Refactor InfoDetail parsing

src/core/StackExchange.Redis.Extensions.Core/Abstractions/IRedisDatabase.cs

@@ -407,12 +407,24 @@ public Task<bool> SetContainsAsync<T>(string key, T item, CommandFlags flag = Co
     /// </summary>
     public Task<Dictionary<string, string>> GetInfoAsync();
 
+    /// <summary>
+    ///     Gets the information about redis.
+    ///     More info see http://redis.io/commands/INFO
+    /// </summary>
+    public Task<Dictionary<string, string>> GetInfoAsync(string section);
+
     /// <summary>
     ///     Gets the information about redis with category.
     ///     More info see http://redis.io/commands/INFO
     /// </summary>
     public Task<InfoDetail[]> GetInfoCategorizedAsync();
 
+    /// <summary>
+    ///     Gets the information about redis with category.
+    ///     More info see http://redis.io/commands/INFO
+    /// </summary>
+    public Task<InfoDetail[]> GetInfoCategorizedAsync(string section);
+
     /// <summary>
     ///     Updates the expiry time of a redis cache object
     /// </summary>

src/core/StackExchange.Redis.Extensions.Core/Helpers/ExceptionThrowHelper.cs

@@ -1,7 +1,10 @@
+// Copyright (c) Ugo Lattanzi.  All Rights Reserved.  Licensed under the MIT license.  See License.txt in the project root for license information.
+
 using System;
 using System.Diagnostics.CodeAnalysis;
 
 namespace StackExchange.Redis.Extensions.Core.Helpers;
+
 internal static class ExceptionThrowHelper
 {
     public static void ThrowIfExistsNullElement<T>(ReadOnlySpan<T> argument, string paramName)

src/core/StackExchange.Redis.Extensions.Core/Helpers/InfoDetailsParser.cs

@@ -0,0 +1,137 @@
+// Copyright (c) Ugo Lattanzi.  All Rights Reserved.  Licensed under the MIT license.  See License.txt in the project root for license information.
+
+using System;
+using System.Collections.Generic;
+
+namespace StackExchange.Redis.Extensions.Core.Helpers;
+
+/// <summary>
+/// A helper class that provides methods to parse Redis info strings into structured data.
+/// </summary>
+/// <remarks>
+/// See <see href="https://redis.io/docs/latest/commands/info/#return-information"/> for details about the format of the info command output.
+/// </remarks>
+internal static class InfoDetailsParser
+{
+    private const string LineSeparator = "\r\n";
+
+    /// <summary>
+    /// Parses the given info string into a flat list of tuples, where each tuple contains the section name, key, and value.
+    /// </summary>
+    /// <param name="info"></param>
+    /// <returns></returns>
+    public static List<(string Section, string Key, string Value)> ParseAsFlatRows(ReadOnlySpan<char> info)
+    {
+        List<(string Section, string Key, string Value)> rows = [];
+
+        var currentSection = string.Empty;
+#if NET9_0_OR_GREATER
+        foreach (var r in info.Split(LineSeparator))
+        {
+            var line = info[r].Trim();
+            if (line.IsEmpty)
+                continue;
+
+            if (TryParseSection(line, out var section))
+                currentSection = section;
+            else if (TryParseDetail(line, out var detail))
+                rows.Add((currentSection, detail.Key, detail.Value));
+        }
+#else
+        var start = 0;
+        while (start < info.Length)
+        {
+            var end = info[start..].IndexOf(LineSeparator);
+            ReadOnlySpan<char> line;
+            if (end < 0)
+            {
+                line = info[start..].Trim();
+                start = info.Length;
+            }
+            else
+            {
+                line = info[start..(start + end)].Trim();
+                start += end + LineSeparator.Length;
+            }
+
+            if (line.IsEmpty)
+                continue;
+
+            if (TryParseSection(line, out var section))
+                currentSection = section;
+            else if (TryParseDetail(line, out var detail))
+                rows.Add((currentSection, detail.Key, detail.Value));
+        }
+
+#endif
+        return rows;
+    }
+
+    /// <summary>
+    /// Parses the given info string into a dictionary of key-value pairs. Ingore section.
+    /// </summary>
+    /// <param name="info"></param>
+    /// <returns></returns>
+    public static Dictionary<string, string> ParseAsDictionary(ReadOnlySpan<char> info)
+    {
+        var dict = new Dictionary<string, string>(StringComparer.Ordinal);
+
+        // No need to trim the line, as TryParseDetail will handle it
+#if NET9_0_OR_GREATER
+        foreach (var r in info.Split(LineSeparator))
+        {
+            var line = info[r];
+            if (TryParseDetail(line, out var detail))
+                dict.TryAdd(detail.Key, detail.Value); // It's possible that `INFO` emits duplicate keys
+        }
+#else
+        var start = 0;
+        while (start < info.Length)
+        {
+            var end = info[start..].IndexOf(LineSeparator);
+            ReadOnlySpan<char> line;
+            if (end < 0)
+            {
+                line = info[start..];
+                start = info.Length;
+            }
+            else
+            {
+                line = info[start..(start + end)];
+                start += end + LineSeparator.Length;
+            }
+
+            if (TryParseDetail(line, out var detail))
+                dict.TryAdd(detail.Key, detail.Value); // It's possible that `INFO` emits duplicate keys
+        }
+
+#endif
+        return dict;
+    }
+
+    private static bool TryParseSection(ReadOnlySpan<char> line, out string section)
+    {
+        section = string.Empty;
+
+        if (line[0] != '#')
+            return false;
+
+        section = new(line[1..].Trim());
+        return true;
+    }
+
+    private static bool TryParseDetail(ReadOnlySpan<char> line, out KeyValuePair<string, string> detail)
+    {
+        var idx = line.IndexOf(':');
+        if (idx <= 0)
+        {
+            detail = default;
+            return false;
+        }
+
+        var key = new string(line[..idx].Trim());
+        var value = new string(line[(idx + 1)..].Trim());
+        detail = new(key, value);
+        return true;
+    }
+}

src/core/StackExchange.Redis.Extensions.Core/Implementations/RedisDatabase.cs

@@ -22,6 +22,9 @@ namespace StackExchange.Redis.Extensions.Core.Implementations;
 /// <inheritdoc/>
 public partial class RedisDatabase : IRedisDatabase
 {
+    private const string InfoScript = "return redis.call('INFO')";
+    private const string InfoSectionScript = "return redis.call('INFO', ARGV[1])";
+
     private readonly IRedisConnectionPoolManager connectionPoolManager;
     private readonly ServerEnumerationStrategy serverEnumerationStrategy;
     private readonly string keyPrefix;
@@ -559,21 +562,38 @@ public Task SaveAsync(SaveType saveType, CommandFlags flag = CommandFlags.None)
     /// <inheritdoc/>
     public async Task<Dictionary<string, string>> GetInfoAsync()
     {
-        var info = (await Database.ScriptEvaluateAsync("return redis.call('INFO')").ConfigureAwait(false)).ToString();
+        var info = (await Database.ScriptEvaluateAsync(InfoScript).ConfigureAwait(false)).ToString();
 
-        return string.IsNullOrEmpty(info)
-            ? new Dictionary<string, string>()
-            : ParseInfo(info);
+        return InfoDetailsParser.ParseAsDictionary(info);
+    }
+
+    /// <inheritdoc/>
+    public async Task<Dictionary<string, string>> GetInfoAsync(string section)
+    {
+        if (string.IsNullOrWhiteSpace(section))
+            return await GetInfoAsync().ConfigureAwait(false);
+
+        var info = (await Database.ScriptEvaluateAsync(InfoSectionScript, values: [section]).ConfigureAwait(false)).ToString();
+        return InfoDetailsParser.ParseAsDictionary(info);
     }
 
     /// <inheritdoc/>
     public async Task<InfoDetail[]> GetInfoCategorizedAsync()
     {
-        var info = (await Database.ScriptEvaluateAsync("return redis.call('INFO')").ConfigureAwait(false)).ToString();
+        var info = (await Database.ScriptEvaluateAsync(InfoScript).ConfigureAwait(false)).ToString();
 
-        return string.IsNullOrEmpty(info)
-            ? []
-            : ParseCategorizedInfo(info);
+        return InfoDetail.ParseFrom(info);
+    }
+
+    /// <inheritdoc/>
+    public async Task<InfoDetail[]> GetInfoCategorizedAsync(string section)
+    {
+        if (string.IsNullOrWhiteSpace(section))
+            return await GetInfoCategorizedAsync().ConfigureAwait(false);
+
+        var info = (await Database.ScriptEvaluateAsync(InfoSectionScript, values: [section]).ConfigureAwait(false)).ToString();
+
+        return InfoDetail.ParseFrom(info);
     }
 
     /// <inheritdoc/>
@@ -614,29 +634,4 @@ public Task<RedisType> KeyTypeAsync(string key, CommandFlags flag = CommandFlags
     /// <inheritdoc/>
     public Task KeyRestoreAsync(string key, byte[] value, TimeSpan? expiry = null, CommandFlags flag = CommandFlags.None)
         => Database.KeyRestoreAsync(key, value, expiry, flag);
-
-    private static Dictionary<string, string> ParseInfo(string info)
-    {
-        // Call Parse Categorized Info to cut back on duplicated code.
-        var data = ParseCategorizedInfo(info);
-
-        // Return a dictionary of the Info Key and Info value
-
-        var result = new Dictionary<string, string>(data.Length);
-
-        foreach (var detail in data)
-            result.TryAdd(detail.Key, detail.InfoValue);
-
-        return result;
-    }
-
-    private static InfoDetail[] ParseCategorizedInfo(string info)
-    {
-        var data = new List<InfoDetail>();
-        var category = string.Empty;
-
-        info.AsSpan().EnumerateLines(ref data, ref category);
-
-        return [.. data];
-    }
 }

src/core/StackExchange.Redis.Extensions.Core/Models/InfoDetail.cs

@@ -1,37 +1,45 @@
 // Copyright (c) Ugo Lattanzi.  All Rights Reserved.  Licensed under the MIT license.  See License.txt in the project root for license information.
 
+using StackExchange.Redis.Extensions.Core.Helpers;
+
 namespace StackExchange.Redis.Extensions.Core.Models;
 
 /// <summary>
 /// A class that contains redis info.
 /// </summary>
-public class InfoDetail
+/// <param name="category">The category name.</param>
+/// <param name="key">The redis key.</param>
+/// <param name="infoValue">The information</param>
+public class InfoDetail(string category, string key, string infoValue)
 {
-    /// <summary>
-    /// Initializes a new instance of the <see cref="InfoDetail"/> class.
-    /// </summary>
-    /// <param name="category">The category name.</param>
-    /// <param name="key">The redis key.</param>
-    /// <param name="infoValue">The information</param>
-    public InfoDetail(string category, string key, string infoValue)
-    {
-        Category = category;
-        Key = key;
-        InfoValue = infoValue;
-    }
-
     /// <summary>
     /// Gets or sets the category name
     /// </summary>
-    public string Category { get; }
+    public string Category { get; } = category;
 
     /// <summary>
     /// Gets or sets the redis key.
     /// </summary>
-    public string Key { get; }
+    public string Key { get; } = key;
 
     /// <summary>
     /// Gets or sets the informations.
     /// </summary>
-    public string InfoValue { get; }
+    public string InfoValue { get; } = infoValue;
+
+    internal static InfoDetail[] ParseFrom(string? info)
+    {
+        var rows = InfoDetailsParser.ParseAsFlatRows(info);
+        if (rows.Count < 1)
+            return [];
+
+        var details = new InfoDetail[rows.Count];
+        for (var i = 0; i < rows.Count; i++)
+        {
+            var (category, key, val) = rows[i];
+            details[i] = new(category, key, val);
+        }
+
+        return details;
+    }
 }