1 files changed, 167 insertions, 159 deletions

diff --git a/notes.c b/notes.c
index 2bab961ac1..5c62862574 100644
--- a/notes.c
+++ b/notes.c
@@ -1,4 +1,5 @@
 #include "cache.h"
+#include "config.h"
 #include "notes.h"
 #include "blob.h"
 #include "tree.h"
@@ -35,8 +36,8 @@ struct int_node {
  * subtree.
  */
 struct leaf_node {
-	unsigned char key_sha1[20];
-	unsigned char val_sha1[20];
+	struct object_id key_oid;
+	struct object_id val_oid;
 };
 
 /*
@@ -51,7 +52,7 @@ struct non_note {
 	struct non_note *next; /* grounded (last->next == NULL) */
 	char *path;
 	unsigned int mode;
-	unsigned char sha1[20];
+	struct object_id oid;
 };
 
 #define PTR_TYPE_NULL     0
@@ -63,10 +64,12 @@ struct non_note {
 #define CLR_PTR_TYPE(ptr)       ((void *) ((uintptr_t) (ptr) & ~3))
 #define SET_PTR_TYPE(ptr, type) ((void *) ((uintptr_t) (ptr) | (type)))
 
-#define GET_NIBBLE(n, sha1) (((sha1[(n) >> 1]) >> ((~(n) & 0x01) << 2)) & 0x0f)
+#define GET_NIBBLE(n, sha1) ((((sha1)[(n) >> 1]) >> ((~(n) & 0x01) << 2)) & 0x0f)
 
+#define KEY_INDEX (GIT_SHA1_RAWSZ - 1)
+#define FANOUT_PATH_SEPARATORS ((GIT_SHA1_HEXSZ / 2) - 1)
 #define SUBTREE_SHA1_PREFIXCMP(key_sha1, subtree_sha1) \
-	(memcmp(key_sha1, subtree_sha1, subtree_sha1[19]))
+	(memcmp(key_sha1, subtree_sha1, subtree_sha1[KEY_INDEX]))
 
 struct notes_tree default_notes_tree;
 
@@ -100,7 +103,7 @@ static void **note_tree_search(struct notes_tree *t, struct int_node **tree,
 
 	if (GET_PTR_TYPE(p) == PTR_TYPE_SUBTREE) {
 		l = (struct leaf_node *) CLR_PTR_TYPE(p);
-		if (!SUBTREE_SHA1_PREFIXCMP(key_sha1, l->key_sha1)) {
+		if (!SUBTREE_SHA1_PREFIXCMP(key_sha1, l->key_oid.hash)) {
 			/* unpack tree and resume search */
 			(*tree)->a[0] = NULL;
 			load_subtree(t, l, *tree, *n);
@@ -118,7 +121,7 @@ static void **note_tree_search(struct notes_tree *t, struct int_node **tree,
 		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)) {
+		if (!SUBTREE_SHA1_PREFIXCMP(key_sha1, l->key_oid.hash)) {
 			/* unpack tree and resume search */
 			(*tree)->a[i] = NULL;
 			load_subtree(t, l, *tree, *n);
@@ -143,7 +146,7 @@ static struct leaf_node *note_tree_find(struct notes_tree *t,
 	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))
+		if (!hashcmp(key_sha1, l->key_oid.hash))
 			return l;
 	}
 	return NULL;
@@ -153,8 +156,8 @@ static struct leaf_node *note_tree_find(struct notes_tree *t,
  * How to consolidate an int_node:
  * If there are > 1 non-NULL entries, give up and return non-zero.
  * Otherwise replace the int_node at the given index in the given parent node
- * with the only entry (or a NULL entry if no entries) from the given tree,
- * and return 0.
+ * with the only NOTE entry (or a NULL entry if no entries) from the given
+ * tree, and return 0.
  */
 static int note_tree_consolidate(struct int_node *tree,
 	struct int_node *parent, unsigned char index)
@@ -173,6 +176,8 @@ static int note_tree_consolidate(struct int_node *tree,
 		}
 	}
 
+	if (p && (GET_PTR_TYPE(p) != PTR_TYPE_NOTE))
+		return -2;
 	/* replace tree with p in parent[index] */
 	parent->a[index] = p;
 	free(tree);
@@ -192,19 +197,19 @@ static void note_tree_remove(struct notes_tree *t,
 		struct leaf_node *entry)
 {
 	struct leaf_node *l;
-	struct int_node *parent_stack[20];
+	struct int_node *parent_stack[GIT_SHA1_RAWSZ];
 	unsigned char i, j;
-	void **p = note_tree_search(t, &tree, &n, entry->key_sha1);
+	void **p = note_tree_search(t, &tree, &n, entry->key_oid.hash);
 
 	assert(GET_PTR_TYPE(entry) == 0); /* no type bits set */
 	if (GET_PTR_TYPE(*p) != PTR_TYPE_NOTE)
 		return; /* type mismatch, nothing to remove */
 	l = (struct leaf_node *) CLR_PTR_TYPE(*p);
-	if (hashcmp(l->key_sha1, entry->key_sha1))
+	if (oidcmp(&l->key_oid, &entry->key_oid))
 		return; /* key mismatch, nothing to remove */
 
 	/* we have found a matching entry */
-	hashcpy(entry->val_sha1, l->val_sha1);
+	oidcpy(&entry->val_oid, &l->val_oid);
 	free(l);
 	*p = SET_PTR_TYPE(NULL, PTR_TYPE_NULL);
 
@@ -214,14 +219,14 @@ static void note_tree_remove(struct notes_tree *t,
 	/* first, build stack of ancestors between root and current node */
 	parent_stack[0] = t->root;
 	for (i = 0; i < n; i++) {
-		j = GET_NIBBLE(i, entry->key_sha1);
+		j = GET_NIBBLE(i, entry->key_oid.hash);
 		parent_stack[i + 1] = CLR_PTR_TYPE(parent_stack[i]->a[j]);
 	}
 	assert(i == n && parent_stack[i] == tree);
 	/* next, unwind stack until note_tree_consolidate() is done */
 	while (i > 0 &&
 	       !note_tree_consolidate(parent_stack[i], parent_stack[i - 1],
-				      GET_NIBBLE(i - 1, entry->key_sha1)))
+				      GET_NIBBLE(i - 1, entry->key_oid.hash)))
 		i--;
 }
 
@@ -244,7 +249,7 @@ static int note_tree_insert(struct notes_tree *t, struct int_node *tree,
 {
 	struct int_node *new_node;
 	struct leaf_node *l;
-	void **p = note_tree_search(t, &tree, &n, entry->key_sha1);
+	void **p = note_tree_search(t, &tree, &n, entry->key_oid.hash);
 	int ret = 0;
 
 	assert(GET_PTR_TYPE(entry) == 0); /* no type bits set */
@@ -252,7 +257,7 @@ static int note_tree_insert(struct notes_tree *t, struct int_node *tree,
 	switch (GET_PTR_TYPE(*p)) {
 	case PTR_TYPE_NULL:
 		assert(!*p);
-		if (is_null_sha1(entry->val_sha1))
+		if (is_null_oid(&entry->val_oid))
 			free(entry);
 		else
 			*p = SET_PTR_TYPE(entry, type);
@@ -260,22 +265,22 @@ static int note_tree_insert(struct notes_tree *t, struct int_node *tree,
 	case PTR_TYPE_NOTE:
 		switch (type) {
 		case PTR_TYPE_NOTE:
-			if (!hashcmp(l->key_sha1, entry->key_sha1)) {
+			if (!oidcmp(&l->key_oid, &entry->key_oid)) {
 				/* skip concatenation if l == entry */
-				if (!hashcmp(l->val_sha1, entry->val_sha1))
+				if (!oidcmp(&l->val_oid, &entry->val_oid))
 					return 0;
 
-				ret = combine_notes(l->val_sha1,
-						    entry->val_sha1);
-				if (!ret && is_null_sha1(l->val_sha1))
+				ret = combine_notes(l->val_oid.hash,
+						    entry->val_oid.hash);
+				if (!ret && is_null_oid(&l->val_oid))
 					note_tree_remove(t, tree, n, entry);
 				free(entry);
 				return ret;
 			}
 			break;
 		case PTR_TYPE_SUBTREE:
-			if (!SUBTREE_SHA1_PREFIXCMP(l->key_sha1,
-						    entry->key_sha1)) {
+			if (!SUBTREE_SHA1_PREFIXCMP(l->key_oid.hash,
+						    entry->key_oid.hash)) {
 				/* unpack 'entry' */
 				load_subtree(t, entry, tree, n);
 				free(entry);
@@ -285,7 +290,7 @@ static int note_tree_insert(struct notes_tree *t, struct int_node *tree,
 		}
 		break;
 	case PTR_TYPE_SUBTREE:
-		if (!SUBTREE_SHA1_PREFIXCMP(entry->key_sha1, l->key_sha1)) {
+		if (!SUBTREE_SHA1_PREFIXCMP(entry->key_oid.hash, l->key_oid.hash)) {
 			/* unpack 'l' and restart insert */
 			*p = NULL;
 			load_subtree(t, l, tree, n);
@@ -299,7 +304,7 @@ static int note_tree_insert(struct notes_tree *t, struct int_node *tree,
 	/* non-matching leaf_node */
 	assert(GET_PTR_TYPE(*p) == PTR_TYPE_NOTE ||
 	       GET_PTR_TYPE(*p) == PTR_TYPE_SUBTREE);
-	if (is_null_sha1(entry->val_sha1)) { /* skip insertion of empty note */
+	if (is_null_oid(&entry->val_oid)) { /* skip insertion of empty note */
 		free(entry);
 		return 0;
 	}
@@ -330,31 +335,20 @@ static void note_tree_free(struct int_node *tree)
 }
 
 /*
- * Convert a partial SHA1 hex string to the corresponding partial SHA1 value.
- * - hex      - Partial SHA1 segment in ASCII hex format
- * - hex_len  - Length of above segment. Must be multiple of 2 between 0 and 40
- * - sha1     - Partial SHA1 value is written here
- * - sha1_len - Max #bytes to store in sha1, Must be >= hex_len / 2, and < 20
- * Returns -1 on error (invalid arguments or invalid SHA1 (not in hex format)).
- * Otherwise, returns number of bytes written to sha1 (i.e. hex_len / 2).
- * Pads sha1 with NULs up to sha1_len (not included in returned length).
+ * Read `len` pairs of hexadecimal digits from `hex` and write the
+ * values to `binary` as `len` bytes. Return 0 on success, or -1 if
+ * the input does not consist of hex digits).
  */
-static int get_sha1_hex_segment(const char *hex, unsigned int hex_len,
-		unsigned char *sha1, unsigned int sha1_len)
+static int hex_to_bytes(unsigned char *binary, const char *hex, size_t len)
 {
-	unsigned int i, len = hex_len >> 1;
-	if (hex_len % 2 != 0 || len > sha1_len)
-		return -1;
-	for (i = 0; i < len; i++) {
+	for (; len; len--, hex += 2) {
 		unsigned int val = (hexval(hex[0]) << 4) | hexval(hex[1]);
+
 		if (val & ~0xff)
 			return -1;
-		*sha1++ = val;
-		hex += 2;
+		*binary++ = val;
 	}
-	for (; i < sha1_len; i++)
-		*sha1++ = 0;
-	return len;
+	return 0;
 }
 
 static int non_note_cmp(const struct non_note *a, const struct non_note *b)
@@ -371,7 +365,7 @@ static void add_non_note(struct notes_tree *t, char *path,
 	n->next = NULL;
 	n->path = path;
 	n->mode = mode;
-	hashcpy(n->sha1, sha1);
+	hashcpy(n->oid.hash, sha1);
 	t->prev_non_note = n;
 
 	if (!t->first_non_note) {
@@ -397,7 +391,7 @@ static void add_non_note(struct notes_tree *t, char *path,
 	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);
+		oidcpy(&p->oid, &n->oid);
 		free(n);
 		t->prev_non_note = p;
 		return;
@@ -411,81 +405,91 @@ static void add_non_note(struct notes_tree *t, char *path,
 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;
+	struct object_id object_oid;
+	size_t 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);
+	buf = fill_tree_descriptor(&desc, &subtree->val_oid);
 	if (!buf)
 		die("Could not read %s for notes-index",
-		     sha1_to_hex(subtree->val_sha1));
-
-	prefix_len = subtree->key_sha1[19];
-	assert(prefix_len * 2 >= n);
-	memcpy(object_sha1, subtree->key_sha1, prefix_len);
+		     oid_to_hex(&subtree->val_oid));
+
+	prefix_len = subtree->key_oid.hash[KEY_INDEX];
+	if (prefix_len >= GIT_SHA1_RAWSZ)
+		BUG("prefix_len (%"PRIuMAX") is out of range", (uintmax_t)prefix_len);
+	if (prefix_len * 2 < n)
+		BUG("prefix_len (%"PRIuMAX") is too small", (uintmax_t)prefix_len);
+	memcpy(object_oid.hash, subtree->key_oid.hash, prefix_len);
 	while (tree_entry(&desc, &entry)) {
-		path_len = strlen(entry.path);
-		len = get_sha1_hex_segment(entry.path, path_len,
-				object_sha1 + prefix_len, 20 - prefix_len);
-		if (len < 0)
-			goto handle_non_note; /* entry.path is not a SHA1 */
-		len += prefix_len;
+		unsigned char type;
+		struct leaf_node *l;
+		size_t path_len = strlen(entry.path);
+
+		if (path_len == 2 * (GIT_SHA1_RAWSZ - prefix_len)) {
+			/* This is potentially the remainder of the SHA-1 */
+
+			if (!S_ISREG(entry.mode))
+				/* notes must be blobs */
+				goto handle_non_note;
+
+			if (hex_to_bytes(object_oid.hash + prefix_len, entry.path,
+					 GIT_SHA1_RAWSZ - prefix_len))
+				goto handle_non_note; /* entry.path is not a SHA1 */
 
-		/*
-		 * If object SHA1 is complete (len == 20), assume note object
-		 * If object SHA1 is incomplete (len < 20), and current
-		 * component consists of 2 hex chars, assume note subtree
-		 */
-		if (len <= 20) {
 			type = PTR_TYPE_NOTE;
-			l = (struct leaf_node *)
-				xcalloc(1, sizeof(struct leaf_node));
-			hashcpy(l->key_sha1, object_sha1);
-			hashcpy(l->val_sha1, entry.oid->hash);
-			if (len < 20) {
-				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;
-			}
-			if (note_tree_insert(t, node, n, l, type,
-					     combine_notes_concatenate))
-				die("Failed to load %s %s into notes tree "
-				    "from %s",
-				    type == PTR_TYPE_NOTE ? "note" : "subtree",
-				    sha1_to_hex(l->key_sha1), t->ref);
+		} else if (path_len == 2) {
+			/* This is potentially an internal node */
+			size_t len = prefix_len;
+
+			if (!S_ISDIR(entry.mode))
+				/* internal nodes must be trees */
+				goto handle_non_note;
+
+			if (hex_to_bytes(object_oid.hash + len++, entry.path, 1))
+				goto handle_non_note; /* entry.path is not a SHA1 */
+
+			/*
+			 * Pad the rest of the SHA-1 with zeros,
+			 * except for the last byte, where we write
+			 * the length:
+			 */
+			memset(object_oid.hash + len, 0, GIT_SHA1_RAWSZ - len - 1);
+			object_oid.hash[KEY_INDEX] = (unsigned char)len;
+
+			type = PTR_TYPE_SUBTREE;
+		} else {
+			/* This can't be part of a note */
+			goto handle_non_note;
 		}
+
+		l = xcalloc(1, sizeof(*l));
+		oidcpy(&l->key_oid, &object_oid);
+		oidcpy(&l->val_oid, entry.oid);
+		if (note_tree_insert(t, node, n, l, type,
+				     combine_notes_concatenate))
+			die("Failed to load %s %s into notes tree "
+			    "from %s",
+			    type == PTR_TYPE_NOTE ? "note" : "subtree",
+			    oid_to_hex(&l->key_oid), t->ref);
+
 		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.
+		 * 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 based on our
+		 * knowledge that the overall notes tree follows a
+		 * strict byte-based progressive fanout structure
+		 * (i.e. using 2/38, 2/2/36, etc. fanouts).
 		 */
 		{
 			struct strbuf non_note_path = STRBUF_INIT;
-			const char *q = sha1_to_hex(subtree->key_sha1);
-			int i;
+			const char *q = oid_to_hex(&subtree->key_oid);
+			size_t i;
 			for (i = 0; i < prefix_len; i++) {
 				strbuf_addch(&non_note_path, *q++);
 				strbuf_addch(&non_note_path, *q++);
@@ -540,14 +544,14 @@ static unsigned char determine_fanout(struct int_node *tree, unsigned char n,
 }
 
 /* hex SHA1 + 19 * '/' + NUL */
-#define FANOUT_PATH_MAX 40 + 19 + 1
+#define FANOUT_PATH_MAX GIT_SHA1_HEXSZ + FANOUT_PATH_SEPARATORS + 1
 
 static void construct_path_with_fanout(const unsigned char *sha1,
 		unsigned char fanout, char *path)
 {
 	unsigned int i = 0, j = 0;
 	const char *hex_sha1 = sha1_to_hex(sha1);
-	assert(fanout < 20);
+	assert(fanout < GIT_SHA1_RAWSZ);
 	while (fanout) {
 		path[i++] = hex_sha1[j++];
 		path[i++] = hex_sha1[j++];
@@ -597,15 +601,17 @@ redo:
 			    flags & FOR_EACH_NOTE_YIELD_SUBTREES) {
 				/* invoke callback with subtree */
 				unsigned int path_len =
-					l->key_sha1[19] * 2 + fanout;
+					l->key_oid.hash[KEY_INDEX] * 2 + fanout;
 				assert(path_len < FANOUT_PATH_MAX - 1);
-				construct_path_with_fanout(l->key_sha1, fanout,
+				construct_path_with_fanout(l->key_oid.hash,
+							   fanout,
 							   path);
 				/* Create trailing slash, if needed */
 				if (path[path_len - 1] != '/')
 					path[path_len++] = '/';
 				path[path_len] = '\0';
-				ret = fn(l->key_sha1, l->val_sha1, path,
+				ret = fn(&l->key_oid, &l->val_oid,
+					 path,
 					 cb_data);
 			}
 			if (n > fanout * 2 ||
@@ -619,8 +625,10 @@ redo:
 			break;
 		case PTR_TYPE_NOTE:
 			l = (struct leaf_node *) CLR_PTR_TYPE(p);
-			construct_path_with_fanout(l->key_sha1, fanout, path);
-			ret = fn(l->key_sha1, l->val_sha1, path, cb_data);
+			construct_path_with_fanout(l->key_oid.hash, fanout,
+						   path);
+			ret = fn(&l->key_oid, &l->val_oid, path,
+				 cb_data);
 			break;
 		}
 		if (ret)
@@ -648,7 +656,7 @@ static void write_tree_entry(struct strbuf *buf, unsigned int mode,
 		unsigned char *sha1)
 {
 	strbuf_addf(buf, "%o %.*s%c", mode, path_len, path, '\0');
-	strbuf_add(buf, sha1, 20);
+	strbuf_add(buf, sha1, GIT_SHA1_RAWSZ);
 }
 
 static void tree_write_stack_init_subtree(struct tree_write_stack *tws,
@@ -660,7 +668,7 @@ static void tree_write_stack_init_subtree(struct tree_write_stack *tws,
 	n = (struct tree_write_stack *)
 		xmalloc(sizeof(struct tree_write_stack));
 	n->next = NULL;
-	strbuf_init(&n->buf, 256 * (32 + 40)); /* assume 256 entries per tree */
+	strbuf_init(&n->buf, 256 * (32 + GIT_SHA1_HEXSZ)); /* assume 256 entries per tree */
 	n->path[0] = n->path[1] = '\0';
 	tws->next = n;
 	tws->path[0] = path[0];
@@ -671,18 +679,18 @@ static int tree_write_stack_finish_subtree(struct tree_write_stack *tws)
 {
 	int ret;
 	struct tree_write_stack *n = tws->next;
-	unsigned char s[20];
+	struct object_id s;
 	if (n) {
 		ret = tree_write_stack_finish_subtree(n);
 		if (ret)
 			return ret;
-		ret = write_sha1_file(n->buf.buf, n->buf.len, tree_type, s);
+		ret = write_sha1_file(n->buf.buf, n->buf.len, tree_type, s.hash);
 		if (ret)
 			return ret;
 		strbuf_release(&n->buf);
 		free(n);
 		tws->next = NULL;
-		write_tree_entry(&tws->buf, 040000, tws->path, 2, s);
+		write_tree_entry(&tws->buf, 040000, tws->path, 2, s.hash);
 		tws->path[0] = tws->path[1] = '\0';
 	}
 	return 0;
@@ -690,7 +698,7 @@ static int tree_write_stack_finish_subtree(struct tree_write_stack *tws)
 
 static int write_each_note_helper(struct tree_write_stack *tws,
 		const char *path, unsigned int mode,
-		const unsigned char *sha1)
+		const struct object_id *oid)
 {
 	size_t path_len = strlen(path);
 	unsigned int n = 0;
@@ -720,7 +728,7 @@ static int write_each_note_helper(struct tree_write_stack *tws,
 
 	/* Finally add given entry to the current tree object */
 	write_tree_entry(&tws->buf, mode, path + 3 * n, path_len - (3 * n),
-			 sha1);
+			 oid->hash);
 
 	return 0;
 }
@@ -740,7 +748,7 @@ static int write_each_non_note_until(const char *note_path,
 			; /* do nothing, prefer note to non-note */
 		else {
 			ret = write_each_note_helper(d->root, n->path, n->mode,
-						     n->sha1);
+						     &n->oid);
 			if (ret)
 				return ret;
 		}
@@ -750,8 +758,8 @@ static int write_each_non_note_until(const char *note_path,
 	return 0;
 }
 
-static int write_each_note(const unsigned char *object_sha1,
-		const unsigned char *note_sha1, char *note_path,
+static int write_each_note(const struct object_id *object_oid,
+		const struct object_id *note_oid, char *note_path,
 		void *cb_data)
 {
 	struct write_each_note_data *d =
@@ -765,11 +773,11 @@ static int write_each_note(const unsigned char *object_sha1,
 		note_path[note_path_len] = '\0';
 		mode = 040000;
 	}
-	assert(note_path_len <= 40 + 19);
+	assert(note_path_len <= GIT_SHA1_HEXSZ + FANOUT_PATH_SEPARATORS);
 
 	/* 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);
+		write_each_note_helper(d->root, note_path, mode, note_oid);
 }
 
 struct note_delete_list {
@@ -777,20 +785,20 @@ struct note_delete_list {
 	const unsigned char *sha1;
 };
 
-static int prune_notes_helper(const unsigned char *object_sha1,
-		const unsigned char *note_sha1, char *note_path,
+static int prune_notes_helper(const struct object_id *object_oid,
+		const struct object_id *note_oid, char *note_path,
 		void *cb_data)
 {
 	struct note_delete_list **l = (struct note_delete_list **) cb_data;
 	struct note_delete_list *n;
 
-	if (has_sha1_file(object_sha1))
+	if (has_object_file(object_oid))
 		return 0; /* nothing to do for this note */
 
 	/* failed to find object => prune this note */
 	n = (struct note_delete_list *) xmalloc(sizeof(*n));
 	n->next = *l;
-	n->sha1 = object_sha1;
+	n->sha1 = object_oid->hash;
 	*l = n;
 	return 0;
 }
@@ -940,8 +948,8 @@ void string_list_add_refs_by_glob(struct string_list *list, const char *glob)
 	if (has_glob_specials(glob)) {
 		for_each_glob_ref(string_list_add_one_ref, glob, list);
 	} else {
-		unsigned char sha1[20];
-		if (get_sha1(glob, sha1))
+		struct object_id oid;
+		if (get_oid(glob, &oid))
 			warning("notes ref %s is invalid", glob);
 		if (!unsorted_string_list_has_string(list, glob))
 			string_list_append(list, glob);
@@ -1017,7 +1025,7 @@ void init_notes(struct notes_tree *t, const char *notes_ref,
 	t->dirty = 0;
 
 	if (flags & NOTES_INIT_EMPTY || !notes_ref ||
-	    get_sha1_treeish(notes_ref, object_oid.hash))
+	    get_oid_treeish(notes_ref, &object_oid))
 		return;
 	if (flags & NOTES_INIT_WRITABLE && read_ref(notes_ref, object_oid.hash))
 		die("Cannot use notes ref %s", notes_ref);
@@ -1025,8 +1033,8 @@ void init_notes(struct notes_tree *t, const char *notes_ref,
 		die("Failed to read notes tree referenced by %s (%s)",
 		    notes_ref, oid_to_hex(&object_oid));
 
-	hashclr(root_tree.key_sha1);
-	hashcpy(root_tree.val_sha1, oid.hash);
+	oidclr(&root_tree.key_oid);
+	oidcpy(&root_tree.val_oid, &oid);
 	load_subtree(t, &root_tree, t->root, 0);
 }
 
@@ -1078,8 +1086,8 @@ void init_display_notes(struct display_notes_opt *opt)
 	string_list_clear(&display_notes_refs, 0);
 }
 
-int add_note(struct notes_tree *t, const unsigned char *object_sha1,
-		const unsigned char *note_sha1, combine_notes_fn combine_notes)
+int add_note(struct notes_tree *t, const struct object_id *object_oid,
+		const struct object_id *note_oid, combine_notes_fn combine_notes)
 {
 	struct leaf_node *l;
 
@@ -1090,8 +1098,8 @@ int add_note(struct notes_tree *t, const unsigned char *object_sha1,
 	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);
+	oidcpy(&l->key_oid, object_oid);
+	oidcpy(&l->val_oid, note_oid);
 	return note_tree_insert(t, t->root, 0, l, PTR_TYPE_NOTE, combine_notes);
 }
 
@@ -1102,25 +1110,25 @@ int remove_note(struct notes_tree *t, const unsigned char *object_sha1)
 	if (!t)
 		t = &default_notes_tree;
 	assert(t->initialized);
-	hashcpy(l.key_sha1, object_sha1);
-	hashclr(l.val_sha1);
+	hashcpy(l.key_oid.hash, object_sha1);
+	oidclr(&l.val_oid);
 	note_tree_remove(t, t->root, 0, &l);
-	if (is_null_sha1(l.val_sha1)) /* no note was removed */
+	if (is_null_oid(&l.val_oid)) /* no note was removed */
 		return 1;
 	t->dirty = 1;
 	return 0;
 }
 
-const unsigned char *get_note(struct notes_tree *t,
-		const unsigned char *object_sha1)
+const struct object_id *get_note(struct notes_tree *t,
+		const struct object_id *oid)
 {
 	struct leaf_node *found;
 
 	if (!t)
 		t = &default_notes_tree;
 	assert(t->initialized);
-	found = note_tree_find(t, t->root, 0, object_sha1);
-	return found ? found->val_sha1 : NULL;
+	found = note_tree_find(t, t->root, 0, oid->hash);
+	return found ? &found->val_oid : NULL;
 }
 
 int for_each_note(struct notes_tree *t, int flags, each_note_fn fn,
@@ -1144,7 +1152,7 @@ int write_notes_tree(struct notes_tree *t, unsigned char *result)
 
 	/* Prepare for traversal of current notes tree */
 	root.next = NULL; /* last forward entry in list is grounded */
-	strbuf_init(&root.buf, 256 * (32 + 40)); /* assume 256 entries */
+	strbuf_init(&root.buf, 256 * (32 + GIT_SHA1_HEXSZ)); /* assume 256 entries */
 	root.path[0] = root.path[1] = '\0';
 	cb_data.root = &root;
 	cb_data.next_non_note = t->first_non_note;
@@ -1207,11 +1215,11 @@ void free_notes(struct notes_tree *t)
  * (raw != 0) gives the %N userformat; otherwise, the note message is given
  * for human consumption.
  */
-static void format_note(struct notes_tree *t, const unsigned char *object_sha1,
+static void format_note(struct notes_tree *t, const struct object_id *object_oid,
 			struct strbuf *sb, const char *output_encoding, int raw)
 {
 	static const char utf8[] = "utf-8";
-	const unsigned char *sha1;
+	const struct object_id *oid;
 	char *msg, *msg_p;
 	unsigned long linelen, msglen;
 	enum object_type type;
@@ -1221,11 +1229,11 @@ static void format_note(struct notes_tree *t, const unsigned char *object_sha1,
 	if (!t->initialized)
 		init_notes(t, NULL, NULL, 0);
 
-	sha1 = get_note(t, object_sha1);
-	if (!sha1)
+	oid = get_note(t, object_oid);
+	if (!oid)
 		return;
 
-	if (!(msg = read_sha1_file(sha1, &type, &msglen)) || type != OBJ_BLOB) {
+	if (!(msg = read_sha1_file(oid->hash, &type, &msglen)) || type != OBJ_BLOB) {
 		free(msg);
 		return;
 	}
@@ -1269,22 +1277,22 @@ static void format_note(struct notes_tree *t, const unsigned char *object_sha1,
 	free(msg);
 }
 
-void format_display_notes(const unsigned char *object_sha1,
+void format_display_notes(const struct object_id *object_oid,
 			  struct strbuf *sb, const char *output_encoding, int raw)
 {
 	int i;
 	assert(display_notes_trees);
 	for (i = 0; display_notes_trees[i]; i++)
-		format_note(display_notes_trees[i], object_sha1, sb,
+		format_note(display_notes_trees[i], object_oid, sb,
 			    output_encoding, raw);
 }
 
 int copy_note(struct notes_tree *t,
-	      const unsigned char *from_obj, const unsigned char *to_obj,
+	      const struct object_id *from_obj, const struct object_id *to_obj,
 	      int force, combine_notes_fn combine_notes)
 {
-	const unsigned char *note = get_note(t, from_obj);
-	const unsigned char *existing_note = get_note(t, to_obj);
+	const struct object_id *note = get_note(t, from_obj);
+	const struct object_id *existing_note = get_note(t, to_obj);
 
 	if (!force && existing_note)
 		return 1;
@@ -1292,7 +1300,7 @@ int copy_note(struct notes_tree *t,
 	if (note)
 		return add_note(t, to_obj, note, combine_notes);
 	else if (existing_note)
-		return add_note(t, to_obj, null_sha1, combine_notes);
+		return add_note(t, to_obj, &null_oid, combine_notes);
 
 	return 0;
 }
@@ -1309,9 +1317,9 @@ void expand_notes_ref(struct strbuf *sb)
 
 void expand_loose_notes_ref(struct strbuf *sb)
 {
-	unsigned char object[20];
+	struct object_id object;
 
-	if (get_sha1(sb->buf, object)) {
+	if (get_oid(sb->buf, &object)) {
 		/* fallback to expand_notes_ref */
 		expand_notes_ref(sb);
 	}