#include "cache.h"
-#include "commit.h"
#include "notes.h"
-#include "refs.h"
+#include "tree.h"
#include "utf8.h"
#include "strbuf.h"
#include "tree-walk.h"
/*
* Leaf nodes come in two variants, note entries and subtree entries,
* distinguished by the LSb of the leaf node pointer (see above).
- * As a note entry, the key is the SHA1 of the referenced commit, and the
+ * As a note entry, the key is the SHA1 of the referenced object, and the
* value is the SHA1 of the note object.
* As a subtree entry, the key is the prefix SHA1 (w/trailing NULs) of the
- * referenced commit, using the last byte of the key to store the length of
+ * referenced object, using the last byte of the key to store the length of
* the prefix. The value is the SHA1 of the tree object containing the notes
* subtree.
*/
#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 SUBTREE_SHA1_PREFIXCMP(key_sha1, subtree_sha1) \
(memcmp(key_sha1, subtree_sha1, subtree_sha1[19]))
-static struct int_node root_node;
-
-static int initialized;
+struct notes_tree default_notes_tree;
static void load_subtree(struct leaf_node *subtree, struct int_node *node,
unsigned int n);
i = GET_NIBBLE(*n, key_sha1);
p = (*tree)->a[i];
- switch(GET_PTR_TYPE(p)) {
+ switch (GET_PTR_TYPE(p)) {
case PTR_TYPE_INTERNAL:
*tree = CLR_PTR_TYPE(p);
(*n)++;
assert(GET_PTR_TYPE(entry) == 0); /* no type bits set */
l = (struct leaf_node *) CLR_PTR_TYPE(*p);
- switch(GET_PTR_TYPE(*p)) {
+ switch (GET_PTR_TYPE(*p)) {
case PTR_TYPE_NULL:
assert(!*p);
*p = SET_PTR_TYPE(entry, type);
if (concatenate_notes(l->val_sha1,
entry->val_sha1))
die("failed to concatenate note %s "
- "into note %s for commit %s",
+ "into note %s for object %s",
sha1_to_hex(entry->val_sha1),
sha1_to_hex(l->val_sha1),
sha1_to_hex(l->key_sha1));
note_tree_insert(new_node, n + 1, entry, type);
}
+/*
+ * 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.
+ */
+static int note_tree_consolidate(struct int_node *tree,
+ struct int_node *parent, unsigned char index)
+{
+ unsigned int i;
+ void *p = NULL;
+
+ assert(tree && parent);
+ assert(CLR_PTR_TYPE(parent->a[index]) == tree);
+
+ for (i = 0; i < 16; i++) {
+ if (GET_PTR_TYPE(tree->a[i]) != PTR_TYPE_NULL) {
+ if (p) /* more than one entry */
+ return -2;
+ p = tree->a[i];
+ }
+ }
+
+ /* replace tree with p in parent[index] */
+ parent->a[index] = p;
+ free(tree);
+ return 0;
+}
+
+/*
+ * To remove a leaf_node:
+ * Search to the tree location appropriate for the given leaf_node's key:
+ * - If location does not hold a matching entry, abort and do nothing.
+ * - Replace the matching leaf_node with a NULL entry (and free the leaf_node).
+ * - Consolidate int_nodes repeatedly, while walking up the tree towards root.
+ */
+static void note_tree_remove(struct notes_tree *t, struct int_node *tree,
+ unsigned char n, struct leaf_node *entry)
+{
+ struct leaf_node *l;
+ struct int_node *parent_stack[20];
+ unsigned char i, j;
+ void **p = note_tree_search(&tree, &n, entry->key_sha1);
+
+ 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))
+ return; /* key mismatch, nothing to remove */
+
+ /* we have found a matching entry */
+ free(l);
+ *p = SET_PTR_TYPE(NULL, PTR_TYPE_NULL);
+
+ /* consolidate this tree level, and parent levels, if possible */
+ if (!n)
+ return; /* cannot consolidate top level */
+ /* 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);
+ 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)))
+ i--;
+}
+
/* Free the entire notes data contained in the given tree */
static void note_tree_free(struct int_node *tree)
{
unsigned int i;
for (i = 0; i < 16; i++) {
void *p = tree->a[i];
- switch(GET_PTR_TYPE(p)) {
+ switch (GET_PTR_TYPE(p)) {
case PTR_TYPE_INTERNAL:
note_tree_free(CLR_PTR_TYPE(p));
/* fall through */
* - 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).
+ * 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).
*/
static void load_subtree(struct leaf_node *subtree, struct int_node *node,
unsigned int n)
{
- unsigned char commit_sha1[20];
+ unsigned char object_sha1[20];
unsigned int prefix_len;
void *buf;
struct tree_desc desc;
prefix_len = subtree->key_sha1[19];
assert(prefix_len * 2 >= n);
- memcpy(commit_sha1, subtree->key_sha1, prefix_len);
+ memcpy(object_sha1, subtree->key_sha1, prefix_len);
while (tree_entry(&desc, &entry)) {
int len = get_sha1_hex_segment(entry.path, strlen(entry.path),
- commit_sha1 + prefix_len, 20 - prefix_len);
+ object_sha1 + prefix_len, 20 - prefix_len);
if (len < 0)
continue; /* entry.path is not a SHA1 sum. Skip */
len += prefix_len;
/*
- * If commit SHA1 is complete (len == 20), assume note object
- * If commit SHA1 is incomplete (len < 20), assume note subtree
+ * If object SHA1 is complete (len == 20), assume note object
+ * If object SHA1 is incomplete (len < 20), assume note subtree
*/
if (len <= 20) {
unsigned char type = PTR_TYPE_NOTE;
struct leaf_node *l = (struct leaf_node *)
xcalloc(sizeof(struct leaf_node), 1);
- hashcpy(l->key_sha1, commit_sha1);
+ hashcpy(l->key_sha1, object_sha1);
hashcpy(l->val_sha1, entry.sha1);
if (len < 20) {
if (!S_ISDIR(entry.mode))
free(buf);
}
-static void initialize_notes(const char *notes_ref_name)
+/*
+ * Determine optimal on-disk fanout for this part of the notes tree
+ *
+ * Given a (sub)tree and the level in the internal tree structure, determine
+ * whether or not the given existing fanout should be expanded for this
+ * (sub)tree.
+ *
+ * Values of the 'fanout' variable:
+ * - 0: No fanout (all notes are stored directly in the root notes tree)
+ * - 1: 2/38 fanout
+ * - 2: 2/2/36 fanout
+ * - 3: 2/2/2/34 fanout
+ * etc.
+ */
+static unsigned char determine_fanout(struct int_node *tree, unsigned char n,
+ unsigned char fanout)
{
- unsigned char sha1[20], commit_sha1[20];
+ /*
+ * The following is a simple heuristic that works well in practice:
+ * For each even-numbered 16-tree level (remember that each on-disk
+ * fanout level corresponds to _two_ 16-tree levels), peek at all 16
+ * entries at that tree level. If all of them are either int_nodes or
+ * subtree entries, then there are likely plenty of notes below this
+ * level, so we return an incremented fanout.
+ */
+ unsigned int i;
+ if ((n % 2) || (n > 2 * fanout))
+ return fanout;
+ for (i = 0; i < 16; i++) {
+ switch (GET_PTR_TYPE(tree->a[i])) {
+ case PTR_TYPE_SUBTREE:
+ case PTR_TYPE_INTERNAL:
+ continue;
+ default:
+ return fanout;
+ }
+ }
+ return fanout + 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);
+ while (fanout) {
+ path[i++] = hex_sha1[j++];
+ path[i++] = hex_sha1[j++];
+ path[i++] = '/';
+ fanout--;
+ }
+ 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)
+{
+ unsigned int i;
+ void *p;
+ int ret = 0;
+ struct leaf_node *l;
+ static char path[40 + 19 + 1]; /* hex SHA1 + 19 * '/' + NUL */
+
+ fanout = determine_fanout(tree, n, fanout);
+ for (i = 0; i < 16; i++) {
+redo:
+ p = tree->a[i];
+ switch (GET_PTR_TYPE(p)) {
+ case PTR_TYPE_INTERNAL:
+ /* recurse into int_node */
+ ret = for_each_note_helper(CLR_PTR_TYPE(p), n + 1,
+ fanout, flags, fn, cb_data);
+ break;
+ case PTR_TYPE_SUBTREE:
+ l = (struct leaf_node *) CLR_PTR_TYPE(p);
+ /*
+ * Subtree entries in the note tree represent parts of
+ * the note tree that have not yet been explored. There
+ * is a direct relationship between subtree entries at
+ * level 'n' in the tree, and the 'fanout' variable:
+ * Subtree entries at level 'n <= 2 * fanout' should be
+ * preserved, since they correspond exactly to a fanout
+ * directory in the on-disk structure. However, subtree
+ * entries at level 'n > 2 * fanout' should NOT be
+ * preserved, but rather consolidated into the above
+ * notes tree level. We achieve this by unconditionally
+ * unpacking subtree entries that exist below the
+ * threshold level at 'n = 2 * fanout'.
+ */
+ if (n <= 2 * fanout &&
+ flags & FOR_EACH_NOTE_YIELD_SUBTREES) {
+ /* invoke callback with subtree */
+ unsigned int path_len =
+ l->key_sha1[19] * 2 + fanout;
+ assert(path_len < 40 + 19);
+ construct_path_with_fanout(l->key_sha1, 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,
+ cb_data);
+ }
+ if (n > fanout * 2 ||
+ !(flags & FOR_EACH_NOTE_DONT_UNPACK_SUBTREES)) {
+ /* unpack subtree and resume traversal */
+ tree->a[i] = NULL;
+ load_subtree(l, tree, n);
+ free(l);
+ goto 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);
+ break;
+ }
+ if (ret)
+ return ret;
+ }
+ return 0;
+}
+
+struct tree_write_stack {
+ struct tree_write_stack *next;
+ struct strbuf buf;
+ char path[2]; /* path to subtree in next, if any */
+};
+
+static inline int matches_tree_write_stack(struct tree_write_stack *tws,
+ const char *full_path)
+{
+ return full_path[0] == tws->path[0] &&
+ full_path[1] == tws->path[1] &&
+ full_path[2] == '/';
+}
+
+static void write_tree_entry(struct strbuf *buf, unsigned int mode,
+ const char *path, unsigned int path_len, const
+ unsigned char *sha1)
+{
+ strbuf_addf(buf, "%06o %.*s%c", mode, path_len, path, '\0');
+ strbuf_add(buf, sha1, 20);
+}
+
+static void tree_write_stack_init_subtree(struct tree_write_stack *tws,
+ const char *path)
+{
+ struct tree_write_stack *n;
+ assert(!tws->next);
+ assert(tws->path[0] == '\0' && tws->path[1] == '\0');
+ 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 */
+ n->path[0] = n->path[1] = '\0';
+ tws->next = n;
+ tws->path[0] = path[0];
+ tws->path[1] = path[1];
+}
+
+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];
+ 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);
+ if (ret)
+ return ret;
+ strbuf_release(&n->buf);
+ free(n);
+ tws->next = NULL;
+ write_tree_entry(&tws->buf, 040000, tws->path, 2, s);
+ tws->path[0] = tws->path[1] = '\0';
+ }
+ return 0;
+}
+
+static int write_each_note_helper(struct tree_write_stack *tws,
+ const char *path, unsigned int mode,
+ const unsigned char *sha1)
+{
+ size_t path_len = strlen(path);
+ unsigned int n = 0;
+ int ret;
+
+ /* Determine common part of tree write stack */
+ while (tws && 3 * n < path_len &&
+ matches_tree_write_stack(tws, path + 3 * n)) {
+ n++;
+ tws = tws->next;
+ }
+
+ /* tws point to last matching tree_write_stack entry */
+ ret = tree_write_stack_finish_subtree(tws);
+ if (ret)
+ return ret;
+
+ /* Start subtrees needed to satisfy path */
+ while (3 * n + 2 < path_len && path[3 * n + 2] == '/') {
+ tree_write_stack_init_subtree(tws, path + 3 * n);
+ n++;
+ tws = tws->next;
+ }
+
+ /* There should be no more directory components in the given path */
+ assert(memchr(path + 3 * n, '/', path_len - (3 * n)) == NULL);
+
+ /* Finally add given entry to the current tree object */
+ write_tree_entry(&tws->buf, mode, path + 3 * n, path_len - (3 * n),
+ sha1);
+
+ return 0;
+}
+
+struct write_each_note_data {
+ struct tree_write_stack *root;
+};
+
+static int write_each_note(const unsigned char *object_sha1,
+ const unsigned char *note_sha1, char *note_path,
+ void *cb_data)
+{
+ struct write_each_note_data *d =
+ (struct write_each_note_data *) cb_data;
+ size_t note_path_len = strlen(note_path);
+ unsigned int mode = 0100644;
+
+ if (note_path[note_path_len - 1] == '/') {
+ /* subtree entry */
+ note_path_len--;
+ note_path[note_path_len] = '\0';
+ mode = 040000;
+ }
+ assert(note_path_len <= 40 + 19);
+
+ 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)
+{
+ unsigned char sha1[20], object_sha1[20];
unsigned mode;
struct leaf_node root_tree;
- if (!notes_ref_name || read_ref(notes_ref_name, commit_sha1) ||
- get_tree_entry(commit_sha1, "", sha1, &mode))
+ if (!t)
+ t = &default_notes_tree;
+ assert(!t->initialized);
+
+ if (!notes_ref)
+ notes_ref = getenv(GIT_NOTES_REF_ENVIRONMENT);
+ if (!notes_ref)
+ notes_ref = notes_ref_name; /* value of core.notesRef config */
+ if (!notes_ref)
+ notes_ref = GIT_NOTES_DEFAULT_REF;
+
+ t->root = (struct int_node *) xcalloc(sizeof(struct int_node), 1);
+ t->ref = notes_ref ? xstrdup(notes_ref) : NULL;
+ t->initialized = 1;
+
+ if (flags & NOTES_INIT_EMPTY || !notes_ref ||
+ read_ref(notes_ref, object_sha1))
return;
+ if (get_tree_entry(object_sha1, "", sha1, &mode))
+ die("Failed to read notes tree referenced by %s (%s)",
+ notes_ref, object_sha1);
hashclr(root_tree.key_sha1);
hashcpy(root_tree.val_sha1, sha1);
- load_subtree(&root_tree, &root_node, 0);
+ load_subtree(&root_tree, t->root, 0);
}
-static unsigned char *lookup_notes(const unsigned char *commit_sha1)
+void add_note(struct notes_tree *t, const unsigned char *object_sha1,
+ const unsigned char *note_sha1)
{
- struct leaf_node *found = note_tree_find(&root_node, 0, commit_sha1);
- if (found)
- return found->val_sha1;
- return NULL;
+ struct leaf_node *l;
+
+ if (!t)
+ t = &default_notes_tree;
+ assert(t->initialized);
+ 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);
}
-void free_notes(void)
+void remove_note(struct notes_tree *t, const unsigned char *object_sha1)
{
- note_tree_free(&root_node);
- memset(&root_node, 0, sizeof(struct int_node));
- initialized = 0;
+ struct leaf_node l;
+
+ if (!t)
+ t = &default_notes_tree;
+ assert(t->initialized);
+ hashcpy(l.key_sha1, object_sha1);
+ hashclr(l.val_sha1);
+ return note_tree_remove(t, t->root, 0, &l);
}
-void get_commit_notes(const struct commit *commit, struct strbuf *sb,
- const char *output_encoding, int flags)
+const unsigned char *get_note(struct notes_tree *t,
+ const unsigned char *object_sha1)
+{
+ struct leaf_node *found;
+
+ if (!t)
+ t = &default_notes_tree;
+ assert(t->initialized);
+ found = note_tree_find(t->root, 0, object_sha1);
+ return found ? found->val_sha1 : NULL;
+}
+
+int for_each_note(struct notes_tree *t, int flags, each_note_fn fn,
+ void *cb_data)
+{
+ if (!t)
+ t = &default_notes_tree;
+ assert(t->initialized);
+ return for_each_note_helper(t->root, 0, 0, flags, fn, cb_data);
+}
+
+int write_notes_tree(struct notes_tree *t, unsigned char *result)
+{
+ struct tree_write_stack root;
+ struct write_each_note_data cb_data;
+ int ret;
+
+ if (!t)
+ t = &default_notes_tree;
+ assert(t->initialized);
+
+ /* 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 */
+ root.path[0] = root.path[1] = '\0';
+ cb_data.root = &root;
+
+ /* 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) ||
+ tree_write_stack_finish_subtree(&root) ||
+ write_sha1_file(root.buf.buf, root.buf.len, tree_type, result);
+ strbuf_release(&root.buf);
+ return ret;
+}
+
+void free_notes(struct notes_tree *t)
+{
+ if (!t)
+ t = &default_notes_tree;
+ if (t->root)
+ note_tree_free(t->root);
+ free(t->root);
+ free(t->ref);
+ memset(t, 0, sizeof(struct notes_tree));
+}
+
+void format_note(struct notes_tree *t, const unsigned char *object_sha1,
+ struct strbuf *sb, const char *output_encoding, int flags)
{
static const char utf8[] = "utf-8";
- unsigned char *sha1;
+ const unsigned char *sha1;
char *msg, *msg_p;
unsigned long linelen, msglen;
enum object_type type;
- if (!initialized) {
- const char *env = getenv(GIT_NOTES_REF_ENVIRONMENT);
- if (env)
- notes_ref_name = getenv(GIT_NOTES_REF_ENVIRONMENT);
- else if (!notes_ref_name)
- notes_ref_name = GIT_NOTES_DEFAULT_REF;
- initialize_notes(notes_ref_name);
- initialized = 1;
- }
+ if (!t)
+ t = &default_notes_tree;
+ if (!t->initialized)
+ init_notes(t, NULL, 0);
- sha1 = lookup_notes(commit->object.sha1);
+ sha1 = get_note(t, object_sha1);
if (!sha1)
return;