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-rw-r--r--notes.c138
-rw-r--r--notes.h34
2 files changed, 112 insertions, 60 deletions
diff --git a/notes.c b/notes.c
index 08a369a..dc4e4f6 100644
--- a/notes.c
+++ b/notes.c
@@ -1,5 +1,6 @@
#include "cache.h"
#include "notes.h"
+#include "blob.h"
#include "tree.h"
#include "utf8.h"
#include "strbuf.h"
@@ -127,55 +128,12 @@ static struct leaf_node *note_tree_find(struct int_node *tree, unsigned char n,
return NULL;
}
-/* Create a new blob object by concatenating the two given blob objects */
-static int concatenate_notes(unsigned char *cur_sha1,
- const unsigned char *new_sha1)
-{
- char *cur_msg, *new_msg, *buf;
- unsigned long cur_len, new_len, buf_len;
- enum object_type cur_type, new_type;
- int ret;
-
- /* read in both note blob objects */
- new_msg = read_sha1_file(new_sha1, &new_type, &new_len);
- if (!new_msg || !new_len || new_type != OBJ_BLOB) {
- free(new_msg);
- return 0;
- }
- cur_msg = read_sha1_file(cur_sha1, &cur_type, &cur_len);
- if (!cur_msg || !cur_len || cur_type != OBJ_BLOB) {
- free(cur_msg);
- free(new_msg);
- hashcpy(cur_sha1, new_sha1);
- return 0;
- }
-
- /* we will separate the notes by a newline anyway */
- if (cur_msg[cur_len - 1] == '\n')
- cur_len--;
-
- /* concatenate cur_msg and new_msg into buf */
- buf_len = cur_len + 1 + new_len;
- buf = (char *) xmalloc(buf_len);
- memcpy(buf, cur_msg, cur_len);
- buf[cur_len] = '\n';
- memcpy(buf + cur_len + 1, new_msg, new_len);
-
- free(cur_msg);
- free(new_msg);
-
- /* create a new blob object from buf */
- ret = write_sha1_file(buf, buf_len, "blob", cur_sha1);
- free(buf);
- return ret;
-}
-
/*
* To insert a leaf_node:
* Search to the tree location appropriate for the given leaf_node's key:
* - If location is unused (NULL), store the tweaked pointer directly there
* - If location holds a note entry that matches the note-to-be-inserted, then
- * concatenate the two notes.
+ * combine the two notes (by calling the given combine_notes function).
* - If location holds a note entry that matches the subtree-to-be-inserted,
* then unpack the subtree-to-be-inserted into the location.
* - If location holds a matching subtree entry, unpack the subtree at that
@@ -184,7 +142,8 @@ static int concatenate_notes(unsigned char *cur_sha1,
* node-to-be-inserted, and store the new int_node into the location.
*/
static void note_tree_insert(struct int_node *tree, unsigned char n,
- struct leaf_node *entry, unsigned char type)
+ struct leaf_node *entry, unsigned char type,
+ combine_notes_fn combine_notes)
{
struct int_node *new_node;
struct leaf_node *l;
@@ -205,12 +164,11 @@ static void note_tree_insert(struct int_node *tree, unsigned char n,
if (!hashcmp(l->val_sha1, entry->val_sha1))
return;
- if (concatenate_notes(l->val_sha1,
- entry->val_sha1))
- die("failed to concatenate note %s "
- "into note %s for object %s",
- sha1_to_hex(entry->val_sha1),
+ if (combine_notes(l->val_sha1, entry->val_sha1))
+ die("failed to combine notes %s and %s"
+ " for object %s",
sha1_to_hex(l->val_sha1),
+ sha1_to_hex(entry->val_sha1),
sha1_to_hex(l->key_sha1));
free(entry);
return;
@@ -233,7 +191,7 @@ static void note_tree_insert(struct int_node *tree, unsigned char n,
*p = NULL;
load_subtree(l, tree, n);
free(l);
- note_tree_insert(tree, n, entry, type);
+ note_tree_insert(tree, n, entry, type, combine_notes);
return;
}
break;
@@ -243,9 +201,9 @@ static void note_tree_insert(struct int_node *tree, unsigned char n,
assert(GET_PTR_TYPE(*p) == PTR_TYPE_NOTE ||
GET_PTR_TYPE(*p) == PTR_TYPE_SUBTREE);
new_node = (struct int_node *) xcalloc(sizeof(struct int_node), 1);
- note_tree_insert(new_node, n + 1, l, GET_PTR_TYPE(*p));
+ note_tree_insert(new_node, n + 1, l, GET_PTR_TYPE(*p), combine_notes);
*p = SET_PTR_TYPE(new_node, PTR_TYPE_INTERNAL);
- note_tree_insert(new_node, n + 1, entry, type);
+ note_tree_insert(new_node, n + 1, entry, type, combine_notes);
}
/*
@@ -406,7 +364,8 @@ static void load_subtree(struct leaf_node *subtree, struct int_node *node,
l->key_sha1[19] = (unsigned char) len;
type = PTR_TYPE_SUBTREE;
}
- note_tree_insert(node, n, l, type);
+ note_tree_insert(node, n, l, type,
+ combine_notes_concatenate);
}
}
free(buf);
@@ -659,7 +618,64 @@ static int write_each_note(const unsigned char *object_sha1,
return write_each_note_helper(d->root, note_path, mode, note_sha1);
}
-void init_notes(struct notes_tree *t, const char *notes_ref, int flags)
+int combine_notes_concatenate(unsigned char *cur_sha1,
+ const unsigned char *new_sha1)
+{
+ char *cur_msg = NULL, *new_msg = NULL, *buf;
+ unsigned long cur_len, new_len, buf_len;
+ enum object_type cur_type, new_type;
+ int ret;
+
+ /* read in both note blob objects */
+ if (!is_null_sha1(new_sha1))
+ new_msg = read_sha1_file(new_sha1, &new_type, &new_len);
+ if (!new_msg || !new_len || new_type != OBJ_BLOB) {
+ free(new_msg);
+ return 0;
+ }
+ if (!is_null_sha1(cur_sha1))
+ cur_msg = read_sha1_file(cur_sha1, &cur_type, &cur_len);
+ if (!cur_msg || !cur_len || cur_type != OBJ_BLOB) {
+ free(cur_msg);
+ free(new_msg);
+ hashcpy(cur_sha1, new_sha1);
+ return 0;
+ }
+
+ /* we will separate the notes by a newline anyway */
+ if (cur_msg[cur_len - 1] == '\n')
+ cur_len--;
+
+ /* concatenate cur_msg and new_msg into buf */
+ buf_len = cur_len + 1 + new_len;
+ buf = (char *) xmalloc(buf_len);
+ memcpy(buf, cur_msg, cur_len);
+ buf[cur_len] = '\n';
+ memcpy(buf + cur_len + 1, new_msg, new_len);
+ free(cur_msg);
+ free(new_msg);
+
+ /* create a new blob object from buf */
+ ret = write_sha1_file(buf, buf_len, blob_type, cur_sha1);
+ free(buf);
+ return ret;
+}
+
+int combine_notes_overwrite(unsigned char *cur_sha1,
+ const unsigned char *new_sha1)
+{
+ hashcpy(cur_sha1, new_sha1);
+ return 0;
+}
+
+int combine_notes_ignore(unsigned char *cur_sha1,
+ const unsigned char *new_sha1)
+{
+ return 0;
+}
+
+void init_notes(struct notes_tree *t, const char *notes_ref,
+ combine_notes_fn combine_notes, int flags)
{
unsigned char sha1[20], object_sha1[20];
unsigned mode;
@@ -676,8 +692,12 @@ void init_notes(struct notes_tree *t, const char *notes_ref, int flags)
if (!notes_ref)
notes_ref = GIT_NOTES_DEFAULT_REF;
+ if (!combine_notes)
+ combine_notes = combine_notes_concatenate;
+
t->root = (struct int_node *) xcalloc(sizeof(struct int_node), 1);
t->ref = notes_ref ? xstrdup(notes_ref) : NULL;
+ t->combine_notes = combine_notes;
t->initialized = 1;
if (flags & NOTES_INIT_EMPTY || !notes_ref ||
@@ -693,17 +713,19 @@ void init_notes(struct notes_tree *t, const char *notes_ref, int flags)
}
void add_note(struct notes_tree *t, const unsigned char *object_sha1,
- const unsigned char *note_sha1)
+ const unsigned char *note_sha1, combine_notes_fn combine_notes)
{
struct leaf_node *l;
if (!t)
t = &default_notes_tree;
assert(t->initialized);
+ if (!combine_notes)
+ combine_notes = t->combine_notes;
l = (struct leaf_node *) xmalloc(sizeof(struct leaf_node));
hashcpy(l->key_sha1, object_sha1);
hashcpy(l->val_sha1, note_sha1);
- note_tree_insert(t->root, 0, l, PTR_TYPE_NOTE);
+ note_tree_insert(t->root, 0, l, PTR_TYPE_NOTE, combine_notes);
}
void remove_note(struct notes_tree *t, const unsigned char *object_sha1)
@@ -788,7 +810,7 @@ void format_note(struct notes_tree *t, const unsigned char *object_sha1,
if (!t)
t = &default_notes_tree;
if (!t->initialized)
- init_notes(t, NULL, 0);
+ init_notes(t, NULL, NULL, 0);
sha1 = get_note(t, object_sha1);
if (!sha1)
diff --git a/notes.h b/notes.h
index 12acc38..20d6e17 100644
--- a/notes.h
+++ b/notes.h
@@ -2,6 +2,30 @@
#define NOTES_H
/*
+ * Function type for combining two notes annotating the same object.
+ *
+ * When adding a new note annotating the same object as an existing note, it is
+ * up to the caller to decide how to combine the two notes. The decision is
+ * made by passing in a function of the following form. The function accepts
+ * two SHA1s -- of the existing note and the new note, respectively. The
+ * function then combines the notes in whatever way it sees fit, and writes the
+ * resulting SHA1 into the first SHA1 argument (cur_sha1). A non-zero return
+ * value indicates failure.
+ *
+ * The two given SHA1s must both be non-NULL and different from each other.
+ *
+ * The default combine_notes function (you get this when passing NULL) is
+ * combine_notes_concatenate(), which appends the contents of the new note to
+ * the contents of the existing note.
+ */
+typedef int combine_notes_fn(unsigned char *cur_sha1, const unsigned char *new_sha1);
+
+/* Common notes combinators */
+int combine_notes_concatenate(unsigned char *cur_sha1, const unsigned char *new_sha1);
+int combine_notes_overwrite(unsigned char *cur_sha1, const unsigned char *new_sha1);
+int combine_notes_ignore(unsigned char *cur_sha1, const unsigned char *new_sha1);
+
+/*
* Notes tree object
*
* Encapsulates the internal notes tree structure associated with a notes ref.
@@ -13,6 +37,7 @@
extern struct notes_tree {
struct int_node *root;
char *ref;
+ combine_notes_fn *combine_notes;
int initialized;
} default_notes_tree;
@@ -36,10 +61,15 @@ extern struct notes_tree {
*
* If you pass t == NULL, the default internal notes_tree will be initialized.
*
+ * The combine_notes function that is passed becomes the default combine_notes
+ * function for the given notes_tree. If NULL is passed, the default
+ * combine_notes function is combine_notes_concatenate().
+ *
* Precondition: The notes_tree structure is zeroed (this can be achieved with
* memset(t, 0, sizeof(struct notes_tree)))
*/
-void init_notes(struct notes_tree *t, const char *notes_ref, int flags);
+void init_notes(struct notes_tree *t, const char *notes_ref,
+ combine_notes_fn combine_notes, int flags);
/*
* Add the given note object to the given notes_tree structure
@@ -49,7 +79,7 @@ void init_notes(struct notes_tree *t, const char *notes_ref, int flags);
* zero.
*/
void add_note(struct notes_tree *t, const unsigned char *object_sha1,
- const unsigned char *note_sha1);
+ const unsigned char *note_sha1, combine_notes_fn combine_notes);
/*
* Remove the given note object from the given notes_tree structure