diff options
| -rw-r--r-- | Objects/unicodeobject.c | 85 |
1 files changed, 46 insertions, 39 deletions
diff --git a/Objects/unicodeobject.c b/Objects/unicodeobject.c index 57c031f..52eb61d 100644 --- a/Objects/unicodeobject.c +++ b/Objects/unicodeobject.c @@ -1172,85 +1172,92 @@ int utf8_encoding_error(const Py_UNICODE **source, } #endif +/* Allocation strategy: we default to Latin-1, then do one resize + whenever we hit an order boundary. The assumption is that + characters from higher orders usually occur often enough to warrant + this. +*/ + PyObject *PyUnicode_EncodeUTF8(const Py_UNICODE *s, int size, const char *errors) { PyObject *v; char *p; - unsigned int cbAllocated = 2 * size; - unsigned int cbWritten = 0; int i = 0; - + int overalloc = 2; + int len; + /* Short-cut for emtpy strings */ if (size == 0) return PyString_FromStringAndSize(NULL, 0); - /* We allocate 4 more bytes to have room for at least one full - UTF-8 sequence; saves a few cycles in the loop below */ - v = PyString_FromStringAndSize(NULL, cbAllocated + 4); + v = PyString_FromStringAndSize(NULL, overalloc * size); if (v == NULL) return NULL; p = PyString_AS_STRING(v); + while (i < size) { Py_UCS4 ch = s[i++]; - if (ch < 0x80) { + if (ch < 0x80) + /* Encode ASCII */ *p++ = (char) ch; - cbWritten++; - } else if (ch < 0x0800) { + /* Encode Latin-1 */ *p++ = (char)(0xc0 | (ch >> 6)); *p++ = (char)(0x80 | (ch & 0x3f)); - cbWritten += 2; } else { - - /* Assure that we have enough room for high order Unicode - ordinals */ - if (cbWritten >= cbAllocated) { - cbAllocated += 4 * 10; - if (_PyString_Resize(&v, cbAllocated + 4)) - goto onError; - p = PyString_AS_STRING(v) + cbWritten; - } - + /* Encode UCS2 Unicode ordinals */ if (ch < 0x10000) { - /* Check for high surrogate */ + + /* Special case: check for high surrogate */ if (0xD800 <= ch && ch <= 0xDBFF && i != size) { Py_UCS4 ch2 = s[i]; - /* Check for low surrogate */ + /* Check for low surrogate and combine the two to + form a UCS4 value */ if (0xDC00 <= ch2 && ch2 <= 0xDFFF) { - ch = ((ch - 0xD800) << 10 | (ch2 - 0xDC00)) + 0x00010000; - *p++ = (char)(0xf0 | (ch >> 18)); - *p++ = (char)(0x80 | ((ch >> 12) & 0x3f)); - *p++ = (char)(0x80 | ((ch >> 6) & 0x3f)); - *p++ = (char)(0x80 | (ch & 0x3f)); - i++; - cbWritten += 4; - continue; + ch = ((ch - 0xD800) << 10 | (ch2 - 0xDC00)) + 0x10000; + i++; + goto encodeUCS4; } /* Fall through: handles isolated high surrogates */ } + + if (overalloc < 3) { + len = (int)(p - PyString_AS_STRING(v)); + overalloc = 3; + if (_PyString_Resize(&v, overalloc * size)) + goto onError; + p = PyString_AS_STRING(v) + len; + } *p++ = (char)(0xe0 | (ch >> 12)); *p++ = (char)(0x80 | ((ch >> 6) & 0x3f)); *p++ = (char)(0x80 | (ch & 0x3f)); - cbWritten += 3; - - } else { - *p++ = (char)(0xf0 | (ch>>18)); - *p++ = (char)(0x80 | ((ch>>12) & 0x3f)); - *p++ = (char)(0x80 | ((ch>>6) & 0x3f)); - *p++ = (char)(0x80 | (ch & 0x3f)); - cbWritten += 4; + continue; + } + + /* Encode UCS4 Unicode ordinals */ + encodeUCS4: + if (overalloc < 4) { + len = (int)(p - PyString_AS_STRING(v)); + overalloc = 4; + if (_PyString_Resize(&v, overalloc * size)) + goto onError; + p = PyString_AS_STRING(v) + len; } + *p++ = (char)(0xf0 | (ch >> 18)); + *p++ = (char)(0x80 | ((ch >> 12) & 0x3f)); + *p++ = (char)(0x80 | ((ch >> 6) & 0x3f)); + *p++ = (char)(0x80 | (ch & 0x3f)); } } *p = '\0'; - if (_PyString_Resize(&v, cbWritten)) + if (_PyString_Resize(&v, (int)(p - PyString_AS_STRING(v)))) goto onError; return v; |