Cellular: AT handler read string up to delimiter or stop tag

Author: Mirela Chirica

UNITTESTS/features/cellular/framework/AT/athandler/athandlertest.cpp

@@ -579,7 +579,7 @@ TEST_F(TestATHandler, test_ATHandler_read_string)
     EXPECT_TRUE(NSAPI_ERROR_DEVICE_ERROR == at.get_last_error());
     at.clear_error();
     // Device error because empty buffer and attempt to fill_buffer by consume_char('\"')
-    EXPECT_TRUE(-1 == at.read_string(buf1, 1));
+    EXPECT_TRUE(0 == at.read_string(buf1, 1));
 
     // *** 1 BYTE ***
     at.clear_error();
@@ -599,7 +599,7 @@ TEST_F(TestATHandler, test_ATHandler_read_string)
 
     // *** CRLF ***
     at.clear_error();
-    char table3[] = "\r\ns\r\n\0";
+    char table3[] = "\r\n,s\r\n\0";
     at.flush();
     filehandle_stub_table = table3;
     filehandle_stub_table_pos = 0;
@@ -670,13 +670,9 @@ TEST_F(TestATHandler, test_ATHandler_read_string)
     at.resp_start();
     // TO read 1 byte from: "s"OK\r\n -> read "
     at.read_bytes(buf5, 1);
-    // TO read max 1 byte from: s"OK\r\n -> read s
+    // TO read max 1 byte from: s"OK\r\n -> read s + read to stop_tag(OKCRLF)
     EXPECT_TRUE(1 == at.read_string(buf4, 1 + 1/*for NULL*/));
 
-    // *** Consume " and run into OKCRLF  ***
-    // TO read max 1 byte from: "OK\r\n -> consume " and find stop tag OKCRLF
-    EXPECT_TRUE(0 == at.read_string(buf4, 1 + 1/*for NULL*/));
-
     // *** Try to read after stop tag was found  ***
     // stop tag found do not read further
     EXPECT_TRUE(-1 == at.read_string(buf4, 1 + 1/*for NULL*/));
@@ -706,7 +702,7 @@ TEST_F(TestATHandler, test_ATHandler_read_string)
     mbed_poll_stub::revents_value = POLLIN;
     mbed_poll_stub::int_value = 1;
     at.resp_start("s");
-    // TO read from buffer having only " -> consume " -> trying to read when nothing in buffer
+    // TO read from buffer having only " -> trying to find delimiter or stop_tag(OKCRLF)
     EXPECT_TRUE(-1 == at.read_string(buf4, 5));
     EXPECT_TRUE(NSAPI_ERROR_DEVICE_ERROR == at.get_last_error());
 
@@ -739,6 +735,21 @@ TEST_F(TestATHandler, test_ATHandler_read_string)
     // TO read from
     EXPECT_TRUE(6 == at.read_string(buf9, 6 + 1/*for NULL*/));
 
+    at.clear_error();
+    char table11[] = "\"1016\",\"39AB\",9\r\n\0";
+    mbed_poll_stub::int_value = 0;
+    at.flush();
+    filehandle_stub_table = table11;
+    filehandle_stub_table_pos = 0;
+    mbed_poll_stub::revents_value = POLLIN;
+    mbed_poll_stub::int_value = 1;
+    at.resp_start();
+    EXPECT_TRUE(4 == at.read_string(buf4, 4 + 1/*for NULL*/));
+    EXPECT_TRUE(!strncmp(buf4, "1016", 4));
+    EXPECT_TRUE(4 == at.read_string(buf4, 4 + 1/*for NULL*/));
+    EXPECT_TRUE(!strncmp(buf4, "39AB", 4));
+    EXPECT_TRUE(9 == at.read_int());
+
     // *** CRLF part of the string ***
     at.clear_error();
     char table10[] = "\"s\"\r\nOK\r\n\0";

features/cellular/framework/AT/ATHandler.cpp

@@ -460,14 +460,9 @@ ssize_t ATHandler::read_string(char *buf, size_t size, bool read_even_stop_tag)
         return -1;
     }
 
-    consume_char('\"');
-
-    if (_last_err) {
-        return -1;
-    }
-
-    size_t len = 0;
+    int len = 0;
     size_t match_pos = 0;
+    bool delimiter_found = false;
 
     for (; len < (size - 1 + match_pos); len++) {
         int c = get_char();
@@ -476,6 +471,7 @@ ssize_t ATHandler::read_string(char *buf, size_t size, bool read_even_stop_tag)
             return -1;
         } else if (c == _delimiter) {
             buf[len] = '\0';
+            delimiter_found = true;
             break;
         } else if (c == '\"') {
             match_pos = 0;
@@ -501,6 +497,26 @@ ssize_t ATHandler::read_string(char *buf, size_t size, bool read_even_stop_tag)
         buf[len] = '\0';
     }
 
+    // Consume to delimiter or stop_tag
+    if (!delimiter_found && !_stop_tag->found) {
+        match_pos = 0;
+        while(1) {
+            int c = get_char();
+            if (c == -1) {
+                set_error(NSAPI_ERROR_DEVICE_ERROR);
+                break;
+            } else if (c == _delimiter) {
+                break;
+            } else if (_stop_tag->len && c == _stop_tag->tag[match_pos]) {
+                match_pos++;
+                if (match_pos == _stop_tag->len) {
+                    _stop_tag->found = true;
+                    break;
+                }
+            }
+        }
+    }
+
     return len;
 }
 
@@ -830,6 +846,7 @@ void ATHandler::resp_start(const char *prefix, bool stop)
         return;
     }
 
+    set_scope(NotSet);
     // Try get as much data as possible
     rewind_buffer();
     (void)fill_buffer(false);