perf(QueryParser): constants instead of inline strings

Author: jaredcnance

src/JsonApiDotNetCore/Services/QueryParser.cs

@@ -3,7 +3,6 @@
 using System.Linq;
 using JsonApiDotNetCore.Configuration;
 using JsonApiDotNetCore.Controllers;
-using JsonApiDotNetCore.Extensions;
 using JsonApiDotNetCore.Internal;
 using JsonApiDotNetCore.Internal.Query;
 using JsonApiDotNetCore.Models;
@@ -18,8 +17,17 @@ public class QueryParser : IQueryParser {
         private readonly IControllerContext _controllerContext;
         private readonly JsonApiOptions _options;
 
+        private const string FILTER = "filter";
+        private const string SORT = "sort";
+        private const string INCLUDE = "include";
+        private const string PAGE = "page";
+        private const string FIELDS = "fields";
         private const char OPEN_BRACKET = '[';
         private const char CLOSE_BRACKET = ']';
+        private const char COMMA = ',';
+        private const char COLON = ':';
+        private const string COLON_STR = ":";
+
         public QueryParser(
             IControllerContext controllerContext,
             JsonApiOptions options) {
@@ -32,31 +40,31 @@ public virtual QuerySet Parse(IQueryCollection query) {
             var disabledQueries = _controllerContext.GetControllerAttribute<DisableQueryAttribute>() ? .QueryParams ?? QueryParams.None;
 
             foreach (var pair in query) {
-                if (pair.Key.StartsWith("filter")) {
+                if (pair.Key.StartsWith(FILTER)) {
                     if (disabledQueries.HasFlag(QueryParams.Filter) == false)
                         querySet.Filters.AddRange(ParseFilterQuery(pair.Key, pair.Value));
                     continue;
                 }
 
-                if (pair.Key.StartsWith("sort")) {
+                if (pair.Key.StartsWith(SORT)) {
                     if (disabledQueries.HasFlag(QueryParams.Sort) == false)
                         querySet.SortParameters = ParseSortParameters(pair.Value);
                     continue;
                 }
 
-                if (pair.Key.StartsWith("include")) {
+                if (pair.Key.StartsWith(INCLUDE)) {
                     if (disabledQueries.HasFlag(QueryParams.Include) == false)
                         querySet.IncludedRelationships = ParseIncludedRelationships(pair.Value);
                     continue;
                 }
 
-                if (pair.Key.StartsWith("page")) {
+                if (pair.Key.StartsWith(PAGE)) {
                     if (disabledQueries.HasFlag(QueryParams.Page) == false)
                         querySet.PageQuery = ParsePageQuery(querySet.PageQuery, pair.Key, pair.Value);
                     continue;
                 }
 
-                if (pair.Key.StartsWith("fields")) {
+                if (pair.Key.StartsWith(FIELDS)) {
                     if (disabledQueries.HasFlag(QueryParams.Fields) == false)
                         querySet.Fields = ParseFieldsQuery(pair.Key, pair.Value);
                     continue;
@@ -76,10 +84,9 @@ protected virtual List<FilterQuery> ParseFilterQuery(string key, string value) {
 
             var propertyName = key.Split(OPEN_BRACKET, CLOSE_BRACKET) [1];
 
-            var values = value.Split(',');
+            var values = value.Split(COMMA);
             foreach (var val in values) {
-                (var operation,
-                    var filterValue) = ParseFilterOperation(val);
+                (var operation, var filterValue) = ParseFilterOperation(val);
                 queries.Add(new FilterQuery(propertyName, filterValue, operation));
             }
 
@@ -90,7 +97,7 @@ protected virtual(string operation, string value) ParseFilterOperation(string va
             if (value.Length < 3)
                 return (string.Empty, value);
 
-            var operation = value.Split(':');
+            var operation = value.Split(COLON);
 
             if (operation.Length == 1)
                 return (string.Empty, value);
@@ -100,7 +107,7 @@ protected virtual(string operation, string value) ParseFilterOperation(string va
                 return (string.Empty, value);
 
             var prefix = operation[0];
-            value = string.Join(":", operation.Skip(1));
+            value = string.Join(COLON_STR, operation.Skip(1));
 
             return (prefix, value);
         }
@@ -110,11 +117,14 @@ protected virtual PageQuery ParsePageQuery(PageQuery pageQuery, string key, stri
             //                  page[number]=1
             pageQuery = pageQuery ?? new PageQuery();
 
-            var propertyName = key.Split('[', ']') [1];
+            var propertyName = key.Split(OPEN_BRACKET, CLOSE_BRACKET) [1];
+
+            const string SIZE = "size";
+            const string NUMBER = "number";
 
-            if (propertyName == "size")
+            if (propertyName == SIZE)
                 pageQuery.PageSize = Convert.ToInt32(value);
-            else if (propertyName == "number")
+            else if (propertyName == NUMBER)
                 pageQuery.PageOffset = Convert.ToInt32(value);
 
             return pageQuery;
@@ -123,11 +133,11 @@ protected virtual PageQuery ParsePageQuery(PageQuery pageQuery, string key, stri
         // sort=id,name
         // sort=-id
         protected virtual List<SortQuery> ParseSortParameters(string value) {
-            const char SORT_DELIMITER = ',';
+            var sortParameters = new List<SortQuery>();
+
             const char DESCENDING_SORT_OPERATOR = '-';
+            var sortSegments = value.Split(COMMA);
 
-            var sortParameters = new List<SortQuery>();
-            var sortSegments = value.Split(SORT_DELIMITER);
             foreach (var sortSegment in sortSegments) {
 
                 var propertyName = sortSegment;
@@ -147,24 +157,26 @@ protected virtual List<SortQuery> ParseSortParameters(string value) {
         }
 
         protected virtual List<string> ParseIncludedRelationships(string value) {
-            if (value.Contains("."))
+            const string NESTED_DELIMITER = ".";
+            if (value.Contains(NESTED_DELIMITER))
                 throw new JsonApiException(400, "Deeply nested relationships are not supported");
 
             return value
-                .Split(',')
+                .Split(COMMA)
                 .ToList();
         }
 
         protected virtual List<string> ParseFieldsQuery(string key, string value) {
             // expected: fields[TYPE]=prop1,prop2
-            var typeName = key.Split('[', ']') [1];
+            var typeName = key.Split(OPEN_BRACKET, CLOSE_BRACKET) [1];
 
-            var includedFields = new List<string> { "Id" };
+            const string ID = "Id";
+            var includedFields = new List<string> { ID };
 
             if (typeName != _controllerContext.RequestEntity.EntityName)
                 return includedFields;
 
-            var fields = value.Split(',');
+            var fields = value.Split(COMMA);
             foreach (var field in fields) {
                 var internalAttrName = _controllerContext.RequestEntity
                     .Attributes
@@ -176,11 +188,17 @@ protected virtual List<string> ParseFieldsQuery(string key, string value) {
             return includedFields;
         }
 
-        protected virtual AttrAttribute GetAttribute(string propertyName) => _controllerContext
-            .RequestEntity
-            .Attributes
-            .FirstOrDefault(attr =>
-                string.Equals(attr.PublicAttributeName, propertyName, StringComparison.OrdinalIgnoreCase)
-            );
+        protected virtual AttrAttribute GetAttribute(string propertyName) {
+            try {
+                return _controllerContext
+                    .RequestEntity
+                    .Attributes
+                    .Single(attr =>
+                        string.Equals(attr.PublicAttributeName, propertyName, StringComparison.OrdinalIgnoreCase)
+                    );
+            } catch (InvalidOperationException e) {
+                throw new JsonApiException(400, $"Attribute '{propertyName}' does not exist on resource '{_controllerContext.RequestEntity.EntityName}'");
+            }
+        }
     }
 }