From: Jakub Jelinek <jakub@redhat.com>
To: Ulrich Drepper <drepper@redhat.com>,
Isamu Hasegawa <isamu@yamato.ibm.com>
Cc: Glibc hackers <libc-hacker@sources.redhat.com>
Subject: [PATCH] Decrease regex memory usage
Date: Thu, 04 Jul 2002 08:25:00 -0000 [thread overview]
Message-ID: <20020704172542.U20867@sunsite.ms.mff.cuni.cz> (raw)
Hi!
Just reshuffling some structures can save memory especially on
64-bit arches.
E.g. re_token_t which would take 12 resp. 24 bytes now occupies 8 resp. 16
bytes, and as current code allocates sizeof(re_token_t)*length_of_regexp,
it might be a lot for long regular expressions (consider e.g. ksymoops
which uses several kilobytes long patterns).
BTW: I wonder whether it wouldn't be good to have a STRING node to replace
a lot of consecutive CHARACTER nodes, especially in MB_CUR_MAX == 1 mode.
Right now searching for regular expression
Veryveryveryloooooooooooooooooooooooooooooooooooooooooongstring[ ]*endofit
will occupy a lot of memory and will be slower than if the string could be
compared with strcmp when the first character is found.
2002-07-04 Jakub Jelinek <jakub@redhat.com>
* posix/regex_internal.h (re_token_t): Shrink the structure to 8
resp. 16 bytes on 32-bit resp. 64-bit platforms.
(re_charset_t, re_string_t): Reorder structure members for 64-bit
arches.
--- libc/posix/regex_internal.h.jj Wed Jun 5 10:27:39 2002
+++ libc/posix/regex_internal.h Thu Jul 4 16:13:16 2002
@@ -142,24 +142,18 @@ typedef enum
#ifdef RE_ENABLE_I18N
typedef struct
{
- /* If this character set is the non-matching list. */
- unsigned int non_match : 1;
-
/* Multibyte characters. */
wchar_t *mbchars;
- int nmbchars;
/* Collating symbols. */
# ifdef _LIBC
int32_t *coll_syms;
# endif
- int ncoll_syms;
/* Equivalence classes. */
# ifdef _LIBC
int32_t *equiv_classes;
# endif
- int nequiv_classes;
/* Range expressions. */
# ifdef _LIBC
@@ -169,17 +163,32 @@ typedef struct
wchar_t *range_starts;
wchar_t *range_ends;
# endif /* not _LIBC */
- int nranges;
/* Character classes. */
wctype_t *char_classes;
+
+ /* If this character set is the non-matching list. */
+ unsigned int non_match : 1;
+
+ /* # of multibyte characters. */
+ int nmbchars;
+
+ /* # of collating symbols. */
+ int ncoll_syms;
+
+ /* # of equivalence classes. */
+ int nequiv_classes;
+
+ /* # of range expressions. */
+ int nranges;
+
+ /* # of character classes. */
int nchar_classes;
} re_charset_t;
#endif /* RE_ENABLE_I18N */
typedef struct
{
- re_token_type_t type;
union
{
unsigned char c; /* for CHARACTER */
@@ -195,6 +204,11 @@ typedef struct
re_node_set *bkref_eclosure;
} *ctx_info;
} opr;
+#if __GNUC__ >= 2
+ re_token_type_t type : 8;
+#else
+ re_token_type_t type;
+#endif
unsigned int constraint : 10; /* context constraint */
unsigned int duplicated : 1;
#ifdef RE_ENABLE_I18N
@@ -214,9 +228,6 @@ struct re_string_t
/* Indicate the raw buffer which is the original string passed as an
argument of regexec(), re_search(), etc.. */
const unsigned char *raw_mbs;
- /* Index in RAW_MBS. Each character mbs[i] corresponds to
- raw_mbs[raw_mbs_idx + i]. */
- int raw_mbs_idx;
/* Store the multibyte string. In case of "case insensitive mode" like
REG_ICASE, upper cases of the string are stored, otherwise MBS points
the same address that RAW_MBS points. */
@@ -230,6 +241,9 @@ struct re_string_t
wint_t *wcs;
mbstate_t cur_state;
#endif
+ /* Index in RAW_MBS. Each character mbs[i] corresponds to
+ raw_mbs[raw_mbs_idx + i]. */
+ int raw_mbs_idx;
/* The length of the valid characters in the buffers. */
int valid_len;
/* The length of the buffers MBS, MBS_CASE, and WCS. */
Jakub
next reply other threads:[~2002-07-04 15:25 UTC|newest]
Thread overview: 2+ messages / expand[flat|nested] mbox.gz Atom feed top
2002-07-04 8:25 Jakub Jelinek [this message]
2002-07-10 15:35 ` Ulrich Drepper
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