Parsing: Add cbor_value_get_next_byte()

Replaces direct access to the "ptr" member.

Signed-off-by: Thiago Macieira <thiago.macieira@intel.com>

src/cbor.h

@@ -244,6 +244,8 @@ CBOR_API CborError cbor_parser_init(const uint8_t *buffer, size_t size, int flag
 
 CBOR_INLINE_API bool cbor_value_at_end(const CborValue *it)
 { return it->remaining == 0; }
+CBOR_INLINE_API const uint8_t *cbor_value_get_next_byte(const CborValue *it)
+{ return it->ptr; }
 CBOR_API CborError cbor_value_advance_fixed(CborValue *it);
 CBOR_API CborError cbor_value_advance(CborValue *it);
 CBOR_INLINE_API bool cbor_value_is_container(const CborValue *it)

src/cborparser.c

@@ -333,11 +333,33 @@ CborError cbor_parser_init(const uint8_t *buffer, size_t size, int flags, CborPa
  * \fn bool cbor_value_at_end(const CborValue *it)
  *
  * Returns true if \a it has reached the end of the iteration, usually when
- * advancing after the last item in an array or map. In the case of the
- * outermost CborValue object, this function returns true after decoding a
- * single element.
+ * advancing after the last item in an array or map.
  *
- * \sa cbor_value_advance(), cbor_value_is_valid()
+ * In the case of the outermost CborValue object, this function returns true
+ * after decoding a single element. A pointer to the first byte of the
+ * remaining data (if any) can be obtained with cbor_value_get_next_byte().
+ *
+ * \sa cbor_value_advance(), cbor_value_is_valid(), cbor_value_get_next_byte()
+ */
+
+/**
+ * \fn const uint8_t *cbor_value_get_next_byte(const CborValue *it)
+ *
+ * Returns a pointer to the next byte that would be decoded if this CborValue
+ * object were advanced.
+ *
+ * This function is useful if cbor_value_at_end() returns true for the
+ * outermost CborValue: the pointer returned is the first byte of the data
+ * remaining in the buffer, if any. Code can decide whether to begin decoding a
+ * new CBOR data stream from this point, or parse some other data appended to
+ * the same buffer.
+ *
+ * This function may be used even after a parsing error. If that occurred,
+ * then this function returns a pointer to where the parsing error occurred.
+ * Note that the error recovery is not precise and the pointer may not indicate
+ * the exact byte containing bad data.
+ *
+ * \sa cbor_value_at_end()
  */
 
 /**

tests/parser/tst_parser.cpp

@@ -188,7 +188,7 @@ void compareOne_real(const QByteArray &data, const QString &expected, int line,
     QCOMPARE(decoded, expected);
 
     // check that we consumed everything
-    QCOMPARE((void*)first.ptr, (void*)data.constEnd());
+    QCOMPARE((void*)cbor_value_get_next_byte(&first), (void*)data.constEnd());
 
     compareFailed = false;
 }
@@ -1177,7 +1177,7 @@ void tst_Parser::validation()
 
     err = parseOne(&first, &decoded);
     QCOMPARE(int(err), int(expectedError));
-    QCOMPARE(int(first.ptr - reinterpret_cast<const quint8 *>(data.constBegin())), offset);
+    QCOMPARE(int(cbor_value_get_next_byte(&first) - reinterpret_cast<const quint8 *>(data.constBegin())), offset);
 }
 
 void tst_Parser::resumeParsing_data()