reactos/dll/win32/jscript/jsstr.h

198 lines
5.4 KiB
C
Raw Normal View History

/*
* 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
*/
/*
* jsstr_t is a common header for all string representations. The exact layout of the string
* representation may be:
*
* - inline string - string bytes directly follow string headers.
* - heap string - a structure containing a pointer to buffer on the heap.
* - roper string - a product of concatenation of two strings. Instead of copying whole
* buffers, we may store just references to concatenated strings.
*
* String layout may change over life time of the string. Currently possible transformation
* is when a rope string becomes a heap stream. That happens when we need a real, linear
* zero-terminated buffer (a flat buffer). At this point the type of the string is changed
* and the new buffer is stored in the string, so that subsequent operations requiring
* a flat string won't need to flatten it again.
*
* In the future more layouts and transformations may be added.
*/
#pragma once
struct _jsstr_t {
unsigned length_flags;
unsigned ref;
};
#define JSSTR_LENGTH_SHIFT 4
#define JSSTR_MAX_LENGTH (1 << (32-JSSTR_LENGTH_SHIFT))
#define JSSTR_FLAGS_MASK ((1 << JSSTR_LENGTH_SHIFT)-1)
#define JSSTR_FLAG_LBIT 1
#define JSSTR_FLAG_FLAT 2
#define JSSTR_FLAG_TAG_MASK 3
typedef enum {
JSSTR_INLINE = JSSTR_FLAG_FLAT,
JSSTR_HEAP = JSSTR_FLAG_FLAT|JSSTR_FLAG_LBIT,
JSSTR_ROPE = JSSTR_FLAG_LBIT
} jsstr_tag_t;
static inline unsigned jsstr_length(jsstr_t *str)
{
return str->length_flags >> JSSTR_LENGTH_SHIFT;
}
static inline jsstr_tag_t jsstr_tag(jsstr_t *str)
{
return str->length_flags & JSSTR_FLAG_TAG_MASK;
}
static inline BOOL jsstr_is_inline(jsstr_t *str)
{
return jsstr_tag(str) == JSSTR_INLINE;
}
static inline BOOL jsstr_is_heap(jsstr_t *str)
{
return jsstr_tag(str) == JSSTR_HEAP;
}
static inline BOOL jsstr_is_rope(jsstr_t *str)
{
return jsstr_tag(str) == JSSTR_ROPE;
}
typedef struct {
jsstr_t str;
WCHAR buf[1];
} jsstr_inline_t;
typedef struct {
jsstr_t str;
WCHAR *buf;
} jsstr_heap_t;
typedef struct {
jsstr_t str;
jsstr_t *left;
jsstr_t *right;
unsigned depth;
} jsstr_rope_t;
jsstr_t *jsstr_alloc_len(const WCHAR*,unsigned) DECLSPEC_HIDDEN;
WCHAR *jsstr_alloc_buf(unsigned,jsstr_t**) DECLSPEC_HIDDEN;
static inline jsstr_t *jsstr_alloc(const WCHAR *str)
{
return jsstr_alloc_len(str, strlenW(str));
}
void jsstr_free(jsstr_t*) DECLSPEC_HIDDEN;
static inline void jsstr_release(jsstr_t *str)
{
if(!--str->ref) {
if(jsstr_is_inline(str))
heap_free(str);
else
jsstr_free(str);
}
}
static inline jsstr_t *jsstr_addref(jsstr_t *str)
{
str->ref++;
return str;
}
static inline jsstr_inline_t *jsstr_as_inline(jsstr_t *str)
{
return CONTAINING_RECORD(str, jsstr_inline_t, str);
}
static inline jsstr_heap_t *jsstr_as_heap(jsstr_t *str)
{
return CONTAINING_RECORD(str, jsstr_heap_t, str);
}
static inline jsstr_rope_t *jsstr_as_rope(jsstr_t *str)
{
return CONTAINING_RECORD(str, jsstr_rope_t, str);
}
const WCHAR *jsstr_rope_flatten(jsstr_rope_t*) DECLSPEC_HIDDEN;
static inline const WCHAR *jsstr_flatten(jsstr_t *str)
{
return jsstr_is_inline(str) ? jsstr_as_inline(str)->buf
: jsstr_is_heap(str) ? jsstr_as_heap(str)->buf
: jsstr_rope_flatten(jsstr_as_rope(str));
}
void jsstr_extract(jsstr_t*,unsigned,unsigned,WCHAR*) DECLSPEC_HIDDEN;
static inline unsigned jsstr_flush(jsstr_t *str, WCHAR *buf)
{
unsigned len = jsstr_length(str);
if(jsstr_is_inline(str)) {
memcpy(buf, jsstr_as_inline(str)->buf, len*sizeof(WCHAR));
}else if(jsstr_is_heap(str)) {
memcpy(buf, jsstr_as_heap(str)->buf, len*sizeof(WCHAR));
}else {
jsstr_rope_t *rope = jsstr_as_rope(str);
jsstr_flush(rope->left, buf);
jsstr_flush(rope->right, buf+jsstr_length(rope->left));
}
return len;
}
static inline jsstr_t *jsstr_substr(jsstr_t *str, unsigned off, unsigned len)
{
jsstr_t *ret;
WCHAR *ptr;
ptr = jsstr_alloc_buf(len, &ret);
if(ptr)
jsstr_extract(str, off, len, ptr);
return ret;
}
int jsstr_cmp(jsstr_t*,jsstr_t*) DECLSPEC_HIDDEN;
static inline BOOL jsstr_eq(jsstr_t *left, jsstr_t *right)
{
return jsstr_length(left) == jsstr_length(right) && !jsstr_cmp(left, right);
}
jsstr_t *jsstr_concat(jsstr_t*,jsstr_t*) DECLSPEC_HIDDEN;
jsstr_t *jsstr_nan(void) DECLSPEC_HIDDEN;
jsstr_t *jsstr_empty(void) DECLSPEC_HIDDEN;
jsstr_t *jsstr_undefined(void) DECLSPEC_HIDDEN;
jsstr_t *jsstr_null_bstr(void) DECLSPEC_HIDDEN;
BOOL is_null_bstr(jsstr_t*) DECLSPEC_HIDDEN;
BOOL init_strings(void) DECLSPEC_HIDDEN;
void free_strings(void) DECLSPEC_HIDDEN;
const char *debugstr_jsstr(jsstr_t*) DECLSPEC_HIDDEN;