Only compile regex's once

This commit is contained in:
Přemysl Eric Janouch 2014-07-13 04:30:23 +02:00
parent 4904128c98
commit 475c83618a
3 changed files with 126 additions and 70 deletions

View File

@ -1417,45 +1417,6 @@ set_boolean_if_valid (bool *out, const char *s)
return true;
}
static void
regerror_to_str (int code, const regex_t *preg, struct str *out)
{
size_t required = regerror (code, preg, NULL, 0);
str_ensure_space (out, required);
out->len += regerror (code, preg,
out->str + out->len, out->alloc - out->len) - 1;
}
static size_t regex_error_domain_tag;
#define REGEX_ERROR (error_resolve_domain (&regex_error_domain_tag))
enum
{
REGEX_ERROR_COMPILATION_FAILED
};
static bool
regex_match (const char *regex, const char *s, struct error **e)
{
regex_t re;
int err = regcomp (&re, regex, REG_EXTENDED | REG_NOSUB);
if (err)
{
struct str desc;
str_init (&desc);
regerror_to_str (err, &re, &desc);
error_set (e, REGEX_ERROR, REGEX_ERROR_COMPILATION_FAILED,
"failed to compile regular expression: %s", desc.str);
str_free (&desc);
return false;
}
bool result = regexec (&re, s, 0, NULL, 0) != REG_NOMATCH;
regfree (&re);
return result;
}
static bool
read_line (FILE *fp, struct str *s)
{
@ -1512,6 +1473,73 @@ xssl_get_error (SSL *ssl, int result, const char **error_info)
}
}
// --- Regular expressions -----------------------------------------------------
static size_t regex_error_domain_tag;
#define REGEX_ERROR (error_resolve_domain (&regex_error_domain_tag))
enum
{
REGEX_ERROR_COMPILATION_FAILED
};
static regex_t *
regex_compile (const char *regex, int flags, struct error **e)
{
regex_t *re = xmalloc (sizeof *re);
int err = regcomp (re, regex, flags);
if (!err)
return re;
struct str desc;
str_init (&desc);
size_t required = regerror (err, re, NULL, 0);
str_ensure_space (&desc, required);
desc.len += regerror (err, re,
desc.str + desc.len, desc.alloc - desc.len) - 1;
free (re);
error_set (e, REGEX_ERROR, REGEX_ERROR_COMPILATION_FAILED,
"%s: %s", "failed to compile regular expression", desc.str);
str_free (&desc);
return NULL;
}
static void
regex_free (void *regex)
{
regfree (regex);
free (regex);
}
// The cost of hashing a string is likely to be significantly smaller than that
// of compiling the whole regular expression anew, so here is a simple cache.
// Adding basic support for subgroups is easy: check `re_nsub' and output into
// a `struct str_vector' (if all we want is the substrings).
static void
regex_cache_init (struct str_map *cache)
{
str_map_init (cache);
cache->free = regex_free;
}
static bool
regex_cache_match (struct str_map *cache, const char *regex, int flags,
const char *s, struct error **e)
{
regex_t *re = str_map_find (cache, regex);
if (!re)
{
re = regex_compile (regex, flags, e);
if (!re)
return false;
str_map_set (cache, regex, re);
}
return regexec (re, s, 0, NULL, 0) != REG_NOMATCH;
}
// --- IRC utilities -----------------------------------------------------------
struct irc_message

View File

@ -103,13 +103,24 @@ enum validation_result
#define IRC_NICKNAME_MAX 9
#define IRC_HOSTNAME_MAX 63
// Anything to keep it as short as possible
#define SN "[0-9A-Za-z][-0-9A-Za-z]*[0-9A-Za-z]*"
#define N4 "[0-9]{1,3}"
#define N6 "[0-9ABCDEFabcdef]{1,}"
static bool
irc_regex_match (const char *regex, const char *s)
{
static struct str_map cache;
static bool initialized;
#define LE "A-Za-z"
#define SP "\\[\\]\\\\`_^{|}"
if (!initialized)
{
regex_cache_init (&cache);
initialized = true;
}
struct error *e = NULL;
bool result = regex_cache_match (&cache, regex,
REG_EXTENDED | REG_NOSUB, s, &e);
hard_assert (!e);
return result;
}
static const char *
irc_validate_to_str (enum validation_result result)
@ -124,14 +135,20 @@ irc_validate_to_str (enum validation_result result)
}
}
// TODO: at least cache the resulting `regex_t' in a `struct str_map'
// Anything to keep it as short as possible
#define SN "[0-9A-Za-z][-0-9A-Za-z]*[0-9A-Za-z]*"
#define N4 "[0-9]{1,3}"
#define N6 "[0-9ABCDEFabcdef]{1,}"
#define LE "A-Za-z"
#define SP "\\[\\]\\\\`_^{|}"
static enum validation_result
irc_validate_hostname (const char *hostname)
{
if (!*hostname)
return VALIDATION_ERROR_EMPTY;
if (!regex_match ("^" SN "(\\." SN ")*$", hostname, NULL))
if (!irc_regex_match ("^" SN "(\\." SN ")*$", hostname))
return VALIDATION_ERROR_INVALID;
if (strlen (hostname) > IRC_HOSTNAME_MAX)
return VALIDATION_ERROR_TOO_LONG;
@ -141,11 +158,11 @@ irc_validate_hostname (const char *hostname)
static bool
irc_is_valid_hostaddr (const char *hostaddr)
{
if (regex_match ("^" N4 "\\." N4 "\\." N4 "\\." N4 "$", hostaddr, NULL)
|| regex_match ("^" N6 ":" N6 ":" N6 ":" N6 ":"
N6 ":" N6 ":" N6 ":" N6 "$", hostaddr, NULL)
|| regex_match ("^0:0:0:0:0:(0|[Ff]{4}):"
N4 "\\." N4 "\\." N4 "\\." N4 "$", hostaddr, NULL))
if (irc_regex_match ("^" N4 "\\." N4 "\\." N4 "\\." N4 "$", hostaddr)
|| irc_regex_match ("^" N6 ":" N6 ":" N6 ":" N6 ":"
N6 ":" N6 ":" N6 ":" N6 "$", hostaddr)
|| irc_regex_match ("^0:0:0:0:0:(0|[Ff]{4}):"
N4 "\\." N4 "\\." N4 "\\." N4 "$", hostaddr))
return true;
return false;
}
@ -162,7 +179,7 @@ irc_validate_nickname (const char *nickname)
{
if (!*nickname)
return VALIDATION_ERROR_EMPTY;
if (!regex_match ("^[" LE SP "][-0-9" LE SP "]*$", nickname, NULL))
if (!irc_regex_match ("^[" LE SP "][-0-9" LE SP "]*$", nickname))
return VALIDATION_ERROR_INVALID;
if (strlen (nickname) > IRC_NICKNAME_MAX)
return VALIDATION_ERROR_TOO_LONG;

View File

@ -118,6 +118,7 @@ enum
struct bot_context
{
struct str_map config; ///< User configuration
regex_t *admin_re; ///< Regex to match our administrator
int irc_fd; ///< Socket FD of the server
struct str read_buffer; ///< Input yet to be processed
@ -140,6 +141,7 @@ bot_context_init (struct bot_context *self)
str_map_init (&self->config);
self->config.free = free;
load_config_defaults (&self->config, g_config_table);
self->admin_re = NULL;
self->irc_fd = -1;
str_init (&self->read_buffer);
@ -160,6 +162,8 @@ static void
bot_context_free (struct bot_context *self)
{
str_map_free (&self->config);
if (self->admin_re)
regex_free (self->admin_re);
str_free (&self->read_buffer);
// TODO: terminate the plugins properly before this is called
@ -1110,25 +1114,10 @@ is_private_message (const struct irc_message *msg)
static bool
is_sent_by_admin (struct bot_context *ctx, const struct irc_message *msg)
{
const char *admin = str_map_find (&ctx->config, "admin");
// No administrator set -> everyone is an administrator
if (!admin)
if (!ctx->admin_re)
return true;
// TODO: precompile the regex
struct error *e = NULL;
if (regex_match (admin, msg->prefix, NULL))
return true;
if (e)
{
print_error ("%s: %s", "invalid admin mask", e->message);
error_free (e);
return true;
}
return false;
return regexec (ctx->admin_re, msg->prefix, 0, NULL, 0) != REG_NOMATCH;
}
static void respond_to_user (struct bot_context *ctx, const struct
@ -1591,6 +1580,26 @@ irc_connect (struct bot_context *ctx, struct error **e)
return true;
}
static bool
load_admin_regex (struct bot_context *ctx)
{
hard_assert (!ctx->admin_re);
const char *admin = str_map_find (&ctx->config, "admin");
if (!admin)
return true;
struct error *e = NULL;
ctx->admin_re = regex_compile (admin, REG_EXTENDED | REG_NOSUB, &e);
if (!e)
return true;
print_error ("invalid configuration value for `%s': %s",
"admin", e->message);
error_free (e);
return false;
}
static void
on_signal_pipe_readable (const struct pollfd *fd, struct bot_context *ctx)
{
@ -1758,6 +1767,8 @@ main (int argc, char *argv[])
(poller_dispatcher_func) on_signal_pipe_readable, &ctx);
plugin_load_all_from_config (&ctx);
if (!load_admin_regex (&ctx))
exit (EXIT_FAILURE);
if (!irc_connect (&ctx, &e))
{
print_error ("%s", e->message);