merge(third_party/git): Merge squashed git subtree at v2.23.0 r/373

Merge commit '1b593e1ea4d2af0f6444d9a7788d5d99abd6fde5' as 'third_party/git'

1 files changed, 216 insertions, 0 deletions

diff --git a/third_party/git/pack-objects.c b/third_party/git/pack-objects.c
new file mode 100644
index 000000000000..52560293b626
--- /dev/null
+++ b/third_party/git/pack-objects.c
@@ -0,0 +1,216 @@
+#include "cache.h"
+#include "object.h"
+#include "pack.h"
+#include "pack-objects.h"
+#include "packfile.h"
+#include "config.h"
+
+static uint32_t locate_object_entry_hash(struct packing_data *pdata,
+					 const struct object_id *oid,
+					 int *found)
+{
+	uint32_t i, mask = (pdata->index_size - 1);
+
+	i = oidhash(oid) & mask;
+
+	while (pdata->index[i] > 0) {
+		uint32_t pos = pdata->index[i] - 1;
+
+		if (oideq(oid, &pdata->objects[pos].idx.oid)) {
+			*found = 1;
+			return i;
+		}
+
+		i = (i + 1) & mask;
+	}
+
+	*found = 0;
+	return i;
+}
+
+static inline uint32_t closest_pow2(uint32_t v)
+{
+	v = v - 1;
+	v |= v >> 1;
+	v |= v >> 2;
+	v |= v >> 4;
+	v |= v >> 8;
+	v |= v >> 16;
+	return v + 1;
+}
+
+static void rehash_objects(struct packing_data *pdata)
+{
+	uint32_t i;
+	struct object_entry *entry;
+
+	pdata->index_size = closest_pow2(pdata->nr_objects * 3);
+	if (pdata->index_size < 1024)
+		pdata->index_size = 1024;
+
+	free(pdata->index);
+	pdata->index = xcalloc(pdata->index_size, sizeof(*pdata->index));
+
+	entry = pdata->objects;
+
+	for (i = 0; i < pdata->nr_objects; i++) {
+		int found;
+		uint32_t ix = locate_object_entry_hash(pdata,
+						       &entry->idx.oid,
+						       &found);
+
+		if (found)
+			BUG("Duplicate object in hash");
+
+		pdata->index[ix] = i + 1;
+		entry++;
+	}
+}
+
+struct object_entry *packlist_find(struct packing_data *pdata,
+				   const struct object_id *oid,
+				   uint32_t *index_pos)
+{
+	uint32_t i;
+	int found;
+
+	if (!pdata->index_size)
+		return NULL;
+
+	i = locate_object_entry_hash(pdata, oid, &found);
+
+	if (index_pos)
+		*index_pos = i;
+
+	if (!found)
+		return NULL;
+
+	return &pdata->objects[pdata->index[i] - 1];
+}
+
+static void prepare_in_pack_by_idx(struct packing_data *pdata)
+{
+	struct packed_git **mapping, *p;
+	int cnt = 0, nr = 1U << OE_IN_PACK_BITS;
+
+	ALLOC_ARRAY(mapping, nr);
+	/*
+	 * oe_in_pack() on an all-zero'd object_entry
+	 * (i.e. in_pack_idx also zero) should return NULL.
+	 */
+	mapping[cnt++] = NULL;
+	for (p = get_all_packs(pdata->repo); p; p = p->next, cnt++) {
+		if (cnt == nr) {
+			free(mapping);
+			return;
+		}
+		p->index = cnt;
+		mapping[cnt] = p;
+	}
+	pdata->in_pack_by_idx = mapping;
+}
+
+/*
+ * A new pack appears after prepare_in_pack_by_idx() has been
+ * run. This is likely a race.
+ *
+ * We could map this new pack to in_pack_by_idx[] array, but then we
+ * have to deal with full array anyway. And since it's hard to test
+ * this fall back code, just stay simple and fall back to using
+ * in_pack[] array.
+ */
+void oe_map_new_pack(struct packing_data *pack)
+{
+	uint32_t i;
+
+	REALLOC_ARRAY(pack->in_pack, pack->nr_alloc);
+
+	for (i = 0; i < pack->nr_objects; i++)
+		pack->in_pack[i] = oe_in_pack(pack, pack->objects + i);
+
+	FREE_AND_NULL(pack->in_pack_by_idx);
+}
+
+/* assume pdata is already zero'd by caller */
+void prepare_packing_data(struct repository *r, struct packing_data *pdata)
+{
+	pdata->repo = r;
+
+	if (git_env_bool("GIT_TEST_FULL_IN_PACK_ARRAY", 0)) {
+		/*
+		 * do not initialize in_pack_by_idx[] to force the
+		 * slow path in oe_in_pack()
+		 */
+	} else {
+		prepare_in_pack_by_idx(pdata);
+	}
+
+	pdata->oe_size_limit = git_env_ulong("GIT_TEST_OE_SIZE",
+					     1U << OE_SIZE_BITS);
+	pdata->oe_delta_size_limit = git_env_ulong("GIT_TEST_OE_DELTA_SIZE",
+						   1UL << OE_DELTA_SIZE_BITS);
+	init_recursive_mutex(&pdata->odb_lock);
+}
+
+struct object_entry *packlist_alloc(struct packing_data *pdata,
+				    const unsigned char *sha1,
+				    uint32_t index_pos)
+{
+	struct object_entry *new_entry;
+
+	if (pdata->nr_objects >= pdata->nr_alloc) {
+		pdata->nr_alloc = (pdata->nr_alloc  + 1024) * 3 / 2;
+		REALLOC_ARRAY(pdata->objects, pdata->nr_alloc);
+
+		if (!pdata->in_pack_by_idx)
+			REALLOC_ARRAY(pdata->in_pack, pdata->nr_alloc);
+		if (pdata->delta_size)
+			REALLOC_ARRAY(pdata->delta_size, pdata->nr_alloc);
+
+		if (pdata->tree_depth)
+			REALLOC_ARRAY(pdata->tree_depth, pdata->nr_alloc);
+
+		if (pdata->layer)
+			REALLOC_ARRAY(pdata->layer, pdata->nr_alloc);
+	}
+
+	new_entry = pdata->objects + pdata->nr_objects++;
+
+	memset(new_entry, 0, sizeof(*new_entry));
+	hashcpy(new_entry->idx.oid.hash, sha1);
+
+	if (pdata->index_size * 3 <= pdata->nr_objects * 4)
+		rehash_objects(pdata);
+	else
+		pdata->index[index_pos] = pdata->nr_objects;
+
+	if (pdata->in_pack)
+		pdata->in_pack[pdata->nr_objects - 1] = NULL;
+
+	if (pdata->tree_depth)
+		pdata->tree_depth[pdata->nr_objects - 1] = 0;
+
+	if (pdata->layer)
+		pdata->layer[pdata->nr_objects - 1] = 0;
+
+	return new_entry;
+}
+
+void oe_set_delta_ext(struct packing_data *pdata,
+		      struct object_entry *delta,
+		      const unsigned char *sha1)
+{
+	struct object_entry *base;
+
+	ALLOC_GROW(pdata->ext_bases, pdata->nr_ext + 1, pdata->alloc_ext);
+	base = &pdata->ext_bases[pdata->nr_ext++];
+	memset(base, 0, sizeof(*base));
+	hashcpy(base->idx.oid.hash, sha1);
+
+	/* These flags mark that we are not part of the actual pack output. */
+	base->preferred_base = 1;
+	base->filled = 1;
+
+	delta->ext_base = 1;
+	delta->delta_idx = base - pdata->ext_bases + 1;
+}