From 311ac6c6189df40b68a03503e2744c03c317d8b6 Mon Sep 17 00:00:00 2001
From: Sebastian Harl <sh@tokkee.org>
Date: Tue, 1 Apr 2014 21:52:39 +0200
Subject: [PATCH] store: Added sdb_store_lookup().

This function looks up objects from the store which match a user-specified
matcher. For each such object, a user-specified callback is executed.
---
 src/core/store_lookup.c    | 31 +++++++++++++++++++++++++++++++
 src/include/core/store.h   | 20 ++++++++++++++++++++
 t/core/store_lookup_test.c | 30 ++++++++++++++++++++++++++++++
 3 files changed, 81 insertions(+)

diff --git a/src/core/store_lookup.c b/src/core/store_lookup.c
index d4a3d6c..35c53e5 100644
--- a/src/core/store_lookup.c
+++ b/src/core/store_lookup.c
@@ -111,6 +111,26 @@ typedef struct {
 } host_matcher_t;
 #define HOST_M(m) ((host_matcher_t *)(m))
 
+typedef struct {
+	sdb_store_matcher_t *m;
+	sdb_store_lookup_cb  cb;
+	void *user_data;
+} lookup_iter_data_t;
+
+/*
+ * private helper functions
+ */
+
+static int
+lookup_iter(sdb_store_base_t *obj, void *user_data)
+{
+	lookup_iter_data_t *d = user_data;
+
+	if (! sdb_store_matcher_matches(d->m, obj))
+		return d->cb(obj, d->user_data);
+	return 0;
+} /* lookup_iter */
+
 /*
  * matcher implementations
  */
@@ -543,5 +563,16 @@ sdb_store_matcher_matches(sdb_store_matcher_t *m, sdb_store_base_t *obj)
 	return matchers[m->type](m, obj);
 } /* sdb_store_matcher_matches */
 
+int
+sdb_store_lookup(sdb_store_matcher_t *m, sdb_store_lookup_cb cb,
+		void *user_data)
+{
+	lookup_iter_data_t data = { m, cb, user_data };
+
+	if (! cb)
+		return -1;
+	return sdb_store_iterate(lookup_iter, &data);
+} /* sdb_store_lookup */
+
 /* vim: set tw=78 sw=4 ts=4 noexpandtab : */
 
diff --git a/src/include/core/store.h b/src/include/core/store.h
index a149b1d..25bd91a 100644
--- a/src/include/core/store.h
+++ b/src/include/core/store.h
@@ -194,6 +194,26 @@ sdb_store_con_matcher(sdb_store_matcher_t *left, sdb_store_matcher_t *right);
 int
 sdb_store_matcher_matches(sdb_store_matcher_t *m, sdb_store_base_t *obj);
 
+/*
+ * sdb_store_lookup_cb:
+ * Lookup callback. It is called for each matching object when looking up data
+ * in the store. The lookup aborts if the callback returns non-zero.
+ */
+typedef int (*sdb_store_lookup_cb)(sdb_store_base_t *obj, void *user_data);
+
+/*
+ * sdb_store_lookup:
+ * Look up objects in the store. The specified callback function is called for
+ * each object in the store matching 'm'.
+ *
+ * Returns:
+ *  - 0 on success
+ *  - a negative value else
+ */
+int
+sdb_store_lookup(sdb_store_matcher_t *m, sdb_store_lookup_cb cb,
+		void *user_data);
+
 /*
  * Flags for serialization functions.
  *
diff --git a/t/core/store_lookup_test.c b/t/core/store_lookup_test.c
index 74274f8..465bb08 100644
--- a/t/core/store_lookup_test.c
+++ b/t/core/store_lookup_test.c
@@ -317,6 +317,35 @@ START_TEST(test_store_match_op)
 }
 END_TEST
 
+static int
+lookup_cb(sdb_store_base_t *obj, void *user_data)
+{
+	intptr_t *i = user_data;
+
+	fail_unless(obj != NULL,
+			"sdb_store_lookup callback received NULL obj; expected: "
+			"<store base obj>");
+	fail_unless(i != NULL,
+			"sdb_store_lookup callback received NULL user_data; "
+			"expected: <pointer to data>");
+
+	++(*i);
+	return 0;
+} /* lookup_cb */
+
+START_TEST(test_lookup)
+{
+	intptr_t i = 0;
+	int check;
+
+	check = sdb_store_lookup(NULL, lookup_cb, &i);
+	fail_unless(check == 0,
+			"sdb_store_lookup() = %d; expected: 0", check);
+	fail_unless(i == 3,
+			"sdb_store_lookup called callback %d times; expected: 3", (int)i);
+}
+END_TEST
+
 Suite *
 core_store_lookup_suite(void)
 {
@@ -327,6 +356,7 @@ core_store_lookup_suite(void)
 	tcase_add_checked_fixture(tc, populate, sdb_store_clear);
 	tcase_add_test(tc, test_store_match);
 	tcase_add_test(tc, test_store_match_op);
+	tcase_add_test(tc, test_lookup);
 	suite_add_tcase(s, tc);
 
 	return s;
-- 
2.30.2