Merge branch 'cp/unit-test-reftable-pq'

The tests for "pq" part of reftable library got rewritten to use
the unit test framework.

* cp/unit-test-reftable-pq:
  t-reftable-pq: add tests for merged_iter_pqueue_top()
  t-reftable-pq: add test for index based comparison
  t-reftable-pq: make merged_iter_pqueue_check() callable by reference
  t-reftable-pq: make merged_iter_pqueue_check() static
  t: move reftable/pq_test.c to the unit testing framework
  reftable: change the type of array indices to 'size_t' in reftable/pq.c
  reftable: remove unnecessary curly braces in reftable/pq.c

t/unit-tests/t-reftable-pq.c

@@ -0,0 +1,152 @@
+/*
+Copyright 2020 Google LLC
+
+Use of this source code is governed by a BSD-style
+license that can be found in the LICENSE file or at
+https://developers.google.com/open-source/licenses/bsd
+*/
+
+#include "test-lib.h"
+#include "reftable/constants.h"
+#include "reftable/pq.h"
+
+static void merged_iter_pqueue_check(const struct merged_iter_pqueue *pq)
+{
+	for (size_t i = 1; i < pq->len; i++) {
+		size_t parent = (i - 1) / 2;
+		check(pq_less(&pq->heap[parent], &pq->heap[i]));
+	}
+}
+
+static int pq_entry_equal(struct pq_entry *a, struct pq_entry *b)
+{
+	return !reftable_record_cmp(a->rec, b->rec) && (a->index == b->index);
+}
+
+static void t_pq_record(void)
+{
+	struct merged_iter_pqueue pq = { 0 };
+	struct reftable_record recs[54];
+	size_t N = ARRAY_SIZE(recs) - 1, i;
+	char *last = NULL;
+
+	for (i = 0; i < N; i++) {
+		reftable_record_init(&recs[i], BLOCK_TYPE_REF);
+		recs[i].u.ref.refname = xstrfmt("%02"PRIuMAX, (uintmax_t)i);
+	}
+
+	i = 1;
+	do {
+		struct pq_entry e = {
+			.rec = &recs[i],
+		};
+
+		merged_iter_pqueue_add(&pq, &e);
+		merged_iter_pqueue_check(&pq);
+		i = (i * 7) % N;
+	} while (i != 1);
+
+	while (!merged_iter_pqueue_is_empty(pq)) {
+		struct pq_entry top = merged_iter_pqueue_top(pq);
+		struct pq_entry e = merged_iter_pqueue_remove(&pq);
+		merged_iter_pqueue_check(&pq);
+
+		check(pq_entry_equal(&top, &e));
+		check(reftable_record_type(e.rec) == BLOCK_TYPE_REF);
+		if (last)
+			check_int(strcmp(last, e.rec->u.ref.refname), <, 0);
+		last = e.rec->u.ref.refname;
+	}
+
+	for (i = 0; i < N; i++)
+		reftable_record_release(&recs[i]);
+	merged_iter_pqueue_release(&pq);
+}
+
+static void t_pq_index(void)
+{
+	struct merged_iter_pqueue pq = { 0 };
+	struct reftable_record recs[13];
+	char *last = NULL;
+	size_t N = ARRAY_SIZE(recs), i;
+
+	for (i = 0; i < N; i++) {
+		reftable_record_init(&recs[i], BLOCK_TYPE_REF);
+		recs[i].u.ref.refname = (char *) "refs/heads/master";
+	}
+
+	i = 1;
+	do {
+		struct pq_entry e = {
+			.rec = &recs[i],
+			.index = i,
+		};
+
+		merged_iter_pqueue_add(&pq, &e);
+		merged_iter_pqueue_check(&pq);
+		i = (i * 7) % N;
+	} while (i != 1);
+
+	for (i = N - 1; i > 0; i--) {
+		struct pq_entry top = merged_iter_pqueue_top(pq);
+		struct pq_entry e = merged_iter_pqueue_remove(&pq);
+		merged_iter_pqueue_check(&pq);
+
+		check(pq_entry_equal(&top, &e));
+		check(reftable_record_type(e.rec) == BLOCK_TYPE_REF);
+		check_int(e.index, ==, i);
+		if (last)
+			check_str(last, e.rec->u.ref.refname);
+		last = e.rec->u.ref.refname;
+	}
+
+	merged_iter_pqueue_release(&pq);
+}
+
+static void t_merged_iter_pqueue_top(void)
+{
+	struct merged_iter_pqueue pq = { 0 };
+	struct reftable_record recs[13];
+	size_t N = ARRAY_SIZE(recs), i;
+
+	for (i = 0; i < N; i++) {
+		reftable_record_init(&recs[i], BLOCK_TYPE_REF);
+		recs[i].u.ref.refname = (char *) "refs/heads/master";
+	}
+
+	i = 1;
+	do {
+		struct pq_entry e = {
+			.rec = &recs[i],
+			.index = i,
+		};
+
+		merged_iter_pqueue_add(&pq, &e);
+		merged_iter_pqueue_check(&pq);
+		i = (i * 7) % N;
+	} while (i != 1);
+
+	for (i = N - 1; i > 0; i--) {
+		struct pq_entry top = merged_iter_pqueue_top(pq);
+		struct pq_entry e = merged_iter_pqueue_remove(&pq);
+
+		merged_iter_pqueue_check(&pq);
+		check(pq_entry_equal(&top, &e));
+		check(reftable_record_equal(top.rec, &recs[i], GIT_SHA1_RAWSZ));
+		for (size_t j = 0; i < pq.len; j++) {
+			check(pq_less(&top, &pq.heap[j]));
+			check_int(top.index, >, j);
+		}
+	}
+
+	merged_iter_pqueue_release(&pq);
+}
+
+int cmd_main(int argc, const char *argv[])
+{
+	TEST(t_pq_record(), "pq works with record-based comparison");
+	TEST(t_pq_index(), "pq works with index-based comparison");
+	TEST(t_merged_iter_pqueue_top(), "merged_iter_pqueue_top works");
+
+	return test_done();
+}