reactos/dll/win32/jscript/jsstr.c

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/*
* Copyright 2012 Jacek Caban for CodeWeavers
*
* This library is free software; you can redistribute it and/or
* modify it under the terms of the GNU Lesser General Public
* License as published by the Free Software Foundation; either
* version 2.1 of the License, or (at your option) any later version.
*
* This library is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
* Lesser General Public License for more details.
*
* You should have received a copy of the GNU Lesser General Public
* License along with this library; if not, write to the Free Software
* Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301, USA
*/
#include <assert.h>
#include "jscript.h"
#include "wine/debug.h"
/*
* This is the length of a string that is considered to be long enough to be
* worth the rope to avoid copy.
* This probably could be tuned, but keep it low for a while to better test rope's code.
*/
#define JSSTR_SHORT_STRING_LENGTH 8
/*
* This is the max rope depth. While faster to allocate, ropes may become slow at access.
*/
#define JSSTR_MAX_ROPE_DEPTH 100
const char *debugstr_jsstr(jsstr_t *str)
{
return jsstr_is_inline(str) ? debugstr_wn(jsstr_as_inline(str)->buf, jsstr_length(str))
: jsstr_is_heap(str) ? debugstr_wn(jsstr_as_heap(str)->buf, jsstr_length(str))
: wine_dbg_sprintf("%s...", debugstr_jsstr(jsstr_as_rope(str)->left));
}
void jsstr_free(jsstr_t *str)
{
switch(jsstr_tag(str)) {
case JSSTR_HEAP:
heap_free(jsstr_as_heap(str)->buf);
break;
case JSSTR_ROPE: {
jsstr_rope_t *rope = jsstr_as_rope(str);
jsstr_release(rope->left);
jsstr_release(rope->right);
break;
}
case JSSTR_INLINE:
break;
}
heap_free(str);
}
static inline void jsstr_init(jsstr_t *str, unsigned len, jsstr_tag_t tag)
{
str->length_flags = len << JSSTR_LENGTH_SHIFT | tag;
str->ref = 1;
}
jsstr_t *jsstr_alloc_buf(unsigned len, WCHAR **buf)
{
jsstr_inline_t *ret;
if(len > JSSTR_MAX_LENGTH)
return NULL;
ret = heap_alloc(FIELD_OFFSET(jsstr_inline_t, buf[len+1]));
if(!ret)
return NULL;
jsstr_init(&ret->str, len, JSSTR_INLINE);
ret->buf[len] = 0;
*buf = ret->buf;
return &ret->str;
}
jsstr_t *jsstr_alloc_len(const WCHAR *buf, unsigned len)
{
jsstr_t *ret;
WCHAR *ptr;
ret = jsstr_alloc_buf(len, &ptr);
if(ret)
memcpy(ptr, buf, len*sizeof(WCHAR));
return ret;
}
static void jsstr_rope_extract(jsstr_rope_t *str, unsigned off, unsigned len, WCHAR *buf)
{
unsigned left_len = jsstr_length(str->left);
if(left_len <= off) {
jsstr_extract(str->right, off-left_len, len, buf);
}else if(left_len >= len+off) {
jsstr_extract(str->left, off, len, buf);
}else {
left_len -= off;
jsstr_extract(str->left, off, left_len, buf);
jsstr_extract(str->right, 0, len-left_len, buf+left_len);
}
}
void jsstr_extract(jsstr_t *str, unsigned off, unsigned len, WCHAR *buf)
{
switch(jsstr_tag(str)) {
case JSSTR_INLINE:
memcpy(buf, jsstr_as_inline(str)->buf+off, len*sizeof(WCHAR));
return;
case JSSTR_HEAP:
memcpy(buf, jsstr_as_heap(str)->buf+off, len*sizeof(WCHAR));
return;
case JSSTR_ROPE:
jsstr_rope_extract(jsstr_as_rope(str), off, len, buf);
return;
}
}
static int jsstr_cmp_str(jsstr_t *jsstr, const WCHAR *str, unsigned len)
{
int ret;
switch(jsstr_tag(jsstr)) {
case JSSTR_INLINE:
ret = memcmp(jsstr_as_inline(jsstr)->buf, str, len*sizeof(WCHAR));
return ret || jsstr_length(jsstr) == len ? ret : 1;
case JSSTR_HEAP:
ret = memcmp(jsstr_as_heap(jsstr)->buf, str, len*sizeof(WCHAR));
return ret || jsstr_length(jsstr) == len ? ret : 1;
case JSSTR_ROPE: {
jsstr_rope_t *rope = jsstr_as_rope(jsstr);
unsigned left_len = jsstr_length(rope->left);
ret = jsstr_cmp_str(rope->left, str, min(len, left_len));
if(ret || len <= left_len)
return ret;
return jsstr_cmp_str(rope->right, str+left_len, len-left_len);
}
}
assert(0);
return 0;
}
#define TMP_BUF_SIZE 256
static int ropes_cmp(jsstr_rope_t *left, jsstr_rope_t *right)
{
WCHAR left_buf[TMP_BUF_SIZE], right_buf[TMP_BUF_SIZE];
unsigned left_len = jsstr_length(&left->str);
unsigned right_len = jsstr_length(&right->str);
unsigned cmp_off = 0, cmp_size;
int ret;
/* FIXME: We can avoid temporary buffers here. */
while(cmp_off < min(left_len, right_len)) {
cmp_size = min(left_len, right_len) - cmp_off;
if(cmp_size > TMP_BUF_SIZE)
cmp_size = TMP_BUF_SIZE;
jsstr_rope_extract(left, cmp_off, cmp_size, left_buf);
jsstr_rope_extract(right, cmp_off, cmp_size, right_buf);
ret = memcmp(left_buf, right_buf, cmp_size);
if(ret)
return ret;
cmp_off += cmp_size;
}
return left_len - right_len;
}
static inline const WCHAR *jsstr_try_flat(jsstr_t *str)
{
return jsstr_is_inline(str) ? jsstr_as_inline(str)->buf
: jsstr_is_heap(str) ? jsstr_as_heap(str)->buf
: NULL;
}
int jsstr_cmp(jsstr_t *str1, jsstr_t *str2)
{
unsigned len1 = jsstr_length(str1);
unsigned len2 = jsstr_length(str2);
const WCHAR *str;
int ret;
str = jsstr_try_flat(str2);
if(str) {
ret = jsstr_cmp_str(str1, str, min(len1, len2));
return ret || len1 == len2 ? ret : -1;
}
str = jsstr_try_flat(str1);
if(str) {
ret = jsstr_cmp_str(str2, str, min(len1, len2));
return ret || len1 == len2 ? -ret : 1;
}
return ropes_cmp(jsstr_as_rope(str1), jsstr_as_rope(str2));
}
jsstr_t *jsstr_concat(jsstr_t *str1, jsstr_t *str2)
{
unsigned len1, len2;
jsstr_t *ret;
WCHAR *ptr;
len1 = jsstr_length(str1);
if(!len1)
return jsstr_addref(str2);
len2 = jsstr_length(str2);
if(!len2)
return jsstr_addref(str1);
if(len1 + len2 >= JSSTR_SHORT_STRING_LENGTH) {
unsigned depth, depth2;
jsstr_rope_t *rope;
depth = jsstr_is_rope(str1) ? jsstr_as_rope(str1)->depth : 0;
depth2 = jsstr_is_rope(str2) ? jsstr_as_rope(str2)->depth : 0;
if(depth2 > depth)
depth = depth2;
if(depth++ < JSSTR_MAX_ROPE_DEPTH) {
if(len1+len2 > JSSTR_MAX_LENGTH)
return NULL;
rope = heap_alloc(sizeof(*rope));
if(!rope)
return NULL;
jsstr_init(&rope->str, len1+len2, JSSTR_ROPE);
rope->left = jsstr_addref(str1);
rope->right = jsstr_addref(str2);
rope->depth = depth;
return &rope->str;
}
}
ret = jsstr_alloc_buf(len1+len2, &ptr);
if(!ret)
return NULL;
jsstr_flush(str1, ptr);
jsstr_flush(str2, ptr+len1);
return ret;
}
C_ASSERT(sizeof(jsstr_heap_t) <= sizeof(jsstr_rope_t));
const WCHAR *jsstr_rope_flatten(jsstr_rope_t *str)
{
WCHAR *buf;
buf = heap_alloc((jsstr_length(&str->str)+1) * sizeof(WCHAR));
if(!buf)
return NULL;
jsstr_flush(str->left, buf);
jsstr_flush(str->right, buf+jsstr_length(str->left));
buf[jsstr_length(&str->str)] = 0;
/* Trasform to heap string */
jsstr_release(str->left);
jsstr_release(str->right);
str->str.length_flags |= JSSTR_FLAG_FLAT;
return jsstr_as_heap(&str->str)->buf = buf;
}
static jsstr_t *empty_str, *nan_str, *undefined_str, *null_bstr_str;
jsstr_t *jsstr_nan(void)
{
return jsstr_addref(nan_str);
}
jsstr_t *jsstr_empty(void)
{
return jsstr_addref(empty_str);
}
jsstr_t *jsstr_undefined(void)
{
return jsstr_addref(undefined_str);
}
jsstr_t *jsstr_null_bstr(void)
{
return jsstr_addref(null_bstr_str);
}
BOOL is_null_bstr(jsstr_t *str)
{
return str == null_bstr_str;
}
BOOL init_strings(void)
{
static const WCHAR NaNW[] = { 'N','a','N',0 };
static const WCHAR undefinedW[] = {'u','n','d','e','f','i','n','e','d',0};
WCHAR *ptr;
if(!(empty_str = jsstr_alloc_buf(0, &ptr)))
return FALSE;
if(!(nan_str = jsstr_alloc(NaNW)))
return FALSE;
if(!(undefined_str = jsstr_alloc(undefinedW)))
return FALSE;
if(!(null_bstr_str = jsstr_alloc_buf(0, &ptr)))
return FALSE;
return TRUE;
}
void free_strings(void)
{
if(empty_str)
jsstr_release(empty_str);
if(nan_str)
jsstr_release(nan_str);
if(undefined_str)
jsstr_release(undefined_str);
if(null_bstr_str)
jsstr_release(null_bstr_str);
}