From 4718026de2ecab773d21b25efc989e18b9c4dc99 Mon Sep 17 00:00:00 2001 From: Ulrich Drepper Date: Fri, 28 Apr 2006 18:42:24 +0000 Subject: * nis/nss_nis/nis-service.c: Avoid passing pointer to static variable around. Reduce number of memory allocations by creating list of memory pools. --- nis/nss_nis/nis-service.c | 140 +++++++++++++++++++++++++++++++++------------- 1 file changed, 100 insertions(+), 40 deletions(-) (limited to 'nis') diff --git a/nis/nss_nis/nis-service.c b/nis/nss_nis/nis-service.c index 40772ae743..f5d886fc90 100644 --- a/nis/nss_nis/nis-service.c +++ b/nis/nss_nis/nis-service.c @@ -40,17 +40,18 @@ __libc_lock_define_initialized (static, lock) struct response_t { struct response_t *next; - char val[0]; + size_t size; + char mem[0]; }; -struct intern_t +typedef struct intern_t { struct response_t *start; struct response_t *next; -}; -typedef struct intern_t intern_t; + size_t offset; +} intern_t; -static intern_t intern = { NULL, NULL }; +static intern_t intern; struct search_t { @@ -68,26 +69,50 @@ static int saveit (int instatus, char *inkey, int inkeylen, char *inval, int invallen, char *indata) { - intern_t *intern = (intern_t *) indata; - if (instatus != YP_TRUE) return 1; if (inkey && inkeylen > 0 && inval && invallen > 0) { - struct response_t *newp = malloc (sizeof (struct response_t) - + invallen + 1); - if (newp == NULL) - return 1; /* We have no error code for out of memory */ + struct response_t *bucket = intern.next; - if (intern->start == NULL) - intern->start = newp; - else - intern->next->next = newp; - intern->next = newp; + if (__builtin_expect (bucket == NULL, 0)) + { +#define MINSIZE 4096 - 4 * sizeof (void *) + const size_t minsize = MAX (MINSIZE, 2 * (invallen + 1)); + bucket = malloc (sizeof (struct response_t) + minsize); + if (bucket == NULL) + /* We have no error code for out of memory. */ + return 1; + + bucket->next = NULL; + bucket->size = minsize; + intern.start = intern.next = bucket; + intern.offset = 0; + } + else if (__builtin_expect (invallen + 1 > bucket->size - intern.offset, + 0)) + { + /* We need a new (larger) buffer. */ + const size_t newsize = 2 * MAX (bucket->size, invallen + 1); + struct response_t *newp = malloc (sizeof (struct response_t) + + newsize); + if (newp == NULL) + /* We have no error code for out of memory. */ + return 1; + + /* Mark the old bucket as full. */ + bucket->size = intern.offset; + + newp->next = NULL; + newp->size = newsize; + bucket = intern.next = bucket->next = newp; + intern.offset = 0; + } - newp->next = NULL; - *((char *) mempcpy (newp->val, inval, invallen)) = '\0'; + *((char *) mempcpy (&bucket->mem[intern.offset], inval, invallen)) + = '\0'; + intern.offset += invallen + 1; } return 0; @@ -153,15 +178,19 @@ dosearch (int instatus, char *inkey, int inkeylen, char *inval, } static enum nss_status -internal_nis_endservent (intern_t * intern) +internal_nis_endservent (void) { - while (intern->start != NULL) + struct response_t *curr = intern.next; + + while (curr != NULL) { - intern->next = intern->start; - intern->start = intern->start->next; - free (intern->next); + struct response_t *last = curr; + curr = curr->next; + free (last); } + intern.next = intern.start = NULL; + return NSS_STATUS_SUCCESS; } @@ -172,7 +201,7 @@ _nss_nis_endservent (void) __libc_lock_lock (lock); - status = internal_nis_endservent (&intern); + status = internal_nis_endservent (); __libc_lock_unlock (lock); @@ -180,7 +209,7 @@ _nss_nis_endservent (void) } static enum nss_status -internal_nis_setservent (intern_t *intern) +internal_nis_setservent (void) { char *domainname; struct ypall_callback ypcb; @@ -189,12 +218,16 @@ internal_nis_setservent (intern_t *intern) if (yp_get_default_domain (&domainname)) return NSS_STATUS_UNAVAIL; - (void) internal_nis_endservent (intern); + (void) internal_nis_endservent (); ypcb.foreach = saveit; - ypcb.data = (char *) intern; + ypcb.data = NULL; status = yperr2nss (yp_all (domainname, "services.byname", &ypcb)); - intern->next = intern->start; + + /* Mark the last buffer as full. */ + intern.next->size = intern.offset; + + intern.next = intern.start; return status; } @@ -206,7 +239,7 @@ _nss_nis_setservent (int stayopen) __libc_lock_lock (lock); - status = internal_nis_setservent (&intern); + status = internal_nis_setservent (); __libc_lock_unlock (lock); @@ -215,29 +248,56 @@ _nss_nis_setservent (int stayopen) static enum nss_status internal_nis_getservent_r (struct servent *serv, char *buffer, - size_t buflen, int *errnop, intern_t *data) + size_t buflen, int *errnop) { struct parser_data *pdata = (void *) buffer; int parse_res; char *p; - if (data->start == NULL) - internal_nis_setservent (data); + if (intern.start == NULL) + internal_nis_setservent (); - /* Get the next entry until we found a correct one. */ + /* Get the next entry until we found a correct one. */ do { - if (data->next == NULL) - return NSS_STATUS_NOTFOUND; + struct response_t *bucket = intern.next; - p = strncpy (buffer, data->next->val, buflen); - while (isspace (*p)) - ++p; + if (intern.offset >= bucket->size) + { + if (bucket->next == NULL) + return NSS_STATUS_NOTFOUND; + + /* We look at all the content in the current bucket. Go on + to the next. */ + bucket = intern.next = bucket->next; + intern.offset = 0; + } + + for (p = &bucket->mem[intern.offset]; isspace (*p); ++p) + ++intern.offset; + + size_t len = strlen (p) + 1; + if (__builtin_expect (len > buflen, 0)) + { + *errnop = ERANGE; + return NSS_STATUS_TRYAGAIN; + } + + /* We unfortunately have to copy the data in the user-provided + buffer because that buffer might be around for a very long + time and the servent structure must remain valid. If we would + rely on the BUCKET memory the next 'setservent' or 'endservent' + call would destroy it. + + The important thing is that it is a single NUL-terminated + string. This is what the parsing routine expects. */ + p = memcpy (buffer, &bucket->mem[intern.offset], len); parse_res = _nss_files_parse_servent (p, serv, pdata, buflen, errnop); if (__builtin_expect (parse_res == -1, 0)) return NSS_STATUS_TRYAGAIN; - data->next = data->next->next; + + intern.offset += len; } while (!parse_res); @@ -252,7 +312,7 @@ _nss_nis_getservent_r (struct servent *serv, char *buffer, size_t buflen, __libc_lock_lock (lock); - status = internal_nis_getservent_r (serv, buffer, buflen, errnop, &intern); + status = internal_nis_getservent_r (serv, buffer, buflen, errnop); __libc_lock_unlock (lock); -- cgit v1.2.1