jellyfin/Emby.Server.Implementations/Services/ServicePath.cs
2020-07-22 14:34:51 +02:00

551 lines
20 KiB
C#

#pragma warning disable CS1591
using System;
using System.Collections.Generic;
using System.Globalization;
using System.IO;
using System.Linq;
using System.Reflection;
using System.Text;
using System.Text.Json.Serialization;
namespace Emby.Server.Implementations.Services
{
public class RestPath
{
private const string WildCard = "*";
private const char WildCardChar = '*';
private const string PathSeperator = "/";
private const char PathSeperatorChar = '/';
private const char ComponentSeperator = '.';
private const string VariablePrefix = "{";
private readonly bool[] componentsWithSeparators;
private readonly string restPath;
public bool IsWildCardPath { get; private set; }
private readonly string[] literalsToMatch;
private readonly string[] variablesNames;
private readonly bool[] isWildcard;
private readonly int wildcardCount = 0;
internal static string[] IgnoreAttributesNamed = new[]
{
nameof(JsonIgnoreAttribute)
};
private static Type _excludeType = typeof(Stream);
public int VariableArgsCount { get; set; }
/// <summary>
/// The number of segments separated by '/' determinable by path.Split('/').Length
/// e.g. /path/to/here.ext == 3
/// </summary>
public int PathComponentsCount { get; set; }
/// <summary>
/// Gets or sets the total number of segments after subparts have been exploded ('.')
/// e.g. /path/to/here.ext == 4.
/// </summary>
public int TotalComponentsCount { get; set; }
public string[] Verbs { get; private set; }
public Type RequestType { get; private set; }
public Type ServiceType { get; private set; }
public string Path => this.restPath;
public string Summary { get; private set; }
public string Description { get; private set; }
public bool IsHidden { get; private set; }
public static string[] GetPathPartsForMatching(string pathInfo)
{
return pathInfo.ToLowerInvariant().Split(new[] { PathSeperatorChar }, StringSplitOptions.RemoveEmptyEntries);
}
public static List<string> GetFirstMatchHashKeys(string[] pathPartsForMatching)
{
var hashPrefix = pathPartsForMatching.Length + PathSeperator;
return GetPotentialMatchesWithPrefix(hashPrefix, pathPartsForMatching);
}
public static List<string> GetFirstMatchWildCardHashKeys(string[] pathPartsForMatching)
{
const string hashPrefix = WildCard + PathSeperator;
return GetPotentialMatchesWithPrefix(hashPrefix, pathPartsForMatching);
}
private static List<string> GetPotentialMatchesWithPrefix(string hashPrefix, string[] pathPartsForMatching)
{
var list = new List<string>();
foreach (var part in pathPartsForMatching)
{
list.Add(hashPrefix + part);
if (part.IndexOf(ComponentSeperator) == -1)
{
continue;
}
var subParts = part.Split(ComponentSeperator);
foreach (var subPart in subParts)
{
list.Add(hashPrefix + subPart);
}
}
return list;
}
public RestPath(Func<Type, object> createInstanceFn, Func<Type, Func<string, object>> getParseFn, Type requestType, Type serviceType, string path, string verbs, bool isHidden = false, string summary = null, string description = null)
{
this.RequestType = requestType;
this.ServiceType = serviceType;
this.Summary = summary;
this.IsHidden = isHidden;
this.Description = description;
this.restPath = path;
this.Verbs = string.IsNullOrWhiteSpace(verbs) ? ServiceExecExtensions.AllVerbs : verbs.ToUpperInvariant().Split(new[] { ' ', ',' }, StringSplitOptions.RemoveEmptyEntries);
var componentsList = new List<string>();
// We only split on '.' if the restPath has them. Allows for /{action}.{type}
var hasSeparators = new List<bool>();
foreach (var component in this.restPath.Split(PathSeperatorChar))
{
if (string.IsNullOrEmpty(component))
{
continue;
}
if (component.IndexOf(VariablePrefix, StringComparison.OrdinalIgnoreCase) != -1
&& component.IndexOf(ComponentSeperator) != -1)
{
hasSeparators.Add(true);
componentsList.AddRange(component.Split(ComponentSeperator));
}
else
{
hasSeparators.Add(false);
componentsList.Add(component);
}
}
var components = componentsList.ToArray();
this.TotalComponentsCount = components.Length;
this.literalsToMatch = new string[this.TotalComponentsCount];
this.variablesNames = new string[this.TotalComponentsCount];
this.isWildcard = new bool[this.TotalComponentsCount];
this.componentsWithSeparators = hasSeparators.ToArray();
this.PathComponentsCount = this.componentsWithSeparators.Length;
string firstLiteralMatch = null;
for (var i = 0; i < components.Length; i++)
{
var component = components[i];
if (component.StartsWith(VariablePrefix))
{
var variableName = component.Substring(1, component.Length - 2);
if (variableName[variableName.Length - 1] == WildCardChar)
{
this.isWildcard[i] = true;
variableName = variableName.Substring(0, variableName.Length - 1);
}
this.variablesNames[i] = variableName;
this.VariableArgsCount++;
}
else
{
this.literalsToMatch[i] = component.ToLowerInvariant();
if (firstLiteralMatch == null)
{
firstLiteralMatch = this.literalsToMatch[i];
}
}
}
for (var i = 0; i < components.Length - 1; i++)
{
if (!this.isWildcard[i])
{
continue;
}
if (this.literalsToMatch[i + 1] == null)
{
throw new ArgumentException(
"A wildcard path component must be at the end of the path or followed by a literal path component.");
}
}
this.wildcardCount = this.isWildcard.Length;
this.IsWildCardPath = this.wildcardCount > 0;
this.FirstMatchHashKey = !this.IsWildCardPath
? this.PathComponentsCount + PathSeperator + firstLiteralMatch
: WildCardChar + PathSeperator + firstLiteralMatch;
this.typeDeserializer = new StringMapTypeDeserializer(createInstanceFn, getParseFn, this.RequestType);
_propertyNamesMap = new HashSet<string>(
GetSerializableProperties(RequestType).Select(x => x.Name),
StringComparer.OrdinalIgnoreCase);
}
internal static IEnumerable<PropertyInfo> GetSerializableProperties(Type type)
{
foreach (var prop in GetPublicProperties(type))
{
if (prop.GetMethod == null
|| _excludeType == prop.PropertyType)
{
continue;
}
var ignored = false;
foreach (var attr in prop.GetCustomAttributes(true))
{
if (IgnoreAttributesNamed.Contains(attr.GetType().Name))
{
ignored = true;
break;
}
}
if (!ignored)
{
yield return prop;
}
}
}
private static IEnumerable<PropertyInfo> GetPublicProperties(Type type)
{
if (type.IsInterface)
{
var propertyInfos = new List<PropertyInfo>();
var considered = new List<Type>()
{
type
};
var queue = new Queue<Type>();
queue.Enqueue(type);
while (queue.Count > 0)
{
var subType = queue.Dequeue();
foreach (var subInterface in subType.GetTypeInfo().ImplementedInterfaces)
{
if (considered.Contains(subInterface))
{
continue;
}
considered.Add(subInterface);
queue.Enqueue(subInterface);
}
var newPropertyInfos = GetTypesPublicProperties(subType)
.Where(x => !propertyInfos.Contains(x));
propertyInfos.InsertRange(0, newPropertyInfos);
}
return propertyInfos;
}
return GetTypesPublicProperties(type)
.Where(x => x.GetIndexParameters().Length == 0);
}
private static IEnumerable<PropertyInfo> GetTypesPublicProperties(Type subType)
{
foreach (var pi in subType.GetRuntimeProperties())
{
var mi = pi.GetMethod ?? pi.SetMethod;
if (mi != null && mi.IsStatic)
{
continue;
}
yield return pi;
}
}
/// <summary>
/// Provide for quick lookups based on hashes that can be determined from a request url.
/// </summary>
public string FirstMatchHashKey { get; private set; }
private readonly StringMapTypeDeserializer typeDeserializer;
private readonly HashSet<string> _propertyNamesMap;
public int MatchScore(string httpMethod, string[] withPathInfoParts)
{
var isMatch = IsMatch(httpMethod, withPathInfoParts, out var wildcardMatchCount);
if (!isMatch)
{
return -1;
}
// Routes with least wildcard matches get the highest score
var score = Math.Max(100 - wildcardMatchCount, 1) * 1000
// Routes with less variable (and more literal) matches
+ Math.Max(10 - VariableArgsCount, 1) * 100;
// Exact verb match is better than ANY
if (Verbs.Length == 1 && string.Equals(httpMethod, Verbs[0], StringComparison.OrdinalIgnoreCase))
{
score += 10;
}
else
{
score += 1;
}
return score;
}
/// <summary>
/// For performance withPathInfoParts should already be a lower case string
/// to minimize redundant matching operations.
/// </summary>
public bool IsMatch(string httpMethod, string[] withPathInfoParts, out int wildcardMatchCount)
{
wildcardMatchCount = 0;
if (withPathInfoParts.Length != this.PathComponentsCount && !this.IsWildCardPath)
{
return false;
}
if (!Verbs.Contains(httpMethod, StringComparer.OrdinalIgnoreCase))
{
return false;
}
if (!ExplodeComponents(ref withPathInfoParts))
{
return false;
}
if (this.TotalComponentsCount != withPathInfoParts.Length && !this.IsWildCardPath)
{
return false;
}
int pathIx = 0;
for (var i = 0; i < this.TotalComponentsCount; i++)
{
if (this.isWildcard[i])
{
if (i < this.TotalComponentsCount - 1)
{
// Continue to consume up until a match with the next literal
while (pathIx < withPathInfoParts.Length
&& !string.Equals(withPathInfoParts[pathIx], this.literalsToMatch[i + 1], StringComparison.InvariantCultureIgnoreCase))
{
pathIx++;
wildcardMatchCount++;
}
// Ensure there are still enough parts left to match the remainder
if ((withPathInfoParts.Length - pathIx) < (this.TotalComponentsCount - i - 1))
{
return false;
}
}
else
{
// A wildcard at the end matches the remainder of path
wildcardMatchCount += withPathInfoParts.Length - pathIx;
pathIx = withPathInfoParts.Length;
}
}
else
{
var literalToMatch = this.literalsToMatch[i];
if (literalToMatch == null)
{
// Matching an ordinary (non-wildcard) variable consumes a single part
pathIx++;
continue;
}
if (withPathInfoParts.Length <= pathIx
|| !string.Equals(withPathInfoParts[pathIx], literalToMatch, StringComparison.InvariantCultureIgnoreCase))
{
return false;
}
pathIx++;
}
}
return pathIx == withPathInfoParts.Length;
}
private bool ExplodeComponents(ref string[] withPathInfoParts)
{
var totalComponents = new List<string>();
for (var i = 0; i < withPathInfoParts.Length; i++)
{
var component = withPathInfoParts[i];
if (string.IsNullOrEmpty(component))
{
continue;
}
if (this.PathComponentsCount != this.TotalComponentsCount
&& this.componentsWithSeparators[i])
{
var subComponents = component.Split(ComponentSeperator);
if (subComponents.Length < 2)
{
return false;
}
totalComponents.AddRange(subComponents);
}
else
{
totalComponents.Add(component);
}
}
withPathInfoParts = totalComponents.ToArray();
return true;
}
public object CreateRequest(string pathInfo, Dictionary<string, string> queryStringAndFormData, object fromInstance)
{
var requestComponents = pathInfo.Split(new[] { PathSeperatorChar }, StringSplitOptions.RemoveEmptyEntries);
ExplodeComponents(ref requestComponents);
if (requestComponents.Length != this.TotalComponentsCount)
{
var isValidWildCardPath = this.IsWildCardPath
&& requestComponents.Length >= this.TotalComponentsCount - this.wildcardCount;
if (!isValidWildCardPath)
{
throw new ArgumentException(
string.Format(
CultureInfo.InvariantCulture,
"Path Mismatch: Request Path '{0}' has invalid number of components compared to: '{1}'",
pathInfo,
this.restPath));
}
}
var requestKeyValuesMap = new Dictionary<string, string>();
var pathIx = 0;
for (var i = 0; i < this.TotalComponentsCount; i++)
{
var variableName = this.variablesNames[i];
if (variableName == null)
{
pathIx++;
continue;
}
if (!this._propertyNamesMap.Contains(variableName))
{
if (string.Equals("ignore", variableName, StringComparison.OrdinalIgnoreCase))
{
pathIx++;
continue;
}
throw new ArgumentException("Could not find property "
+ variableName + " on " + RequestType.GetMethodName());
}
var value = requestComponents.Length > pathIx ? requestComponents[pathIx] : null; // wildcard has arg mismatch
if (value != null && this.isWildcard[i])
{
if (i == this.TotalComponentsCount - 1)
{
// Wildcard at end of path definition consumes all the rest
var sb = new StringBuilder();
sb.Append(value);
for (var j = pathIx + 1; j < requestComponents.Length; j++)
{
sb.Append(PathSeperatorChar)
.Append(requestComponents[j]);
}
value = sb.ToString();
}
else
{
// Wildcard in middle of path definition consumes up until it
// hits a match for the next element in the definition (which must be a literal)
// It may consume 0 or more path parts
var stopLiteral = i == this.TotalComponentsCount - 1 ? null : this.literalsToMatch[i + 1];
if (!string.Equals(requestComponents[pathIx], stopLiteral, StringComparison.OrdinalIgnoreCase))
{
var sb = new StringBuilder(value);
pathIx++;
while (!string.Equals(requestComponents[pathIx], stopLiteral, StringComparison.OrdinalIgnoreCase))
{
sb.Append(PathSeperatorChar)
.Append(requestComponents[pathIx++]);
}
value = sb.ToString();
}
else
{
value = null;
}
}
}
else
{
// Variable consumes single path item
pathIx++;
}
requestKeyValuesMap[variableName] = value;
}
if (queryStringAndFormData != null)
{
// Query String and form data can override variable path matches
// path variables < query string < form data
foreach (var name in queryStringAndFormData)
{
requestKeyValuesMap[name.Key] = name.Value;
}
}
return this.typeDeserializer.PopulateFromMap(fromInstance, requestKeyValuesMap);
}
public class RestPathMap : SortedDictionary<string, List<RestPath>>
{
public RestPathMap() : base(StringComparer.OrdinalIgnoreCase)
{
}
}
}
}