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Optimize builder and HTTP policy allocations (#768)

This commit is contained in:
James Newton-King 2018-09-06 13:25:35 +12:00 committed by GitHub
parent abc378d3dc
commit fe8c633224
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4 changed files with 79 additions and 123 deletions
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96
src/Microsoft.AspNetCore.Routing/Matching/DfaMatcherBuilder.cs
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@ -64,7 +64,7 @@ namespace Microsoft.AspNetCore.Routing.Matching
// Since we're doing a BFS we will process each 'level' of the tree in stages
// this list will hold the set of items we need to process at the current
// stage.
var work = new List<(RouteEndpoint endpoint, List<DfaNode> parents)>();
var work = new List<(RouteEndpoint endpoint, List<DfaNode> parents)>(_endpoints.Count);
List<(RouteEndpoint endpoint, List<DfaNode> parents)> previousWork = null;
var root = new DfaNode() { PathDepth = 0, Label = "/" };
@ -290,38 +290,13 @@ namespace Microsoft.AspNetCore.Routing.Matching
maxSegmentCount++;
var states = new DfaState[stateCount];
var tableBuilders = new (JumpTableBuilder pathBuilder, PolicyJumpTableBuilder policyBuilder)[stateCount];
AddNode(root, states, tableBuilders);
var exitDestination = stateCount - 1;
AddNode(root, states, exitDestination);
var exit = stateCount - 1;
states[exit] = new DfaState(Array.Empty<Candidate>(), null, null);
tableBuilders[exit] = (new JumpTableBuilder() { DefaultDestination = exit, ExitDestination = exit, }, null);
for (var i = 0; i < tableBuilders.Length; i++)
{
if (tableBuilders[i].pathBuilder?.DefaultDestination == JumpTableBuilder.InvalidDestination)
{
tableBuilders[i].pathBuilder.DefaultDestination = exit;
}
if (tableBuilders[i].pathBuilder?.ExitDestination == JumpTableBuilder.InvalidDestination)
{
tableBuilders[i].pathBuilder.ExitDestination = exit;
}
if (tableBuilders[i].policyBuilder?.ExitDestination == JumpTableBuilder.InvalidDestination)
{
tableBuilders[i].policyBuilder.ExitDestination = exit;
}
}
for (var i = 0; i < states.Length; i++)
{
states[i] = new DfaState(
states[i].Candidates,
tableBuilders[i].pathBuilder?.Build(),
tableBuilders[i].policyBuilder?.Build());
}
states[exitDestination] = new DfaState(
Array.Empty<Candidate>(),
JumpTableBuilder.Build(exitDestination, exitDestination, null),
null);
return new DfaMatcher(_selector, states, maxSegmentCount);
}
@ -329,29 +304,26 @@ namespace Microsoft.AspNetCore.Routing.Matching
private int AddNode(
DfaNode node,
DfaState[] states,
(JumpTableBuilder pathBuilder, PolicyJumpTableBuilder policyBuilder)[] tableBuilders)
int exitDestination)
{
node.Matches?.Sort(_comparer);
var currentStateIndex = _stateIndex;
var candidates = CreateCandidates(node.Matches);
states[currentStateIndex] = new DfaState(candidates, null, null);
var pathBuilder = new JumpTableBuilder();
tableBuilders[currentStateIndex] = (pathBuilder, null);
var currentDefaultDestination = exitDestination;
var currentExitDestination = exitDestination;
(string text, int destination)[] pathEntries = null;
PolicyJumpTableEdge[] policyEntries = null;
if (node.Literals != null)
{
pathEntries = new (string text, int destination)[node.Literals.Count];
var index = 0;
foreach (var kvp in node.Literals)
{
if (kvp.Key == null)
{
continue;
}
var transition = Transition(kvp.Value);
pathBuilder.AddEntry(kvp.Key, transition);
pathEntries[index++] = (kvp.Key, transition);
}
}
@ -361,39 +333,43 @@ namespace Microsoft.AspNetCore.Routing.Matching
{
// This node has a single transition to but it should accept zero-width segments
// this can happen when a node only has catchall parameters.
pathBuilder.DefaultDestination = Transition(node.Parameters);
pathBuilder.ExitDestination = pathBuilder.DefaultDestination;
currentExitDestination = currentDefaultDestination = Transition(node.Parameters);
}
else if (node.Parameters != null && node.CatchAll != null)
{
// This node has a separate transition for zero-width segments
// this can happen when a node has both parameters and catchall parameters.
pathBuilder.DefaultDestination = Transition(node.Parameters);
pathBuilder.ExitDestination = Transition(node.CatchAll);
currentDefaultDestination = Transition(node.Parameters);
currentExitDestination = Transition(node.CatchAll);
}
else if (node.Parameters != null)
{
// This node has paramters but no catchall.
pathBuilder.DefaultDestination = Transition(node.Parameters);
currentDefaultDestination = Transition(node.Parameters);
}
else if (node.CatchAll != null)
{
// This node has a catchall but no parameters
pathBuilder.DefaultDestination = Transition(node.CatchAll);
pathBuilder.ExitDestination = pathBuilder.DefaultDestination;
currentExitDestination = currentDefaultDestination = Transition(node.CatchAll);
}
if (node.PolicyEdges != null && node.PolicyEdges.Count > 0)
{
var policyBuilder = new PolicyJumpTableBuilder(node.NodeBuilder);
tableBuilders[currentStateIndex] = (pathBuilder, policyBuilder);
policyEntries = new PolicyJumpTableEdge[node.PolicyEdges.Count];
var index = 0;
foreach (var kvp in node.PolicyEdges)
{
policyBuilder.AddEntry(kvp.Key, Transition(kvp.Value));
policyEntries[index++] = new PolicyJumpTableEdge(kvp.Key, Transition(kvp.Value));
}
}
var candidates = CreateCandidates(node.Matches);
states[currentStateIndex] = new DfaState(
candidates,
JumpTableBuilder.Build(currentDefaultDestination, currentExitDestination, pathEntries),
BuildPolicy(currentExitDestination, node.NodeBuilder, policyEntries));
return currentStateIndex;
int Transition(DfaNode next)
@ -406,11 +382,21 @@ namespace Microsoft.AspNetCore.Routing.Matching
else
{
_stateIndex++;
return AddNode(next, states, tableBuilders);
return AddNode(next, states, exitDestination);
}
}
}
private static PolicyJumpTable BuildPolicy(int exitDestination, INodeBuilderPolicy nodeBuilder, PolicyJumpTableEdge[] policyEntries)
{
if (policyEntries == null)
{
return null;
}
return nodeBuilder.BuildJumpTable(exitDestination, policyEntries);
}
// Builds an array of candidates for a node, assigns a 'score' for each
// endpoint.
internal Candidate[] CreateCandidates(IReadOnlyList<Endpoint> endpoints)

24
src/Microsoft.AspNetCore.Routing/Matching/HttpMethodMatcherPolicy.cs
View File

@ -80,7 +80,7 @@ namespace Microsoft.AspNetCore.Routing.Matching
//
// For now we're just building up the set of keys. We don't add any endpoints
// to lists now because we don't want ordering problems.
var allHttpMethods = new HashSet<string>(StringComparer.OrdinalIgnoreCase);
var allHttpMethods = new List<string>();
var edges = new Dictionary<EdgeKey, List<Endpoint>>();
for (var i = 0; i < endpoints.Count; i++)
{
@ -120,11 +120,16 @@ namespace Microsoft.AspNetCore.Routing.Matching
// Also if it's not the *any* method key, then track it.
if (!string.Equals(AnyMethod, httpMethod, StringComparison.OrdinalIgnoreCase))
{
allHttpMethods.Add(httpMethod);
if (!ContainsHttpMethod(allHttpMethods, httpMethod))
{
allHttpMethods.Add(httpMethod);
}
}
}
}
allHttpMethods.Sort(StringComparer.OrdinalIgnoreCase);
// Now in a second loop, add endpoints to these lists. We've enumerated all of
// the states, so we want to see which states this endpoint matches.
for (var i = 0; i < endpoints.Count; i++)
@ -185,7 +190,7 @@ namespace Microsoft.AspNetCore.Routing.Matching
if (!edges.TryGetValue(new EdgeKey(AnyMethod, false), out var matches))
{
// Methods sorted for testability.
var endpoint = CreateRejectionEndpoint(allHttpMethods.OrderBy(m => m));
var endpoint = CreateRejectionEndpoint(allHttpMethods);
matches = new List<Endpoint>() { endpoint, };
edges[new EdgeKey(AnyMethod, false)] = matches;
}
@ -261,6 +266,19 @@ namespace Microsoft.AspNetCore.Routing.Matching
Http405EndpointDisplayName);
}
private static bool ContainsHttpMethod(List<string> httpMethods, string httpMethod)
{
for (var i = 0; i < httpMethods.Count; i++)
{
if (StringComparer.OrdinalIgnoreCase.Equals(httpMethods[i], httpMethod))
{
return true;
}
}
return false;
}
private class HttpMethodPolicyJumpTable : PolicyJumpTable
{
private readonly int _exitDestination;

50
src/Microsoft.AspNetCore.Routing/Matching/JumpTableBuilder.cs
View File

@ -2,39 +2,24 @@
// Licensed under the Apache License, Version 2.0. See License.txt in the project root for license information.
using System;
using System.Collections.Generic;
namespace Microsoft.AspNetCore.Routing.Matching
{
internal class JumpTableBuilder
internal static class JumpTableBuilder
{
public static readonly int InvalidDestination = -1;
private readonly List<(string text, int destination)> _entries = new List<(string text, int destination)>();
// The destination state when none of the text entries match.
public int DefaultDestination { get; set; } = InvalidDestination;
// The destination state for a zero-length segment. This is a special
// case because parameters don't match a zero-length segment.
public int ExitDestination { get; set; } = InvalidDestination;
public void AddEntry(string text, int destination)
public static JumpTable Build(int defaultDestination, int exitDestination, (string text, int destination)[] pathEntries)
{
_entries.Add((text, destination));
}
public JumpTable Build()
{
if (DefaultDestination == InvalidDestination)
if (defaultDestination == InvalidDestination)
{
var message = $"{nameof(DefaultDestination)} is not set. Please report this as a bug.";
var message = $"{nameof(defaultDestination)} is not set. Please report this as a bug.";
throw new InvalidOperationException(message);
}
if (ExitDestination == InvalidDestination)
if (exitDestination == InvalidDestination)
{
var message = $"{nameof(ExitDestination)} is not set. Please report this as a bug.";
var message = $"{nameof(exitDestination)} is not set. Please report this as a bug.";
throw new InvalidOperationException(message);
}
@ -49,16 +34,16 @@ namespace Microsoft.AspNetCore.Routing.Matching
// We have an optimized fast path for zero entries since we don't have to
// do any string comparisons.
if (_entries.Count == 0)
if (pathEntries == null || pathEntries.Length == 0)
{
return new ZeroEntryJumpTable(DefaultDestination, ExitDestination);
return new ZeroEntryJumpTable(defaultDestination, exitDestination);
}
// The IL Emit jump table is not faster for a single entry
if (_entries.Count == 1)
if (pathEntries.Length == 1)
{
var entry = _entries[0];
return new SingleEntryJumpTable(DefaultDestination, ExitDestination, entry.text, entry.destination);
var entry = pathEntries[0];
return new SingleEntryJumpTable(defaultDestination, exitDestination, entry.text, entry.destination);
}
// We choose a hard upper bound of 100 as the limit for when we switch to a dictionary
@ -72,9 +57,9 @@ namespace Microsoft.AspNetCore.Routing.Matching
// Additionally if we're on 32bit, the scalability is worse, so switch to the dictionary at 50
// entries.
var threshold = IntPtr.Size == 8 ? 100 : 50;
if (_entries.Count >= threshold)
if (pathEntries.Length >= threshold)
{
return new DictionaryJumpTable(DefaultDestination, ExitDestination, _entries.ToArray());
return new DictionaryJumpTable(defaultDestination, exitDestination, pathEntries);
}
// If we have more than a single string, the IL emit strategy is the fastest - but we need to decide
@ -82,18 +67,17 @@ namespace Microsoft.AspNetCore.Routing.Matching
JumpTable fallback;
// Based on our testing a linear search is still faster than a dictionary at ten entries.
if (_entries.Count <= 10)
if (pathEntries.Length <= 10)
{
fallback = new LinearSearchJumpTable(DefaultDestination, ExitDestination, _entries.ToArray());
fallback = new LinearSearchJumpTable(defaultDestination, exitDestination, pathEntries);
}
else
{
fallback = new DictionaryJumpTable(DefaultDestination, ExitDestination, _entries.ToArray());
fallback = new DictionaryJumpTable(defaultDestination, exitDestination, pathEntries);
}
#if IL_EMIT
return new ILEmitTrieJumpTable(DefaultDestination, ExitDestination, _entries.ToArray(), vectorize: null, fallback);
return new ILEmitTrieJumpTable(defaultDestination, exitDestination, pathEntries, vectorize: null, fallback);
#else
return fallback;
#endif

32
src/Microsoft.AspNetCore.Routing/Matching/PolicyJumpTableBuilder.cs
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@ -1,32 +0,0 @@
// Copyright (c) .NET Foundation. All rights reserved.
// Licensed under the Apache License, Version 2.0. See License.txt in the project root for license information.
using System.Collections.Generic;
namespace Microsoft.AspNetCore.Routing.Matching
{
internal class PolicyJumpTableBuilder
{
private readonly INodeBuilderPolicy _nodeBuilder;
private readonly List<PolicyJumpTableEdge> _entries;
public PolicyJumpTableBuilder(INodeBuilderPolicy nodeBuilder)
{
_nodeBuilder = nodeBuilder;
_entries = new List<PolicyJumpTableEdge>();
}
// The destination state for a non-match.
public int ExitDestination { get; set; } = JumpTableBuilder.InvalidDestination;
public void AddEntry(object state, int destination)
{
_entries.Add(new PolicyJumpTableEdge(state, destination));
}
public PolicyJumpTable Build()
{
return _nodeBuilder.BuildJumpTable(ExitDestination, _entries);
}
}
}