From ee14a2bd3d95b5d15e4d72ee2582b366e5009a86 Mon Sep 17 00:00:00 2001

From: =?UTF-8?q?Zbigniew=20J=C4=99drzejewski-Szmek?= <zbyszek@in.waw.pl>

Date: Sat, 26 Jan 2019 11:27:18 +0100

Subject: [PATCH] basic/prioq: add prioq_peek_item()

(cherry-picked from commit ef21b3b5bf824e652addf850bcfd9374c7b33ce8)

Related: #1664976

---

 src/basic/prioq.c     |  7 +++----

 src/basic/prioq.h     |  8 +++++++-

 src/test/test-prioq.c | 23 +++++++++++++++++------

 3 files changed, 27 insertions(+), 11 deletions(-)

diff --git a/src/basic/prioq.c b/src/basic/prioq.c

index ef28a086d..0bf58c1f1 100644

--- a/src/basic/prioq.c

+++ b/src/basic/prioq.c

@@ -259,15 +259,14 @@ int prioq_reshuffle(Prioq *q, void *data, unsigned *idx) {

         return 1;

 }

-void *prioq_peek(Prioq *q) {

-

+void *prioq_peek_by_index(Prioq *q, unsigned idx) {

         if (!q)

                 return NULL;

-        if (q->n_items <= 0)

+        if (idx >= q->n_items)

                 return NULL;

-        return q->items[0].data;

+        return q->items[idx].data;

 }

 void *prioq_pop(Prioq *q) {

diff --git a/src/basic/prioq.h b/src/basic/prioq.h

index e03617526..c38152352 100644

--- a/src/basic/prioq.h

+++ b/src/basic/prioq.h

@@ -18,8 +18,14 @@ int prioq_put(Prioq *q, void *data, unsigned *idx);

 int prioq_remove(Prioq *q, void *data, unsigned *idx);

 int prioq_reshuffle(Prioq *q, void *data, unsigned *idx);

-void *prioq_peek(Prioq *q) _pure_;

+void *prioq_peek_by_index(Prioq *q, unsigned idx) _pure_;

+static inline void *prioq_peek(Prioq *q) {

+        return prioq_peek_by_index(q, 0);

+}

 void *prioq_pop(Prioq *q);

+#define PRIOQ_FOREACH_ITEM(q, p)                                \

+        for (unsigned _i = 0; (p = prioq_peek_by_index(q, _i)); _i++)

+

 unsigned prioq_size(Prioq *q) _pure_;

 bool prioq_isempty(Prioq *q) _pure_;

diff --git a/src/test/test-prioq.c b/src/test/test-prioq.c

index 89c41d8ce..ece13808e 100644

--- a/src/test/test-prioq.c

+++ b/src/test/test-prioq.c

@@ -87,6 +87,7 @@ static void test_struct(void) {

         Set *s;

         unsigned previous = 0, i;

         int r;

+        struct test *t;

         srand(0);

@@ -96,9 +97,12 @@ static void test_struct(void) {

         s = set_new(&test_hash_ops);

         assert_se(s);

-        for (i = 0; i < SET_SIZE; i++) {

-                struct test *t;

+        assert_se(prioq_peek(q) == NULL);

+        assert_se(prioq_peek_by_index(q, 0) == NULL);

+        assert_se(prioq_peek_by_index(q, 1) == NULL);

+        assert_se(prioq_peek_by_index(q, (unsigned) -1) == NULL);

+        for (i = 0; i < SET_SIZE; i++) {

                 t = new0(struct test, 1);

                 assert_se(t);

                 t->value = (unsigned) rand();

@@ -112,9 +116,18 @@ static void test_struct(void) {

                 }

         }

-        for (;;) {

-                struct test *t;

+        for (i = 0; i < SET_SIZE; i++)

+                assert_se(prioq_peek_by_index(q, i));

+        assert_se(prioq_peek_by_index(q, SET_SIZE) == NULL);

+

+        unsigned count = 0;

+        PRIOQ_FOREACH_ITEM(q, t) {

+                assert_se(t);

+                count++;

+        }

+        assert_se(count == SET_SIZE);

+        for (;;) {

                 t = set_steal_first(s);

                 if (!t)

                         break;

@@ -126,8 +139,6 @@ static void test_struct(void) {

         }

         for (i = 0; i < SET_SIZE * 3 / 4; i++) {

-                struct test *t;

-

                 assert_se(prioq_size(q) == (SET_SIZE * 3 / 4) - i);

                 t = prioq_pop(q);