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

Author: gitster

Makefile

@@ -1341,6 +1341,7 @@ UNIT_TEST_PROGRAMS += t-oidtree
 UNIT_TEST_PROGRAMS += t-prio-queue
 UNIT_TEST_PROGRAMS += t-reftable-basics
 UNIT_TEST_PROGRAMS += t-reftable-merged
+UNIT_TEST_PROGRAMS += t-reftable-pq
 UNIT_TEST_PROGRAMS += t-reftable-record
 UNIT_TEST_PROGRAMS += t-strbuf
 UNIT_TEST_PROGRAMS += t-strcmp-offset
@@ -2681,7 +2682,6 @@ REFTABLE_OBJS += reftable/writer.o
 
 REFTABLE_TEST_OBJS += reftable/block_test.o
 REFTABLE_TEST_OBJS += reftable/dump.o
-REFTABLE_TEST_OBJS += reftable/pq_test.o
 REFTABLE_TEST_OBJS += reftable/readwrite_test.o
 REFTABLE_TEST_OBJS += reftable/stack_test.o
 REFTABLE_TEST_OBJS += reftable/test_framework.o

reftable/pq.c

@@ -22,27 +22,21 @@ int pq_less(struct pq_entry *a, struct pq_entry *b)
 
 struct pq_entry merged_iter_pqueue_remove(struct merged_iter_pqueue *pq)
 {
-	int i = 0;
+	size_t i = 0;
 	struct pq_entry e = pq->heap[0];
 	pq->heap[0] = pq->heap[pq->len - 1];
 	pq->len--;
 
-	i = 0;
 	while (i < pq->len) {
-		int min = i;
-		int j = 2 * i + 1;
-		int k = 2 * i + 2;
-		if (j < pq->len && pq_less(&pq->heap[j], &pq->heap[i])) {
+		size_t min = i;
+		size_t j = 2 * i + 1;
+		size_t k = 2 * i + 2;
+		if (j < pq->len && pq_less(&pq->heap[j], &pq->heap[i]))
 			min = j;
-		}
-		if (k < pq->len && pq_less(&pq->heap[k], &pq->heap[min])) {
+		if (k < pq->len && pq_less(&pq->heap[k], &pq->heap[min]))
 			min = k;
-		}
-
-		if (min == i) {
+		if (min == i)
 			break;
-		}
-
 		SWAP(pq->heap[i], pq->heap[min]);
 		i = min;
 	}
@@ -52,20 +46,17 @@ struct pq_entry merged_iter_pqueue_remove(struct merged_iter_pqueue *pq)
 
 void merged_iter_pqueue_add(struct merged_iter_pqueue *pq, const struct pq_entry *e)
 {
-	int i = 0;
+	size_t i = 0;
 
 	REFTABLE_ALLOC_GROW(pq->heap, pq->len + 1, pq->cap);
 	pq->heap[pq->len++] = *e;
 
 	i = pq->len - 1;
 	while (i > 0) {
-		int j = (i - 1) / 2;
-		if (pq_less(&pq->heap[j], &pq->heap[i])) {
+		size_t j = (i - 1) / 2;
+		if (pq_less(&pq->heap[j], &pq->heap[i]))
 			break;
-		}
-
 		SWAP(pq->heap[j], pq->heap[i]);
-
 		i = j;
 	}
 }

reftable/pq.h

@@ -22,7 +22,6 @@ struct merged_iter_pqueue {
 	size_t cap;
 };
 
-void merged_iter_pqueue_check(struct merged_iter_pqueue pq);
 struct pq_entry merged_iter_pqueue_remove(struct merged_iter_pqueue *pq);
 void merged_iter_pqueue_add(struct merged_iter_pqueue *pq, const struct pq_entry *e);
 void merged_iter_pqueue_release(struct merged_iter_pqueue *pq);

reftable/pq_test.c

@@ -11,7 +11,6 @@ license that can be found in the LICENSE file or at
 
 int basics_test_main(int argc, const char **argv);
 int block_test_main(int argc, const char **argv);
-int pq_test_main(int argc, const char **argv);
 int record_test_main(int argc, const char **argv);
 int readwrite_test_main(int argc, const char **argv);
 int stack_test_main(int argc, const char **argv);

reftable/reftable-tests.h

@@ -7,7 +7,6 @@ int cmd__reftable(int argc, const char **argv)
 	/* test from simple to complex. */
 	block_test_main(argc, argv);
 	tree_test_main(argc, argv);
-	pq_test_main(argc, argv);
 	readwrite_test_main(argc, argv);
 	stack_test_main(argc, argv);
 	return 0;

t/helper/test-reftable.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();
+}