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-rw-r--r--notes.c1298
1 files changed, 1298 insertions, 0 deletions
diff --git a/notes.c b/notes.c
new file mode 100644
index 0000000000..93e9868d5d
--- /dev/null
+++ b/notes.c
@@ -0,0 +1,1298 @@
+#include "cache.h"
+#include "notes.h"
+#include "blob.h"
+#include "tree.h"
+#include "utf8.h"
+#include "strbuf.h"
+#include "tree-walk.h"
+#include "string-list.h"
+#include "refs.h"
+
+/*
+ * Use a non-balancing simple 16-tree structure with struct int_node as
+ * internal nodes, and struct leaf_node as leaf nodes. Each int_node has a
+ * 16-array of pointers to its children.
+ * The bottom 2 bits of each pointer is used to identify the pointer type
+ * - ptr & 3 == 0 - NULL pointer, assert(ptr == NULL)
+ * - ptr & 3 == 1 - pointer to next internal node - cast to struct int_node *
+ * - ptr & 3 == 2 - pointer to note entry - cast to struct leaf_node *
+ * - ptr & 3 == 3 - pointer to subtree entry - cast to struct leaf_node *
+ *
+ * The root node is a statically allocated struct int_node.
+ */
+struct int_node {
+ void *a[16];
+};
+
+/*
+ * 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 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 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.
+ */
+struct leaf_node {
+ unsigned char key_sha1[20];
+ 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
+#define PTR_TYPE_SUBTREE 3
+
+#define GET_PTR_TYPE(ptr) ((uintptr_t) (ptr) & 3)
+#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 SUBTREE_SHA1_PREFIXCMP(key_sha1, subtree_sha1) \
+ (memcmp(key_sha1, subtree_sha1, subtree_sha1[19]))
+
+struct notes_tree default_notes_tree;
+
+static struct string_list display_notes_refs;
+static struct notes_tree **display_notes_trees;
+
+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:
+ * 1. Start at the root node, with n = 0
+ * 2. If a[0] at the current level is a matching subtree entry, unpack that
+ * subtree entry and remove it; restart search at the current level.
+ * 3. Use the nth nibble of the key as an index into a:
+ * - If a[n] is an int_node, recurse from #2 into that node and increment n
+ * - If a matching subtree entry, unpack that subtree entry (and remove it);
+ * restart search at the current level.
+ * - Otherwise, we have found one of the following:
+ * - a subtree entry which does not match the key
+ * - a note entry which may or may not match the key
+ * - 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 notes_tree *t, struct int_node **tree,
+ unsigned char *n, const unsigned char *key_sha1)
+{
+ struct leaf_node *l;
+ unsigned char i;
+ void *p = (*tree)->a[0];
+
+ 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)) {
+ /* unpack tree and resume search */
+ (*tree)->a[0] = NULL;
+ load_subtree(t, l, *tree, *n);
+ free(l);
+ return note_tree_search(t, tree, n, key_sha1);
+ }
+ }
+
+ i = GET_NIBBLE(*n, key_sha1);
+ p = (*tree)->a[i];
+ switch (GET_PTR_TYPE(p)) {
+ case PTR_TYPE_INTERNAL:
+ *tree = CLR_PTR_TYPE(p);
+ (*n)++;
+ 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(t, l, *tree, *n);
+ free(l);
+ return note_tree_search(t, tree, n, key_sha1);
+ }
+ /* fall through */
+ default:
+ return &((*tree)->a[i]);
+ }
+}
+
+/*
+ * To find a leaf_node:
+ * 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 notes_tree *t,
+ struct int_node *tree, unsigned char n,
+ const unsigned char *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))
+ return l;
+ }
+ return NULL;
+}
+
+/*
+ * 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.
+ * - Copy the matching entry's value into the given entry.
+ * - 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(t, &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 */
+ hashcpy(entry->val_sha1, l->val_sha1);
+ 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--;
+}
+
+/*
+ * 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
+ * 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
+ * location, and restart the insert operation from that level.
+ * - 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 int 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(t, &tree, &n, entry->key_sha1);
+ int ret = 0;
+
+ assert(GET_PTR_TYPE(entry) == 0); /* no type bits set */
+ l = (struct leaf_node *) CLR_PTR_TYPE(*p);
+ switch (GET_PTR_TYPE(*p)) {
+ case PTR_TYPE_NULL:
+ assert(!*p);
+ if (is_null_sha1(entry->val_sha1))
+ free(entry);
+ else
+ *p = SET_PTR_TYPE(entry, type);
+ return 0;
+ case PTR_TYPE_NOTE:
+ switch (type) {
+ case PTR_TYPE_NOTE:
+ if (!hashcmp(l->key_sha1, entry->key_sha1)) {
+ /* skip concatenation if l == entry */
+ if (!hashcmp(l->val_sha1, entry->val_sha1))
+ return 0;
+
+ ret = combine_notes(l->val_sha1,
+ entry->val_sha1);
+ if (!ret && is_null_sha1(l->val_sha1))
+ 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)) {
+ /* unpack 'entry' */
+ load_subtree(t, entry, tree, n);
+ free(entry);
+ return 0;
+ }
+ break;
+ }
+ break;
+ case PTR_TYPE_SUBTREE:
+ if (!SUBTREE_SHA1_PREFIXCMP(entry->key_sha1, l->key_sha1)) {
+ /* unpack 'l' and restart insert */
+ *p = NULL;
+ load_subtree(t, l, tree, n);
+ free(l);
+ return note_tree_insert(t, tree, n, entry, type,
+ combine_notes);
+ }
+ break;
+ }
+
+ /* 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 */
+ free(entry);
+ return 0;
+ }
+ new_node = (struct int_node *) xcalloc(sizeof(struct int_node), 1);
+ ret = note_tree_insert(t, new_node, n + 1, l, GET_PTR_TYPE(*p),
+ combine_notes);
+ if (ret)
+ return ret;
+ *p = SET_PTR_TYPE(new_node, PTR_TYPE_INTERNAL);
+ return note_tree_insert(t, new_node, n + 1, entry, type, combine_notes);
+}
+
+/* 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)) {
+ case PTR_TYPE_INTERNAL:
+ note_tree_free(CLR_PTR_TYPE(p));
+ /* fall through */
+ case PTR_TYPE_NOTE:
+ case PTR_TYPE_SUBTREE:
+ free(CLR_PTR_TYPE(p));
+ }
+ }
+}
+
+/*
+ * 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).
+ */
+static int get_sha1_hex_segment(const char *hex, unsigned int hex_len,
+ unsigned char *sha1, unsigned int sha1_len)
+{
+ unsigned int i, len = hex_len >> 1;
+ if (hex_len % 2 != 0 || len > sha1_len)
+ return -1;
+ for (i = 0; i < len; i++) {
+ unsigned int val = (hexval(hex[0]) << 4) | hexval(hex[1]);
+ if (val & ~0xff)
+ return -1;
+ *sha1++ = val;
+ hex += 2;
+ }
+ for (; i < sha1_len; i++)
+ *sha1++ = 0;
+ return len;
+}
+
+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)
+ 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);
+ 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;
+
+ /*
+ * 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(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) || 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);
+ }
+ 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);
+}
+
+/*
+ * 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)
+{
+ /*
+ * 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 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;
+ 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(t, 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(t, 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, "%o %.*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;
+ 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 = 0, 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)
+{
+ 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);
+
+ /* 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);
+}
+
+struct note_delete_list {
+ struct note_delete_list *next;
+ const unsigned char *sha1;
+};
+
+static int prune_notes_helper(const unsigned char *object_sha1,
+ const unsigned char *note_sha1, 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))
+ 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;
+ *l = n;
+ return 0;
+}
+
+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 two newlines anyway */
+ if (cur_msg[cur_len - 1] == '\n')
+ cur_len--;
+
+ /* concatenate cur_msg and new_msg into buf */
+ buf_len = cur_len + 2 + new_len;
+ buf = (char *) xmalloc(buf_len);
+ memcpy(buf, cur_msg, cur_len);
+ buf[cur_len] = '\n';
+ buf[cur_len + 1] = '\n';
+ memcpy(buf + cur_len + 2, 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;
+}
+
+static int string_list_add_note_lines(struct string_list *sort_uniq_list,
+ const unsigned char *sha1)
+{
+ char *data;
+ unsigned long len;
+ enum object_type t;
+ struct strbuf buf = STRBUF_INIT;
+ struct strbuf **lines = NULL;
+ int i, list_index;
+
+ if (is_null_sha1(sha1))
+ return 0;
+
+ /* read_sha1_file NUL-terminates */
+ data = read_sha1_file(sha1, &t, &len);
+ if (t != OBJ_BLOB || !data || !len) {
+ free(data);
+ return t != OBJ_BLOB || !data;
+ }
+
+ strbuf_attach(&buf, data, len, len + 1);
+ lines = strbuf_split(&buf, '\n');
+
+ for (i = 0; lines[i]; i++) {
+ if (lines[i]->buf[lines[i]->len - 1] == '\n')
+ strbuf_setlen(lines[i], lines[i]->len - 1);
+ if (!lines[i]->len)
+ continue; /* skip empty lines */
+ list_index = string_list_find_insert_index(sort_uniq_list,
+ lines[i]->buf, 0);
+ if (list_index < 0)
+ continue; /* skip duplicate lines */
+ string_list_insert_at_index(sort_uniq_list, list_index,
+ lines[i]->buf);
+ }
+
+ strbuf_list_free(lines);
+ strbuf_release(&buf);
+ return 0;
+}
+
+static int string_list_join_lines_helper(struct string_list_item *item,
+ void *cb_data)
+{
+ struct strbuf *buf = cb_data;
+ strbuf_addstr(buf, item->string);
+ strbuf_addch(buf, '\n');
+ return 0;
+}
+
+int combine_notes_cat_sort_uniq(unsigned char *cur_sha1,
+ const unsigned char *new_sha1)
+{
+ struct string_list sort_uniq_list = { NULL, 0, 0, 1 };
+ struct strbuf buf = STRBUF_INIT;
+ int ret = 1;
+
+ /* read both note blob objects into unique_lines */
+ if (string_list_add_note_lines(&sort_uniq_list, cur_sha1))
+ goto out;
+ if (string_list_add_note_lines(&sort_uniq_list, new_sha1))
+ goto out;
+
+ /* create a new blob object from sort_uniq_list */
+ if (for_each_string_list(&sort_uniq_list,
+ string_list_join_lines_helper, &buf))
+ goto out;
+
+ ret = write_sha1_file(buf.buf, buf.len, blob_type, cur_sha1);
+
+out:
+ strbuf_release(&buf);
+ string_list_clear(&sort_uniq_list, 0);
+ return ret;
+}
+
+static int string_list_add_one_ref(const char *path, const unsigned char *sha1,
+ int flag, void *cb)
+{
+ struct string_list *refs = cb;
+ if (!unsorted_string_list_has_string(refs, path))
+ string_list_append(refs, path);
+ return 0;
+}
+
+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))
+ warning("notes ref %s is invalid", glob);
+ if (!unsorted_string_list_has_string(list, glob))
+ string_list_append(list, glob);
+ }
+}
+
+void string_list_add_refs_from_colon_sep(struct string_list *list,
+ const char *globs)
+{
+ struct strbuf globbuf = STRBUF_INIT;
+ struct strbuf **split;
+ int i;
+
+ strbuf_addstr(&globbuf, globs);
+ split = strbuf_split(&globbuf, ':');
+
+ for (i = 0; split[i]; i++) {
+ if (!split[i]->len)
+ continue;
+ if (split[i]->buf[split[i]->len-1] == ':')
+ strbuf_setlen(split[i], split[i]->len-1);
+ string_list_add_refs_by_glob(list, split[i]->buf);
+ }
+
+ strbuf_list_free(split);
+ strbuf_release(&globbuf);
+}
+
+static int notes_display_config(const char *k, const char *v, void *cb)
+{
+ int *load_refs = cb;
+
+ if (*load_refs && !strcmp(k, "notes.displayref")) {
+ if (!v)
+ config_error_nonbool(k);
+ string_list_add_refs_by_glob(&display_notes_refs, v);
+ }
+
+ return 0;
+}
+
+const char *default_notes_ref(void)
+{
+ const char *notes_ref = NULL;
+ 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;
+ return notes_ref;
+}
+
+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;
+ struct leaf_node root_tree;
+
+ if (!t)
+ t = &default_notes_tree;
+ assert(!t->initialized);
+
+ if (!notes_ref)
+ notes_ref = default_notes_ref();
+
+ if (!combine_notes)
+ 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;
+ t->dirty = 0;
+
+ 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, sha1_to_hex(object_sha1));
+
+ hashclr(root_tree.key_sha1);
+ hashcpy(root_tree.val_sha1, sha1);
+ load_subtree(t, &root_tree, t->root, 0);
+}
+
+struct notes_tree **load_notes_trees(struct string_list *refs)
+{
+ struct string_list_item *item;
+ int counter = 0;
+ struct notes_tree **trees;
+ trees = xmalloc((refs->nr+1) * sizeof(struct notes_tree *));
+ for_each_string_list_item(item, refs) {
+ struct notes_tree *t = xcalloc(1, sizeof(struct notes_tree));
+ init_notes(t, item->string, combine_notes_ignore, 0);
+ trees[counter++] = t;
+ }
+ trees[counter] = NULL;
+ return trees;
+}
+
+void init_display_notes(struct display_notes_opt *opt)
+{
+ char *display_ref_env;
+ int load_config_refs = 0;
+ display_notes_refs.strdup_strings = 1;
+
+ assert(!display_notes_trees);
+
+ if (!opt || opt->use_default_notes > 0 ||
+ (opt->use_default_notes == -1 && !opt->extra_notes_refs.nr)) {
+ string_list_append(&display_notes_refs, default_notes_ref());
+ display_ref_env = getenv(GIT_NOTES_DISPLAY_REF_ENVIRONMENT);
+ if (display_ref_env) {
+ string_list_add_refs_from_colon_sep(&display_notes_refs,
+ display_ref_env);
+ load_config_refs = 0;
+ } else
+ load_config_refs = 1;
+ }
+
+ git_config(notes_display_config, &load_config_refs);
+
+ if (opt) {
+ struct string_list_item *item;
+ for_each_string_list_item(item, &opt->extra_notes_refs)
+ string_list_add_refs_by_glob(&display_notes_refs,
+ item->string);
+ }
+
+ display_notes_trees = load_notes_trees(&display_notes_refs);
+ 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)
+{
+ struct leaf_node *l;
+
+ if (!t)
+ t = &default_notes_tree;
+ assert(t->initialized);
+ t->dirty = 1;
+ 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);
+ return note_tree_insert(t, t->root, 0, l, PTR_TYPE_NOTE, combine_notes);
+}
+
+int remove_note(struct notes_tree *t, const unsigned char *object_sha1)
+{
+ struct leaf_node l;
+
+ if (!t)
+ t = &default_notes_tree;
+ assert(t->initialized);
+ hashcpy(l.key_sha1, object_sha1);
+ hashclr(l.val_sha1);
+ note_tree_remove(t, t->root, 0, &l);
+ if (is_null_sha1(l.val_sha1)) /* 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)
+{
+ 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;
+}
+
+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, 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;
+ 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);
+ return ret;
+}
+
+void prune_notes(struct notes_tree *t, int flags)
+{
+ struct note_delete_list *l = NULL;
+
+ if (!t)
+ t = &default_notes_tree;
+ assert(t->initialized);
+
+ for_each_note(t, 0, prune_notes_helper, &l);
+
+ while (l) {
+ if (flags & NOTES_PRUNE_VERBOSE)
+ printf("%s\n", sha1_to_hex(l->sha1));
+ if (!(flags & NOTES_PRUNE_DRYRUN))
+ remove_note(t, l->sha1);
+ l = l->next;
+ }
+}
+
+void free_notes(struct notes_tree *t)
+{
+ if (!t)
+ t = &default_notes_tree;
+ 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));
+}
+
+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";
+ const unsigned char *sha1;
+ char *msg, *msg_p;
+ unsigned long linelen, msglen;
+ enum object_type type;
+
+ if (!t)
+ t = &default_notes_tree;
+ if (!t->initialized)
+ init_notes(t, NULL, NULL, 0);
+
+ sha1 = get_note(t, object_sha1);
+ if (!sha1)
+ return;
+
+ if (!(msg = read_sha1_file(sha1, &type, &msglen)) || !msglen ||
+ type != OBJ_BLOB) {
+ free(msg);
+ return;
+ }
+
+ if (output_encoding && *output_encoding &&
+ strcmp(utf8, output_encoding)) {
+ char *reencoded = reencode_string(msg, output_encoding, utf8);
+ if (reencoded) {
+ free(msg);
+ msg = reencoded;
+ msglen = strlen(msg);
+ }
+ }
+
+ /* we will end the annotation by a newline anyway */
+ if (msglen && msg[msglen - 1] == '\n')
+ msglen--;
+
+ if (flags & NOTES_SHOW_HEADER) {
+ const char *ref = t->ref;
+ if (!ref || !strcmp(ref, GIT_NOTES_DEFAULT_REF)) {
+ strbuf_addstr(sb, "\nNotes:\n");
+ } else {
+ if (!prefixcmp(ref, "refs/"))
+ ref += 5;
+ if (!prefixcmp(ref, "notes/"))
+ ref += 6;
+ strbuf_addf(sb, "\nNotes (%s):\n", ref);
+ }
+ }
+
+ for (msg_p = msg; msg_p < msg + msglen; msg_p += linelen + 1) {
+ linelen = strchrnul(msg_p, '\n') - msg_p;
+
+ if (flags & NOTES_INDENT)
+ strbuf_addstr(sb, " ");
+ strbuf_add(sb, msg_p, linelen);
+ strbuf_addch(sb, '\n');
+ }
+
+ free(msg);
+}
+
+void format_display_notes(const unsigned char *object_sha1,
+ struct strbuf *sb, const char *output_encoding, int flags)
+{
+ int i;
+ assert(display_notes_trees);
+ for (i = 0; display_notes_trees[i]; i++)
+ format_note(display_notes_trees[i], object_sha1, sb,
+ output_encoding, flags);
+}
+
+int copy_note(struct notes_tree *t,
+ const unsigned char *from_obj, const unsigned char *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);
+
+ if (!force && existing_note)
+ return 1;
+
+ 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 0;
+}
+
+void expand_notes_ref(struct strbuf *sb)
+{
+ if (!prefixcmp(sb->buf, "refs/notes/"))
+ return; /* we're happy */
+ else if (!prefixcmp(sb->buf, "notes/"))
+ strbuf_insert(sb, 0, "refs/", 5);
+ else
+ strbuf_insert(sb, 0, "refs/notes/", 11);
+}