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Another refactoring - added sequence_length inline function

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git-svn-id: http://svn.code.sf.net/p/utfcpp/code@53 a809a056-fc17-0410-9590-b4f493f8b08e
This commit is contained in:
ntrifunovic 2006-09-03 17:32:47 +00:00
parent 94c65497d9
commit dc0adbba22
1 changed files with 54 additions and 40 deletions
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68
source/utf8.h
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@ -116,6 +116,20 @@ namespace internal
return (cp <= CODE_POINT_MAX && !is_surrogate(cp) && cp != 0xfffe && cp != 0xffff);
}
inline size_t sequence_length(uint8_t lead)
{
if (lead < 0x80)
return 1;
else if ((lead >> 5) == 0x6)
return 2;
else if ((lead >> 4) == 0xe)
return 3;
else if ((lead >> 3) == 0x1e)
return 4;
else
return 0;
}
enum utf_error {OK, NOT_ENOUGH_ROOM, INVALID_LEAD, INCOMPLETE_SEQUENCE, OVERLONG_SEQUENCE, INVALID_CODE_POINT};
template <typename octet_iterator>
@ -123,9 +137,10 @@ namespace internal
{
uint32_t cp = mask8(*it);
// Check the lead octet
typedef typename std::iterator_traits<octet_iterator>::difference_type octet_difference_type;
octet_difference_type sequence_length;
if (cp < 0x80) {
size_t length = sequence_length(mask8(*it));
// "Shortcut" for ASCII characters
if (length == 1) {
if (end - it > 0) {
if (code_point)
*code_point = cp;
@ -135,20 +150,16 @@ namespace internal
else
return NOT_ENOUGH_ROOM;
}
else if ((cp >> 5) == 0x6)
sequence_length = 2;
else if ((cp >> 4) == 0xe)
sequence_length = 3;
else if ((cp >> 3) == 0x1e)
sequence_length = 4;
else
return INVALID_LEAD;
// Do we have enough memory?
if (end - it < sequence_length)
if (end - it < length)
return NOT_ENOUGH_ROOM;
// Check trail octets and calculate the code point
switch (sequence_length) {
switch (length) {
case 0:
return INVALID_LEAD;
break;
case 2:
if (is_trail(*(++it))) {
cp = ((cp << 6) & 0x7ff) + ((*it) & 0x3f);
@ -200,7 +211,7 @@ namespace internal
}
// Is the code point valid?
if (!is_code_point_valid(cp)) {
for (octet_difference_type i = 0; i < sequence_length - 1; ++i)
for (size_t i = 0; i < length - 1; ++i)
--it;
return INVALID_CODE_POINT;
}
@ -209,22 +220,22 @@ namespace internal
*code_point = cp;
if (cp < 0x80) {
if (sequence_length != 1) {
for (octet_difference_type i = 0; i < sequence_length - 1; ++i)
if (length != 1) {
for (size_t i = 0; i < length - 1; ++i)
--it;
return OVERLONG_SEQUENCE;
}
}
else if (cp < 0x800) {
if (sequence_length != 2) {
for (octet_difference_type i = 0; i < sequence_length - 1; ++i)
if (length != 2) {
for (size_t i = 0; i < length - 1; ++i)
--it;
return OVERLONG_SEQUENCE;
}
}
else if (cp < 0x10000) {
if (sequence_length != 3) {
for (octet_difference_type i = 0; i < sequence_length - 1; ++i)
if (length != 3) {
for (size_t i = 0; i < length - 1; ++i)
--it;
return OVERLONG_SEQUENCE;
}
@ -430,25 +441,28 @@ namespace internal
uint32_t next(octet_iterator& it)
{
uint32_t cp = internal::mask8(*it);
if (cp < 0x80)
;
else if ((internal::mask8(*it) >> 5) == 0x6) {
size_t length = utf8::internal::sequence_length(*it);
switch (length) {
case 1:
break;
case 2:
it++;
cp = ((cp << 6) & 0x7ff) + ((*it) & 0x3f);
}
else if ((internal::mask8(*it) >> 4) == 0xe) {
break;
case 3:
++it;
cp = ((cp << 12) & 0xffff) + ((internal::mask8(*it) << 6) & 0xfff);
++it;
cp += (*it) & 0x3f;
}
else if ((internal::mask8(*it) >> 3) == 0x1e) {
break;
case 4:
++it;
cp = ((cp << 18) & 0x1fffff) + ((internal::mask8(*it) << 12) & 0x3ffff);
++it;
cp += (internal::mask8(*it) << 6) & 0xfff;
++it;
cp += (*it) & 0x3f;
break;
}
++it;
return cp;