util: refactor sync_dir and mkdir_recursive

Moving these functions to libnotmuch_util will allow re-use from
either multiple CLI compilation units or from the library. To avoid
future surprises, replace printing to stderr with the usual status
string mechanism.

2 files changed, 105 insertions, 1 deletions

diff --git a/util/path-util.c b/util/path-util.c
index 3267a967..5511c09b 100644
--- a/util/path-util.c
+++ b/util/path-util.c
@@ -5,10 +5,17 @@
 #define _GNU_SOURCE
 
 #include "path-util.h"
-
+#include "compat.h"
+#include <string.h>
+#include <stdio.h>
+#include <errno.h>
+#include <sys/stat.h>
+#include <fcntl.h>
+#include <unistd.h>
 #include <limits.h>
 #include <stdlib.h>
 
+#include <talloc.h>
 
 char *
 notmuch_canonicalize_file_name (const char *path)
@@ -25,3 +32,91 @@ notmuch_canonicalize_file_name (const char *path)
 #error undefined PATH_MAX _and_ missing canonicalize_file_name not supported
 #endif
 }
+
+/* Call fsync() on a directory path. */
+notmuch_status_t
+sync_dir (const char *dir, char **status_string)
+{
+    int fd, r;
+
+    fd = open (dir, O_RDONLY);
+    if (fd == -1) {
+	if (status_string)
+	    IGNORE_RESULT (asprintf (status_string,
+				     "Error: open %s: %s\n", dir, strerror (errno)));
+	return NOTMUCH_STATUS_FILE_ERROR;
+    }
+
+    r = fsync (fd);
+    if (r && status_string)
+	IGNORE_RESULT (asprintf (status_string,
+				 "Error: fsync %s: %s\n", dir, strerror (errno)));
+
+    close (fd);
+
+    return r == 0 ? NOTMUCH_STATUS_SUCCESS : NOTMUCH_STATUS_FILE_ERROR;
+}
+
+/*
+ * Make the given directory and its parents as necessary, using the
+ * given mode. Partial results are not cleaned up on errors.
+ */
+notmuch_status_t
+mkdir_recursive (const void *ctx, const char *path, int mode,
+		 char **status_string)
+{
+    notmuch_status_t status;
+    struct stat st;
+    int r;
+    char *parent = NULL, *slash;
+
+    /* First check the common case: directory already exists. */
+    r = stat (path, &st);
+    if (r == 0) {
+	if (! S_ISDIR (st.st_mode)) {
+	    if (status_string)
+		IGNORE_RESULT (asprintf (status_string, "Error: '%s' is not a directory: %s\n",
+					 path, strerror (EEXIST)));
+	    return NOTMUCH_STATUS_FILE_ERROR;
+	}
+
+	return NOTMUCH_STATUS_SUCCESS;
+    } else if (errno != ENOENT) {
+	if (status_string)
+	    IGNORE_RESULT (asprintf (status_string,
+				     "Error: stat '%s': %s\n", path, strerror (errno)));
+	return NOTMUCH_STATUS_FILE_ERROR;
+    }
+
+    /* mkdir parents, if any */
+    slash = strrchr (path, '/');
+    if (slash && slash != path) {
+	parent = talloc_strndup (ctx, path, slash - path);
+	if (! parent) {
+	    if (status_string)
+		IGNORE_RESULT (asprintf (status_string,
+					 "Error: %s\n",
+					 strerror (ENOMEM)));
+	    return NOTMUCH_STATUS_FILE_ERROR;
+	}
+
+	status = mkdir_recursive (ctx, parent, mode, status_string);
+	if (status)
+	    return status;
+    }
+
+    if (mkdir (path, mode)) {
+	if (status_string)
+	    IGNORE_RESULT (asprintf (status_string,
+				     "Error: mkdir '%s': %s\n",
+				     path, strerror (errno)));
+	return NOTMUCH_STATUS_FILE_ERROR;
+    }
+
+    if (parent) {
+	status = sync_dir (parent, status_string);
+	if (status)
+	    return status;
+    }
+    return NOTMUCH_STATUS_SUCCESS;
+}
diff --git a/util/path-util.h b/util/path-util.h
index ac85f696..4cbbbf1d 100644
--- a/util/path-util.h
+++ b/util/path-util.h
@@ -5,6 +5,9 @@
 #ifndef NOTMUCH_UTIL_PATH_UTIL_H_
 #define NOTMUCH_UTIL_PATH_UTIL_H_
 
+/* For notmuch_status_t */
+#include "notmuch.h"
+
 #ifdef __cplusplus
 extern "C" {
 #endif
@@ -12,6 +15,12 @@ extern "C" {
 char *
 notmuch_canonicalize_file_name (const char *path);
 
+notmuch_status_t
+mkdir_recursive (const void *ctx, const char *path, int mode, char **status_string);
+
+notmuch_status_t
+sync_dir (const char *path, char **status_string);
+
 #ifdef __cplusplus
 }
 #endif