New file with new function to dot-lock an mbox file and copy it to a safe

	* camel-movemail.c: New file with new function to dot-lock an mbox
	file and copy it to a safe private directory.

svn path=/trunk/; revision=2356

5 files changed, 305 insertions, 0 deletions

diff --git a/camel/ChangeLog b/camel/ChangeLog
index 1d99752ea1..8859243025 100644
--- a/camel/ChangeLog
+++ b/camel/ChangeLog
@@ -1,3 +1,8 @@
+2000-04-09  Dan Winship  <danw@helixcode.com>
+
+	* camel-movemail.c: New file with new function to dot-lock an mbox
+	file and copy it to a safe private directory.
+
 2000-04-08  Christopher James Lahey  <clahey@helixcode.com>
 
 	* providers/smtp/.cvsignore: Added a .cvsignore file.
diff --git a/camel/Makefile.am b/camel/Makefile.am
index eefc48bd10..16e180a392 100644
--- a/camel/Makefile.am
+++ b/camel/Makefile.am
@@ -49,6 +49,7 @@ libcamel_la_SOURCES = 				\
 	camel-mime-message.c			\
 	camel-mime-part.c			\
 	camel-mime-part-utils.c			\
+	camel-movemail.c			\
 	camel-multipart.c			\
 	camel-op-queue.c			\
 	camel-provider.c			\
@@ -93,6 +94,7 @@ libcamelinclude_HEADERS =			\
 	camel-mime-message.h			\
 	camel-mime-part.h			\
 	camel-mime-part-utils.h			\
+	camel-movemail.h			\
 	camel-multipart.h			\
 	camel-op-queue.h			\
 	camel-provider.h			\
diff --git a/camel/camel-movemail.c b/camel/camel-movemail.c
new file mode 100644
index 0000000000..e15e26e7ae
--- /dev/null
+++ b/camel/camel-movemail.c
@@ -0,0 +1,252 @@
+/* -*- Mode: C; tab-width: 8; indent-tabs-mode: t; c-basic-offset: 8 -*- */
+/* camel-movemail.c: mbox copying function */
+
+/*
+ * Author:
+ *  Dan Winship <danw@helixcode.com>
+ *
+ * Copyright 2000 Helix Code, Inc. (http://www.helixcode.com)
+ *
+ * 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 2 of the
+ * License, 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; if not, write to the Free Software
+ * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307
+ * USA
+ */
+
+#include <config.h>
+
+#include <sys/stat.h>
+#include <errno.h>
+#include <fcntl.h>
+#include <stdlib.h>
+#include <stdio.h>
+#include <time.h>
+#include <unistd.h>
+
+#include "camel-movemail.h"
+#include "camel-exception.h"
+
+/**
+ * camel_movemail: Copy an mbox file from a shared spool directory to a
+ * new folder in a Camel store
+ * @source: source file
+ * @dest: destination file
+ * @ex: a CamelException
+ *
+ * This copies an mbox file from a shared directory with multiple
+ * readers and writers into a private (presumably Camel-controlled)
+ * directory. Dot locking is used on the source file (but not the
+ * destination).
+ *
+ * Return value: 1 if mail was copied, 0 if the source file contained
+ * no mail, -1 if an error occurred.
+ **/
+int
+camel_movemail (const char *source, const char *dest, CamelException *ex)
+{
+	gboolean locked, error;
+	int sfd, dfd, tmpfd;
+	char *locktmpfile, *lockfile;
+	struct stat st;
+	time_t now, timeout;
+	int nread, nwrote;
+	char buf[BUFSIZ];
+
+	camel_exception_clear (ex);
+
+	/* Stat and then open the spool file. If it doesn't exist or
+	 * is empty, the user has no mail. (There's technically a race
+	 * condition here in that an MDA might have just now locked it
+	 * to deliver a message, but we don't care. In that case,
+	 * assuming it's unlocked is equivalent to pretending we were
+	 * called a fraction earlier.)
+	 */
+	if (stat (source, &st) == -1) {
+		if (errno == ENOENT)
+			return 0;
+
+		camel_exception_setv (ex, CAMEL_EXCEPTION_SYSTEM,
+				      "Could not check mail file %s: %s",
+				      source, g_strerror (errno));
+		return -1;
+	}
+	if (st.st_size == 0)
+		return 0;
+
+	sfd = open (source, O_RDWR);
+	if (sfd == -1) {
+		camel_exception_setv (ex, CAMEL_EXCEPTION_SYSTEM,
+				      "Could not open mail file %s: %s",
+				      source, g_strerror (errno));
+		return -1;
+	}
+
+	dfd = open (dest, O_WRONLY | O_CREAT, S_IRUSR | S_IWUSR);
+	if (dfd == -1) {
+		camel_exception_setv (ex, CAMEL_EXCEPTION_SYSTEM,
+				      "Could not open temporary mail "
+				      "file %s: %s", dest, g_strerror (errno));
+		close (sfd);
+		return -1;
+	}
+
+	/* Create the unique lock file. */
+	locktmpfile = g_strdup_printf ("%s.lock.XXXXXX", source);
+#ifdef HAVE_MKSTEMP
+	tmpfd = mkstemp (locktmpfile);
+#else
+	if (mktemp (locktmpfile)) {
+		tmpfd = open (locktmpfile, O_RDWR | O_CREAT | O_EXCL,
+			      S_IRUSR | S_IWUSR);
+	} else
+		tmpfd = -1;
+#endif
+	if (tmpfd == -1) {
+		camel_exception_setv (ex, CAMEL_EXCEPTION_SYSTEM,
+				      "Could not create lock file "
+				      "for %s: %s", source, g_strerror (errno));
+		close (sfd);
+		close (dfd);
+		unlink (dest);
+		return -1;
+	}
+	close (tmpfd);
+
+	lockfile = g_strdup_printf ("%s.lock", source);
+	locked = FALSE;
+	time (&timeout);
+	timeout += 30;
+
+	/* Loop trying to lock the file for 30 seconds. */
+	while (time (&now) < timeout) {
+		/* Try to make the lock. */
+		if (symlink (locktmpfile, lockfile) == 0) {
+			locked = TRUE;
+			break;
+		}
+
+		/* If we fail for a reason other than that someone
+		 * else has the lock, then abort.
+		 */
+		if (errno != EEXIST) {
+			camel_exception_setv (ex, CAMEL_EXCEPTION_SYSTEM,
+					      "Could not create lock "
+					      "file for %s: %s", source,
+					      g_strerror (errno));
+			break;
+		}
+
+		/* Check the modtime on the lock file. */
+		if (stat (lockfile, &st) == -1) {
+			/* If the lockfile disappeared, try again. */
+			if (errno == ENOENT)
+				continue;
+
+			/* Some other error. Abort. */
+			camel_exception_setv (ex, CAMEL_EXCEPTION_SYSTEM,
+					      "Could not test lock "
+					      "file for %s: %s", source,
+					      g_strerror (errno));
+			break;
+		}
+
+		/* If the lock file is stale, remove it and try again. */
+		if (st.st_mtime < now - 60) {
+			unlink (lockfile);
+			continue;
+		}
+
+		/* Otherwise, sleep and try again. */
+		sleep (5);
+	}
+
+	if (!locked) {
+		/* Something has gone awry. */
+		if (now >= timeout) {
+			camel_exception_setv (ex, CAMEL_EXCEPTION_SYSTEM,
+					      "Timed out trying to get "
+					      "lock file on %s. Try again "
+					      "later.", source);
+		}
+		g_free (lockfile);
+		unlink (locktmpfile);
+		g_free (locktmpfile);
+		close (sfd);
+		close (dfd);
+		unlink (dest);
+		return -1;
+	}
+
+	/* OK. We have the file locked now. */
+
+	/* FIXME: Set a timer to keep the file locked. */
+
+	error = FALSE;
+	while (1) {
+		int written = 0;
+
+		nread = read (sfd, buf, sizeof (buf));
+		if (nread == 0)
+			break;
+		else if (nread == -1) {
+			camel_exception_setv (ex, CAMEL_EXCEPTION_SYSTEM,
+					      "Error reading mail file: %s",
+					      g_strerror (errno));
+			error = TRUE;
+			break;
+		}
+
+		while (nread) {
+			nwrote = write (dfd, buf + written, nread);
+			if (nwrote == -1) {
+				camel_exception_setv (ex, CAMEL_EXCEPTION_SYSTEM,
+						      "Error writing "
+						      "mail temp file: %s",
+						      g_strerror (errno));
+				error = TRUE;
+				break;
+			}
+			written += nwrote;
+			nread -= nwrote;
+		}
+	}
+
+	/* If no errors occurred copying the data, and we successfully
+	 * close the destination file, then truncate the source file.
+	 * If there is some sort of error, delete the destination file.
+	 */
+	if (!error) {
+		if (close (dfd) == 0)
+			ftruncate (sfd, 0);
+		else {
+			camel_exception_setv (ex, CAMEL_EXCEPTION_SYSTEM,
+					      "Failed to store mail in "
+					      "temp file %s: %s", dest,
+					      g_strerror (errno));
+			unlink (dest);
+			error = TRUE;
+		}
+	} else {
+		close (dfd);
+		unlink (dest);
+	}
+	close (sfd);
+
+	/* Clean up lock files. */
+	unlink (lockfile);
+	g_free (lockfile);
+	unlink (locktmpfile);
+	g_free (locktmpfile);
+
+	return error ? -1 : 1;
+}
diff --git a/camel/camel-movemail.h b/camel/camel-movemail.h
new file mode 100644
index 0000000000..a4b20141ac
--- /dev/null
+++ b/camel/camel-movemail.h
@@ -0,0 +1,45 @@
+/* -*- Mode: C; tab-width: 8; indent-tabs-mode: t; c-basic-offset: 8 -*- */
+/* camel-movemail.h: mbox copy function */
+
+/* 
+ * Author: 
+ *  Dan Winship <danw@helixcode.com>
+ *
+ * Copyright 2000 Helix Code, Inc. (http://www.helixcode.com)
+ *
+ * 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 2 of the
+ * License, 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; if not, write to the Free Software
+ * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307
+ * USA
+ */
+
+
+#ifndef CAMEL_MOVEMAIL_H
+#define CAMEL_MOVEMAIL_H 1
+
+
+#ifdef __cplusplus
+extern "C" {
+#pragma }
+#endif /* __cplusplus }*/
+
+#include "camel-exception.h"
+
+int camel_movemail (const char *source, const char *dest, CamelException *ex);
+
+
+#ifdef __cplusplus
+}
+#endif /* __cplusplus */
+
+#endif /* CAMEL_MOVEMAIL_H */
diff --git a/camel/camel.h b/camel/camel.h
index a92d69e04d..0c9a045afb 100644
--- a/camel/camel.h
+++ b/camel/camel.h
@@ -46,6 +46,7 @@ extern "C" {
 #include <camel/camel-mime-body-part.h>
 #include <camel/camel-mime-message.h>
 #include <camel/camel-mime-part.h>
+#include <camel/camel-movemail.h>
 #include <camel/camel-multipart.h>
 #include <camel/camel-op-queue.h>
 #include <camel/camel-provider.h>