make the atom functions not use global state

This greatly helps with memory management on applications that
may want to daemonize and open/close database several times.

Also the lifetime and "owner" of memory for all data is now
explicitly bound to owning struct apk_database, which might
be helpful when writing language bindings. As side effect, the
interned "atoms" are unique only within what apk_database, so
comparing packages from different apk_database may not work
as expected.

Fixes #10697

1 files changed, 64 insertions, 0 deletions

diff --git a/src/atom.c b/src/atom.c
new file mode 100644
index 0000000..e2ff83e
--- /dev/null
+++ b/src/atom.c
@@ -0,0 +1,64 @@
+/* apk_atom.c - Alpine Package Keeper (APK)
+ *
+ * Copyright (C) 2005-2008 Natanael Copa <n@tanael.org>
+ * Copyright (C) 2008-2020 Timo Teräs <timo.teras@iki.fi>
+ * All rights reserved.
+ *
+ * SPDX-License-Identifier: GPL-2.0-only
+ */
+
+#include "apk_atom.h"
+
+apk_blob_t apk_atom_null = APK_BLOB_NULL;
+
+struct apk_atom_hashnode {
+	struct hlist_node hash_node;
+	apk_blob_t blob;
+};
+
+static apk_blob_t atom_hash_get_key(apk_hash_item item)
+{
+	return ((struct apk_atom_hashnode *) item)->blob;
+}
+
+static struct apk_hash_ops atom_ops = {
+	.node_offset = offsetof(struct apk_atom_hashnode, hash_node),
+	.get_key = atom_hash_get_key,
+	.hash_key = apk_blob_hash,
+	.compare = apk_blob_compare,
+	.delete_item = (apk_hash_delete_f) free,
+};
+
+void apk_atom_init(struct apk_atom_pool *atoms)
+{
+	apk_hash_init(&atoms->hash, &atom_ops, 10000);
+}
+
+void apk_atom_free(struct apk_atom_pool *atoms)
+{
+	apk_hash_free(&atoms->hash);
+}
+
+apk_blob_t *apk_atom_get(struct apk_atom_pool *atoms, apk_blob_t blob, int duplicate)
+{
+	struct apk_atom_hashnode *atom;
+	unsigned long hash = apk_hash_from_key(&atoms->hash, blob);
+
+	if (blob.len < 0 || !blob.ptr) return &apk_atom_null;
+
+	atom = (struct apk_atom_hashnode *) apk_hash_get_hashed(&atoms->hash, blob, hash);
+	if (atom) return &atom->blob;
+
+	if (duplicate) {
+		char *ptr;
+		atom = malloc(sizeof(*atom) + blob.len);
+		ptr = (char*) (atom + 1);
+		memcpy(ptr, blob.ptr, blob.len);
+		atom->blob = APK_BLOB_PTR_LEN(ptr, blob.len);
+	} else {
+		atom = malloc(sizeof(*atom));
+		atom->blob = blob;
+	}
+	apk_hash_insert_hashed(&atoms->hash, atom, hash);
+	return &atom->blob;
+}