Add TryOpenStream/Storage

ironfede · Nov 17, 2024 · 17626c3 · 17626c3
1 parent 6feff0f
commit 17626c3
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Showing 3 changed files with 59 additions and 22 deletions.
diff --git a/OpenMcdf.Tests/StorageTests.cs b/OpenMcdf.Tests/StorageTests.cs
@@ -8,22 +8,25 @@ public sealed class StorageTests
     [DataRow("MultipleStorage2.cfs", 1)]
     [DataRow("MultipleStorage3.cfs", 1)]
     [DataRow("MultipleStorage4.cfs", 1)]
-    [System.Diagnostics.CodeAnalysis.SuppressMessage("Style", "IDE0063:Use simple 'using' statement", Justification = "Conditional build")]
-    public void Read(string fileName, long storageCount)
+    public void EnumerateEntries(string fileName, long storageCount)
     {
-        using (var rootStorage = RootStorage.OpenRead(fileName))
-        {
-            IEnumerable<EntryInfo> storageEntries = rootStorage.EnumerateEntries();
-            Assert.AreEqual(storageCount, storageEntries.Count());
-        }
+        using var rootStorage = RootStorage.OpenRead(fileName);
+        IEnumerable<EntryInfo> storageEntries = rootStorage.EnumerateEntries();
+        Assert.AreEqual(storageCount, storageEntries.Count());
+    }
 
-#if WINDOWS
-        using (var rootStorage = StructuredStorage.Storage.Open(fileName))
-        {
-            IEnumerable<string> entries = rootStorage.EnumerateEntries();
-            Assert.AreEqual(storageCount, entries.Count());
-        }
-#endif
+    [TestMethod]
+    [DataRow("MultipleStorage.cfs")]
+    public void OpenStorage(string fileName)
+    {
+        using var rootStorage = RootStorage.OpenRead(fileName);
+        Assert.IsTrue(rootStorage.TryOpenStorage("MyStorage", out Storage? _));
+        Assert.IsFalse(rootStorage.TryOpenStorage("", out Storage? _));
+
+        Assert.ThrowsException<DirectoryNotFoundException>(() => rootStorage.OpenStorage(""));
+
+        Storage storage = rootStorage.OpenStorage("MyStorage");
+        Assert.AreEqual("MyStorage", storage.EntryInfo.Name);
     }
 
     [TestMethod]

diff --git a/OpenMcdf.Tests/StreamTests.cs b/OpenMcdf.Tests/StreamTests.cs
@@ -3,6 +3,20 @@
 [TestClass]
 public sealed class StreamTests
 {
+    [TestMethod]
+    [DataRow("TestStream_v3_0.cfs")]
+    public void OpenStream(string fileName)
+    {
+        using var rootStorage = RootStorage.OpenRead(fileName);
+        Assert.IsTrue(rootStorage.TryOpenStream("TestStream", out CfbStream? _));
+        Assert.IsFalse(rootStorage.TryOpenStream("", out CfbStream? _));
+
+        Assert.ThrowsException<FileNotFoundException>(() => rootStorage.OpenStream(""));
+
+        CfbStream stream = rootStorage.OpenStream("TestStream");
+        Assert.AreEqual("TestStream", stream.EntryInfo.Name);
+    }
+
     [TestMethod]
     [DataRow(Version.V3, 0)]
     [DataRow(Version.V3, 63)]

diff --git a/OpenMcdf/Storage.cs b/OpenMcdf/Storage.cs
@@ -1,4 +1,6 @@
-namespace OpenMcdf;
+using System.Diagnostics.CodeAnalysis;
+
+namespace OpenMcdf;
 
 /// <summary>
 /// An object in a compound file that is analogous to a file system directory.
@@ -114,28 +116,46 @@ public CfbStream CreateStream(string name)
     }
 
     public Storage OpenStorage(string name)
+        => TryOpenStorage(name, out Storage? storage)
+            ? storage!
+            : throw new DirectoryNotFoundException($"Storage not found: {name}.");
+
+    public bool TryOpenStorage(string name, [MaybeNullWhen(false)] out Storage? storage)
     {
         ThrowHelper.ThrowIfNameIsInvalid(name);
 
         this.ThrowIfDisposed(Context.IsDisposed);
 
-        directoryTree.TryGetDirectoryEntry(name, out DirectoryEntry? entry);
+        directoryTree.TryGetDirectoryEntry(name,  out DirectoryEntry? entry);
         if (entry is null || entry.Type is not StorageType.Storage)
-            throw new DirectoryNotFoundException($"Storage not found: {name}.");
-        return new Storage(ContextSite, entry, this);
+        {
+            storage = null;
+            return false;
+        }
+
+        storage = new Storage(ContextSite, entry, this);
+        return true;
     }
 
     public CfbStream OpenStream(string name)
+         => TryOpenStream(name, out CfbStream? stream)
+            ? stream!
+            : throw new FileNotFoundException($"Stream not found: {name}.", name);
+
+    public bool TryOpenStream(string name, [MaybeNullWhen(false)] out CfbStream? stream)
     {
         ThrowHelper.ThrowIfNameIsInvalid(name);
-
         this.ThrowIfDisposed(Context.IsDisposed);
-
         directoryTree.TryGetDirectoryEntry(name, out DirectoryEntry? entry);
+
         if (entry is null || entry.Type is not StorageType.Stream)
-            throw new FileNotFoundException($"Stream not found: {name}.", name);
+        {
+            stream = null;
+            return false;
+        }
 
-        return new CfbStream(ContextSite, entry, this);
+        stream = new CfbStream(ContextSite, entry, this);
+        return true;
     }
 
     public void CopyTo(Storage destination)