libliftoff/log.c
Roman Gilg c05f290f95
feat: log continuous debug messages into per-device buffers
Instead of exposing to consumers write streaming log data into a per-device
buffer that gets created on request and destroyed after the buffer has been
written to the log.

Passing a NULL string to the internal continuous log function triggers a write
of the buffer to the log.

BREAKING CHANGE: continuous log function is moved from log header to private
header.
2020-03-10 11:59:42 +01:00

114 lines
2.3 KiB
C

#include <errno.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include "log.h"
#include "private.h"
static enum liftoff_log_importance log_importance = LIFTOFF_ERROR;
static void log_stderr(enum liftoff_log_importance verbosity, const char *fmt,
va_list args)
{
vfprintf(stderr, fmt, args);
fprintf(stderr, "\n");
}
static liftoff_log_func log_callback = log_stderr;
void liftoff_log_init(enum liftoff_log_importance verbosity,
liftoff_log_func callback) {
log_importance = verbosity;
if (callback) {
log_callback = callback;
} else {
log_callback = log_stderr;
}
}
bool log_has(enum liftoff_log_importance verbosity)
{
return verbosity <= log_importance;
}
void liftoff_log(enum liftoff_log_importance verbosity, const char *fmt, ...)
{
if (!log_has(verbosity)) {
return;
}
va_list args;
va_start(args, fmt);
log_callback(verbosity, fmt, args);
va_end(args);
}
void liftoff_log_errno(enum liftoff_log_importance verbosity, const char *msg)
{
liftoff_log(verbosity, "%s: %s", msg, strerror(errno));
}
void debug_cnt(struct liftoff_device *device, const char *fmt, ...)
{
if (!log_has(LIFTOFF_DEBUG)) {
return;
}
if (fmt == NULL) {
if (device->log_buf == 0) {
return;
}
liftoff_log(LIFTOFF_DEBUG, "%s", device->log_buf);
free(device->log_buf);
device->log_buf = NULL;
device->log_buf_index = 0;
device->log_buf_len = 0;
return;
}
va_list args;
va_start(args, fmt);
if (device->log_buf == NULL) {
device->log_buf = malloc(4096);
if (device->log_buf == NULL) {
liftoff_log_errno(LIFTOFF_ERROR, "malloc");
goto cleanup_out;
}
device->log_buf_len = 4096 / sizeof(char);
}
do {
size_t max_len = device->log_buf_len - device->log_buf_index;
int ret;
ret = vsnprintf(device->log_buf + device->log_buf_index,
max_len, fmt, args);
if (ret < 0) {
goto cleanup_out;
}
if (ret - (int)max_len > 0) {
device->log_buf_index = device->log_buf_len;
device->log_buf_len *= 2;
if (realloc(device->log_buf, device->log_buf_len) == NULL) {
liftoff_log_errno(LIFTOFF_ERROR, "realloc");
goto cleanup_out;
}
} else {
device->log_buf_index += ret;
goto final_out;
}
} while (1);
cleanup_out:
free(device->log_buf);
device->log_buf = NULL;
device->log_buf_index = 0;
device->log_buf_len = 0;
final_out:
va_end(args);
}