lib: Implement new notmuch_directory_t API.

This new directory ojbect provides all the infrastructure needed to
detect when files or directories are deleted or renamed. There's still
code needed on top of this (within "notmuch new") to actually do that
detection.

1 files changed, 57 insertions, 177 deletions

diff --git a/lib/database.cc b/lib/database.cc
index a3824956..510d13cb 100644
--- a/lib/database.cc
+++ b/lib/database.cc
@@ -63,10 +63,11 @@ typedef struct {
  *
  *	tag:	   Any tags associated with this message by the user.
  *
- *	direntry:  A colon-separated pair of values (INTEGER:STRING),
- *		   where INTEGER is the document ID of a directory
- *		   document, and STRING is the name of a file within
- *		   that directory for this mail message.
+ *	file-direntry:  A colon-separated pair of values
+ *		        (INTEGER:STRING), where INTEGER is the
+ *		        document ID of a directory document, and
+ *		        STRING is the name of a file within that
+ *		        directory for this mail message.
  *
  *    A mail document also has two values:
  *
@@ -88,22 +89,28 @@ typedef struct {
  * maintain data necessary to allow for efficient polling of mail
  * directories.
  *
- * The directory document contains the following terms:
+ * All directory documents contain one term:
  *
  *	directory:	The directory path (relative to the database path)
  *			Or the SHA1 sum of the directory path (if the
  *			path itself is too long to fit in a Xapian
  *			term).
  *
- *	parent:		The document ID of the parent directory document.
- *			Top-level directories will have a parent value of 0.
+ * And all directory documents for directories other than top-level
+ * directories also contain the following term:
  *
- * and has a single value:
+ *	directory-direntry: A colon-separated pair of values
+ *		            (INTEGER:STRING), where INTEGER is the
+ *		            document ID of the parent directory
+ *		            document, and STRING is the name of this
+ *		            directory within that parent.
+ *
+ * All directory documents have a single value:
  *
  *	TIMESTAMP:	The mtime of the directory (at last scan)
  *
  * The data portion of a directory document contains the path of the
- * directory (relative to the datbase path).
+ * directory (relative to the database path).
  */
 
 /* With these prefix values we follow the conventions published here:
@@ -122,25 +129,25 @@ typedef struct {
  */
 
 prefix_t BOOLEAN_PREFIX_INTERNAL[] = {
-    { "type", "T" },
-    { "reference", "XREFERENCE" },
-    { "replyto", "XREPLYTO" },
-    { "directory", "XDIRECTORY" },
-    { "direntry", "XDIRENTRY" },
-    { "parent", "XPARENT" },
+    { "type",			"T" },
+    { "reference",		"XREFERENCE" },
+    { "replyto",		"XREPLYTO" },
+    { "directory",		"XDIRECTORY" },
+    { "file-direntry",		"XFDIRENTRY" },
+    { "directory-direntry",	"XDDIRENTRY" },
 };
 
 prefix_t BOOLEAN_PREFIX_EXTERNAL[] = {
-    { "thread", "G" },
-    { "tag", "K" },
-    { "id", "Q" }
+    { "thread",			"G" },
+    { "tag",			"K" },
+    { "id",			"Q" }
 };
 
 prefix_t PROBABILISTIC_PREFIX[]= {
-    { "from", "XFROM" },
-    { "to", "XTO" },
-    { "attachment", "XATTACHMENT" },
-    { "subject", "XSUBJECT"}
+    { "from",			"XFROM" },
+    { "to",			"XTO" },
+    { "attachment",		"XATTACHMENT" },
+    { "subject",		"XSUBJECT"}
 };
 
 int
@@ -241,11 +248,11 @@ find_doc_ids (notmuch_database_t *notmuch,
     talloc_free (term);
 }
 
-static notmuch_private_status_t
-find_unique_doc_id (notmuch_database_t *notmuch,
-		    const char *prefix_name,
-		    const char *value,
-		    unsigned int *doc_id)
+notmuch_private_status_t
+_notmuch_database_find_unique_doc_id (notmuch_database_t *notmuch,
+				      const char *prefix_name,
+				      const char *value,
+				      unsigned int *doc_id)
 {
     Xapian::PostingIterator i, end;
 
@@ -275,26 +282,6 @@ find_document_for_doc_id (notmuch_database_t *notmuch, unsigned doc_id)
     return notmuch->xapian_db->get_document (doc_id);
 }
 
-static notmuch_private_status_t
-find_unique_document (notmuch_database_t *notmuch,
-		      const char *prefix_name,
-		      const char *value,
-		      Xapian::Document *document,
-		      unsigned int *doc_id)
-{
-    notmuch_private_status_t status;
-
-    status = find_unique_doc_id (notmuch, prefix_name, value, doc_id);
-
-    if (status) {
-	*document = Xapian::Document ();
-	return status;
-    }
-
-    *document = find_document_for_doc_id (notmuch, *doc_id);
-    return NOTMUCH_PRIVATE_STATUS_SUCCESS;
-}
-
 notmuch_message_t *
 notmuch_database_find_message (notmuch_database_t *notmuch,
 			       const char *message_id)
@@ -302,7 +289,8 @@ notmuch_database_find_message (notmuch_database_t *notmuch,
     notmuch_private_status_t status;
     unsigned int doc_id;
 
-    status = find_unique_doc_id (notmuch, "id", message_id, &doc_id);
+    status = _notmuch_database_find_unique_doc_id (notmuch, "id",
+						   message_id, &doc_id);
 
     if (status == NOTMUCH_PRIVATE_STATUS_NO_DOCUMENT_FOUND)
 	return NULL;
@@ -593,13 +581,6 @@ notmuch_database_get_path (notmuch_database_t *notmuch)
     return notmuch->path;
 }
 
-static notmuch_private_status_t
-find_directory_document (notmuch_database_t *notmuch, const char *db_path,
-			 Xapian::Document *doc, unsigned int *doc_id)
-{
-    return find_unique_document (notmuch, "directory", db_path, doc, doc_id);
-}
-
 /* We allow the user to use arbitrarily long paths for directories. But
  * we have a term-length limit. So if we exceed that, we'll use the
  * SHA-1 of the path for the database term.
@@ -608,8 +589,8 @@ find_directory_document (notmuch_database_t *notmuch, const char *db_path,
  * does not, then the caller is responsible to free() the returned
  * value.
  */
-static const char *
-directory_db_path (const char *path)
+const char *
+_notmuch_database_get_directory_db_path (const char *path)
 {
     int term_len = strlen (_find_prefix ("directory")) + strlen (path);
 
@@ -705,38 +686,25 @@ _notmuch_database_find_directory_id (notmuch_database_t *notmuch,
 				     const char *path,
 				     unsigned int *directory_id)
 {
-    notmuch_private_status_t private_status;
-    notmuch_status_t status = NOTMUCH_STATUS_SUCCESS;
-    const char *db_path;
+    notmuch_directory_t *directory;
+    notmuch_status_t status;
 
     if (path == NULL) {
 	*directory_id = 0;
 	return NOTMUCH_STATUS_SUCCESS;
     }
 
-    db_path = directory_db_path (path);
-
-    private_status = find_unique_doc_id (notmuch, "directory",
-					 db_path, directory_id);
-    if (private_status == NOTMUCH_PRIVATE_STATUS_NO_DOCUMENT_FOUND) {
-	status = notmuch_database_set_directory_mtime (notmuch,
-						       path, 0);
-	if (status)
-	    goto DONE;
-
-	private_status = find_unique_doc_id (notmuch, "directory",
-					     db_path, directory_id);
-	status = COERCE_STATUS (private_status, "_find_directory_id");
+    directory = _notmuch_directory_create (notmuch, path, &status);
+    if (status) {
+	*directory_id = -1;
+	return status;
     }
 
-  DONE:
-    if (db_path != path)
-	free ((char *) db_path);
+    *directory_id = _notmuch_directory_get_document_id (directory);
 
-    if (status)
-	*directory_id = -1;
+    notmuch_directory_destroy (directory);
 
-    return status;
+    return NOTMUCH_STATUS_SUCCESS;
 }
 
 const char *
@@ -817,101 +785,13 @@ _notmuch_database_relative_path (notmuch_database_t *notmuch,
     return relative;
 }
 
-notmuch_status_t
-notmuch_database_set_directory_mtime (notmuch_database_t *notmuch,
-				      const char *path,
-				      time_t mtime)
-{
-    Xapian::Document doc;
-    Xapian::WritableDatabase *db;
-    unsigned int doc_id;
-    notmuch_private_status_t status;
-    notmuch_status_t ret = NOTMUCH_STATUS_SUCCESS;
-    const char *parent, *db_path = NULL;
-    unsigned int parent_id;
-    void *local = talloc_new (notmuch);
-
-    if (notmuch->mode == NOTMUCH_DATABASE_MODE_READ_ONLY) {
-	fprintf (stderr, "Attempted to update a read-only database.\n");
-	return NOTMUCH_STATUS_READONLY_DATABASE;
-    }
-
-    path = _notmuch_database_relative_path (notmuch, path);
-
-    db = static_cast <Xapian::WritableDatabase *> (notmuch->xapian_db);
-    db_path = directory_db_path (path);
-
-    try {
-	status = find_directory_document (notmuch, db_path, &doc, &doc_id);
-
-	doc.add_value (NOTMUCH_VALUE_TIMESTAMP,
-		       Xapian::sortable_serialise (mtime));
-
-	if (status == NOTMUCH_PRIVATE_STATUS_NO_DOCUMENT_FOUND) {
-	    char *term = talloc_asprintf (local, "%s%s",
-					  _find_prefix ("directory"), db_path);
-	    doc.add_term (term);
-
-	    doc.set_data (path);
-
-	    _notmuch_database_split_path (local, path, &parent, NULL);
-
-	    _notmuch_database_find_directory_id (notmuch, parent, &parent_id);
-
-	    term = talloc_asprintf (local, "%s%u",
-				    _find_prefix ("parent"),
-				    parent_id);
-	    doc.add_term (term);
-
-	    db->add_document (doc);
-	} else {
-	    db->replace_document (doc_id, doc);
-	}
-
-    } catch (const Xapian::Error &error) {
-	fprintf (stderr, "A Xapian exception occurred setting directory mtime: %s.\n",
-		 error.get_msg().c_str());
-	notmuch->exception_reported = TRUE;
-	ret = NOTMUCH_STATUS_XAPIAN_EXCEPTION;
-    }
-
-    if (db_path != path)
-	free ((char *) db_path);
-
-    talloc_free (local);
-
-    return ret;
-}
-
-time_t
-notmuch_database_get_directory_mtime (notmuch_database_t *notmuch,
-				      const char *path)
+notmuch_directory_t *
+notmuch_database_get_directory (notmuch_database_t *notmuch,
+				const char *path)
 {
-    Xapian::Document doc;
-    unsigned int doc_id;
-    notmuch_private_status_t status;
-    const char *db_path = NULL;
-    time_t ret = 0;
-
-    db_path = directory_db_path (path);
-
-    try {
-	status = find_directory_document (notmuch, db_path, &doc, &doc_id);
-
-	if (status == NOTMUCH_PRIVATE_STATUS_NO_DOCUMENT_FOUND)
-	    goto DONE;
-
-	ret =  Xapian::sortable_unserialise (doc.get_value (NOTMUCH_VALUE_TIMESTAMP));
-    } catch (Xapian::Error &error) {
-	ret = 0;
-	goto DONE;
-    }
-
-  DONE:
-    if (db_path != path)
-	free ((char *) db_path);
+    notmuch_status_t status;
 
-    return ret;
+    return _notmuch_directory_create (notmuch, path, &status);
 }
 
 /* Find the thread ID to which the message with 'message_id' belongs.
@@ -1284,7 +1164,7 @@ notmuch_database_remove_message (notmuch_database_t *notmuch,
 {
     Xapian::WritableDatabase *db;
     void *local = talloc_new (notmuch);
-    const char *direntry_prefix = _find_prefix ("direntry");
+    const char *prefix = _find_prefix ("file-direntry");
     char *direntry, *term;
     Xapian::PostingIterator i, end;
     Xapian::Document document;
@@ -1302,7 +1182,7 @@ notmuch_database_remove_message (notmuch_database_t *notmuch,
     if (status)
 	return status;
 
-    term = talloc_asprintf (notmuch, "%s%s", direntry_prefix, direntry);
+    term = talloc_asprintf (notmuch, "%s%s", prefix, direntry);
 
     find_doc_ids_for_term (notmuch, term, &i, &end);
 
@@ -1314,11 +1194,11 @@ notmuch_database_remove_message (notmuch_database_t *notmuch,
 	document.remove_term (term);
 
 	j = document.termlist_begin ();
-	j.skip_to (direntry_prefix);
+	j.skip_to (prefix);
 
-	/* Was this the last direntry in the message? */
+	/* Was this the last file-direntry in the message? */
 	if (j == document.termlist_end () ||
-	    strncmp ((*j).c_str (), direntry_prefix, strlen (direntry_prefix)))
+	    strncmp ((*j).c_str (), prefix, strlen (prefix)))
 	{
 	    db->delete_document (document.get_docid ());
 	} else {