Notes API: Allow multiple concurrent notes trees with new struct notes_tree
The new struct notes_tree encapsulates access to a specific notes tree.
It is provided to allow callers to make use of several different notes trees
simultaneously.
A struct notes_tree * parameter is added to every function in the notes API.
In all cases, NULL can be passed, in which case the fallback "default" notes
tree (default_notes_tree) is used.
Signed-off-by: Johan Herland <johan@herland.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
diff --git a/notes.h b/notes.h
index c49b7a5..12acc38 100644
--- a/notes.h
+++ b/notes.h
@@ -2,6 +2,21 @@
#define NOTES_H
/*
+ * Notes tree object
+ *
+ * Encapsulates the internal notes tree structure associated with a notes ref.
+ * Whenever a struct notes_tree pointer is required below, you may pass NULL in
+ * order to use the default/internal notes tree. E.g. you only need to pass a
+ * non-NULL value if you need to refer to several different notes trees
+ * simultaneously.
+ */
+extern struct notes_tree {
+ struct int_node *root;
+ char *ref;
+ int initialized;
+} default_notes_tree;
+
+/*
* Flags controlling behaviour of notes tree initialization
*
* Default behaviour is to initialize the notes tree from the tree object
@@ -10,48 +25,54 @@
#define NOTES_INIT_EMPTY 1
/*
- * Initialize internal notes tree structure with the notes tree at the given
+ * Initialize the given notes_tree with the notes tree structure at the given
* ref. If given ref is NULL, the value of the $GIT_NOTES_REF environment
* variable is used, and if that is missing, the default notes ref is used
* ("refs/notes/commits").
*
- * If you need to re-intialize the internal notes tree structure (e.g. loading
- * from a different notes ref), please first de-initialize the current notes
- * tree by calling free_notes().
+ * If you need to re-intialize a notes_tree structure (e.g. when switching from
+ * one notes ref to another), you must first de-initialize the notes_tree
+ * structure by calling free_notes(struct notes_tree *).
+ *
+ * If you pass t == NULL, the default internal notes_tree will be initialized.
+ *
+ * Precondition: The notes_tree structure is zeroed (this can be achieved with
+ * memset(t, 0, sizeof(struct notes_tree)))
*/
-void init_notes(const char *notes_ref, int flags);
+void init_notes(struct notes_tree *t, const char *notes_ref, int flags);
/*
- * Add the given note object to the internal notes tree structure
+ * Add the given note object to the given notes_tree structure
*
- * IMPORTANT: The changes made by add_note() to the internal notes tree structure
+ * IMPORTANT: The changes made by add_note() to the given notes_tree structure
* are not persistent until a subsequent call to write_notes_tree() returns
* zero.
*/
-void add_note(const unsigned char *object_sha1,
+void add_note(struct notes_tree *t, const unsigned char *object_sha1,
const unsigned char *note_sha1);
/*
- * Remove the given note object from the internal notes tree structure
+ * Remove the given note object from the given notes_tree structure
*
- * IMPORTANT: The changes made by remove_note() to the internal notes tree
+ * IMPORTANT: The changes made by remove_note() to the given notes_tree
* structure are not persistent until a subsequent call to write_notes_tree()
* returns zero.
*/
-void remove_note(const unsigned char *object_sha1);
+void remove_note(struct notes_tree *t, const unsigned char *object_sha1);
/*
* Get the note object SHA1 containing the note data for the given object
*
* Return NULL if the given object has no notes.
*/
-const unsigned char *get_note(const unsigned char *object_sha1);
+const unsigned char *get_note(struct notes_tree *t,
+ const unsigned char *object_sha1);
/*
* Flags controlling behaviour of for_each_note()
*
* Default behaviour of for_each_note() is to traverse every single note object
- * in the notes tree, unpacking subtree entries along the way.
+ * in the given notes tree, unpacking subtree entries along the way.
* The following flags can be used to alter the default behaviour:
*
* - DONT_UNPACK_SUBTREES causes for_each_note() NOT to unpack and recurse into
@@ -75,7 +96,7 @@
#define FOR_EACH_NOTE_YIELD_SUBTREES 2
/*
- * Invoke the specified callback function for each note
+ * Invoke the specified callback function for each note in the given notes_tree
*
* If the callback returns nonzero, the note walk is aborted, and the return
* value from the callback is returned from for_each_note(). Hence, a zero
@@ -92,30 +113,30 @@
typedef int each_note_fn(const unsigned char *object_sha1,
const unsigned char *note_sha1, char *note_path,
void *cb_data);
-int for_each_note(int flags, each_note_fn fn, void *cb_data);
+int for_each_note(struct notes_tree *t, int flags, each_note_fn fn,
+ void *cb_data);
/*
- * Write the internal notes tree structure to the object database
+ * Write the given notes_tree structure to the object database
*
- * Creates a new tree object encapsulating the current state of the
- * internal notes tree, and stores its SHA1 into the 'result' argument.
+ * Creates a new tree object encapsulating the current state of the given
+ * notes_tree, and stores its SHA1 into the 'result' argument.
*
* Returns zero on success, non-zero on failure.
*
- * IMPORTANT: Changes made to the internal notes tree structure are not
- * persistent until this function has returned zero. Please also remember
- * to create a corresponding commit object, and update the appropriate
- * notes ref.
+ * IMPORTANT: Changes made to the given notes_tree are not persistent until
+ * this function has returned zero. Please also remember to create a
+ * corresponding commit object, and update the appropriate notes ref.
*/
-int write_notes_tree(unsigned char *result);
+int write_notes_tree(struct notes_tree *t, unsigned char *result);
/*
- * Free (and de-initialize) the internal notes tree structure
+ * Free (and de-initialize) the given notes_tree structure
*
- * IMPORTANT: Changes made to the notes tree since the last, successful
+ * IMPORTANT: Changes made to the given notes_tree since the last, successful
* call to write_notes_tree() will be lost.
*/
-void free_notes(void);
+void free_notes(struct notes_tree *t);
/* Flags controlling how notes are formatted */
#define NOTES_SHOW_HEADER 1
@@ -124,12 +145,14 @@
/*
* Fill the given strbuf with the notes associated with the given object.
*
- * If the internal notes structure is not initialized, it will be auto-
+ * If the given notes_tree structure is not initialized, it will be auto-
* initialized to the default value (see documentation for init_notes() above).
+ * If the given notes_tree is NULL, the internal/default notes_tree will be
+ * used instead.
*
* 'flags' is a bitwise combination of the above formatting flags.
*/
-void format_note(const unsigned char *object_sha1, struct strbuf *sb,
- const char *output_encoding, int flags);
+void format_note(struct notes_tree *t, const unsigned char *object_sha1,
+ struct strbuf *sb, const char *output_encoding, int flags);
#endif
