Imported Upstream version 4.1.0~20110819git450e8f3upstream/4.1.0_20110819git450e8f3

1 files changed, 299 insertions, 0 deletions

diff --git a/logfile.c b/logfile.c
new file mode 100644
index 0000000..edee89d
--- /dev/null
+++ b/logfile.c
@@ -0,0 +1,299 @@
+/* Copyright (c) 2008, 2009
+ *      Juergen Weigert (jnweiger@immd4.informatik.uni-erlangen.de)
+ *      Michael Schroeder (mlschroe@immd4.informatik.uni-erlangen.de)
+ *      Micah Cowan (micah@cowan.name)
+ *      Sadrul Habib Chowdhury (sadrul@users.sourceforge.net)
+ * Copyright (c) 1993-2002, 2003, 2005, 2006, 2007
+ *      Juergen Weigert (jnweiger@immd4.informatik.uni-erlangen.de)
+ *      Michael Schroeder (mlschroe@immd4.informatik.uni-erlangen.de)
+ * Copyright (c) 1987 Oliver Laumann
+ *
+ * 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; either version 3, or (at your option)
+ * any later version.
+ *
+ * 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 (see the file COPYING); if not, see
+ * http://www.gnu.org/licenses/, or contact Free Software Foundation, Inc.,
+ * 51 Franklin Street, Fifth Floor, Boston, MA  02111-1301  USA
+ *
+ ****************************************************************
+ */
+
+#include <sys/types.h>		/* dev_t, ino_t, off_t, ... */
+#include <sys/stat.h>		/* struct stat */
+#include <fcntl.h>		/* O_WRONLY for logfile_reopen */
+
+
+#include "config.h"
+#include "screen.h"
+#include "extern.h"
+#include "logfile.h"
+
+static void changed_logfile __P((struct logfile *));
+static struct logfile *lookup_logfile __P((char *));
+static int stolen_logfile __P((struct logfile *));
+
+static struct logfile *logroot = NULL;
+
+static void
+changed_logfile(l)
+struct logfile *l;
+{
+  struct stat o, *s = l->st;
+
+  if (fstat(fileno(l->fp), &o) < 0)		/* get trouble later */
+    return;
+  if (o.st_size > s->st_size)		/* aha, appended text */
+    {
+      s->st_size = o.st_size;		/* this should have changed */
+      s->st_mtime = o.st_mtime;		/* only size and mtime */
+    }
+}
+
+/*
+ * Requires fd to be open and need_fd to be closed.
+ * If possible, need_fd will be open afterwards and refer to 
+ * the object originally reffered by fd. fd will be closed then.
+ * Works just like ``fcntl(fd, DUPFD, need_fd); close(fd);''
+ * 
+ * need_fd is returned on success, else -1 is returned.
+ */
+int
+lf_move_fd(fd, need_fd)
+int need_fd, fd;
+{
+  int r = -1;
+  
+  if (fd == need_fd)
+    return fd;
+  if (fd >=0 && fd < need_fd)
+    r = lf_move_fd(dup(fd), need_fd);
+  close(fd);
+  return r;
+}
+
+static int
+logfile_reopen(name, wantfd, l)
+char *name;
+int wantfd;
+struct logfile *l;
+{
+  int got_fd;
+
+  close(wantfd);
+  if (((got_fd = open(name, O_WRONLY | O_CREAT | O_APPEND, 0666)) < 0) ||
+      lf_move_fd(got_fd, wantfd) < 0)
+    {
+      logfclose(l);
+      debug1("logfile_reopen: failed for %s\n", name);
+      return -1;
+    }
+  changed_logfile(l);
+  debug2("logfile_reopen: %d = %s\n", wantfd, name);
+  return 0;
+}
+
+static int (* lf_reopen_fn)() = logfile_reopen;
+
+/* 
+ * Whenever logfwrite discoveres that it is required to close and
+ * reopen the logfile, the function registered here is called.
+ * If you do not register anything here, the above logfile_reopen()
+ * will be used instead.
+ * Your function should perform the same steps as logfile_reopen():
+ * a) close the original filedescriptor without flushing any output
+ * b) open a new logfile for future output on the same filedescriptor number.
+ * c) zero out st_dev, st_ino to tell the stolen_logfile() indcator to 
+ *    reinitialise itself.
+ * d) return 0 on success.
+ */
+void
+logreopen_register(fn)
+int (*fn) __P((char *, int, struct logfile *));
+{
+  lf_reopen_fn = fn ? fn : logfile_reopen;
+}
+
+/*
+ * If the logfile has been removed, truncated, unlinked or the like,
+ * return nonzero.
+ * The l->st structure initialised by logfopen is updated
+ * on every call.
+ */
+static int
+stolen_logfile(l)
+struct logfile *l;
+{
+  struct stat o, *s = l->st;
+
+  o = *s;
+  if (fstat(fileno(l->fp), s) < 0)		/* remember that stat failed */
+    s->st_ino = s->st_dev = 0;
+  ASSERT(s == l->st);
+  if (!o.st_dev && !o.st_ino)			/* nothing to compare with */
+    return 0;
+
+  if ((!s->st_dev && !s->st_ino) ||	/* stat failed, that's new! */
+      !s->st_nlink ||			/* red alert: file unlinked */
+      (s->st_size < o.st_size) ||		/*           file truncated */
+      (s->st_mtime != o.st_mtime) ||		/*            file modified */
+      ((s->st_ctime != o.st_ctime) &&   	/*     file changed (moved) */
+       !(s->st_mtime == s->st_ctime && 		/*  and it was not a change */
+         o.st_ctime < s->st_ctime)))		/* due to delayed nfs write */
+    {
+      debug1("stolen_logfile: %s stolen!\n", l->name);
+      debug3("st_dev %d, st_ino %d, st_nlink %d\n", 
+             (int)s->st_dev, (int)s->st_ino, (int)s->st_nlink);
+      debug2("s->st_size %d, o.st_size %d\n", (int)s->st_size, (int)o.st_size);
+      debug2("s->st_mtime %d, o.st_mtime %d\n", 
+             (int)s->st_mtime, (int)o.st_mtime);
+      debug2("s->st_ctime %d, o.st_ctime %d\n", 
+             (int)s->st_ctime, (int)o.st_ctime);
+      return -1;
+    }
+
+  debug1("stolen_logfile: %s o.k.\n", l->name);
+  return 0;
+}
+
+static struct logfile *
+lookup_logfile(name)
+char *name;
+{
+  struct logfile *l;
+
+  for (l = logroot; l; l = l->next)
+    if (!strcmp(name, l->name))
+      return l;
+  return NULL;
+}
+
+struct logfile *
+logfopen(name, fp)
+char *name;
+FILE *fp;
+{
+  struct logfile *l;
+
+  if (!fp)
+    {
+      if (!(l = lookup_logfile(name)))
+        return NULL;
+      l->opencount++;
+      return l;
+    }
+
+  if (!(l = (struct logfile *)malloc(sizeof(struct logfile))))
+    return NULL;
+  if (!(l->st = (struct stat *)malloc(sizeof(struct stat))))
+    {
+      free((char *)l);
+      return NULL;
+    }
+
+  if (!(l->name = SaveStr(name)))
+    {
+      free((char *)l->st);
+      free((char *)l);
+      return NULL;
+    }
+  l->fp = fp;
+  l->opencount = 1;
+  l->writecount = 0;
+  l->flushcount = 0;
+  changed_logfile(l);
+
+  l->next = logroot;
+  logroot = l;
+  return l;
+}
+
+int
+islogfile(name)
+char *name;
+{
+  if (!name)
+    return logroot ? 1 : 0;
+  return lookup_logfile(name) ? 1 : 0;
+}
+
+int
+logfclose(l)
+struct logfile *l;
+{
+  struct logfile **lp;
+
+  for (lp = &logroot; *lp; lp = &(*lp)->next)
+    if (*lp == l)
+      break;
+
+  if (!*lp)
+    return -1;
+
+  if ((--l->opencount) > 0)
+    return 0;
+  if (l->opencount < 0)
+    abort();
+
+  *lp = l->next;
+  fclose(l->fp);
+  free(l->name);
+  free((char *)l);
+  return 0;
+}
+
+/* 
+ * XXX
+ * write and flush both *should* check the file's stat, if it disappeared
+ * or changed, re-open it.
+ */
+int
+logfwrite(l, buf, n)
+struct logfile *l;
+char *buf;
+int n;
+{
+  int r;
+
+  if (stolen_logfile(l) && lf_reopen_fn(l->name, fileno(l->fp), l))
+    return -1;
+  r = fwrite(buf, n, 1, l->fp);
+  l->writecount += l->flushcount + 1;
+  l->flushcount = 0;
+  changed_logfile(l); 
+  return r;
+}
+
+int
+logfflush(l)
+struct logfile *l;
+{
+  int r = 0;
+
+  if (!l)
+    for (l = logroot; l; l = l->next)
+      {
+	if (stolen_logfile(l) && lf_reopen_fn(l->name, fileno(l->fp), l))
+	  return -1;
+	r |= fflush(l->fp);
+	l->flushcount++;
+	changed_logfile(l); 
+      }
+  else
+    {
+      if (stolen_logfile(l) && lf_reopen_fn(l->name, fileno(l->fp), l))
+	return -1;
+      r = fflush(l->fp);
+      l->flushcount++;
+      changed_logfile(l); 
+    }
+  return r;
+}
+