte sequence
{
ch &= 0x0F;
cnt = 2;
}
else if ((ch & 0xF8) == 0xF0) // 4-byte sequence
{
ch &= 0x07;
cnt = 3;
}
else if ((ch & 0xFC) == 0xF8) // 5-byte sequence
{
ch &= 0x03;
cnt = 4;
}
else if ((ch & 0xFE) == 0xFC) // 6-byte sequence
{
ch &= 0x01;
cnt = 5;
}
else
{
// invalid UTF-8 sequence
return(false);
}
while ( cnt-- > 0
&& idx < in_data.size())
{
int tmp = in_data[idx++];
if ((tmp & 0xC0) != 0x80)
{
// invalid UTF-8 sequence
return(false);
}
ch = (ch << 6) | (tmp & 0x3f);
}
if (cnt >= 0)
{
// short UTF-8 sequence
return(false);
}
out_data.push_back(ch);
}
return(true);
} // decode_utf8
static int get_word(const vector<UINT8> &in_data, size_t &idx, bool be)
{
int ch;
if ((idx + 2) > in_data.size())
{
ch = -1;
}
else if (be)
{
ch = (in_data[idx] << 8) | in_data[idx + 1];
}
else
{
ch = in_data[idx] | (in_data[idx + 1] << 8);
}
idx += 2;
return(ch);
}
static bool decode_utf16(const vector<UINT8> &in_data, deque<int> &out_data, char_encoding_e &enc)
{
out_data.clear();
if (in_data.size() & 1)
{
// can't have and odd length
return(false);
}
if (in_data.size() < 2)
{
// we require the BOM or at least 1 char
return(false);
}
size_t idx = 2;
if ( (in_data[0] == 0xfe)
&& (in_data[1] == 0xff))
{
enc = char_encoding_e::e_UTF16_BE;
}
else if ( (in_data[0] == 0xff)
&& (in_data[1] == 0xfe))
{
enc = char_encoding_e::e_UTF16_LE;
}
else
{
/*
* If we have a few words, we can take a guess, assuming the first few
* chars are ASCII
*/
enc = char_encoding_e::e_ASCII;
idx = 0;
if (in_data.size() >= 6)
{
if ( (in_data[0] == 0)
&& (in_data[2] == 0)
&& (in_data[4] == 0))
{
enc = char_encoding_e::e_UTF16_BE;
}
else if ( (in_data[1] == 0)
&& (in_data[3] == 0)
&& (in_data[5] == 0))
{
enc = char_encoding_e::e_UTF16_LE;
}
}
if (enc == char_encoding_e::e_ASCII)
{
return(false);
}
}
bool be = (enc == char_encoding_e::e_UTF16_BE);
while (idx < in_data.size())
{
int ch = get_word(in_data, idx, be);
if ((ch & 0xfc00) == 0xd800)
{
ch &= 0x3ff;
ch <<= 10;
int tmp = get_word(in_data, idx, be);
if ((tmp & 0xfc00) != 0xdc00)
{
return(false);
}
ch |= (tmp & 0x3ff);
ch += 0x10000;
out_data.push_back(ch);
}
else if ( ( ch >= 0
&& ch < 0xD800)
|| ch >= 0xE000)
{
out_data.push_back(ch);
}
else
{
// invalid character
return(false);
}
}
return(true);
} // decode_utf16
static bool decode_bom(const vector<UINT8> &in_data, char_encoding_e &enc)
{
enc = char_encoding_e::e_ASCII;
if (in_data.size() >= 2)
{
if ( (in_data[0] == 0xfe)
&& (in_data[1] == 0xff))
{
enc = char_encoding_e::e_UTF16_BE;
return(true);
}
if ( (in_data[0] == 0xff)
&& (in_data[1] == 0xfe))
{
enc = char_encoding_e::e_UTF16_LE;
return(true);
}
if ( (in_data.size() >= 3)
&& (in_data[0] == 0xef)
&& (in_data[1] == 0xbb)
&& (in_data[2] == 0xbf))
{
enc = char_encoding_e::e_UTF8;
return(true);
}
}
return(false);
}
bool decode_unicode(const vector<UINT8> &in_data, deque<int> &out_data, char_encoding_e &enc, bool &has_bom)
{
// check for a BOM
if (decode_bom(in_data, enc))
{
has_bom = true;
if (enc == char_encoding_e::e_UTF8)
{
return(decode_utf8(in_data, out_data));
}
return(decode_utf16(in_data, out_data, enc));
}
has_bom = false;
// Check for simple ASCII
size_t non_ascii_cnt;
size_t zero_cnt;
if (is_ascii(in_data, non_ascii_cnt, zero_cnt))
{
enc = char_encoding_e::e_ASCII;
return(decode_bytes(in_data, out_data));
}
// There are a lot of 0's in UTF-16 (~50%)
if ( (zero_cnt > (in_data.size() / 4))
&& (zero_cnt <= (in_data.size() / 2)))
{
// likely is UTF-16
if (decode_utf16(in_data, out_data, enc))
{
return(true);
}
}
if (decode_utf8(in_data, out_data))
{
enc = char_encoding_e::e_UTF8;
return(true);
}
// it is an unrecognized byte sequence
enc = char_encoding_e::e_BYTE;
return(decode_bytes(in_data, out_data));
} // decode_unicode
static void write_byte(int ch)
{
if ((ch & 0xff) == ch)
{
if (cpd.fout)
{
fputc(ch, cpd.fout);
}
if (cpd.bout)
{
cpd.bout->push_back(static_cast<UINT8>(ch));
}
}
else
{
// illegal code - do not store
}
}
static void write_utf8(int ch)
{
vector<UINT8> vv;
vv.reserve(6);
encode_utf8(ch, vv);
for (unsigned char char_val : vv)
{
write_byte(char_val);
}
}
static void write_utf16(int ch, bool be)
{
// U+0000 to U+D7FF and U+E000 to U+FFFF
if ( ( ch >= 0
&& ch < 0xD800)
|| ( ch >= 0xE000
&& ch < 0x10000))
{
if (be)
{
write_byte(ch >> 8);
write_byte(ch & 0xff);
}
else
{
write_byte(ch & 0xff);
write_byte(ch >> 8);
}
}
else if ( ch >= 0x10000
&& ch < 0x110000)
{
int v1 = ch - 0x10000;
int w1 = 0xD800 + (v1 >> 10);
int w2 = 0xDC00 + (v1 & 0x3ff);
if (be)
{
write_byte(w1 >> 8);
write_byte(w1 & 0xff);
write_byte(w2 >> 8);
write_byte(w2 & 0xff);
}
else
{
write_byte(w1 & 0xff);
write_byte(w1 >> 8);
write_byte(w2 & 0xff);
write_byte(w2 >> 8);
}
}
else
{
// illegal code - do not store
}
} // write_utf16
void write_bom()
{
switch (cpd.enc)
{
case char_encoding_e::e_UTF8:
write_byte(0xef);
write_byte(0xbb);
write_byte(0xbf);
break;
case char_encoding_e::e_UTF16_LE:
write_utf16(0xfeff, false);
break;
case char_encoding_e::e_UTF16_BE:
write_utf16(0xfeff, true);
break;
default:
// char_encoding_e::e_ASCII
// char_encoding_e::e_BYTE
// do nothing
// Coveralls will complain
break;
}
}
void write_char(int ch)
{
if (ch >= 0)
{
switch (cpd.enc)
{
case char_encoding_e::e_BYTE:
write_byte(ch & 0xff);
break;
case char_encoding_e::e_ASCII:
default:
write_byte(ch);
break;
case char_encoding_e::e_UTF8:
write_utf8(ch);
break;
case char_encoding_e::e_UTF16_LE:
write_utf16(ch, false);
break;
case char_encoding_e::e_UTF16_BE:
write_utf16(ch, true);
break;
}
}
}
void write_string(const UncText &text)
{
for (size_t idx = 0; idx < text.size(); idx++)
{
write_char(text[idx]);
}
}