[PATCH v3 02/20] insert: open Maildir tmp file

[Peter Wang <novalazy@gmail.com>]

Open a unique file in the Maildir tmp directory.
The new message is not yet copied into the file.
---
 notmuch-insert.c | 105 ++++++++++++++++++++++++++++++++++++++++++++++++++++++-
 1 file changed, 104 insertions(+), 1 deletion(-)

diff --git a/notmuch-insert.c b/notmuch-insert.c
index c1d359c..7d100ae 100644
--- a/notmuch-insert.c
+++ b/notmuch-insert.c
@@ -20,12 +20,107 @@
 
 #include "notmuch-client.h"
 
+#include <sys/types.h>
+#include <sys/stat.h>
+#include <fcntl.h>
+
+/* Like gethostname but guarantees that a null-terminated hostname is
+ * returned, even if it has to make one up.
+ * Returns true unless hostname contains a slash. */
+static notmuch_bool_t
+safe_gethostname (char *hostname, size_t len)
+{
+    if (gethostname (hostname, len) == -1) {
+	strncpy (hostname, "unknown", len);
+    }
+    hostname[len - 1] = '\0';
+
+    return (strchr (hostname, '/') == NULL);
+}
+
+/* Open a unique file in the Maildir 'tmp' directory.
+ * Returns the file descriptor on success, or -1 on failure.
+ * On success, file paths for the message in the 'tmp' and 'new'
+ * directories are returned via tmppath and newpath. */
+static int
+maildir_open_tmp_file (void *ctx, const char *dir,
+		       char **tmppath, char **newpath)
+{
+    pid_t pid;
+    char hostname[256];
+    struct timeval tv;
+    char *filename;
+    int fd = -1;
+
+    /* We follow the Dovecot file name generation algorithm. */
+    pid = getpid ();
+    if (! safe_gethostname (hostname, sizeof (hostname))) {
+	fprintf (stderr, "Error: invalid host name.\n");
+	return -1;
+    }
+    do {
+	gettimeofday (&tv, NULL);
+	filename = talloc_asprintf (ctx, "%ld.M%ldP%d.%s",
+				    tv.tv_sec, tv.tv_usec, pid, hostname);
+	if (! filename) {
+	    fprintf (stderr, "Out of memory\n");
+	    return -1;
+	}
+
+	*tmppath = talloc_asprintf (ctx, "%s/tmp/%s", dir, filename);
+	if (! *tmppath) {
+	    fprintf (stderr, "Out of memory\n");
+	    return -1;
+	}
+
+	fd = open (*tmppath, O_WRONLY | O_CREAT | O_TRUNC | O_EXCL, 0600);
+    } while (fd == -1 && errno == EEXIST);
+
+    if (fd == -1) {
+	fprintf (stderr, "Error: opening %s: %s\n", *tmppath, strerror (errno));
+	return -1;
+    }
+
+    *newpath = talloc_asprintf (ctx, "%s/new/%s", dir, filename);
+    if (! *newpath) {
+	fprintf (stderr, "Out of memory\n");
+	close (fd);
+	unlink (*tmppath);
+	return -1;
+    }
+
+    talloc_free (filename);
+
+    return fd;
+}
+
+static notmuch_bool_t
+insert_message (void *ctx, notmuch_database_t *notmuch, int fdin,
+	        const char *dir)
+{
+    char *tmppath;
+    char *newpath;
+    int fdout;
+
+    fdout = maildir_open_tmp_file (ctx, dir, &tmppath, &newpath);
+    if (fdout < 0) {
+	return FALSE;
+    }
+
+    /* For now we just delete the tmp file immediately. */
+    close (fdout);
+    unlink (tmppath);
+    return FALSE;
+}
+
 int
 notmuch_insert_command (void *ctx, int argc, char *argv[])
 {
     notmuch_config_t *config;
     notmuch_database_t *notmuch;
     const char *db_path;
+    char *maildir;
+    notmuch_bool_t ret;
 
     config = notmuch_config_open (ctx, NULL, NULL);
     if (config == NULL)
@@ -33,11 +128,19 @@ notmuch_insert_command (void *ctx, int argc, char *argv[])
 
     db_path = notmuch_config_get_database_path (config);
 
+    maildir = talloc_asprintf (ctx, "%s", db_path);
+    if (! maildir) {
+	fprintf (stderr, "Out of memory\n");
+	return 1;
+    }
+
     if (notmuch_database_open (notmuch_config_get_database_path (config),
 			       NOTMUCH_DATABASE_MODE_READ_WRITE, &notmuch))
 	return 1;
 
+    ret = insert_message (ctx, notmuch, STDIN_FILENO, maildir);
+
     notmuch_database_destroy (notmuch);
 
-    return 1;
+    return (ret) ? 0 : 1;
 }
-- 
1.7.12.1