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Improve performance of search in the list of the magic strings. #1441

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merged 1 commit into from
Nov 24, 2016
Merged

Improve performance of search in the list of the magic strings. #1441

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82 changes: 54 additions & 28 deletions jerry-core/lit/lit-magic-strings.c
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Original file line number Diff line number Diff line change
Expand Up @@ -37,17 +37,19 @@ lit_get_magic_string_ex_count (void)
const lit_utf8_byte_t *
lit_get_magic_string_utf8 (lit_magic_string_id_t id) /**< magic string id */
{
static const lit_utf8_byte_t * const magic_strings[] JERRY_CONST_DATA =
static const lit_utf8_byte_t * const lit_magic_strings[] JERRY_CONST_DATA =
{
#define LIT_MAGIC_STRING_FIRST_STRING_WITH_SIZE(size, id)
#define LIT_MAGIC_STRING_DEF(id, utf8_string) \
(const lit_utf8_byte_t *) utf8_string,
#include "lit-magic-strings.inc.h"
#undef LIT_MAGIC_STRING_DEF
#undef LIT_MAGIC_STRING_FIRST_STRING_WITH_SIZE
};

JERRY_ASSERT (id < LIT_MAGIC_STRING__COUNT);

return magic_strings[id];
return lit_magic_strings[id];
} /* lit_get_magic_string_utf8 */

/**
Expand All @@ -60,17 +62,44 @@ lit_get_magic_string_size (lit_magic_string_id_t id) /**< magic string id */
{
static const lit_magic_size_t lit_magic_string_sizes[] JERRY_CONST_DATA =
{
#define LIT_MAGIC_STRING_FIRST_STRING_WITH_SIZE(size, id)
#define LIT_MAGIC_STRING_DEF(id, utf8_string) \
sizeof(utf8_string) - 1,
#include "lit-magic-strings.inc.h"
#undef LIT_MAGIC_STRING_DEF
#undef LIT_MAGIC_STRING_FIRST_STRING_WITH_SIZE
};

JERRY_ASSERT (id < LIT_MAGIC_STRING__COUNT);

return lit_magic_string_sizes[id];
} /* lit_get_magic_string_size */

/**
* Get the block start element with the given size from
* the list of ECMA and implementation-defined magic string constants
*
* @return magic string id
*/
lit_magic_string_id_t
lit_get_magic_string_size_block_start (lit_utf8_size_t size) /**< magic string size */
{
static const lit_magic_string_id_t const lit_magic_string_size_block_starts[] JERRY_CONST_DATA =
{
#define LIT_MAGIC_STRING_DEF(id, utf8_string)
#define LIT_MAGIC_STRING_FIRST_STRING_WITH_SIZE(size, id) \
id,
#include "lit-magic-strings.inc.h"
LIT_MAGIC_STRING__COUNT
#undef LIT_MAGIC_STRING_DEF
#undef LIT_MAGIC_STRING_FIRST_STRING_WITH_SIZE
};

JERRY_ASSERT (size <= (sizeof (lit_magic_string_size_block_starts) / sizeof (lit_magic_string_id_t)));

return lit_magic_string_size_block_starts[size];
} /* lit_get_magic_string_size_block_start */

/**
* Get specified magic string as zero-terminated string from external table
*
Expand Down Expand Up @@ -145,22 +174,36 @@ lit_is_utf8_string_magic (const lit_utf8_byte_t *string_p, /**< utf-8 string */
lit_utf8_size_t string_size, /**< string size in bytes */
lit_magic_string_id_t *out_id_p) /**< [out] magic string's id */
{
/* TODO: Improve performance of search */
*out_id_p = LIT_MAGIC_STRING__COUNT;

for (lit_magic_string_id_t id = (lit_magic_string_id_t) 0;
id < LIT_MAGIC_STRING__COUNT;
id = (lit_magic_string_id_t) (id + 1))
if (string_size > lit_get_magic_string_size (LIT_MAGIC_STRING__COUNT - 1))
{
if (lit_compare_utf8_string_and_magic_string (string_p, string_size, id))
{
*out_id_p = id;
return false;
}

int first = (int) lit_get_magic_string_size_block_start (string_size); /**< First magic string element */
int last = (int) (lit_get_magic_string_size_block_start (string_size + 1) - 1); /**< Last magic string element */

while (first <= last)
{
int middle = ((first + last) / 2); /**< mid point of search */
int compare = memcmp (lit_get_magic_string_utf8 (middle), string_p, string_size);

if (compare == 0)
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newline before if

{
*out_id_p = (lit_magic_string_id_t) middle;
return true;
}
else if (compare > 0)
{
last = middle - 1;
}
else
{
first = middle + 1;
}
}

*out_id_p = LIT_MAGIC_STRING__COUNT;

return false;
} /* lit_is_utf8_string_magic */

Expand Down Expand Up @@ -194,23 +237,6 @@ bool lit_is_ex_utf8_string_magic (const lit_utf8_byte_t *string_p, /**< utf-8 st
return false;
} /* lit_is_ex_utf8_string_magic */

/**
* Compare utf-8 string and magic string for equality
*
* @return true if strings are equal
* false otherwise
*/
bool
lit_compare_utf8_string_and_magic_string (const lit_utf8_byte_t *string_p, /**< utf-8 string */
lit_utf8_size_t string_size, /**< string size in bytes */
lit_magic_string_id_t magic_string_id) /**< magic string's id */
{
return lit_compare_utf8_strings (string_p,
string_size,
lit_get_magic_string_utf8 (magic_string_id),
lit_get_magic_string_size (magic_string_id));
} /* lit_compare_utf8_string_and_magic_string */

/**
* Compare utf-8 string and external magic string for equality
*
Expand Down
8 changes: 4 additions & 4 deletions jerry-core/lit/lit-magic-strings.h
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Original file line number Diff line number Diff line change
Expand Up @@ -28,11 +28,12 @@
*/
typedef enum
{
#define LIT_MAGIC_STRING_FIRST_STRING_WITH_SIZE(size, id)
#define LIT_MAGIC_STRING_DEF(id, ascii_zt_string) \
id,
#include "lit-magic-strings.inc.h"
#undef LIT_MAGIC_STRING_DEF

#undef LIT_MAGIC_STRING_FIRST_STRING_WITH_SIZE
LIT_MAGIC_STRING__COUNT /**< number of magic strings */
} lit_magic_string_id_t;

Expand All @@ -45,17 +46,16 @@ extern uint32_t lit_get_magic_string_ex_count (void);

extern const lit_utf8_byte_t *lit_get_magic_string_utf8 (lit_magic_string_id_t);
extern lit_utf8_size_t lit_get_magic_string_size (lit_magic_string_id_t);
extern lit_magic_string_id_t lit_get_magic_string_size_block_start (lit_utf8_size_t);

extern const lit_utf8_byte_t *lit_get_magic_string_ex_utf8 (lit_magic_string_ex_id_t);
extern lit_utf8_size_t lit_get_magic_string_ex_size (lit_magic_string_ex_id_t);

extern void lit_magic_strings_ex_set (const lit_utf8_byte_t **, uint32_t, const lit_utf8_size_t *);

extern bool lit_is_utf8_string_magic (const lit_utf8_byte_t *, lit_utf8_size_t, lit_magic_string_id_t *);
extern bool lit_is_ex_utf8_string_magic (const lit_utf8_byte_t *, lit_utf8_size_t, lit_magic_string_ex_id_t *);

extern bool lit_compare_utf8_string_and_magic_string (const lit_utf8_byte_t *, lit_utf8_size_t,
lit_magic_string_id_t);
extern bool lit_is_ex_utf8_string_magic (const lit_utf8_byte_t *, lit_utf8_size_t, lit_magic_string_ex_id_t *);

extern bool lit_compare_utf8_string_and_magic_string_ex (const lit_utf8_byte_t *, lit_utf8_size_t,
lit_magic_string_ex_id_t);
Expand Down
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