reactos/dll/win32/jscript/jsstr.c

   1 /*
   2  * Copyright 2012 Jacek Caban for CodeWeavers
   3  *
   4  * This library is free software; you can redistribute it and/or
   5  * modify it under the terms of the GNU Lesser General Public
   6  * License as published by the Free Software Foundation; either
   7  * version 2.1 of the License, or (at your option) any later version.
   8  *
   9  * This library is distributed in the hope that it will be useful,
  10  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  11  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  12  * Lesser General Public License for more details.
  13  *
  14  * You should have received a copy of the GNU Lesser General Public
  15  * License along with this library; if not, write to the Free Software
  16  * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301, USA
  17  */
  18
  19 #include <assert.h>
  20
  21 #include "jscript.h"
  22
  23 #include <wine/debug.h>
  24
  25 /*
  26  * This is the length of a string that is considered to be long enough to be
  27  * worth the rope to avoid copy.
  28  * This probably could be tuned, but keep it low for a while to better test rope's code.
  29  */
  30 #define JSSTR_SHORT_STRING_LENGTH 8
  31
  32 /*
  33  * This is the max rope depth. While faster to allocate, ropes may become slow at access.
  34  */
  35 #define JSSTR_MAX_ROPE_DEPTH 100
  36
  37 const char *debugstr_jsstr(jsstr_t *str)
  38 {
  39     return jsstr_is_inline(str) ? debugstr_wn(jsstr_as_inline(str)->buf, jsstr_length(str))
  40         : jsstr_is_heap(str) ? debugstr_wn(jsstr_as_heap(str)->buf, jsstr_length(str))
  41         : wine_dbg_sprintf("%s...", debugstr_jsstr(jsstr_as_rope(str)->left));
  42 }
  43
  44 void jsstr_free(jsstr_t *str)
  45 {
  46     switch(jsstr_tag(str)) {
  47     case JSSTR_HEAP:
  48         heap_free(jsstr_as_heap(str)->buf);
  49         break;
  50     case JSSTR_ROPE: {
  51         jsstr_rope_t *rope = jsstr_as_rope(str);
  52         jsstr_release(rope->left);
  53         jsstr_release(rope->right);
  54         break;
  55     }
  56     case JSSTR_INLINE:
  57         break;
  58     }
  59
  60     heap_free(str);
  61 }
  62
  63 static inline void jsstr_init(jsstr_t *str, unsigned len, jsstr_tag_t tag)
  64 {
  65     str->length_flags = len << JSSTR_LENGTH_SHIFT | tag;
  66     str->ref = 1;
  67 }
  68
  69 WCHAR *jsstr_alloc_buf(unsigned len, jsstr_t **r)
  70 {
  71     jsstr_inline_t *ret;
  72
  73     if(len > JSSTR_MAX_LENGTH)
  74         return NULL;
  75
  76     ret = heap_alloc(FIELD_OFFSET(jsstr_inline_t, buf[len+1]));
  77     if(!ret)
  78         return NULL;
  79
  80     jsstr_init(&ret->str, len, JSSTR_INLINE);
  81     ret->buf[len] = 0;
  82     *r = &ret->str;
  83     return ret->buf;
  84 }
  85
  86 jsstr_t *jsstr_alloc_len(const WCHAR *buf, unsigned len)
  87 {
  88     jsstr_t *ret;
  89     WCHAR *ptr;
  90
  91     ptr = jsstr_alloc_buf(len, &ret);
  92     if(ptr)
  93         memcpy(ptr, buf, len*sizeof(WCHAR));
  94
  95     return ret;
  96 }
  97
  98 static void jsstr_rope_extract(jsstr_rope_t *str, unsigned off, unsigned len, WCHAR *buf)
  99 {
 100     unsigned left_len = jsstr_length(str->left);
 101
 102     if(left_len <= off) {
 103         jsstr_extract(str->right, off-left_len, len, buf);
 104     }else if(left_len >= len+off) {
 105         jsstr_extract(str->left, off, len, buf);
 106     }else {
 107         left_len -= off;
 108         jsstr_extract(str->left, off, left_len, buf);
 109         jsstr_extract(str->right, 0, len-left_len, buf+left_len);
 110     }
 111 }
 112
 113 void jsstr_extract(jsstr_t *str, unsigned off, unsigned len, WCHAR *buf)
 114 {
 115     switch(jsstr_tag(str)) {
 116     case JSSTR_INLINE:
 117         memcpy(buf, jsstr_as_inline(str)->buf+off, len*sizeof(WCHAR));
 118         return;
 119     case JSSTR_HEAP:
 120         memcpy(buf, jsstr_as_heap(str)->buf+off, len*sizeof(WCHAR));
 121         return;
 122     case JSSTR_ROPE:
 123         jsstr_rope_extract(jsstr_as_rope(str), off, len, buf);
 124         return;
 125     }
 126 }
 127
 128 static int jsstr_cmp_str(jsstr_t *jsstr, const WCHAR *str, unsigned len)
 129 {
 130     int ret;
 131
 132     switch(jsstr_tag(jsstr)) {
 133     case JSSTR_INLINE:
 134         ret = memcmp(jsstr_as_inline(jsstr)->buf, str, len*sizeof(WCHAR));
 135         return ret || jsstr_length(jsstr) == len ? ret : 1;
 136     case JSSTR_HEAP:
 137         ret = memcmp(jsstr_as_heap(jsstr)->buf, str, len*sizeof(WCHAR));
 138         return ret || jsstr_length(jsstr) == len ? ret : 1;
 139     case JSSTR_ROPE: {
 140         jsstr_rope_t *rope = jsstr_as_rope(jsstr);
 141         unsigned left_len = jsstr_length(rope->left);
 142
 143         ret = jsstr_cmp_str(rope->left, str, min(len, left_len));
 144         if(ret || len <= left_len)
 145             return ret;
 146         return jsstr_cmp_str(rope->right, str+left_len, len-left_len);
 147     }
 148     }
 149
 150     assert(0);
 151     return 0;
 152 }
 153
 154 #define TMP_BUF_SIZE 256
 155
 156 static int ropes_cmp(jsstr_rope_t *left, jsstr_rope_t *right)
 157 {
 158     WCHAR left_buf[TMP_BUF_SIZE], right_buf[TMP_BUF_SIZE];
 159     unsigned left_len = jsstr_length(&left->str);
 160     unsigned right_len = jsstr_length(&right->str);
 161     unsigned cmp_off = 0, cmp_size;
 162     int ret;
 163
 164     /* FIXME: We can avoid temporary buffers here. */
 165     while(cmp_off < min(left_len, right_len)) {
 166         cmp_size = min(left_len, right_len) - cmp_off;
 167         if(cmp_size > TMP_BUF_SIZE)
 168             cmp_size = TMP_BUF_SIZE;
 169
 170         jsstr_rope_extract(left, cmp_off, cmp_size, left_buf);
 171         jsstr_rope_extract(right, cmp_off, cmp_size, right_buf);
 172         ret = memcmp(left_buf, right_buf, cmp_size);
 173         if(ret)
 174             return ret;
 175
 176         cmp_off += cmp_size;
 177     }
 178
 179     return left_len - right_len;
 180 }
 181
 182 static inline const WCHAR *jsstr_try_flat(jsstr_t *str)
 183 {
 184     return jsstr_is_inline(str) ? jsstr_as_inline(str)->buf
 185         : jsstr_is_heap(str) ? jsstr_as_heap(str)->buf
 186         : NULL;
 187 }
 188
 189 int jsstr_cmp(jsstr_t *str1, jsstr_t *str2)
 190 {
 191     unsigned len1 = jsstr_length(str1);
 192     unsigned len2 = jsstr_length(str2);
 193     const WCHAR *str;
 194     int ret;
 195
 196     str = jsstr_try_flat(str2);
 197     if(str) {
 198         ret = jsstr_cmp_str(str1, str, min(len1, len2));
 199         return ret || len1 == len2 ? ret : -1;
 200     }
 201
 202     str = jsstr_try_flat(str1);
 203     if(str) {
 204         ret = jsstr_cmp_str(str2, str, min(len1, len2));
 205         return ret || len1 == len2 ? -ret : 1;
 206     }
 207
 208     return ropes_cmp(jsstr_as_rope(str1), jsstr_as_rope(str2));
 209 }
 210
 211 jsstr_t *jsstr_concat(jsstr_t *str1, jsstr_t *str2)
 212 {
 213     unsigned len1, len2;
 214     jsstr_t *ret;
 215     WCHAR *ptr;
 216
 217     len1 = jsstr_length(str1);
 218     if(!len1)
 219         return jsstr_addref(str2);
 220
 221     len2 = jsstr_length(str2);
 222     if(!len2)
 223         return jsstr_addref(str1);
 224
 225     if(len1 + len2 >= JSSTR_SHORT_STRING_LENGTH) {
 226         unsigned depth, depth2;
 227         jsstr_rope_t *rope;
 228
 229         depth = jsstr_is_rope(str1) ? jsstr_as_rope(str1)->depth : 0;
 230         depth2 = jsstr_is_rope(str2) ? jsstr_as_rope(str2)->depth : 0;
 231         if(depth2 > depth)
 232             depth = depth2;
 233
 234         if(depth++ < JSSTR_MAX_ROPE_DEPTH) {
 235             if(len1+len2 > JSSTR_MAX_LENGTH)
 236                 return NULL;
 237
 238             rope = heap_alloc(sizeof(*rope));
 239             if(!rope)
 240                 return NULL;
 241
 242             jsstr_init(&rope->str, len1+len2, JSSTR_ROPE);
 243             rope->left = jsstr_addref(str1);
 244             rope->right = jsstr_addref(str2);
 245             rope->depth = depth;
 246             return &rope->str;
 247         }
 248     }
 249
 250     ptr = jsstr_alloc_buf(len1+len2, &ret);
 251     if(!ret)
 252         return NULL;
 253
 254     jsstr_flush(str1, ptr);
 255     jsstr_flush(str2, ptr+len1);
 256     return ret;
 257
 258 }
 259
 260 C_ASSERT(sizeof(jsstr_heap_t) <= sizeof(jsstr_rope_t));
 261
 262 const WCHAR *jsstr_rope_flatten(jsstr_rope_t *str)
 263 {
 264     WCHAR *buf;
 265
 266     buf = heap_alloc((jsstr_length(&str->str)+1) * sizeof(WCHAR));
 267     if(!buf)
 268         return NULL;
 269
 270     jsstr_flush(str->left, buf);
 271     jsstr_flush(str->right, buf+jsstr_length(str->left));
 272     buf[jsstr_length(&str->str)] = 0;
 273
 274     /* Trasform to heap string */
 275     jsstr_release(str->left);
 276     jsstr_release(str->right);
 277     str->str.length_flags |= JSSTR_FLAG_FLAT;
 278     return jsstr_as_heap(&str->str)->buf = buf;
 279 }
 280
 281 static jsstr_t *empty_str, *nan_str, *undefined_str, *null_bstr_str;
 282
 283 jsstr_t *jsstr_nan(void)
 284 {
 285     return jsstr_addref(nan_str);
 286 }
 287
 288 jsstr_t *jsstr_empty(void)
 289 {
 290     return jsstr_addref(empty_str);
 291 }
 292
 293 jsstr_t *jsstr_undefined(void)
 294 {
 295     return jsstr_addref(undefined_str);
 296 }
 297
 298 jsstr_t *jsstr_null_bstr(void)
 299 {
 300     return jsstr_addref(null_bstr_str);
 301 }
 302
 303 BOOL is_null_bstr(jsstr_t *str)
 304 {
 305     return str == null_bstr_str;
 306 }
 307
 308 BOOL init_strings(void)
 309 {
 310     static const WCHAR NaNW[] = { 'N','a','N',0 };
 311     static const WCHAR undefinedW[] = {'u','n','d','e','f','i','n','e','d',0};
 312
 313     if(!jsstr_alloc_buf(0, &empty_str))
 314         return FALSE;
 315     if(!(nan_str = jsstr_alloc(NaNW)))
 316         return FALSE;
 317     if(!(undefined_str = jsstr_alloc(undefinedW)))
 318         return FALSE;
 319     if(!jsstr_alloc_buf(0, &null_bstr_str))
 320         return FALSE;
 321      return TRUE;
 322 }
 323
 324 void free_strings(void)
 325 {
 326     if(empty_str)
 327         jsstr_release(empty_str);
 328     if(nan_str)
 329         jsstr_release(nan_str);
 330     if(undefined_str)
 331         jsstr_release(undefined_str);
 332     if(null_bstr_str)
 333         jsstr_release(null_bstr_str);
 334 }