[PATCH v2 1/4] util: refactor sync_dir and mkdir_recursive

[David Bremner <david@tethera.net>]

Moving these functions to libnotmuch_util will allow re-user from
either multiple CLI compilation units or from the library. To avoid
future surprises, replace printing to stderr with the usual status
string mechanism.
---
 notmuch-insert.c | 84 +++++------------------------------------
 util/path-util.c | 97 +++++++++++++++++++++++++++++++++++++++++++++++-
 util/path-util.h |  8 ++++
 3 files changed, 114 insertions(+), 75 deletions(-)

diff --git a/notmuch-insert.c b/notmuch-insert.c
index e44607ad..66c4f434 100644
--- a/notmuch-insert.c
+++ b/notmuch-insert.c
@@ -21,13 +21,13 @@
  * Author: Peter Wang <novalazy@gmail.com>
  */
 
-#include "notmuch-client.h"
-#include "tag-util.h"
 
-#include <sys/types.h>
-#include <sys/stat.h>
 #include <fcntl.h>
+
+#include "notmuch-client.h"
+#include "tag-util.h"
 #include "string-util.h"
+#include "path-util.h"
 
 static volatile sig_atomic_t interrupted;
 
@@ -64,26 +64,6 @@ safe_gethostname (char *hostname, size_t len)
     }
 }
 
-/* Call fsync() on a directory path. */
-static bool
-sync_dir (const char *dir)
-{
-    int fd, r;
-
-    fd = open (dir, O_RDONLY);
-    if (fd == -1) {
-	fprintf (stderr, "Error: open %s: %s\n", dir, strerror (errno));
-	return false;
-    }
-
-    r = fsync (fd);
-    if (r)
-	fprintf (stderr, "Error: fsync %s: %s\n", dir, strerror (errno));
-
-    close (fd);
-
-    return r == 0;
-}
 
 /*
  * Check the specified folder name does not contain a directory
@@ -105,54 +85,6 @@ is_valid_folder_name (const char *folder)
     }
 }
 
-/*
- * Make the given directory and its parents as necessary, using the
- * given mode. Return true on success, false otherwise. Partial
- * results are not cleaned up on errors.
- */
-static bool
-mkdir_recursive (const void *ctx, const char *path, int mode)
-{
-    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)) {
-	    fprintf (stderr, "Error: '%s' is not a directory: %s\n",
-		     path, strerror (EEXIST));
-	    return false;
-	}
-
-	return true;
-    } else if (errno != ENOENT) {
-	fprintf (stderr, "Error: stat '%s': %s\n", path, strerror (errno));
-	return false;
-    }
-
-    /* mkdir parents, if any */
-    slash = strrchr (path, '/');
-    if (slash && slash != path) {
-	parent = talloc_strndup (ctx, path, slash - path);
-	if (! parent) {
-	    fprintf (stderr, "Error: %s\n", strerror (ENOMEM));
-	    return false;
-	}
-
-	if (! mkdir_recursive (ctx, parent, mode))
-	    return false;
-    }
-
-    if (mkdir (path, mode)) {
-	fprintf (stderr, "Error: mkdir '%s': %s\n", path, strerror (errno));
-	return false;
-    }
-
-    return parent ? sync_dir (parent) : true;
-}
-
 /*
  * Create the given maildir folder, i.e. maildir and its
  * subdirectories cur/new/tmp. Return true on success, false
@@ -165,6 +97,7 @@ maildir_create_folder (const void *ctx, const char *maildir, bool world_readable
     const int mode = (world_readable ? 0755 : 0700);
     char *subdir;
     unsigned int i;
+    char **status_string = NULL;
 
     for (i = 0; i < ARRAY_SIZE (subdirs); i++) {
 	subdir = talloc_asprintf (ctx, "%s/%s", maildir, subdirs[i]);
@@ -173,7 +106,7 @@ maildir_create_folder (const void *ctx, const char *maildir, bool world_readable
 	    return false;
 	}
 
-	if (! mkdir_recursive (ctx, subdir, mode))
+	if (mkdir_recursive (ctx, subdir, mode, status_string))
 	    return false;
     }
 
@@ -347,6 +280,7 @@ static char *
 maildir_write_new (const void *ctx, int fdin, const char *maildir, bool world_readable)
 {
     char *cleanpath, *tmppath, *newpath, *newdir;
+    char *status_string = NULL;
 
     tmppath = maildir_write_tmp (ctx, fdin, maildir, world_readable);
     if (! tmppath)
@@ -375,13 +309,15 @@ maildir_write_new (const void *ctx, int fdin, const char *maildir, bool world_re
 	goto FAIL;
     }
 
-    if (! sync_dir (newdir))
+    if (sync_dir (newdir, &status_string))
 	goto FAIL;
 
     return newpath;
 
   FAIL:
     unlink (cleanpath);
+    if (status_string)
+	fputs (status_string, stderr);
 
     return NULL;
 }
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..673c3b6f 100644
--- a/util/path-util.h
+++ b/util/path-util.h
@@ -5,6 +5,8 @@
 #ifndef NOTMUCH_UTIL_PATH_UTIL_H_
 #define NOTMUCH_UTIL_PATH_UTIL_H_
 
+#include "notmuch.h"
+
 #ifdef __cplusplus
 extern "C" {
 #endif
@@ -12,6 +14,12 @@ 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
-- 
2.43.0