diff options
Diffstat (limited to 'notes.c')
| -rw-r--r-- | notes.c | 1298 |
1 files changed, 1298 insertions, 0 deletions
diff --git a/notes.c b/notes.c new file mode 100644 index 0000000000..f63fd572d6 --- /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; +} + +/* + * Add the lines from the named object to list, with trailing + * newlines removed. + */ +static int string_list_add_note_lines(struct string_list *list, + const unsigned char *sha1) +{ + char *data; + unsigned long len; + enum object_type t; + + 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; + } + + /* + * If the last line of the file is EOL-terminated, this will + * add an empty string to the list. But it will be removed + * later, along with any empty strings that came from empty + * lines within the file. + */ + string_list_split(list, data, '\n', -1); + free(data); + 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 = STRING_LIST_INIT_DUP; + 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; + string_list_remove_empty_items(&sort_uniq_list, 0); + sort_string_list(&sort_uniq_list); + string_list_remove_duplicates(&sort_uniq_list, 0); + + /* 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 string_list split = STRING_LIST_INIT_NODUP; + char *globs_copy = xstrdup(globs); + int i; + + string_list_split_in_place(&split, globs_copy, ':', -1); + string_list_remove_empty_items(&split, 0); + + for (i = 0; i < split.nr; i++) + string_list_add_refs_by_glob(list, split.items[i].string); + + string_list_clear(&split, 0); + free(globs_copy); +} + +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)); +} + +/* + * Fill the given strbuf with the notes associated with the given object. + * + * If the given notes_tree structure is not initialized, it will be auto- + * initialized to the default value (see documentation for init_notes() above). + * If the given notes_tree is NULL, the internal/default notes_tree will be + * used instead. + * + * (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, + struct strbuf *sb, const char *output_encoding, int raw) +{ + 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 && + !is_encoding_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 (!raw) { + 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 (!raw) + 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 raw) +{ + 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, raw); +} + +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); +} |