allow no buffering write

bsock.c

@@ -41,21 +41,33 @@ bsock_io_posix()
 struct bsock *
 bsock_create(void *io_ctx, struct bsock_ringbuf_io *io, size_t rbuf_sz, size_t wbuf_sz)
 {
+	if (rbuf_sz == 0) {
+		errno = EINVAL;
+		return NULL;
+	}
+
 	struct bsock *bsock = malloc(sizeof(struct bsock));
 	if (bsock == NULL) {
+		errno = ENOMEM;
 		return NULL;
 	}
 
 	struct bsock_ringbuf rbuf = { 0 }, wbuf = { 0 };
 	char *buf = malloc(rbuf_sz);
 	if (buf == NULL) {
+		errno = ENOMEM;
 		goto fail;
 	}
 	bsock_ringbuf_init(&rbuf, buf, rbuf_sz);
 
-	buf = malloc(wbuf_sz);
-	if (buf == NULL) {
-		goto fail;
+	if (wbuf_sz > 0) {
+		buf = malloc(wbuf_sz);
+		if (buf == NULL) {
+			errno = ENOMEM;
+			goto fail;
+		}
+	} else {
+		buf = NULL;
 	}
 	bsock_ringbuf_init(&wbuf, buf, wbuf_sz);
 

ringbuf.c

@@ -95,7 +95,7 @@ bsock_ringbuf_write(struct bsock_ringbuf *rb, void *ctx, struct bsock_ringbuf_io
 			return ret;
 		}
 
-		assert(rb->sz == 0);
+		free_sz = rb->max_sz - rb->sz;
 		if (len > rb->max_sz) {
 			return io->write(ctx, buf, len);
 		}

test.c

@@ -132,13 +132,23 @@ bsock_test(void)
 	memset(buf3, 0, 1024);
 	bsock_ringbuf_init(&rbuf, buf, 768);
 	assert_write(&rbuf, (void *)(uintptr_t)pipes[1], &io, sbuf, 512);
-	assert(bsock_ringbuf_write(&rbuf, (void *)(uintptr_t)pipes[1], &io, sbuf, 1024));
+	assert(bsock_ringbuf_write(&rbuf, (void *)(uintptr_t)pipes[1], &io, sbuf, 1024) == 1024);
 	assert(read(pipes[0], buf3, 512) == 512);
 	assert(memcmp(sbuf, buf3, 512) == 0);
 	assert(read(pipes[0], buf3, 1024) == 1024);
 	assert(memcmp(sbuf, buf3, 1024) == 0);
 	assert(ringbuf_verify(&rbuf, buf + 512, 0));
 
+
+	printf("ringbuf - write no buffering\n");
+	assert(pipe(pipes) == 0);
+	memset(buf3, 0, 1024);
+	bsock_ringbuf_init(&rbuf, NULL, 0);
+	assert(bsock_ringbuf_write(&rbuf, (void *)(uintptr_t)pipes[1], &io, sbuf, 1024) == 1024);
+	assert(read(pipes[0], buf3, 1024) == 1024);
+	assert(memcmp(sbuf, buf3, 1024) == 0);
+	assert(ringbuf_verify(&rbuf, NULL, 0));
+
 	printf("ringbuf - poll/flush fp\n");
 	assert(pipe(pipes) == 0);
 	assert(write(pipes[0], sbuf, 512) == 512);