lib: add stream_fifo_init, more const

Add utilities that init and deinit a stream_fifo - this lets us
use an on-stack fifo in some places, avoiding malloc'ing. Also
add const to some apis (no functional changes there).

Signed-off-by: Mark Stapp <mjs@voltanet.io>

2 files changed, 51 insertions, 26 deletions

diff --git a/lib/stream.c b/lib/stream.c
index fcfbc78e3d..17520f978e 100644
--- a/lib/stream.c
+++ b/lib/stream.c
@@ -120,34 +120,34 @@ void stream_free(struct stream *s)
 	XFREE(MTYPE_STREAM, s);
 }
 
-struct stream *stream_copy(struct stream *new, struct stream *src)
+struct stream *stream_copy(struct stream *dest, const struct stream *src)
 {
 	STREAM_VERIFY_SANE(src);
 
-	assert(new != NULL);
-	assert(STREAM_SIZE(new) >= src->endp);
+	assert(dest != NULL);
+	assert(STREAM_SIZE(dest) >= src->endp);
 
-	new->endp = src->endp;
-	new->getp = src->getp;
+	dest->endp = src->endp;
+	dest->getp = src->getp;
 
-	memcpy(new->data, src->data, src->endp);
+	memcpy(dest->data, src->data, src->endp);
 
-	return new;
+	return dest;
 }
 
-struct stream *stream_dup(struct stream *s)
+struct stream *stream_dup(const struct stream *s)
 {
-	struct stream *new;
+	struct stream *snew;
 
 	STREAM_VERIFY_SANE(s);
 
-	if ((new = stream_new(s->endp)) == NULL)
+	if ((snew = stream_new(s->endp)) == NULL)
 		return NULL;
 
-	return (stream_copy(new, s));
+	return (stream_copy(snew, s));
 }
 
-struct stream *stream_dupcat(struct stream *s1, struct stream *s2,
+struct stream *stream_dupcat(const struct stream *s1, const struct stream *s2,
 			     size_t offset)
 {
 	struct stream *new;
@@ -187,19 +187,19 @@ size_t stream_resize_inplace(struct stream **sptr, size_t newsize)
 	return orig->size;
 }
 
-size_t stream_get_getp(struct stream *s)
+size_t stream_get_getp(const struct stream *s)
 {
 	STREAM_VERIFY_SANE(s);
 	return s->getp;
 }
 
-size_t stream_get_endp(struct stream *s)
+size_t stream_get_endp(const struct stream *s)
 {
 	STREAM_VERIFY_SANE(s);
 	return s->endp;
 }
 
-size_t stream_get_size(struct stream *s)
+size_t stream_get_size(const struct stream *s)
 {
 	STREAM_VERIFY_SANE(s);
 	return s->size;
@@ -1133,11 +1133,17 @@ struct stream_fifo *stream_fifo_new(void)
 {
 	struct stream_fifo *new;
 
-	new = XCALLOC(MTYPE_STREAM_FIFO, sizeof(struct stream_fifo));
-	pthread_mutex_init(&new->mtx, NULL);
+	new = XMALLOC(MTYPE_STREAM_FIFO, sizeof(struct stream_fifo));
+	stream_fifo_init(new);
 	return new;
 }
 
+void stream_fifo_init(struct stream_fifo *fifo)
+{
+	memset(fifo, 0, sizeof(struct stream_fifo));
+	pthread_mutex_init(&fifo->mtx, NULL);
+}
+
 /* Add new stream to fifo. */
 void stream_fifo_push(struct stream_fifo *fifo, struct stream *s)
 {
@@ -1245,9 +1251,14 @@ size_t stream_fifo_count_safe(struct stream_fifo *fifo)
 	return atomic_load_explicit(&fifo->count, memory_order_acquire);
 }
 
-void stream_fifo_free(struct stream_fifo *fifo)
+void stream_fifo_deinit(struct stream_fifo *fifo)
 {
 	stream_fifo_clean(fifo);
 	pthread_mutex_destroy(&fifo->mtx);
+}
+
+void stream_fifo_free(struct stream_fifo *fifo)
+{
+	stream_fifo_deinit(fifo);
 	XFREE(MTYPE_STREAM_FIFO, fifo);
 }
diff --git a/lib/stream.h b/lib/stream.h
index 23d83bf930..7cacf57d27 100644
--- a/lib/stream.h
+++ b/lib/stream.h
@@ -150,23 +150,25 @@ struct stream_fifo {
  */
 extern struct stream *stream_new(size_t);
 extern void stream_free(struct stream *);
-extern struct stream *stream_copy(struct stream *, struct stream *src);
-extern struct stream *stream_dup(struct stream *);
+/* Copy 'src' into 'dest', returns 'dest' */
+extern struct stream *stream_copy(struct stream *dest,
+				  const struct stream *src);
+extern struct stream *stream_dup(const struct stream *s);
 
 extern size_t stream_resize_inplace(struct stream **sptr, size_t newsize);
 
-extern size_t stream_get_getp(struct stream *);
-extern size_t stream_get_endp(struct stream *);
-extern size_t stream_get_size(struct stream *);
-extern uint8_t *stream_get_data(struct stream *);
+extern size_t stream_get_getp(const struct stream *s);
+extern size_t stream_get_endp(const struct stream *s);
+extern size_t stream_get_size(const struct stream *s);
+extern uint8_t *stream_get_data(struct stream *s);
 
 /**
  * Create a new stream structure; copy offset bytes from s1 to the new
  * stream; copy s2 data to the new stream; copy rest of s1 data to the
  * new stream.
  */
-extern struct stream *stream_dupcat(struct stream *s1, struct stream *s2,
-				    size_t offset);
+extern struct stream *stream_dupcat(const struct stream *s1,
+				    const struct stream *s2, size_t offset);
 
 extern void stream_set_getp(struct stream *, size_t);
 extern void stream_set_endp(struct stream *, size_t);
@@ -283,6 +285,18 @@ extern uint8_t *stream_pnt(struct stream *);
 extern struct stream_fifo *stream_fifo_new(void);
 
 /*
+ * Init or re-init an on-stack fifo. This allows use of a fifo struct without
+ * requiring a malloc/free cycle.
+ * Note well that the fifo must be de-inited with the 'fifo_deinit' api.
+ */
+void stream_fifo_init(struct stream_fifo *fifo);
+
+/*
+ * Deinit an on-stack fifo.
+ */
+void stream_fifo_deinit(struct stream_fifo *fifo);
+
+/*
  * Push a stream onto a stream_fifo.
  *
  * fifo