Fix read/read-bytes to report errors via status out-parameter

src/tcp_stream.carp

@@ -42,11 +42,11 @@ and accepted server connections.
     "TcpStream_send_MINUS_len_")
   (private read-)
   (hidden read-)
-  (register read- (Fn [&TcpStream] String) "TcpStream_read_")
+  (register read- (Fn [&TcpStream &Int] String) "TcpStream_read_")
   (private read-bytes-)
   (hidden read-bytes-)
   (register read-bytes-
-    (Fn [&TcpStream] (Array Byte))
+    (Fn [&TcpStream &Int] (Array Byte))
     "TcpStream_read_MINUS_bytes_")
   (private read-append-)
   (hidden read-append-)
@@ -82,10 +82,18 @@ and accepted server connections.
   (doc read
     "reads up to 4096 bytes from the stream. Returns the data as a string, or an error.
 Returns an empty string on connection close.")
-  (defn read [stream] (let [s (read- stream)] (Result.Success s)))
-
-  (doc read-bytes "reads up to 4096 bytes as a byte array.")
-  (defn read-bytes [stream] (Result.Success (read-bytes- stream)))
+  (defn read [stream]
+    (let [status 0
+          data (read- stream &status)]
+      (if (< status 0) (Result.Error (System.error-text)) (Result.Success data))))
+
+  (doc read-bytes
+    "reads up to 4096 bytes as a byte array. Returns an empty array on
+connection close, or an error if the read failed.")
+  (defn read-bytes [stream]
+    (let [status 0
+          data (read-bytes- stream &status)]
+      (if (< status 0) (Result.Error (System.error-text)) (Result.Success data))))
 
   (doc read-append
     "reads from the stream and appends to an existing byte buffer.

src/tcp_stream.h

@@ -55,23 +55,31 @@ int TcpStream_send_MINUS_len_(TcpStream* s, String* msg, int len) {
   return (int)send_all(s->fd, *msg, (size_t)len);
 }
 
-String TcpStream_read_(TcpStream* s) {
+String TcpStream_read_(TcpStream* s, int *status) {
   String buf = CARP_MALLOC(SOCK_BUF_SIZE + 1);
   ssize_t r = read(s->fd, buf, SOCK_BUF_SIZE);
-  if (r < 0) {
-    buf[0] = '\0';
+  if (r > 0) {
+    buf[r] = '\0';
+    *status = (int)r;
     return buf;
   }
-  buf[r] = '\0';
+  buf[0] = '\0';
+  *status = r == 0 ? 0 : -1;
   return buf;
 }
 
-Array TcpStream_read_MINUS_bytes_(TcpStream* s) {
+Array TcpStream_read_MINUS_bytes_(TcpStream* s, int *status) {
   Array buf;
   buf.capacity = SOCK_BUF_SIZE;
   buf.data = CARP_MALLOC(SOCK_BUF_SIZE);
   ssize_t r = read(s->fd, buf.data, SOCK_BUF_SIZE);
-  buf.len = r < 0 ? 0 : (int)r;
+  if (r > 0) {
+    buf.len = (int)r;
+    *status = (int)r;
+    return buf;
+  }
+  buf.len = 0;
+  *status = r == 0 ? 0 : -1;
   return buf;
 }
 

src/unix_stream.carp

@@ -36,11 +36,11 @@
     "UnixStream_send_MINUS_bytes_")
   (private read-)
   (hidden read-)
-  (register read- (Fn [&UnixStream] String) "UnixStream_read_")
+  (register read- (Fn [&UnixStream &Int] String) "UnixStream_read_")
   (private read-bytes-)
   (hidden read-bytes-)
   (register read-bytes-
-    (Fn [&UnixStream] (Array Byte))
+    (Fn [&UnixStream &Int] (Array Byte))
     "UnixStream_read_MINUS_bytes_")
   (private read-append-)
   (hidden read-append-)
@@ -83,10 +83,18 @@ Returns bytes sent or an error.")
   (doc read
     "reads up to 4096 bytes from the stream. Returns the data as a string, or an error.
 Returns an empty string on connection close.")
-  (defn read [stream] (let [s (read- stream)] (Result.Success s)))
-
-  (doc read-bytes "reads up to 4096 bytes as a byte array.")
-  (defn read-bytes [stream] (Result.Success (read-bytes- stream)))
+  (defn read [stream]
+    (let [status 0
+          data (read- stream &status)]
+      (if (< status 0) (Result.Error (System.error-text)) (Result.Success data))))
+
+  (doc read-bytes
+    "reads up to 4096 bytes as a byte array. Returns an empty array on
+connection close, or an error if the read failed.")
+  (defn read-bytes [stream]
+    (let [status 0
+          data (read-bytes- stream &status)]
+      (if (< status 0) (Result.Error (System.error-text)) (Result.Success data))))
 
   (doc read-append
     "reads from the stream and appends to an existing byte buffer.

src/unix_stream.h

@@ -39,23 +39,31 @@ int UnixStream_send_MINUS_bytes_(UnixStream* s, Array* data) {
   return (int)send_all(s->fd, (const char*)data->data, data->len);
 }
 
-String UnixStream_read_(UnixStream* s) {
+String UnixStream_read_(UnixStream* s, int *status) {
   String buf = CARP_MALLOC(SOCK_BUF_SIZE + 1);
   ssize_t r = read(s->fd, buf, SOCK_BUF_SIZE);
-  if (r < 0) {
-    buf[0] = '\0';
+  if (r > 0) {
+    buf[r] = '\0';
+    *status = (int)r;
     return buf;
   }
-  buf[r] = '\0';
+  buf[0] = '\0';
+  *status = r == 0 ? 0 : -1;
   return buf;
 }
 
-Array UnixStream_read_MINUS_bytes_(UnixStream* s) {
+Array UnixStream_read_MINUS_bytes_(UnixStream* s, int *status) {
   Array buf;
   buf.capacity = SOCK_BUF_SIZE;
   buf.data = CARP_MALLOC(SOCK_BUF_SIZE);
   ssize_t r = read(s->fd, buf.data, SOCK_BUF_SIZE);
-  buf.len = r < 0 ? 0 : (int)r;
+  if (r > 0) {
+    buf.len = (int)r;
+    *status = (int)r;
+    return buf;
+  }
+  buf.len = 0;
+  *status = r == 0 ? 0 : -1;
   return buf;
 }