/// <summary>
/// Asynchronously reads the next node. Use this instead of the direct call to Read since this asserts that there actually is a next node.
/// </summary>
/// <param name="jsonReader">The <see cref="JsonReader"/> to read from.</param>
/// <returns>A task that represents the asynchronous read operation.
/// The value of the TResult parameter contains the node type of the node that reader is positioned on after reading.</returns>
internal static async Task <JsonNodeType> ReadNextAsync(this IJsonReaderAsync jsonReader)
{
Debug.Assert(jsonReader != null, "jsonReader != null");
#if DEBUG
bool result = await jsonReader.ReadAsync()
.ConfigureAwait(false);
Debug.Assert(result, "JsonReader.Read returned false in an unexpected place.");
#else
await jsonReader.ReadAsync();
#endif
return(jsonReader.NodeType);
}
/// <summary>
/// Asynchronously skips over a JSON value (primitive, object or array).
/// </summary>
/// <param name="jsonReader">The <see cref="JsonReader"/> to read from.</param>
/// <remarks>
/// Pre-Condition: JsonNodeType.PrimitiveValue, JsonNodeType.StartArray or JsonNodeType.StartObject
/// Post-Condition: JsonNodeType.PrimitiveValue, JsonNodeType.EndArray or JsonNodeType.EndObject
/// </remarks>
/// <returns>A task that represents the asynchronous read operation.</returns>
internal static async Task SkipValueAsync(this IJsonReaderAsync jsonReader)
{
Debug.Assert(jsonReader != null, "jsonReader != null");
int depth = 0;
do
{
switch (jsonReader.NodeType)
{
case JsonNodeType.StartArray:
case JsonNodeType.StartObject:
depth++;
break;
case JsonNodeType.EndArray:
case JsonNodeType.EndObject:
Debug.Assert(depth > 0, "Seen too many scope ends.");
depth--;
break;
default:
Debug.Assert(
jsonReader.NodeType != JsonNodeType.EndOfInput,
"We should not have reached end of input, since the scopes should be well formed. Otherwise JsonReader should have failed by now.");
break;
}
}while (await jsonReader.ReadAsync().ConfigureAwait(false) && depth > 0);
if (depth > 0)
{
// Not all open scopes were closed:
// "Invalid JSON. Unexpected end of input was found in JSON content. Not all object and array scopes were closed."
throw CreateException(Strings.JsonReader_EndOfInputWithOpenScope);
}
}
/// <summary>
/// Asynchronously reads the next node from the <paramref name="jsonReader"/> and verifies that it is of the expected node type.
/// </summary>
/// <param name="jsonReader">The <see cref="JsonReader"/> to read from.</param>
/// <param name="expectedNodeType">The expected <see cref="JsonNodeType"/> of the read node.</param>
private static async Task ReadNextAsync(this IJsonReaderAsync jsonReader, JsonNodeType expectedNodeType)
{
Debug.Assert(jsonReader != null, "jsonReader != null");
Debug.Assert(expectedNodeType != JsonNodeType.None, "expectedNodeType != JsonNodeType.None");
jsonReader.ValidateNodeType(expectedNodeType);
await jsonReader.ReadAsync().ConfigureAwait(false);
}
/// <summary>
/// Asynchronously skips over a JSON value (primitive, object or array), and append raw string to StringBuilder.
/// </summary>
/// <param name="jsonReader">The <see cref="JsonReader"/> to read from.</param>
/// <param name="jsonRawValueStringBuilder">The StringBuilder to receive JSON raw string.</param>
/// <returns>A task that represents the asynchronous read operation.</returns>
internal static async Task SkipValueAsync(this IJsonReaderAsync jsonReader, StringBuilder jsonRawValueStringBuilder)
{
Debug.Assert(jsonReader != null, "jsonReader != null");
using (StringWriter stringWriter = new StringWriter(jsonRawValueStringBuilder, CultureInfo.InvariantCulture))
{
JsonWriter jsonWriter = new JsonWriter(stringWriter, jsonReader.IsIeee754Compatible);
int depth = 0;
do
{
switch (jsonReader.NodeType)
{
case JsonNodeType.PrimitiveValue:
if (await jsonReader.GetValueAsync().ConfigureAwait(false) == null)
{
await jsonWriter.WriteValueAsync((string)null)
.ConfigureAwait(false);
}
else
{
object primitiveValue = await jsonReader.GetValueAsync()
.ConfigureAwait(false);
await jsonWriter.WritePrimitiveValueAsync(primitiveValue)
.ConfigureAwait(false);
}
break;
case JsonNodeType.StartArray:
await jsonWriter.StartArrayScopeAsync()
.ConfigureAwait(false);
depth++;
break;
case JsonNodeType.StartObject:
await jsonWriter.StartObjectScopeAsync()
.ConfigureAwait(false);
depth++;
break;
case JsonNodeType.EndArray:
await jsonWriter.EndArrayScopeAsync()
.ConfigureAwait(false);
Debug.Assert(depth > 0, "Seen too many scope ends.");
depth--;
break;
case JsonNodeType.EndObject:
await jsonWriter.EndObjectScopeAsync()
.ConfigureAwait(false);
Debug.Assert(depth > 0, "Seen too many scope ends.");
depth--;
break;
case JsonNodeType.Property:
string propertyName = await jsonReader.GetPropertyNameAsync()
.ConfigureAwait(false);
await jsonWriter.WriteNameAsync(propertyName)
.ConfigureAwait(false);
break;
default:
Debug.Assert(
jsonReader.NodeType != JsonNodeType.EndOfInput,
"We should not have reached end of input, since the scopes should be well formed. Otherwise JsonReader should have failed by now.");
break;
}
}while (await jsonReader.ReadAsync().ConfigureAwait(false) && depth > 0);
if (depth > 0)
{
// Not all open scopes were closed:
// "Invalid JSON. Unexpected end of input was found in JSON content. Not all object and array scopes were closed."
throw CreateException(Strings.JsonReader_EndOfInputWithOpenScope);
}
await jsonWriter.FlushAsync()
.ConfigureAwait(false);
}
}