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Replace string with ReadOnlySpan and ReadOnlyMemory in Deserializers to Reduce Allocations #3423

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Replace string with ReadOnlySpan and ReadOnlyMemory in Deserializers to Reduce Allocations #3423

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42 changes: 21 additions & 21 deletions src/Microsoft.OData.Core/Json/JsonReaderExtensions.cs
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Original file line number Diff line number Diff line change
Expand Up @@ -76,28 +76,28 @@ internal static void ReadEndArray(this IJsonReader jsonReader)
/// </summary>
/// <param name="jsonReader">The <see cref="JsonReader"/> to read from.</param>
/// <returns>The property name of the current property node.</returns>
internal static string GetPropertyName(this IJsonReader jsonReader)
internal static ReadOnlySpan<char> GetPropertyName(this IJsonReader jsonReader)
{
Debug.Assert(jsonReader != null, "jsonReader != null");
Debug.Assert(jsonReader.NodeType == JsonNodeType.Property, "jsonReader.NodeType == JsonNodeType.Property");

// NOTE: the JSON reader already verifies that property names are strings and not null/empty
string propertyName = (string)jsonReader.GetValue();

return propertyName;
return propertyName.AsSpan();
}

/// <summary>
/// Reads the next node from the <paramref name="jsonReader"/>, verifies that it is a Property node and returns the property name.
/// </summary>
/// <param name="jsonReader">The <see cref="JsonReader"/> to read from.</param>
/// <returns>The property name of the property node read.</returns>
internal static string ReadPropertyName(this IJsonReader jsonReader)
internal static ReadOnlySpan<char> ReadPropertyName(this IJsonReader jsonReader)
{
Debug.Assert(jsonReader != null, "jsonReader != null");

jsonReader.ValidateNodeType(JsonNodeType.Property);
string propertyName = jsonReader.GetPropertyName();
ReadOnlySpan<char> propertyName = jsonReader.GetPropertyName();
jsonReader.ReadNext();
return propertyName;
}
Expand Down Expand Up @@ -260,7 +260,7 @@ internal static void SkipValue(this IJsonReader jsonReader, StringBuilder jsonRa
break;

case JsonNodeType.Property:
jsonWriter.WriteName(jsonReader.GetPropertyName());
jsonWriter.WriteName(jsonReader.GetPropertyName().ToString());
break;

default:
Expand Down Expand Up @@ -366,7 +366,7 @@ internal static ODataValue ReadODataValue(this IJsonReader jsonReader)
while (jsonReader.NodeType != JsonNodeType.EndObject)
{
ODataProperty property = new ODataProperty();
property.Name = jsonReader.ReadPropertyName();
property.Name = jsonReader.ReadPropertyName().ToString();
property.Value = jsonReader.ReadODataValue();
propertyList.Add(property);
}
Expand Down Expand Up @@ -481,7 +481,7 @@ internal static ValueTask ReadEndArrayAsync(this IJsonReader jsonReader)
/// <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 property name of the current property node.</returns>
internal static Task<string> GetPropertyNameAsync(this IJsonReader jsonReader)
internal static Task<ReadOnlyMemory<char>> GetPropertyNameAsync(this IJsonReader jsonReader)
{
Debug.Assert(jsonReader != null, "jsonReader != null");
Debug.Assert(jsonReader.NodeType == JsonNodeType.Property, "jsonReader.NodeType == JsonNodeType.Property");
Expand All @@ -490,16 +490,16 @@ internal static Task<string> GetPropertyNameAsync(this IJsonReader jsonReader)
Task<object> getValueTask = jsonReader.GetValueAsync();
if (getValueTask.IsCompletedSuccessfully)
{
return Task.FromResult((string)getValueTask.Result);
return Task.FromResult(((string)getValueTask.Result).AsMemory());
}

return AwaitGetValueAsync(getValueTask);

static async Task<string> AwaitGetValueAsync(Task<object> pendingGetValueTask)
static async Task<ReadOnlyMemory<char>> AwaitGetValueAsync(Task<object> pendingGetValueTask)
{
object value = await pendingGetValueTask.ConfigureAwait(false);

return (string)value;
return ((string)value).AsMemory();
}
}

Expand All @@ -509,7 +509,7 @@ static async Task<string> AwaitGetValueAsync(Task<object> pendingGetValueTask)
/// <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 property name of the property node read.</returns>
internal static Task<string> ReadPropertyNameAsync(this IJsonReader jsonReader)
internal static Task<ReadOnlyMemory<char>> ReadPropertyNameAsync(this IJsonReader jsonReader)
{
Debug.Assert(jsonReader != null, "jsonReader != null");

Expand All @@ -519,13 +519,13 @@ internal static Task<string> ReadPropertyNameAsync(this IJsonReader jsonReader)
}
catch (ODataException ex)
{
return Task.FromException<string>(ex);
return Task.FromException<ReadOnlyMemory<char>>(ex);
}

Task<string> getPropertyNameTask = jsonReader.GetPropertyNameAsync();
Task<ReadOnlyMemory<char>> getPropertyNameTask = jsonReader.GetPropertyNameAsync();
if (getPropertyNameTask.IsCompletedSuccessfully)
{
string propertyName = getPropertyNameTask.Result;
ReadOnlyMemory<char> propertyName = getPropertyNameTask.Result;
Task<JsonNodeType> readNextTask = jsonReader.ReadNextAsync();
if (readNextTask.IsCompletedSuccessfully)
{
Expand All @@ -537,16 +537,16 @@ internal static Task<string> ReadPropertyNameAsync(this IJsonReader jsonReader)

return AwaitGetPropertyNameAsync(jsonReader, getPropertyNameTask);

static async Task<string> AwaitReadNextAsync(Task pendingReadNextTask, string propertyName)
static async Task<ReadOnlyMemory<char>> AwaitReadNextAsync(Task pendingReadNextTask, ReadOnlyMemory<char> propertyName)
{
await pendingReadNextTask.ConfigureAwait(false);

return propertyName;
}

static async Task<string> AwaitGetPropertyNameAsync(IJsonReader jsonReaderParam, Task<string> pendingGetPropertyNameTask)
static async Task<ReadOnlyMemory<char>> AwaitGetPropertyNameAsync(IJsonReader jsonReaderParam, Task<ReadOnlyMemory<char>> pendingGetPropertyNameTask)
{
string propertyName = await pendingGetPropertyNameTask.ConfigureAwait(false);
ReadOnlyMemory<char> propertyName = await pendingGetPropertyNameTask.ConfigureAwait(false);
await jsonReaderParam.ReadNextAsync()
.ConfigureAwait(false);

Expand Down Expand Up @@ -844,9 +844,9 @@ await jsonWriter.EndObjectScopeAsync()
break;

case JsonNodeType.Property:
string propertyName = await jsonReader.GetPropertyNameAsync()
ReadOnlyMemory<char> propertyName = await jsonReader.GetPropertyNameAsync()
.ConfigureAwait(false);
await jsonWriter.WriteNameAsync(propertyName)
await jsonWriter.WriteNameAsync(propertyName.ToString())
.ConfigureAwait(false);
break;

Expand Down Expand Up @@ -1115,8 +1115,8 @@ await jsonReader.ReadStartObjectAsync()
while (jsonReader.NodeType != JsonNodeType.EndObject)
{
ODataProperty property = new ODataProperty();
property.Name = await jsonReader.ReadPropertyNameAsync()
.ConfigureAwait(false);
property.Name = (await jsonReader.ReadPropertyNameAsync()
.ConfigureAwait(false)).ToString();
property.Value = await jsonReader.ReadODataValueAsync()
.ConfigureAwait(false);
properties.Add(property);
Expand Down
12 changes: 6 additions & 6 deletions src/Microsoft.OData.Core/Json/ODataAnnotationNames.cs
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Original file line number Diff line number Diff line change
Expand Up @@ -112,11 +112,11 @@ internal static class ODataAnnotationNames
/// </summary>
/// <param name="annotationName">The name of the annotation in question.</param>
/// <returns>Returns true if the <paramref name="annotationName"/> starts with "odata.", false otherwise.</returns>
internal static bool IsODataAnnotationName(string annotationName)
internal static bool IsODataAnnotationName(ReadOnlySpan<char> annotationName)
{
Debug.Assert(!string.IsNullOrEmpty(annotationName), "!string.IsNullOrEmpty(annotationName)");
Debug.Assert(!annotationName.IsEmpty, "!string.IsNullOrEmpty(annotationName)");

if (annotationName.StartsWith(ODataJsonConstants.ODataAnnotationNamespacePrefix, StringComparison.Ordinal))
if (annotationName.StartsWith(ODataJsonConstants.ODataAnnotationNamespacePrefix.AsSpan(), StringComparison.Ordinal))
{
return true;
}
Expand All @@ -129,11 +129,11 @@ internal static bool IsODataAnnotationName(string annotationName)
/// </summary>
/// <param name="annotationName">The annotation name in question.</param>
/// <returns>Returns true if the <paramref name="annotationName"/> starts with "odata." and is not one of the reserved odata annotation names; returns false otherwise.</returns>
internal static bool IsUnknownODataAnnotationName(string annotationName)
internal static bool IsUnknownODataAnnotationName(ReadOnlySpan<char> annotationName)
{
Debug.Assert(!string.IsNullOrEmpty(annotationName), "!string.IsNullOrEmpty(annotationName)");
Debug.Assert(!annotationName.IsEmpty, "!string.IsNullOrEmpty(annotationName)");

if (IsODataAnnotationName(annotationName) && !KnownODataAnnotationNames.Contains(annotationName))
if (IsODataAnnotationName(annotationName) && !KnownODataAnnotationNames.Contains(annotationName.ToString()))
{
return true;
}
Expand Down
22 changes: 12 additions & 10 deletions src/Microsoft.OData.Core/Json/ODataJsonBatchPayloadItemPropertiesCache.cs
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Original file line number Diff line number Diff line change
Expand Up @@ -148,13 +148,13 @@ await jsonBatchPayloadItemPropertiesCache.ScanJsonPropertiesAsync()
/// </summary>
/// <param name="propertyName"> Name of the property.</param>
/// <returns>Property value. Null if not found.</returns>
internal object GetPropertyValue(string propertyName)
internal object GetPropertyValue(ReadOnlySpan<char> propertyName)
{
if (this.jsonProperties != null)
{
string canonicalPropertyName = Normalize(propertyName);
ReadOnlySpan<char> canonicalPropertyName = Normalize(propertyName);
object propertyValue;
if (this.jsonProperties.TryGetValue(canonicalPropertyName, out propertyValue))
if (this.jsonProperties.TryGetValue(canonicalPropertyName.ToString(), out propertyValue))
{
return propertyValue;
}
Expand Down Expand Up @@ -186,9 +186,11 @@ private ODataJsonBatchBodyContentReaderStream CreateJsonPayloadBodyContentStream
/// </summary>
/// <param name="propertyName">Name to be normalized.</param>
/// <returns>The normalized name.</returns>
private static string Normalize(string propertyName)
private static ReadOnlySpan<char> Normalize(ReadOnlySpan<char> propertyName)
{
return propertyName.ToUpperInvariant();
Span<char> buffer = new Span<char>(new char[propertyName.Length]);
propertyName.ToUpperInvariant(buffer);
return buffer;
}

/// <summary>
Expand All @@ -211,7 +213,7 @@ private void ScanJsonProperties()
while (this.jsonReader.NodeType != JsonNodeType.EndObject)
{
// Convert to upper case to support case-insensitive request property names
string propertyName = Normalize(this.jsonReader.ReadPropertyName());
string propertyName = Normalize(this.jsonReader.ReadPropertyName()).ToString();

// Throw an ODataException, if a duplicate json property was detected
if (jsonProperties.ContainsKey(propertyName))
Expand Down Expand Up @@ -265,7 +267,7 @@ private void ScanJsonProperties()

while (this.jsonReader.NodeType != JsonNodeType.EndObject)
{
string headerName = this.jsonReader.ReadPropertyName();
string headerName = this.jsonReader.ReadPropertyName().ToString();
string headerValue = this.jsonReader.ReadPrimitiveValue()?.ToString();

// Throw an ODataException, if a duplicate header was detected
Expand Down Expand Up @@ -362,7 +364,7 @@ await this.jsonReader.ReadStartObjectAsync()
while (this.jsonReader.NodeType != JsonNodeType.EndObject)
{
// Convert to upper case to support case-insensitive request property names
string propertyName = Normalize(await this.jsonReader.ReadPropertyNameAsync().ConfigureAwait(false));
string propertyName = Normalize((await this.jsonReader.ReadPropertyNameAsync().ConfigureAwait(false)).Span).ToString();

// Throw an ODataException, if a duplicate json property was detected
if (jsonProperties.ContainsKey(propertyName))
Expand Down Expand Up @@ -416,8 +418,8 @@ await this.jsonReader.ReadStartObjectAsync()

while (this.jsonReader.NodeType != JsonNodeType.EndObject)
{
string headerName = await this.jsonReader.ReadPropertyNameAsync()
.ConfigureAwait(false);
string headerName = (await this.jsonReader.ReadPropertyNameAsync()
.ConfigureAwait(false)).ToString();
string headerValue = (await this.jsonReader.ReadPrimitiveValueAsync().ConfigureAwait(false))?.ToString();

// Throw an ODataException, if a duplicate header was detected
Expand Down
12 changes: 6 additions & 6 deletions src/Microsoft.OData.Core/Json/ODataJsonBatchReader.cs
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Original file line number Diff line number Diff line change
Expand Up @@ -500,12 +500,12 @@ private void DetectReaderMode()
this.batchStream.JsonReader.ReadNext();
this.batchStream.JsonReader.ReadStartObject();

string propertyName = this.batchStream.JsonReader.ReadPropertyName();
if (PropertyNameRequests.Equals(propertyName, StringComparison.OrdinalIgnoreCase))
ReadOnlySpan<char> propertyName = this.batchStream.JsonReader.ReadPropertyName();
if (propertyName.Equals(PropertyNameRequests.AsSpan(), StringComparison.OrdinalIgnoreCase))
{
this.mode = ReaderMode.Requests;
}
else if (PropertyNameResponses.Equals(propertyName, StringComparison.OrdinalIgnoreCase))
else if (propertyName.Equals(PropertyNameResponses.AsSpan(), StringComparison.OrdinalIgnoreCase))
{
this.mode = ReaderMode.Responses;
}
Expand Down Expand Up @@ -623,14 +623,14 @@ await this.batchStream.JsonReader.ReadNextAsync()
await this.batchStream.JsonReader.ReadStartObjectAsync()
.ConfigureAwait(false);

string propertyName = await this.batchStream.JsonReader.ReadPropertyNameAsync()
ReadOnlyMemory<char> propertyName = await this.batchStream.JsonReader.ReadPropertyNameAsync()
.ConfigureAwait(false);

if (PropertyNameRequests.Equals(propertyName, StringComparison.OrdinalIgnoreCase))
if (propertyName.Span.Equals(PropertyNameRequests.AsSpan(), StringComparison.OrdinalIgnoreCase))
{
this.mode = ReaderMode.Requests;
}
else if (PropertyNameResponses.Equals(propertyName, StringComparison.OrdinalIgnoreCase))
else if (propertyName.Span.Equals(PropertyNameResponses.AsSpan(), StringComparison.OrdinalIgnoreCase))
{
this.mode = ReaderMode.Responses;
}
Expand Down
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