200 lines
4.6 KiB
C
200 lines
4.6 KiB
C
/*
|
|
* Copyright (C) 2009 Red Hat Inc, Steven Rostedt <srostedt@redhat.com>
|
|
*
|
|
* ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
|
|
* This program is free software; you can redistribute it and/or
|
|
* modify it under the terms of the GNU Lesser General Public
|
|
* License as published by the Free Software Foundation;
|
|
* version 2.1 of the License (not later!)
|
|
*
|
|
* This program is distributed in the hope that it will be useful,
|
|
* but WITHOUT ANY WARRANTY; without even the implied warranty of
|
|
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
|
|
* GNU Lesser General Public License for more details.
|
|
*
|
|
* You should have received a copy of the GNU Lesser General Public
|
|
* License along with this program; if not, see <http://www.gnu.org/licenses>
|
|
*
|
|
* ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
|
|
*/
|
|
#include <stdio.h>
|
|
#include <stdlib.h>
|
|
#include <string.h>
|
|
#include <stdarg.h>
|
|
|
|
#include "event-parse.h"
|
|
#include "event-utils.h"
|
|
|
|
/*
|
|
* The TRACE_SEQ_POISON is to catch the use of using
|
|
* a trace_seq structure after it was destroyed.
|
|
*/
|
|
#define TRACE_SEQ_POISON ((void *)0xdeadbeef)
|
|
#define TRACE_SEQ_CHECK(s) \
|
|
do { \
|
|
if ((s)->buffer == TRACE_SEQ_POISON) \
|
|
die("Usage of trace_seq after it was destroyed"); \
|
|
} while (0)
|
|
|
|
/**
|
|
* trace_seq_init - initialize the trace_seq structure
|
|
* @s: a pointer to the trace_seq structure to initialize
|
|
*/
|
|
void trace_seq_init(struct trace_seq *s)
|
|
{
|
|
s->len = 0;
|
|
s->readpos = 0;
|
|
s->buffer_size = TRACE_SEQ_BUF_SIZE;
|
|
s->buffer = malloc_or_die(s->buffer_size);
|
|
}
|
|
|
|
/**
|
|
* trace_seq_destroy - free up memory of a trace_seq
|
|
* @s: a pointer to the trace_seq to free the buffer
|
|
*
|
|
* Only frees the buffer, not the trace_seq struct itself.
|
|
*/
|
|
void trace_seq_destroy(struct trace_seq *s)
|
|
{
|
|
if (!s)
|
|
return;
|
|
TRACE_SEQ_CHECK(s);
|
|
free(s->buffer);
|
|
s->buffer = TRACE_SEQ_POISON;
|
|
}
|
|
|
|
static void expand_buffer(struct trace_seq *s)
|
|
{
|
|
s->buffer_size += TRACE_SEQ_BUF_SIZE;
|
|
s->buffer = realloc(s->buffer, s->buffer_size);
|
|
if (!s->buffer)
|
|
die("Can't allocate trace_seq buffer memory");
|
|
}
|
|
|
|
/**
|
|
* trace_seq_printf - sequence printing of trace information
|
|
* @s: trace sequence descriptor
|
|
* @fmt: printf format string
|
|
*
|
|
* It returns 0 if the trace oversizes the buffer's free
|
|
* space, 1 otherwise.
|
|
*
|
|
* The tracer may use either sequence operations or its own
|
|
* copy to user routines. To simplify formating of a trace
|
|
* trace_seq_printf is used to store strings into a special
|
|
* buffer (@s). Then the output may be either used by
|
|
* the sequencer or pulled into another buffer.
|
|
*/
|
|
int
|
|
trace_seq_printf(struct trace_seq *s, const char *fmt, ...)
|
|
{
|
|
va_list ap;
|
|
int len;
|
|
int ret;
|
|
|
|
TRACE_SEQ_CHECK(s);
|
|
|
|
try_again:
|
|
len = (s->buffer_size - 1) - s->len;
|
|
|
|
va_start(ap, fmt);
|
|
ret = vsnprintf(s->buffer + s->len, len, fmt, ap);
|
|
va_end(ap);
|
|
|
|
if (ret >= len) {
|
|
expand_buffer(s);
|
|
goto try_again;
|
|
}
|
|
|
|
s->len += ret;
|
|
|
|
return 1;
|
|
}
|
|
|
|
/**
|
|
* trace_seq_vprintf - sequence printing of trace information
|
|
* @s: trace sequence descriptor
|
|
* @fmt: printf format string
|
|
*
|
|
* The tracer may use either sequence operations or its own
|
|
* copy to user routines. To simplify formating of a trace
|
|
* trace_seq_printf is used to store strings into a special
|
|
* buffer (@s). Then the output may be either used by
|
|
* the sequencer or pulled into another buffer.
|
|
*/
|
|
int
|
|
trace_seq_vprintf(struct trace_seq *s, const char *fmt, va_list args)
|
|
{
|
|
int len;
|
|
int ret;
|
|
|
|
TRACE_SEQ_CHECK(s);
|
|
|
|
try_again:
|
|
len = (s->buffer_size - 1) - s->len;
|
|
|
|
ret = vsnprintf(s->buffer + s->len, len, fmt, args);
|
|
|
|
if (ret >= len) {
|
|
expand_buffer(s);
|
|
goto try_again;
|
|
}
|
|
|
|
s->len += ret;
|
|
|
|
return len;
|
|
}
|
|
|
|
/**
|
|
* trace_seq_puts - trace sequence printing of simple string
|
|
* @s: trace sequence descriptor
|
|
* @str: simple string to record
|
|
*
|
|
* The tracer may use either the sequence operations or its own
|
|
* copy to user routines. This function records a simple string
|
|
* into a special buffer (@s) for later retrieval by a sequencer
|
|
* or other mechanism.
|
|
*/
|
|
int trace_seq_puts(struct trace_seq *s, const char *str)
|
|
{
|
|
int len;
|
|
|
|
TRACE_SEQ_CHECK(s);
|
|
|
|
len = strlen(str);
|
|
|
|
while (len > ((s->buffer_size - 1) - s->len))
|
|
expand_buffer(s);
|
|
|
|
memcpy(s->buffer + s->len, str, len);
|
|
s->len += len;
|
|
|
|
return len;
|
|
}
|
|
|
|
int trace_seq_putc(struct trace_seq *s, unsigned char c)
|
|
{
|
|
TRACE_SEQ_CHECK(s);
|
|
|
|
while (s->len >= (s->buffer_size - 1))
|
|
expand_buffer(s);
|
|
|
|
s->buffer[s->len++] = c;
|
|
|
|
return 1;
|
|
}
|
|
|
|
void trace_seq_terminate(struct trace_seq *s)
|
|
{
|
|
TRACE_SEQ_CHECK(s);
|
|
|
|
/* There's always one character left on the buffer */
|
|
s->buffer[s->len] = 0;
|
|
}
|
|
|
|
int trace_seq_do_printf(struct trace_seq *s)
|
|
{
|
|
TRACE_SEQ_CHECK(s);
|
|
return printf("%.*s", s->len, s->buffer);
|
|
}
|