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-rw-r--r--object.c186
1 files changed, 144 insertions, 42 deletions
diff --git a/object.c b/object.c
index 20703f52ed..a16b9f9e93 100644
--- a/object.c
+++ b/object.c
@@ -43,16 +43,24 @@ int type_from_string(const char *str)
die("invalid object type \"%s\"", str);
}
-static unsigned int hash_obj(struct object *obj, unsigned int n)
+/*
+ * Return a numerical hash value between 0 and n-1 for the object with
+ * the specified sha1. n must be a power of 2. Please note that the
+ * return value is *not* consistent across computer architectures.
+ */
+static unsigned int hash_obj(const unsigned char *sha1, unsigned int n)
{
- unsigned int hash;
- memcpy(&hash, obj->sha1, sizeof(unsigned int));
- return hash % n;
+ return sha1hash(sha1) & (n - 1);
}
+/*
+ * Insert obj into the hash table hash, which has length size (which
+ * must be a power of 2). On collisions, simply overflow to the next
+ * empty bucket.
+ */
static void insert_obj_hash(struct object *obj, struct object **hash, unsigned int size)
{
- unsigned int j = hash_obj(obj, size);
+ unsigned int j = hash_obj(obj->sha1, size);
while (hash[j]) {
j++;
@@ -62,22 +70,19 @@ static void insert_obj_hash(struct object *obj, struct object **hash, unsigned i
hash[j] = obj;
}
-static unsigned int hashtable_index(const unsigned char *sha1)
-{
- unsigned int i;
- memcpy(&i, sha1, sizeof(unsigned int));
- return i % obj_hash_size;
-}
-
+/*
+ * Look up the record for the given sha1 in the hash map stored in
+ * obj_hash. Return NULL if it was not found.
+ */
struct object *lookup_object(const unsigned char *sha1)
{
- unsigned int i;
+ unsigned int i, first;
struct object *obj;
if (!obj_hash)
return NULL;
- i = hashtable_index(sha1);
+ first = i = hash_obj(sha1, obj_hash_size);
while ((obj = obj_hash[i]) != NULL) {
if (!hashcmp(sha1, obj->sha1))
break;
@@ -85,12 +90,31 @@ struct object *lookup_object(const unsigned char *sha1)
if (i == obj_hash_size)
i = 0;
}
+ if (obj && i != first) {
+ /*
+ * Move object to where we started to look for it so
+ * that we do not need to walk the hash table the next
+ * time we look for it.
+ */
+ struct object *tmp = obj_hash[i];
+ obj_hash[i] = obj_hash[first];
+ obj_hash[first] = tmp;
+ }
return obj;
}
+/*
+ * Increase the size of the hash map stored in obj_hash to the next
+ * power of 2 (but at least 32). Copy the existing values to the new
+ * hash map.
+ */
static void grow_object_hash(void)
{
int i;
+ /*
+ * Note that this size must always be power-of-2 to match hash_obj
+ * above.
+ */
int new_hash_size = obj_hash_size < 32 ? 32 : 2 * obj_hash_size;
struct object **new_hash;
@@ -106,13 +130,12 @@ static void grow_object_hash(void)
obj_hash_size = new_hash_size;
}
-void *create_object(const unsigned char *sha1, int type, void *o)
+void *create_object(const unsigned char *sha1, void *o)
{
struct object *obj = o;
obj->parsed = 0;
obj->used = 0;
- obj->type = type;
obj->flags = 0;
hashcpy(obj->sha1, sha1);
@@ -124,18 +147,37 @@ void *create_object(const unsigned char *sha1, int type, void *o)
return obj;
}
+void *object_as_type(struct object *obj, enum object_type type, int quiet)
+{
+ if (obj->type == type)
+ return obj;
+ else if (obj->type == OBJ_NONE) {
+ if (type == OBJ_COMMIT)
+ ((struct commit *)obj)->index = alloc_commit_index();
+ obj->type = type;
+ return obj;
+ }
+ else {
+ if (!quiet)
+ error("object %s is a %s, not a %s",
+ sha1_to_hex(obj->sha1),
+ typename(obj->type), typename(type));
+ return NULL;
+ }
+}
+
struct object *lookup_unknown_object(const unsigned char *sha1)
{
struct object *obj = lookup_object(sha1);
if (!obj)
- obj = create_object(sha1, OBJ_NONE, alloc_object_node());
+ obj = create_object(sha1, alloc_object_node());
return obj;
}
struct object *parse_object_buffer(const unsigned char *sha1, enum object_type type, unsigned long size, void *buffer, int *eaten_p)
{
struct object *obj;
- int eaten = 0;
+ *eaten_p = 0;
obj = NULL;
if (type == OBJ_BLOB) {
@@ -154,7 +196,7 @@ struct object *parse_object_buffer(const unsigned char *sha1, enum object_type t
if (!tree->object.parsed) {
if (parse_tree_buffer(tree, buffer, size))
return NULL;
- eaten = 1;
+ *eaten_p = 1;
}
}
} else if (type == OBJ_COMMIT) {
@@ -162,9 +204,9 @@ struct object *parse_object_buffer(const unsigned char *sha1, enum object_type t
if (commit) {
if (parse_commit_buffer(commit, buffer, size))
return NULL;
- if (!commit->buffer) {
- commit->buffer = buffer;
- eaten = 1;
+ if (!get_cached_commit_buffer(commit, NULL)) {
+ set_commit_buffer(commit, buffer, size);
+ *eaten_p = 1;
}
obj = &commit->object;
}
@@ -179,9 +221,6 @@ struct object *parse_object_buffer(const unsigned char *sha1, enum object_type t
warning("object %s has unknown type id %d", sha1_to_hex(sha1), type);
obj = NULL;
}
- if (obj && obj->type == OBJ_NONE)
- obj->type = type;
- *eaten_p = eaten;
return obj;
}
@@ -255,16 +294,21 @@ int object_list_contains(struct object_list *list, struct object *obj)
return 0;
}
-void add_object_array(struct object *obj, const char *name, struct object_array *array)
-{
- add_object_array_with_mode(obj, name, array, S_IFINVALID);
-}
+/*
+ * A zero-length string to which object_array_entry::name can be
+ * initialized without requiring a malloc/free.
+ */
+static char object_array_slopbuf[1];
-void add_object_array_with_mode(struct object *obj, const char *name, struct object_array *array, unsigned mode)
+static void add_object_array_with_mode_context(struct object *obj, const char *name,
+ struct object_array *array,
+ unsigned mode,
+ struct object_context *context)
{
unsigned nr = array->nr;
unsigned alloc = array->alloc;
struct object_array_entry *objects = array->objects;
+ struct object_array_entry *entry;
if (nr >= alloc) {
alloc = (alloc + 32) * 2;
@@ -272,28 +316,86 @@ void add_object_array_with_mode(struct object *obj, const char *name, struct obj
array->alloc = alloc;
array->objects = objects;
}
- objects[nr].item = obj;
- objects[nr].name = name;
- objects[nr].mode = mode;
+ entry = &objects[nr];
+ entry->item = obj;
+ if (!name)
+ entry->name = NULL;
+ else if (!*name)
+ /* Use our own empty string instead of allocating one: */
+ entry->name = object_array_slopbuf;
+ else
+ entry->name = xstrdup(name);
+ entry->mode = mode;
+ entry->context = context;
array->nr = ++nr;
}
-void object_array_remove_duplicates(struct object_array *array)
+void add_object_array(struct object *obj, const char *name, struct object_array *array)
+{
+ add_object_array_with_mode(obj, name, array, S_IFINVALID);
+}
+
+void add_object_array_with_mode(struct object *obj, const char *name, struct object_array *array, unsigned mode)
+{
+ add_object_array_with_mode_context(obj, name, array, mode, NULL);
+}
+
+void add_object_array_with_context(struct object *obj, const char *name, struct object_array *array, struct object_context *context)
{
- unsigned int ref, src, dst;
+ if (context)
+ add_object_array_with_mode_context(obj, name, array, context->mode, context);
+ else
+ add_object_array_with_mode_context(obj, name, array, S_IFINVALID, context);
+}
+
+void object_array_filter(struct object_array *array,
+ object_array_each_func_t want, void *cb_data)
+{
+ unsigned nr = array->nr, src, dst;
struct object_array_entry *objects = array->objects;
- for (ref = 0; ref + 1 < array->nr; ref++) {
- for (src = ref + 1, dst = src;
- src < array->nr;
- src++) {
- if (!strcmp(objects[ref].name, objects[src].name))
- continue;
+ for (src = dst = 0; src < nr; src++) {
+ if (want(&objects[src], cb_data)) {
if (src != dst)
objects[dst] = objects[src];
dst++;
+ } else {
+ if (objects[src].name != object_array_slopbuf)
+ free(objects[src].name);
+ }
+ }
+ array->nr = dst;
+}
+
+/*
+ * Return true iff array already contains an entry with name.
+ */
+static int contains_name(struct object_array *array, const char *name)
+{
+ unsigned nr = array->nr, i;
+ struct object_array_entry *object = array->objects;
+
+ for (i = 0; i < nr; i++, object++)
+ if (!strcmp(object->name, name))
+ return 1;
+ return 0;
+}
+
+void object_array_remove_duplicates(struct object_array *array)
+{
+ unsigned nr = array->nr, src;
+ struct object_array_entry *objects = array->objects;
+
+ array->nr = 0;
+ for (src = 0; src < nr; src++) {
+ if (!contains_name(array, objects[src].name)) {
+ if (src != array->nr)
+ objects[array->nr] = objects[src];
+ array->nr++;
+ } else {
+ if (objects[src].name != object_array_slopbuf)
+ free(objects[src].name);
}
- array->nr = dst;
}
}
generated by cgit v1.2.3 (git 2.25.1) at 2024-12-22 19:13:10 +0000