Better error handling for network_read and network_read_nb

Author: markjfisher

Changelog.md

@@ -2,6 +2,11 @@
 
 ## [Unreleased]
 
+## [4.5.3] - 2024-08-32
+
+- network_read and network_read_nb will exit if there is a general error.
+  network_read will set fn_bytes_read to the bytes read into the buffer so far, for client to decide what to do.
+
 ## [4.5.2] - 2024-08-25
 
 - [atari] fuji_read_appkey no longer uses malloc, but requires the data buffer passed in to be at least 2 bytes larger than the keysize to work.

common/src/fn_network/network_read.c

@@ -101,12 +101,22 @@ int16_t network_read(char *devicespec, uint8_t *buf, uint16_t len)
         r = network_status(devicespec, &fn_network_bw, &fn_network_conn, &fn_network_error); // TODO: Status return needs fixing.
 #endif
 
-        // check if the status failed
-        if (r != 0) return -r;
+        // check if the status failed. The buffer may be partially filled, up to client if they want to use any of it. The count is in fn_bytes_read
+        if (r != 0) {
+            fn_bytes_read = total_read;
+            // r is the FN_ERR code
+            return -r;
+        }
 
         // EOF hit, exit reading
         if (fn_network_error == 136) break;
 
+        // is there another error? The buffer may be partially filled, up to client if they want to use any of it. The count is in fn_bytes_read
+        if (fn_network_error != 1) {
+            fn_bytes_read = total_read;
+            return -FN_ERR_IO_ERROR;
+        }
+
         // we are waiting for bytes to become available while still connected.
         // Causes tight loop if there's a long delay reading from network into FN, so we may see lots of status requests
         if (fn_network_bw == 0 && fn_network_conn == 1) {

common/src/fn_network/network_read_nb.c

@@ -95,12 +95,19 @@ int16_t network_read_nb(char *devicespec, uint8_t *buf, uint16_t len)
     r = network_status(devicespec, &fn_network_bw, &fn_network_conn, &fn_network_error); // TODO: Status return needs fixing.
 #endif
 
-    // check if the status failed
-    if (r != 0) return -r;
+    // check if the status failed.
+    if (r != 0) {
+        return -r;
+    }
 
     // EOF hit, exit reading
     if (fn_network_error == 136) return 0;
 
+    // is there another error?
+    if (fn_network_error != 1) {
+        return -fn_network_error;
+    }
+
     // we are waiting for bytes to become available while still connected, so no data can be read
     if (fn_network_bw == 0 && fn_network_conn == 1) {
         return 0;

fujinet-network.h

@@ -103,12 +103,12 @@ uint8_t network_open(char* devicespec, uint8_t mode, uint8_t trans);
  * @brief  Non-blocking read from channel
  * 
  * The read will grab whatever is waiting in the FujiNet buffer. If fewer than the requested len, the return count will reflect this.
- * Errors are returned as the negative value of the error.
+ * Errors are returned as the negative value of the FUJI standard error. fn_network_error contains the device specific error code. fn_bytes_read will be 0 on errors.
  * 
  * @param  devicespec pointer to device specification, e.g. "N1:HTTPS://fujinet.online/"
  * @param  buf Buffer
  * @param  len length
- * @return Bytes read, or negative value of fujinet-network error code (See FN_ERR_* values)
+ * @return Bytes read, or negative value of fujinet-network error code (See FN_ERR_* values) with fn_network_error containing real error code
  */
 int16_t network_read_nb(char* devicespec, uint8_t *buf, uint16_t len);
 
@@ -117,12 +117,12 @@ int16_t network_read_nb(char* devicespec, uint8_t *buf, uint16_t len);
  * 
  * The read will block until it has read all the bytes requested from the device, or the EOF is hit.
  * This will block waiting for as much data as it can, so that the client does not need to handle counting.
- * Errors are returned as the negative value of the error.
+ * Errors are returned as the negative value of the error. fn_network_error contains the device specific error code. fn_bytes_read will contain the count of bytes read before error occurred.
  * 
  * @param  devicespec pointer to device specification, e.g. "N1:HTTPS://fujinet.online/"
  * @param  buf Buffer
  * @param  len length
- * @return Bytes read, or negative value of fujinet-network error code (See FN_ERR_* values)
+ * @return Bytes read, or negative value of fujinet-network error code (See FN_ERR_* values) with fn_network_error containing real error code
  */
 int16_t network_read(char* devicespec, uint8_t *buf, uint16_t len);
 

version.txt

@@ -1 +1 @@
-4.5.2
+4.5.3