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authorJohan Herland <johan@herland.net>2010-02-13 21:28:23 (GMT)
committerJunio C Hamano <gitster@pobox.com>2010-02-14 03:36:13 (GMT)
commit851c2b3791f24e319c23331887d4b8150ca4d9ba (patch)
treef178c0cfacf7bbda0079d006da35a03dea9dfd12 /notes.c
parent048cdd4665efafde2902cb72376f2ca497254246 (diff)
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Teach notes code to properly preserve non-notes in the notes tree
The note tree structure allows for non-note entries to coexist with note entries in a notes tree. Although we certainly expect there to be very few non-notes in a notes tree, we should still support them to a certain degree. This patch teaches the notes code to preserve non-notes when updating the notes tree with write_notes_tree(). Non-notes are not affected by fanout restructuring. For non-notes to be handled correctly, we can no longer allow subtree entries that do not match the fanout structure produced by the notes code itself. This means that fanouts like 4/36, 6/34, 8/32, 4/4/32, etc. are no longer recognized as note subtrees; only 2-based fanouts are allowed (2/38, 2/2/36, 2/2/2/34, etc.). Since the notes code has never at any point _produced_ non-2-based fanouts, it is highly unlikely that this change will cause problems for anyone. The patch also adds some tests verifying the correct handling of non-notes in a notes tree. Signed-off-by: Johan Herland <johan@herland.net> Signed-off-by: Junio C Hamano <gitster@pobox.com>
Diffstat (limited to 'notes.c')
-rw-r--r--notes.c219
1 files changed, 180 insertions, 39 deletions
diff --git a/notes.c b/notes.c
index dc4e4f6..d432517 100644
--- a/notes.c
+++ b/notes.c
@@ -37,6 +37,21 @@ struct leaf_node {
unsigned char val_sha1[20];
};
+/*
+ * A notes tree may contain entries that are not notes, and that do not follow
+ * the naming conventions of notes. There are typically none/few of these, but
+ * we still need to keep track of them. Keep a simple linked list sorted alpha-
+ * betically on the non-note path. The list is populated when parsing tree
+ * objects in load_subtree(), and the non-notes are correctly written back into
+ * the tree objects produced by write_notes_tree().
+ */
+struct non_note {
+ struct non_note *next; /* grounded (last->next == NULL) */
+ char *path;
+ unsigned int mode;
+ unsigned char sha1[20];
+};
+
#define PTR_TYPE_NULL 0
#define PTR_TYPE_INTERNAL 1
#define PTR_TYPE_NOTE 2
@@ -53,8 +68,8 @@ struct leaf_node {
struct notes_tree default_notes_tree;
-static void load_subtree(struct leaf_node *subtree, struct int_node *node,
- unsigned int n);
+static void load_subtree(struct notes_tree *t, struct leaf_node *subtree,
+ struct int_node *node, unsigned int n);
/*
* Search the tree until the appropriate location for the given key is found:
@@ -71,7 +86,7 @@ static void load_subtree(struct leaf_node *subtree, struct int_node *node,
* - an unused leaf node (NULL)
* In any case, set *tree and *n, and return pointer to the tree location.
*/
-static void **note_tree_search(struct int_node **tree,
+static void **note_tree_search(struct notes_tree *t, struct int_node **tree,
unsigned char *n, const unsigned char *key_sha1)
{
struct leaf_node *l;
@@ -83,9 +98,9 @@ static void **note_tree_search(struct int_node **tree,
if (!SUBTREE_SHA1_PREFIXCMP(key_sha1, l->key_sha1)) {
/* unpack tree and resume search */
(*tree)->a[0] = NULL;
- load_subtree(l, *tree, *n);
+ load_subtree(t, l, *tree, *n);
free(l);
- return note_tree_search(tree, n, key_sha1);
+ return note_tree_search(t, tree, n, key_sha1);
}
}
@@ -95,15 +110,15 @@ static void **note_tree_search(struct int_node **tree,
case PTR_TYPE_INTERNAL:
*tree = CLR_PTR_TYPE(p);
(*n)++;
- return note_tree_search(tree, n, key_sha1);
+ return note_tree_search(t, tree, n, key_sha1);
case PTR_TYPE_SUBTREE:
l = (struct leaf_node *) CLR_PTR_TYPE(p);
if (!SUBTREE_SHA1_PREFIXCMP(key_sha1, l->key_sha1)) {
/* unpack tree and resume search */
(*tree)->a[i] = NULL;
- load_subtree(l, *tree, *n);
+ load_subtree(t, l, *tree, *n);
free(l);
- return note_tree_search(tree, n, key_sha1);
+ return note_tree_search(t, tree, n, key_sha1);
}
/* fall through */
default:
@@ -116,10 +131,11 @@ static void **note_tree_search(struct int_node **tree,
* Search to the tree location appropriate for the given key:
* If a note entry with matching key, return the note entry, else return NULL.
*/
-static struct leaf_node *note_tree_find(struct int_node *tree, unsigned char n,
+static struct leaf_node *note_tree_find(struct notes_tree *t,
+ struct int_node *tree, unsigned char n,
const unsigned char *key_sha1)
{
- void **p = note_tree_search(&tree, &n, key_sha1);
+ void **p = note_tree_search(t, &tree, &n, key_sha1);
if (GET_PTR_TYPE(*p) == PTR_TYPE_NOTE) {
struct leaf_node *l = (struct leaf_node *) CLR_PTR_TYPE(*p);
if (!hashcmp(key_sha1, l->key_sha1))
@@ -141,13 +157,13 @@ static struct leaf_node *note_tree_find(struct int_node *tree, unsigned char n,
* - Else, create a new int_node, holding both the node-at-location and the
* 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,
+static void note_tree_insert(struct notes_tree *t, struct int_node *tree,
+ unsigned char n, struct leaf_node *entry, unsigned char type,
combine_notes_fn combine_notes)
{
struct int_node *new_node;
struct leaf_node *l;
- void **p = note_tree_search(&tree, &n, entry->key_sha1);
+ void **p = note_tree_search(t, &tree, &n, entry->key_sha1);
assert(GET_PTR_TYPE(entry) == 0); /* no type bits set */
l = (struct leaf_node *) CLR_PTR_TYPE(*p);
@@ -178,7 +194,7 @@ static void note_tree_insert(struct int_node *tree, unsigned char n,
if (!SUBTREE_SHA1_PREFIXCMP(l->key_sha1,
entry->key_sha1)) {
/* unpack 'entry' */
- load_subtree(entry, tree, n);
+ load_subtree(t, entry, tree, n);
free(entry);
return;
}
@@ -189,9 +205,10 @@ static void note_tree_insert(struct int_node *tree, unsigned char n,
if (!SUBTREE_SHA1_PREFIXCMP(entry->key_sha1, l->key_sha1)) {
/* unpack 'l' and restart insert */
*p = NULL;
- load_subtree(l, tree, n);
+ load_subtree(t, l, tree, n);
free(l);
- note_tree_insert(tree, n, entry, type, combine_notes);
+ note_tree_insert(t, tree, n, entry, type,
+ combine_notes);
return;
}
break;
@@ -201,9 +218,10 @@ 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), combine_notes);
+ note_tree_insert(t, 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, combine_notes);
+ note_tree_insert(t, new_node, n + 1, entry, type, combine_notes);
}
/*
@@ -249,7 +267,7 @@ static void note_tree_remove(struct notes_tree *t, struct int_node *tree,
struct leaf_node *l;
struct int_node *parent_stack[20];
unsigned char i, j;
- void **p = note_tree_search(&tree, &n, entry->key_sha1);
+ void **p = note_tree_search(t, &tree, &n, entry->key_sha1);
assert(GET_PTR_TYPE(entry) == 0); /* no type bits set */
if (GET_PTR_TYPE(*p) != PTR_TYPE_NOTE)
@@ -324,14 +342,67 @@ static int get_sha1_hex_segment(const char *hex, unsigned int hex_len,
return len;
}
-static void load_subtree(struct leaf_node *subtree, struct int_node *node,
- unsigned int n)
+static int non_note_cmp(const struct non_note *a, const struct non_note *b)
+{
+ return strcmp(a->path, b->path);
+}
+
+static void add_non_note(struct notes_tree *t, const char *path,
+ unsigned int mode, const unsigned char *sha1)
+{
+ struct non_note *p = t->prev_non_note, *n;
+ n = (struct non_note *) xmalloc(sizeof(struct non_note));
+ n->next = NULL;
+ n->path = xstrdup(path);
+ n->mode = mode;
+ hashcpy(n->sha1, sha1);
+ t->prev_non_note = n;
+
+ if (!t->first_non_note) {
+ t->first_non_note = n;
+ return;
+ }
+
+ if (non_note_cmp(p, n) < 0)
+ ; /* do nothing */
+ else if (non_note_cmp(t->first_non_note, n) <= 0)
+ p = t->first_non_note;
+ else {
+ /* n sorts before t->first_non_note */
+ n->next = t->first_non_note;
+ t->first_non_note = n;
+ return;
+ }
+
+ /* n sorts equal or after p */
+ while (p->next && non_note_cmp(p->next, n) <= 0)
+ p = p->next;
+
+ if (non_note_cmp(p, n) == 0) { /* n ~= p; overwrite p with n */
+ assert(strcmp(p->path, n->path) == 0);
+ p->mode = n->mode;
+ hashcpy(p->sha1, n->sha1);
+ free(n);
+ t->prev_non_note = p;
+ return;
+ }
+
+ /* n sorts between p and p->next */
+ n->next = p->next;
+ p->next = n;
+}
+
+static void load_subtree(struct notes_tree *t, struct leaf_node *subtree,
+ struct int_node *node, unsigned int n)
{
unsigned char object_sha1[20];
unsigned int prefix_len;
void *buf;
struct tree_desc desc;
struct name_entry entry;
+ int len, path_len;
+ unsigned char type;
+ struct leaf_node *l;
buf = fill_tree_descriptor(&desc, subtree->val_sha1);
if (!buf)
@@ -342,31 +413,68 @@ static void load_subtree(struct leaf_node *subtree, struct int_node *node,
assert(prefix_len * 2 >= n);
memcpy(object_sha1, subtree->key_sha1, prefix_len);
while (tree_entry(&desc, &entry)) {
- int len = get_sha1_hex_segment(entry.path, strlen(entry.path),
+ path_len = strlen(entry.path);
+ len = get_sha1_hex_segment(entry.path, path_len,
object_sha1 + prefix_len, 20 - prefix_len);
if (len < 0)
- continue; /* entry.path is not a SHA1 sum. Skip */
+ goto handle_non_note; /* entry.path is not a SHA1 */
len += prefix_len;
/*
* If object SHA1 is complete (len == 20), assume note object
- * If object SHA1 is incomplete (len < 20), assume note subtree
+ * If object SHA1 is incomplete (len < 20), and current
+ * component consists of 2 hex chars, assume note subtree
*/
if (len <= 20) {
- unsigned char type = PTR_TYPE_NOTE;
- struct leaf_node *l = (struct leaf_node *)
+ type = PTR_TYPE_NOTE;
+ l = (struct leaf_node *)
xcalloc(sizeof(struct leaf_node), 1);
hashcpy(l->key_sha1, object_sha1);
hashcpy(l->val_sha1, entry.sha1);
if (len < 20) {
- if (!S_ISDIR(entry.mode))
- continue; /* entry cannot be subtree */
+ if (!S_ISDIR(entry.mode) || path_len != 2)
+ goto handle_non_note; /* not subtree */
l->key_sha1[19] = (unsigned char) len;
type = PTR_TYPE_SUBTREE;
}
- note_tree_insert(node, n, l, type,
+ note_tree_insert(t, node, n, l, type,
combine_notes_concatenate);
}
+ continue;
+
+handle_non_note:
+ /*
+ * Determine full path for this non-note entry:
+ * The filename is already found in entry.path, but the
+ * directory part of the path must be deduced from the subtree
+ * containing this entry. We assume here that the overall notes
+ * tree follows a strict byte-based progressive fanout
+ * structure (i.e. using 2/38, 2/2/36, etc. fanouts, and not
+ * e.g. 4/36 fanout). This means that if a non-note is found at
+ * path "dead/beef", the following code will register it as
+ * being found on "de/ad/beef".
+ * On the other hand, if you use such non-obvious non-note
+ * paths in the middle of a notes tree, you deserve what's
+ * coming to you ;). Note that for non-notes that are not
+ * SHA1-like at the top level, there will be no problems.
+ *
+ * To conclude, it is strongly advised to make sure non-notes
+ * have at least one non-hex character in the top-level path
+ * component.
+ */
+ {
+ char non_note_path[PATH_MAX];
+ char *p = non_note_path;
+ const char *q = sha1_to_hex(subtree->key_sha1);
+ int i;
+ for (i = 0; i < prefix_len; i++) {
+ *p++ = *q++;
+ *p++ = *q++;
+ *p++ = '/';
+ }
+ strcpy(p, entry.path);
+ add_non_note(t, non_note_path, entry.mode, entry.sha1);
+ }
}
free(buf);
}
@@ -426,9 +534,9 @@ static void construct_path_with_fanout(const unsigned char *sha1,
strcpy(path + i, hex_sha1 + j);
}
-static int for_each_note_helper(struct int_node *tree, unsigned char n,
- unsigned char fanout, int flags, each_note_fn fn,
- void *cb_data)
+static int for_each_note_helper(struct notes_tree *t, struct int_node *tree,
+ unsigned char n, unsigned char fanout, int flags,
+ each_note_fn fn, void *cb_data)
{
unsigned int i;
void *p;
@@ -443,7 +551,7 @@ redo:
switch (GET_PTR_TYPE(p)) {
case PTR_TYPE_INTERNAL:
/* recurse into int_node */
- ret = for_each_note_helper(CLR_PTR_TYPE(p), n + 1,
+ ret = for_each_note_helper(t, CLR_PTR_TYPE(p), n + 1,
fanout, flags, fn, cb_data);
break;
case PTR_TYPE_SUBTREE:
@@ -481,7 +589,7 @@ redo:
!(flags & FOR_EACH_NOTE_DONT_UNPACK_SUBTREES)) {
/* unpack subtree and resume traversal */
tree->a[i] = NULL;
- load_subtree(l, tree, n);
+ load_subtree(t, l, tree, n);
free(l);
goto redo;
}
@@ -596,8 +704,29 @@ static int write_each_note_helper(struct tree_write_stack *tws,
struct write_each_note_data {
struct tree_write_stack *root;
+ struct non_note *next_non_note;
};
+static int write_each_non_note_until(const char *note_path,
+ struct write_each_note_data *d)
+{
+ struct non_note *n = d->next_non_note;
+ int cmp, ret;
+ while (n && (!note_path || (cmp = strcmp(n->path, note_path)) <= 0)) {
+ if (note_path && cmp == 0)
+ ; /* do nothing, prefer note to non-note */
+ else {
+ ret = write_each_note_helper(d->root, n->path, n->mode,
+ n->sha1);
+ if (ret)
+ return ret;
+ }
+ n = n->next;
+ }
+ d->next_non_note = n;
+ return 0;
+}
+
static int write_each_note(const unsigned char *object_sha1,
const unsigned char *note_sha1, char *note_path,
void *cb_data)
@@ -615,7 +744,9 @@ static int write_each_note(const unsigned char *object_sha1,
}
assert(note_path_len <= 40 + 19);
- return write_each_note_helper(d->root, note_path, mode, note_sha1);
+ /* Weave non-note entries into note entries */
+ return write_each_non_note_until(note_path, d) ||
+ write_each_note_helper(d->root, note_path, mode, note_sha1);
}
int combine_notes_concatenate(unsigned char *cur_sha1,
@@ -696,6 +827,8 @@ void init_notes(struct notes_tree *t, const char *notes_ref,
combine_notes = combine_notes_concatenate;
t->root = (struct int_node *) xcalloc(sizeof(struct int_node), 1);
+ t->first_non_note = NULL;
+ t->prev_non_note = NULL;
t->ref = notes_ref ? xstrdup(notes_ref) : NULL;
t->combine_notes = combine_notes;
t->initialized = 1;
@@ -709,7 +842,7 @@ void init_notes(struct notes_tree *t, const char *notes_ref,
hashclr(root_tree.key_sha1);
hashcpy(root_tree.val_sha1, sha1);
- load_subtree(&root_tree, t->root, 0);
+ load_subtree(t, &root_tree, t->root, 0);
}
void add_note(struct notes_tree *t, const unsigned char *object_sha1,
@@ -725,7 +858,7 @@ void add_note(struct notes_tree *t, const unsigned char *object_sha1,
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, combine_notes);
+ note_tree_insert(t, t->root, 0, l, PTR_TYPE_NOTE, combine_notes);
}
void remove_note(struct notes_tree *t, const unsigned char *object_sha1)
@@ -748,7 +881,7 @@ const unsigned char *get_note(struct notes_tree *t,
if (!t)
t = &default_notes_tree;
assert(t->initialized);
- found = note_tree_find(t->root, 0, object_sha1);
+ found = note_tree_find(t, t->root, 0, object_sha1);
return found ? found->val_sha1 : NULL;
}
@@ -758,7 +891,7 @@ int for_each_note(struct notes_tree *t, int flags, each_note_fn fn,
if (!t)
t = &default_notes_tree;
assert(t->initialized);
- return for_each_note_helper(t->root, 0, 0, flags, fn, cb_data);
+ return for_each_note_helper(t, t->root, 0, 0, flags, fn, cb_data);
}
int write_notes_tree(struct notes_tree *t, unsigned char *result)
@@ -776,11 +909,13 @@ int write_notes_tree(struct notes_tree *t, unsigned char *result)
strbuf_init(&root.buf, 256 * (32 + 40)); /* assume 256 entries */
root.path[0] = root.path[1] = '\0';
cb_data.root = &root;
+ cb_data.next_non_note = t->first_non_note;
/* Write tree objects representing current notes tree */
ret = for_each_note(t, FOR_EACH_NOTE_DONT_UNPACK_SUBTREES |
FOR_EACH_NOTE_YIELD_SUBTREES,
write_each_note, &cb_data) ||
+ write_each_non_note_until(NULL, &cb_data) ||
tree_write_stack_finish_subtree(&root) ||
write_sha1_file(root.buf.buf, root.buf.len, tree_type, result);
strbuf_release(&root.buf);
@@ -794,6 +929,12 @@ void free_notes(struct notes_tree *t)
if (t->root)
note_tree_free(t->root);
free(t->root);
+ while (t->first_non_note) {
+ t->prev_non_note = t->first_non_note->next;
+ free(t->first_non_note->path);
+ free(t->first_non_note);
+ t->first_non_note = t->prev_non_note;
+ }
free(t->ref);
memset(t, 0, sizeof(struct notes_tree));
}