Initial import

libc/log/vflogf.c

@@ -0,0 +1,116 @@
+/*-*- mode:c;indent-tabs-mode:nil;c-basic-offset:2;tab-width:8;coding:utf-8 -*-│
+│vi: set net ft=c ts=2 sts=2 sw=2 fenc=utf-8                                :vi│
+╞══════════════════════════════════════════════════════════════════════════════╡
+│ Copyright 2020 Justine Alexandra Roberts Tunney                              │
+│                                                                              │
+│ This program is free software; you can redistribute it and/or modify         │
+│ it under the terms of the GNU General Public License as published by         │
+│ the Free Software Foundation; version 2 of the License.                      │
+│                                                                              │
+│ 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             │
+│ General Public License for more details.                                     │
+│                                                                              │
+│ You should have received a copy of the GNU General Public License            │
+│ along with this program; if not, write to the Free Software                  │
+│ Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA                │
+│ 02110-1301 USA                                                               │
+╚─────────────────────────────────────────────────────────────────────────────*/
+#include "libc/bits/bits.h"
+#include "libc/calls/calls.h"
+#include "libc/calls/struct/stat.h"
+#include "libc/calls/struct/timeval.h"
+#include "libc/conv/conv.h"
+#include "libc/dce.h"
+#include "libc/errno.h"
+#include "libc/fmt/fmt.h"
+#include "libc/log/log.h"
+#include "libc/math.h"
+#include "libc/nexgen32e/nexgen32e.h"
+#include "libc/runtime/runtime.h"
+#include "libc/stdio/stdio.h"
+#include "libc/str/str.h"
+#include "libc/time/struct/tm.h"
+#include "libc/time/time.h"
+
+#define kNontrivialSize (8 * 1000 * 1000)
+
+static int loglevel2char(unsigned level) {
+  switch (level) {
+    case kLogInfo:
+      return 'I';
+    case kLogDebug:
+      return 'D';
+    case kLogWarn:
+      return 'W';
+    case kLogFatal:
+      return 'F';
+    default:
+      return '?';
+  }
+}
+
+/**
+ * Takes corrective action if logging is on the fritz.
+ */
+void vflogf_onfail(FILE *f) {
+  errno_t err;
+  struct stat st;
+  if (IsTiny()) return;
+  err = ferror(f);
+  if ((err == ENOSPC || err == EDQUOT || err == EFBIG) &&
+      (fstat(fileno(f), &st) == -1 || st.st_size > kNontrivialSize)) {
+    ftruncate(fileno(f), 0);
+    fseek(f, SEEK_SET, 0);
+    f->beg = f->end = 0;
+    clearerr(f);
+    (fprintf)(f, "performed emergency log truncation: %s\n", strerror(err));
+  }
+}
+
+/**
+ * Writes formatted message w/ timestamp to log.
+ */
+void(vflogf)(unsigned level, const char *file, int line, FILE *f,
+             const char *fmt, va_list va) {
+  static struct timespec ts;
+  struct tm tm;
+  long double t2;
+  const char *prog;
+  int64_t secs, nsec, dots;
+  char zonebuf[8], *zonebufp;
+  char timebuf[24], *timebufp;
+  if (!f) f = g_logfile;
+  if (fileno(f) == -1) return;
+  t2 = nowl();
+  secs = t2;
+  nsec = mod1000000000int64(t2 * 1e9L);
+  if (secs > ts.tv_sec) {
+    localtime_r(&secs, &tm);
+    strftime(timebuf, sizeof(timebuf), "%Y%m%dT%H%M%S", &tm);
+    strftime(zonebuf, sizeof(zonebuf), "%Z", &tm);
+    timebufp = timebuf;
+    zonebufp = zonebuf;
+    dots = nsec;
+  } else {
+    timebufp = "---------------";
+    zonebufp = "---";
+    dots = nsec - ts.tv_nsec;
+  }
+  ts.tv_sec = secs;
+  ts.tv_nsec = nsec;
+  prog = basename(program_invocation_name);
+  if (fprintf(f, "%c%s%s%06ld:%s:%d:%.*s:%d] ", loglevel2char(level), timebufp,
+              zonebufp, mod1000000int64(div1000int64(dots)), file, line,
+              strchrnul(prog, '.') - prog, prog, getpid()) <= 0) {
+    vflogf_onfail(f);
+  }
+  (vfprintf)(f, fmt, va);
+  va_end(va);
+  fputc('\n', f);
+  if (level == kLogFatal) {
+    die();
+    unreachable;
+  }
+}