api: Remove the NNG_FLAG_ALLOC

This flag failed to provide real zero copy that it was intended for,
and it also involved extra allocations.  Further, the API for it was
brittle and error prone.

Modern code should just work directly with nng_msg structures.

1 files changed, 4 insertions, 31 deletions

diff --git a/src/nng.c b/src/nng.c
index 55e23214..c4bad311 100644
--- a/src/nng.c
+++ b/src/nng.c
@@ -79,35 +79,12 @@ nng_recv(nng_socket s, void *buf, size_t *szp, int flags)
 
 	// Note that while it would be nice to make this a zero copy operation,
 	// its not normally possible if a size was specified.
-	if ((rv = nng_recvmsg(s, &msg, flags & ~(NNG_FLAG_ALLOC))) != 0) {
+	if ((rv = nng_recvmsg(s, &msg, flags)) != 0) {
 		return (rv);
 	}
-	if (!(flags & NNG_FLAG_ALLOC)) {
-		memcpy(buf, nng_msg_body(msg),
-		    *szp > nng_msg_len(msg) ? nng_msg_len(msg) : *szp);
-		*szp = nng_msg_len(msg);
-	} else {
-		// We'd really like to avoid a separate data copy, but since
-		// we have allocated messages with headroom, we can't really
-		// make free() work on the base pointer.  We'd have to have
-		// some other API for this.  Folks that want zero copy had
-		// better use nng_recvmsg() instead.
-		void *nbuf;
-
-		if (nng_msg_len(msg) != 0) {
-			if ((nbuf = nni_alloc(nng_msg_len(msg))) == NULL) {
-				nng_msg_free(msg);
-				return (NNG_ENOMEM);
-			}
-
-			*(void **) buf = nbuf;
-			memcpy(nbuf, nni_msg_body(msg), nni_msg_len(msg));
-			*szp = nng_msg_len(msg);
-		} else {
-			*(void **) buf = NULL;
-			*szp           = 0;
-		}
-	}
+	memcpy(buf, nng_msg_body(msg),
+	    *szp > nng_msg_len(msg) ? nng_msg_len(msg) : *szp);
+	*szp = nng_msg_len(msg);
 	nni_msg_free(msg);
 	return (0);
 }
@@ -159,10 +136,6 @@ nng_send(nng_socket s, void *buf, size_t len, int flags)
 	if ((rv = nng_sendmsg(s, msg, flags)) != 0) {
 		// If nng_sendmsg() succeeded, then it took ownership.
 		nng_msg_free(msg);
-	} else {
-		if (flags & NNG_FLAG_ALLOC) {
-			nni_free(buf, len);
-		}
 	}
 	return (rv);
 }