Implement DataView builtin

New API functions:
 - jerry_create_dataview
 - jerry_value_is_dataview
 - jerry_get_dataview_buffer

JerryScript-DCO-1.0-Signed-off-by: Robert Fancsik [email protected]

Author: rerobika

docs/02.API-REFERENCE.md

@@ -63,6 +63,7 @@ Possible compile time enabled feature types:
  - JERRY_FEATURE_LINE_INFO - line info available
  - JERRY_FEATURE_LOGGING - logging
  - JERRY_FEATURE_SYMBOL - symbol support
+ - JERRY_FEATURE_DATAVIEW - DataView support
 
 ## jerry_regexp_flags_t
 
@@ -1296,6 +1297,56 @@ jerry_value_is_constructor (const jerry_value_t value)
 
 - [jerry_release_value](#jerry_release_value)
 
+## jerry_value_is_dataview
+
+**Summary**
+
+Returns whether the given `jerry_value_t` is a DataView object value.
+
+**Prototype**
+
+```c
+bool
+jerry_value_is_dataview (const jerry_value_t value)
+```
+
+- `value` - API value
+- return value
+  - true, if the given `jerry_value_t` is a DataView object
+  - false, otherwise
+
+**Example**
+
+[doctest]: # ()
+
+```c
+#include "jerryscript.h"
+
+int
+main (void)
+{
+  jerry_init (JERRY_INIT_EMPTY);
+
+  jerry_value_t arraybuffer = jerry_create_arraybuffer (16);
+  jerry_value_t dataview = jerry_create_dataview (arraybuffer, 0, 16);
+
+  if (jerry_value_is_dataview (dataview))
+  {
+    // usage of dataview
+  }
+
+  jerry_release_value (dataview);
+  jerry_release_value (arraybuffer);
+
+  jerry_cleanup ();
+}
+```
+
+**See also**
+
+- [jerry_release_value](#jerry_release_value)
+
+
 ## jerry_value_is_error
 
 **Summary**
@@ -3246,6 +3297,62 @@ jerry_create_error_sz (jerry_error_t error_type,
 - [jerry_create_error](#jerry_create_error)
 
 
+## jerry_create_dataview
+
+**Summary**
+
+Create new JavaScript DataView object.
+
+*Note*: This API depends on the ES2015-subset profile.
+*Note*: Returned value must be freed with [jerry_release_value](#jerry_release_value) when it
+is no longer needed.
+
+**Prototype**
+
+```c
+jerry_value_t
+jerry_create_dataview (const jerry_value_t array_buffer,
+                       const jerry_length_t byte_offset,
+                       const jerry_length_t byte_length)
+```
+
+- `array_buffer` - arrayBuffer to create DataView from
+- `byte_offset` - offset in bytes, to the first byte in the buffer
+- `byte_length` - number of elements in the byte array
+- return value
+  - value of the constructed DataView object - if success
+  - created error - otherwise
+
+**Example**
+
+[doctest]: # ()
+
+```c
+#include "jerryscript.h"
+
+int
+main (void)
+{
+  jerry_init (JERRY_INIT_EMPTY);
+
+  jerry_value_t arraybuffer = jerry_create_arraybuffer (16);
+  jerry_value_t dataview = jerry_create_dataview (arraybuffer, 0, 16);
+
+  // usage of dataview
+
+  jerry_release_value (dataview);
+  jerry_release_value (arraybuffer);
+
+  jerry_cleanup ();
+}
+```
+
+**See also**
+
+- [jerry_value_is_dataview](#jerry_value_is_dataview)
+- [jerry_create_arraybuffer](#jerry_create_arraybuffer)
+
+
 ## jerry_create_external_function
 
 **Summary**
@@ -6120,6 +6227,70 @@ jerry_get_arraybuffer_pointer (const jerry_value_t value);
 - [jerry_create_arraybuffer_external](#jerry_create_arraybuffer_external)
 
 
+## jerry_get_dataview_buffer
+
+**Summary**
+
+Get the ArrayBuffer object used by a DataView object.
+Additionally returns the byteLength and byteOffset properties
+of the DataView object.
+
+For the returned ArrayBuffer the [jerry_release_value](#jerry_release_value)
+must be called when it is no longer needed.
+
+**Prototype**
+
+```c
+jerry_value_t
+jerry_get_dataview_buffer (const jerry_value_t value,
+                           jerry_length_t *byteOffset,
+                           jerry_length_t *byteLength);
+```
+
+- `value` - DataView to get the ArrayBuffer from
+- `byteOffset` - (Optional) returns the start offset of the ArrayBuffer for the DataView
+- `byteLength` - (Optional) returns the number of bytes used from the ArrayBuffer for the DataView
+- return
+  - DataView object's underlying ArrayBuffer object
+  - TypeError if the `value` is not a DataView object
+
+**Example**
+
+[doctest]: # ()
+
+```c
+#include "jerryscript.h"
+
+int
+main (void)
+{
+  jerry_init (JERRY_INIT_EMPTY);
+
+  jerry_value_t arraybuffer = jerry_create_arraybuffer (16);
+  jerry_value_t dataview = jerry_create_dataview (arraybuffer, 0, 16);
+  jerry_length_t byteOffset = 0;
+  jerry_length_t byteLength = 0;
+  jerry_value_t buffer = jerry_get_dataview_buffer (dataview, &byteOffset, &byteLength);
+
+  // buffer is an ArrayBuffer object and ArrayBuffer operations can be performed on it
+  // byteOffset is 0
+  // byteLength is 16
+
+  // usage of buffer
+
+  jerry_release_value (buffer);
+  jerry_release_value (dataview);
+  jerry_release_value (arraybuffer);
+
+  jerry_cleanup ();
+}
+```
+
+**See also**
+
+- [jerry_create_dataview](#jerry_create_dataview)
+
+
 ## jerry_get_typedarray_type
 
 **Summary**

jerry-core/api/jerry.c

@@ -22,6 +22,7 @@
 #include "ecma-builtin-helpers.h"
 #include "ecma-builtins.h"
 #include "ecma-comparison.h"
+#include "ecma-dataview-object.h"
 #include "ecma-exceptions.h"
 #include "ecma-eval.h"
 #include "ecma-function-object.h"
@@ -919,6 +920,9 @@ jerry_is_feature_enabled (const jerry_feature_t feature) /**< feature to check *
 #ifndef CONFIG_DISABLE_ES2015_TYPEDARRAY_BUILTIN
           || feature == JERRY_FEATURE_TYPEDARRAY
 #endif /* !CONFIG_DISABLE_ES2015_TYPEDARRAY_BUILTIN */
+#ifndef CONFIG_DISABLE_ES2015_DATAVIEW_BUILTIN
+          || feature == JERRY_FEATURE_DATAVIEW
+#endif /* !CONFIG_DISABLE_ES2015_DATAVIEW_BUILTIN */
 #ifndef CONFIG_DISABLE_DATE_BUILTIN
           || feature == JERRY_FEATURE_DATE
 #endif /* !CONFIG_DISABLE_DATE_BUILTIN */
@@ -3205,6 +3209,129 @@ jerry_get_arraybuffer_pointer (const jerry_value_t value) /**< Array Buffer to u
   return NULL;
 } /* jerry_get_arraybuffer_pointer */
 
+/**
+ * DataView related functions
+ */
+
+/**
+ * Creates a DataView object with the given ArrayBuffer, ByteOffset and ByteLength arguments.
+ *
+ * Notes:
+ *      * returned value must be freed with jerry_release_value, when it is no longer needed.
+ *      * if the DataView bulitin is disabled this will return a TypeError.
+ *
+ * @return value of the constructed DataView object - if success
+ *         created error - otherwise
+ */
+jerry_value_t
+jerry_create_dataview (const jerry_value_t array_buffer, /**< arraybuffer to create DataView from */
+                       const jerry_length_t byte_offset, /**< offset in bytes, to the first byte in the buffer */
+                       const jerry_length_t byte_length) /**< number of elements in the byte array */
+{
+  jerry_assert_api_available ();
+
+#ifndef CONFIG_DISABLE_ES2015_DATAVIEW_BUILTIN
+  if (ecma_is_value_error_reference (array_buffer))
+  {
+    return jerry_throw (ecma_raise_type_error (ECMA_ERR_MSG (wrong_args_msg_p)));
+  }
+
+  ecma_value_t arguments_p[3] =
+  {
+    array_buffer,
+    ecma_make_uint32_value (byte_offset),
+    ecma_make_uint32_value (byte_length)
+  };
+
+  return jerry_return (ecma_op_dataview_create (arguments_p, 3));
+#else /* CONFIG_DISABLE_ES2015_DATAVIEW_BUILTIN */
+  JERRY_UNUSED (array_buffer);
+  JERRY_UNUSED (byte_offset);
+  JERRY_UNUSED (byte_length);
+  return jerry_throw (ecma_raise_type_error (ECMA_ERR_MSG ("DataView is not supported.")));
+#endif /* !CONFIG_DISABLE_ES2015_DATAVIEW_BUILTIN */
+} /* jerry_create_dataview */
+
+/**
+ * Check if the given value is a DataView object.
+ *
+ * @return true - if it is a DataView object
+ *         false - otherwise
+ */
+bool
+jerry_value_is_dataview (const jerry_value_t value) /**< value to check if it is a DataView object */
+{
+  jerry_assert_api_available ();
+
+#ifndef CONFIG_DISABLE_ES2015_DATAVIEW_BUILTIN
+  if (!ecma_is_value_object (value))
+  {
+    return false;
+  }
+
+  ecma_dataview_object_t *dataview_object_p = (ecma_dataview_object_t *) ecma_get_object_from_value (value);
+
+  return (ecma_get_object_type (&dataview_object_p->header.object) == ECMA_OBJECT_TYPE_CLASS
+          && dataview_object_p->header.u.class_prop.class_id == LIT_MAGIC_STRING_DATAVIEW_UL);
+#else /* CONFIG_DISABLE_ES2015_DATAVIEW_BUILTIN */
+  JERRY_UNUSED (value);
+  return false;
+#endif /* !CONFIG_DISABLE_ES2015_DATAVIEW_BUILTIN */
+} /* jerry_value_is_dataview */
+
+/**
+ * Get the underlying ArrayBuffer from a DataView.
+ *
+ * Additionally the byteLength and byteOffset properties are also returned
+ * which were specified when the DataView was created.
+ *
+ * Note:
+ *     the returned value must be freed with a jerry_release_value call
+ *
+ * @return ArrayBuffer of a DataView
+ *         TypeError if the object is not a DataView.
+ */
+jerry_value_t
+jerry_get_dataview_buffer (jerry_value_t value, /**< DataView to get the arraybuffer from */
+                           jerry_length_t *byte_offset, /**< [out] byteOffset property */
+                           jerry_length_t *byte_length) /**< [out] byteLength property */
+{
+  jerry_assert_api_available ();
+
+#ifndef CONFIG_DISABLE_ES2015_DATAVIEW_BUILTIN
+  if (ecma_is_value_error_reference (value))
+  {
+    return jerry_throw (ecma_raise_type_error (ECMA_ERR_MSG (wrong_args_msg_p)));
+  }
+
+  ecma_dataview_object_t *dataview_p = ecma_op_dataview_get_object (value);
+
+  if (JERRY_UNLIKELY (dataview_p == NULL))
+  {
+    return ecma_create_error_reference_from_context ();
+  }
+
+  if (byte_offset != NULL)
+  {
+    *byte_offset = dataview_p->byte_offset;
+  }
+
+  if (byte_length != NULL)
+  {
+    *byte_length = dataview_p->header.u.class_prop.u.length;
+  }
+
+  ecma_object_t *arraybuffer_p = dataview_p->buffer_p;
+  ecma_ref_object (arraybuffer_p);
+
+  return ecma_make_object_value (arraybuffer_p);
+#else /* CONFIG_DISABLE_ES2015_DATAVIEW_BUILTIN */
+  JERRY_UNUSED (value);
+  JERRY_UNUSED (byte_offset);
+  JERRY_UNUSED (byte_length);
+  return jerry_throw (ecma_raise_type_error (ECMA_ERR_MSG ("DataView is not supported.")));
+#endif /* !CONFIG_DISABLE_ES2015_DATAVIEW_BUILTIN */
+} /* jerry_get_dataview_buffer */
 
 /**
  * TypedArray related functions

jerry-core/config.h

@@ -39,6 +39,7 @@
 # define CONFIG_DISABLE_ES2015_ARROW_FUNCTION
 # define CONFIG_DISABLE_ES2015_BUILTIN
 # define CONFIG_DISABLE_ES2015_CLASS
+# define CONFIG_DISABLE_ES2015_DATAVIEW_BUILTIN
 # define CONFIG_DISABLE_ES2015_FUNCTION_PARAMETER_INITIALIZER
 # define CONFIG_DISABLE_ES2015_FUNCTION_REST_PARAMETER
 # define CONFIG_DISABLE_ES2015_ITERATOR_BUILTIN

jerry-core/ecma/base/ecma-gc.c

@@ -683,6 +683,13 @@ ecma_gc_free_object (ecma_object_t *object_p) /**< object to free */
           return;
         }
 #endif /* !CONFIG_DISABLE_ES2015_MAP_BUILTIN */
+#ifndef CONFIG_DISABLE_ES2015_DATAVIEW_BUILTIN
+        case LIT_MAGIC_STRING_DATAVIEW_UL:
+        {
+          ecma_dealloc_extended_object (object_p, sizeof (ecma_dataview_object_t));
+          return;
+        }
+#endif /* !CONFIG_DISABLE_ES2015_DATAVIEW_BUILTIN */
         default:
         {
           /* The undefined id represents an uninitialized class. */

jerry-core/ecma/base/ecma-globals.h

@@ -1564,6 +1564,18 @@ typedef struct
 
 #endif /* !CONFIG_DISABLE_ES2015_TYPEDARRAY_BUILTIN */
 
+#ifndef CONFIG_DISABLE_ES2015_DATAVIEW_BUILTIN
+/**
+ * Description of DataView objects.
+ */
+typedef struct
+{
+  ecma_extended_object_t header; /**< header part */
+  ecma_object_t *buffer_p; /**< [[ViewedArrayBuffer]] internal slot */
+  uint32_t byte_offset; /**< [[ByteOffset]] internal slot */
+} ecma_dataview_object_t;
+#endif /* !CONFIG_DISABLE_ES2015_DATAVIEW_BUILTIN */
+
 /**
  * Flag for indicating whether the symbol is a well known symbol
  *