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 58 static inline unsigned jsstr_length(jsstr_t *str) 59 { 60 return str->length_flags >> JSSTR_LENGTH_SHIFT; 61 } 62 63 static inline jsstr_tag_t jsstr_tag(jsstr_t *str) 64 { 65 return str->length_flags & JSSTR_FLAG_TAG_MASK; 66 } 67 68 static inline BOOL jsstr_is_inline(jsstr_t *str) 69 { 70 return jsstr_tag(str) == JSSTR_INLINE; 71 } 72 73 static inline BOOL jsstr_is_heap(jsstr_t *str) 74 { 75 return jsstr_tag(str) == JSSTR_HEAP; 76 } 77 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; 102 103 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; 109 110 static inline void jsstr_release(jsstr_t *str) 111 { 112 if(!--str->ref) 113 jsstr_free(str); 114 } 115 116 static inline jsstr_t *jsstr_addref(jsstr_t *str) 117 { 118 str->ref++; 119 return str; 120 } 121 122 static inline jsstr_inline_t *jsstr_as_inline(jsstr_t *str) 123 { 124 return CONTAINING_RECORD(str, jsstr_inline_t, str); 125 } 126 127 static inline jsstr_heap_t *jsstr_as_heap(jsstr_t *str) 128 { 129 return CONTAINING_RECORD(str, jsstr_heap_t, str); 130 } 131 132 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; 138 139 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; 147 148 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 } 162 163 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; 175 176 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