/*
* __dmsg --
* Debug message.
*/
static void
__dmsg(WT_DBG *ds, const char *fmt, ...)
{
va_list ap;
WT_ITEM *msg;
WT_SESSION_IMPL *session;
size_t len, space;
char *p;
session = ds->session;
/*
* Debug output chunks are not necessarily terminated with a newline
* character. It's easy if we're dumping to a stream, but if we're
* dumping to an event handler, which is line-oriented, we must buffer
* the output chunk, and pass it to the event handler once we see a
* terminating newline.
*/
if (ds->fp == NULL) {
msg = ds->msg;
for (;;) {
p = (char *)msg->mem + msg->size;
space = msg->memsize - msg->size;
va_start(ap, fmt);
len = (size_t)vsnprintf(p, space, fmt, ap);
va_end(ap);
/* Check if there was enough space. */
if (len < space) {
msg->size += len;
break;
}
/*
* There's not much to do on error without checking for
* an error return on every single printf. Anyway, it's
* pretty unlikely and this is debugging output, I'm not
* going to worry about it.
*/
if (__wt_buf_grow(
session, msg, msg->memsize + len + 128) != 0)
return;
}
if (((uint8_t *)msg->mem)[msg->size - 1] == '\n') {
((uint8_t *)msg->mem)[msg->size - 1] = '\0';
(void)__wt_msg(session, "%s", (char *)msg->mem);
msg->size = 0;
}
} else {
va_start(ap, fmt);
(void)__wt_vfprintf(ds->fp, fmt, ap);
va_end(ap);
}
}
return (vfprintf(fp, fmt, ap) < 0 ? __wt_errno() : 0);
}
/*
* __wt_fprintf --
* Fprintf for a FILE handle.
*/
int
__wt_fprintf(FILE *fp, const char *fmt, ...)
WT_GCC_FUNC_ATTRIBUTE((format (printf, 2, 3)))
{
WT_DECL_RET;
va_list ap;
va_start(ap, fmt);
ret = __wt_vfprintf(fp, fmt, ap);
va_end(ap);
return (ret);
}
/*
* __wt_fflush --
* Flush a FILE handle.
*/
int
__wt_fflush(FILE *fp)
{
/* Flush the handle. */
return (fflush(fp) == 0 ? 0 : __wt_errno());
}
/*
* __wt_eventv --
* Report a message to an event handler.
*/
int
__wt_eventv(WT_SESSION_IMPL *session, bool msg_event, int error,
const char *file_name, int line_number, const char *fmt, va_list ap)
{
WT_EVENT_HANDLER *handler;
WT_DECL_RET;
WT_SESSION *wt_session;
struct timespec ts;
size_t len, remain, wlen;
int prefix_cnt;
const char *err, *prefix;
char *end, *p, tid[128];
/*
* We're using a stack buffer because we want error messages no matter
* what, and allocating a WT_ITEM, or the memory it needs, might fail.
*
* !!!
* SECURITY:
* Buffer placed at the end of the stack in case snprintf overflows.
*/
char s[2048];
/*
* !!!
* This function MUST handle a NULL WT_SESSION_IMPL handle.
*
* Without a session, we don't have event handlers or prefixes for the
* error message. Write the error to stderr and call it a day. (It's
* almost impossible for that to happen given how early we allocate the
* first session, but if the allocation of the first session fails, for
* example, we can end up here without a session.)
*/
if (session == NULL) {
WT_RET(__wt_fprintf(session, stderr,
"WiredTiger Error%s%s: ",
error == 0 ? "" : ": ",
error == 0 ? "" : __wt_strerror(session, error, NULL, 0)));
WT_RET(__wt_vfprintf(session, stderr, fmt, ap));
WT_RET(__wt_fprintf(session, stderr, "\n"));
return (__wt_fflush(session, stderr));
}
p = s;
end = s + sizeof(s);
/*
* We have several prefixes for the error message:
* a timestamp and the process and thread ids, the database error
* prefix, the data-source's name, and the session's name. Write them
* as a comma-separate list, followed by a colon.
*/
prefix_cnt = 0;
if (__wt_epoch(session, &ts) == 0) {
__wt_thread_id(tid, sizeof(tid));
remain = WT_PTRDIFF(end, p);
wlen = (size_t)snprintf(p, remain,
"[%" PRIuMAX ":%" PRIuMAX "][%s]",
(uintmax_t)ts.tv_sec, (uintmax_t)ts.tv_nsec / 1000, tid);
p = wlen >= remain ? end : p + wlen;
prefix_cnt = 1;
}
if ((prefix = S2C(session)->error_prefix) != NULL) {
remain = WT_PTRDIFF(end, p);
wlen = (size_t)snprintf(p, remain,
"%s%s", prefix_cnt == 0 ? "" : ", ", prefix);
p = wlen >= remain ? end : p + wlen;
prefix_cnt = 1;
}
prefix = session->dhandle == NULL ? NULL : session->dhandle->name;
if (prefix != NULL) {
remain = WT_PTRDIFF(end, p);
wlen = (size_t)snprintf(p, remain,
"%s%s", prefix_cnt == 0 ? "" : ", ", prefix);
p = wlen >= remain ? end : p + wlen;
prefix_cnt = 1;
}
if ((prefix = session->name) != NULL) {
remain = WT_PTRDIFF(end, p);
wlen = (size_t)snprintf(p, remain,
"%s%s", prefix_cnt == 0 ? "" : ", ", prefix);
p = wlen >= remain ? end : p + wlen;
prefix_cnt = 1;
}
if (prefix_cnt != 0) {
remain = WT_PTRDIFF(end, p);
wlen = (size_t)snprintf(p, remain, ": ");
p = wlen >= remain ? end : p + wlen;
}
if (file_name != NULL) {
remain = WT_PTRDIFF(end, p);
wlen = (size_t)
snprintf(p, remain, "%s, %d: ", file_name, line_number);
p = wlen >= remain ? end : p + wlen;
}
remain = WT_PTRDIFF(end, p);
wlen = (size_t)vsnprintf(p, remain, fmt, ap);
p = wlen >= remain ? end : p + wlen;
if (error != 0) {
/*
* When the engine calls __wt_err on error, it often outputs an
* error message including the string associated with the error
* it's returning. We could change the calls to call __wt_errx,
* but it's simpler to not append an error string if all we are
* doing is duplicating an existing error string.
*
* Use strcmp to compare: both strings are nul-terminated, and
* we don't want to run past the end of the buffer.
*/
err = __wt_strerror(session, error, NULL, 0);
len = strlen(err);
if (WT_PTRDIFF(p, s) < len || strcmp(p - len, err) != 0) {
remain = WT_PTRDIFF(end, p);
(void)snprintf(p, remain, ": %s", err);
}
}
/*
* If a handler fails, return the error status: if we're in the process
* of handling an error, any return value we provide will be ignored by
* our caller, our caller presumably already has an error value it will
* be returning.
*
* If an application-specified or default informational message handler
* fails, complain using the application-specified or default error
* handler.
*
* If an application-specified error message handler fails, complain
* using the default error handler. If the default error handler fails,
* there's nothing to do.
*/
wt_session = (WT_SESSION *)session;
handler = session->event_handler;
if (msg_event) {
ret = handler->handle_message(handler, wt_session, s);
if (ret != 0)
__handler_failure(session, ret, "message", false);
} else {
ret = handler->handle_error(handler, wt_session, error, s);
if (ret != 0 && handler->handle_error != __handle_error_default)
__handler_failure(session, ret, "error", true);
}
return (ret);
}
