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 /*
20 * jsstr_t is a common header for all string representations. The exact layout of the string
21 * representation may be:
22 *
23 * - inline string - string bytes directly follow string headers.
24 * - heap string - a structure containing a pointer to buffer on the heap.
25 * - roper string - a product of concatenation of two strings. Instead of copying whole
26 * buffers, we may store just references to concatenated strings.
27 *
28 * String layout may change over life time of the string. Currently possible transformation
29 * is when a rope string becomes a heap stream. That happens when we need a real, linear
30 * zero-terminated buffer (a flat buffer). At this point the type of the string is changed
31 * and the new buffer is stored in the string, so that subsequent operations requiring
32 * a flat string won't need to flatten it again.
33 *
34 * In the future more layouts and transformations may be added.
35 */
36
37 #pragma once
38
39 struct _jsstr_t {
40 unsigned length_flags;
41 unsigned ref;
42 };
43
44 #define JSSTR_LENGTH_SHIFT 4
45 #define JSSTR_MAX_LENGTH ((1 << (32-JSSTR_LENGTH_SHIFT))-1)
46 #define JSSTR_FLAGS_MASK ((1 << JSSTR_LENGTH_SHIFT)-1)
47
48 #define JSSTR_FLAG_LBIT 1
49 #define JSSTR_FLAG_FLAT 2
50 #define JSSTR_FLAG_TAG_MASK 3
51
52 typedef enum {
53 JSSTR_INLINE = JSSTR_FLAG_FLAT,
54 JSSTR_HEAP = JSSTR_FLAG_FLAT|JSSTR_FLAG_LBIT,
55 JSSTR_ROPE = JSSTR_FLAG_LBIT
56 } jsstr_tag_t;
57
jsstr_length(jsstr_t * str)58 static inline unsigned jsstr_length(jsstr_t *str)
59 {
60 return str->length_flags >> JSSTR_LENGTH_SHIFT;
61 }
62
jsstr_tag(jsstr_t * str)63 static inline jsstr_tag_t jsstr_tag(jsstr_t *str)
64 {
65 return str->length_flags & JSSTR_FLAG_TAG_MASK;
66 }
67
jsstr_is_inline(jsstr_t * str)68 static inline BOOL jsstr_is_inline(jsstr_t *str)
69 {
70 return jsstr_tag(str) == JSSTR_INLINE;
71 }
72
jsstr_is_heap(jsstr_t * str)73 static inline BOOL jsstr_is_heap(jsstr_t *str)
74 {
75 return jsstr_tag(str) == JSSTR_HEAP;
76 }
77
jsstr_is_rope(jsstr_t * str)78 static inline BOOL jsstr_is_rope(jsstr_t *str)
79 {
80 return jsstr_tag(str) == JSSTR_ROPE;
81 }
82
83 typedef struct {
84 jsstr_t str;
85 WCHAR buf[1];
86 } jsstr_inline_t;
87
88 typedef struct {
89 jsstr_t str;
90 WCHAR *buf;
91 } jsstr_heap_t;
92
93 typedef struct {
94 jsstr_t str;
95 jsstr_t *left;
96 jsstr_t *right;
97 unsigned depth;
98 } jsstr_rope_t;
99
100 jsstr_t *jsstr_alloc_len(const WCHAR*,unsigned) DECLSPEC_HIDDEN;
101 jsstr_t *jsstr_alloc_buf(unsigned,WCHAR**) DECLSPEC_HIDDEN;
102
jsstr_alloc(const WCHAR * str)103 static inline jsstr_t *jsstr_alloc(const WCHAR *str)
104 {
105 return jsstr_alloc_len(str, lstrlenW(str));
106 }
107
108 void jsstr_free(jsstr_t*) DECLSPEC_HIDDEN;
109
jsstr_release(jsstr_t * str)110 static inline void jsstr_release(jsstr_t *str)
111 {
112 if(!--str->ref)
113 jsstr_free(str);
114 }
115
jsstr_addref(jsstr_t * str)116 static inline jsstr_t *jsstr_addref(jsstr_t *str)
117 {
118 str->ref++;
119 return str;
120 }
121
jsstr_as_inline(jsstr_t * str)122 static inline jsstr_inline_t *jsstr_as_inline(jsstr_t *str)
123 {
124 return CONTAINING_RECORD(str, jsstr_inline_t, str);
125 }
126
jsstr_as_heap(jsstr_t * str)127 static inline jsstr_heap_t *jsstr_as_heap(jsstr_t *str)
128 {
129 return CONTAINING_RECORD(str, jsstr_heap_t, str);
130 }
131
jsstr_as_rope(jsstr_t * str)132 static inline jsstr_rope_t *jsstr_as_rope(jsstr_t *str)
133 {
134 return CONTAINING_RECORD(str, jsstr_rope_t, str);
135 }
136
137 const WCHAR *jsstr_rope_flatten(jsstr_rope_t*) DECLSPEC_HIDDEN;
138
jsstr_flatten(jsstr_t * str)139 static inline const WCHAR *jsstr_flatten(jsstr_t *str)
140 {
141 return jsstr_is_inline(str) ? jsstr_as_inline(str)->buf
142 : jsstr_is_heap(str) ? jsstr_as_heap(str)->buf
143 : jsstr_rope_flatten(jsstr_as_rope(str));
144 }
145
146 void jsstr_extract(jsstr_t*,unsigned,unsigned,WCHAR*) DECLSPEC_HIDDEN;
147
jsstr_flush(jsstr_t * str,WCHAR * buf)148 static inline unsigned jsstr_flush(jsstr_t *str, WCHAR *buf)
149 {
150 unsigned len = jsstr_length(str);
151 if(jsstr_is_inline(str)) {
152 memcpy(buf, jsstr_as_inline(str)->buf, len*sizeof(WCHAR));
153 }else if(jsstr_is_heap(str)) {
154 memcpy(buf, jsstr_as_heap(str)->buf, len*sizeof(WCHAR));
155 }else {
156 jsstr_rope_t *rope = jsstr_as_rope(str);
157 jsstr_flush(rope->left, buf);
158 jsstr_flush(rope->right, buf+jsstr_length(rope->left));
159 }
160 return len;
161 }
162
jsstr_substr(jsstr_t * str,unsigned off,unsigned len)163 static inline jsstr_t *jsstr_substr(jsstr_t *str, unsigned off, unsigned len)
164 {
165 jsstr_t *ret;
166 WCHAR *ptr;
167
168 ret = jsstr_alloc_buf(len, &ptr);
169 if(ret)
170 jsstr_extract(str, off, len, ptr);
171 return ret;
172 }
173
174 int jsstr_cmp(jsstr_t*,jsstr_t*) DECLSPEC_HIDDEN;
175
jsstr_eq(jsstr_t * left,jsstr_t * right)176 static inline BOOL jsstr_eq(jsstr_t *left, jsstr_t *right)
177 {
178 return jsstr_length(left) == jsstr_length(right) && !jsstr_cmp(left, right);
179 }
180
181 jsstr_t *jsstr_concat(jsstr_t*,jsstr_t*) DECLSPEC_HIDDEN;
182
183 jsstr_t *jsstr_nan(void) DECLSPEC_HIDDEN;
184 jsstr_t *jsstr_empty(void) DECLSPEC_HIDDEN;
185 jsstr_t *jsstr_undefined(void) DECLSPEC_HIDDEN;
186
187 jsstr_t *jsstr_null_bstr(void) DECLSPEC_HIDDEN;
188 BOOL is_null_bstr(jsstr_t*) DECLSPEC_HIDDEN;
189
190 BOOL init_strings(void) DECLSPEC_HIDDEN;
191 void free_strings(void) DECLSPEC_HIDDEN;
192
193 const char *debugstr_jsstr(jsstr_t*) DECLSPEC_HIDDEN;
194