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Diffstat (limited to 'netcore/System.Private.CoreLib/shared/System/IO/PathHelper.Windows.cs')
| -rw-r--r-- | netcore/System.Private.CoreLib/shared/System/IO/PathHelper.Windows.cs | 251 |
1 files changed, 0 insertions, 251 deletions
diff --git a/netcore/System.Private.CoreLib/shared/System/IO/PathHelper.Windows.cs b/netcore/System.Private.CoreLib/shared/System/IO/PathHelper.Windows.cs deleted file mode 100644 index abf5c346148..00000000000 --- a/netcore/System.Private.CoreLib/shared/System/IO/PathHelper.Windows.cs +++ /dev/null @@ -1,251 +0,0 @@ -// Licensed to the .NET Foundation under one or more agreements. -// The .NET Foundation licenses this file to you under the MIT license. -// See the LICENSE file in the project root for more information. - -#nullable enable -using System.Diagnostics; -using System.Runtime.InteropServices; -using System.Text; - -namespace System.IO -{ - /// <summary> - /// Wrapper to help with path normalization. - /// </summary> - internal static class PathHelper - { - /// <summary> - /// Normalize the given path. - /// </summary> - /// <remarks> - /// Normalizes via Win32 GetFullPathName(). - /// </remarks> - /// <param name="path">Path to normalize</param> - /// <exception cref="PathTooLongException">Thrown if we have a string that is too large to fit into a UNICODE_STRING.</exception> - /// <exception cref="IOException">Thrown if the path is empty.</exception> - /// <returns>Normalized path</returns> - internal static string Normalize(string path) - { - var builder = new ValueStringBuilder(stackalloc char[PathInternal.MaxShortPath]); - - // Get the full path - GetFullPathName(path.AsSpan(), ref builder); - - // If we have the exact same string we were passed in, don't allocate another string. - // TryExpandShortName does this input identity check. - string result = builder.AsSpan().IndexOf('~') >= 0 - ? TryExpandShortFileName(ref builder, originalPath: path) - : builder.AsSpan().Equals(path.AsSpan(), StringComparison.Ordinal) ? path : builder.ToString(); - - // Clear the buffer - builder.Dispose(); - return result; - } - - /// <summary> - /// Normalize the given path. - /// </summary> - /// <remarks> - /// Exceptions are the same as the string overload. - /// </remarks> - internal static string Normalize(ref ValueStringBuilder path) - { - var builder = new ValueStringBuilder(stackalloc char[PathInternal.MaxShortPath]); - - // Get the full path - GetFullPathName(path.AsSpan(terminate: true), ref builder); - - string result = builder.AsSpan().IndexOf('~') >= 0 - ? TryExpandShortFileName(ref builder, originalPath: null) - : builder.ToString(); - - // Clear the buffer - builder.Dispose(); - return result; - } - - /// <summary> - /// Calls GetFullPathName on the given path. - /// </summary> - /// <param name="path">The path name. MUST be null terminated after the span.</param> - /// <param name="builder">Builder that will store the result.</param> - private static void GetFullPathName(ReadOnlySpan<char> path, ref ValueStringBuilder builder) - { - // If the string starts with an extended prefix we would need to remove it from the path before we call GetFullPathName as - // it doesn't root extended paths correctly. We don't currently resolve extended paths, so we'll just assert here. - Debug.Assert(PathInternal.IsPartiallyQualified(path) || !PathInternal.IsExtended(path)); - - uint result; - while ((result = Interop.Kernel32.GetFullPathNameW(ref MemoryMarshal.GetReference(path), (uint)builder.Capacity, ref builder.GetPinnableReference(), IntPtr.Zero)) > builder.Capacity) - { - // Reported size is greater than the buffer size. Increase the capacity. - builder.EnsureCapacity(checked((int)result)); - } - - if (result == 0) - { - // Failure, get the error and throw - int errorCode = Marshal.GetLastWin32Error(); - if (errorCode == 0) - errorCode = Interop.Errors.ERROR_BAD_PATHNAME; - throw Win32Marshal.GetExceptionForWin32Error(errorCode, path.ToString()); - } - - builder.Length = (int)result; - } - - internal static int PrependDevicePathChars(ref ValueStringBuilder content, bool isDosUnc, ref ValueStringBuilder buffer) - { - int length = content.Length; - - length += isDosUnc - ? PathInternal.UncExtendedPrefixLength - PathInternal.UncPrefixLength - : PathInternal.DevicePrefixLength; - - buffer.EnsureCapacity(length + 1); - buffer.Length = 0; - - if (isDosUnc) - { - // Is a \\Server\Share, put \\?\UNC\ in the front - buffer.Append(PathInternal.UncExtendedPathPrefix); - - // Copy Server\Share\... over to the buffer - buffer.Append(content.AsSpan(PathInternal.UncPrefixLength)); - - // Return the prefix difference - return PathInternal.UncExtendedPrefixLength - PathInternal.UncPrefixLength; - } - else - { - // Not an UNC, put the \\?\ prefix in front, then the original string - buffer.Append(PathInternal.ExtendedPathPrefix); - buffer.Append(content.AsSpan()); - return PathInternal.DevicePrefixLength; - } - } - - internal static string TryExpandShortFileName(ref ValueStringBuilder outputBuilder, string? originalPath) - { - // We guarantee we'll expand short names for paths that only partially exist. As such, we need to find the part of the path that actually does exist. To - // avoid allocating a lot we'll create only one input array and modify the contents with embedded nulls. - - Debug.Assert(!PathInternal.IsPartiallyQualified(outputBuilder.AsSpan()), "should have resolved by now"); - - // We'll have one of a few cases by now (the normalized path will have already: - // - // 1. Dos path (C:\) - // 2. Dos UNC (\\Server\Share) - // 3. Dos device path (\\.\C:\, \\?\C:\) - // - // We want to put the extended syntax on the front if it doesn't already have it (for long path support and speed), which may mean switching from \\.\. - // - // Note that we will never get \??\ here as GetFullPathName() does not recognize \??\ and will return it as C:\??\ (or whatever the current drive is). - - int rootLength = PathInternal.GetRootLength(outputBuilder.AsSpan()); - bool isDevice = PathInternal.IsDevice(outputBuilder.AsSpan()); - - // As this is a corner case we're not going to add a stackalloc here to keep the stack pressure down. - ValueStringBuilder inputBuilder = default; - - bool isDosUnc = false; - int rootDifference = 0; - bool wasDotDevice = false; - - // Add the extended prefix before expanding to allow growth over MAX_PATH - if (isDevice) - { - // We have one of the following (\\?\ or \\.\) - inputBuilder.Append(outputBuilder.AsSpan()); - - if (outputBuilder[2] == '.') - { - wasDotDevice = true; - inputBuilder[2] = '?'; - } - } - else - { - isDosUnc = !PathInternal.IsDevice(outputBuilder.AsSpan()) && outputBuilder.Length > 1 && outputBuilder[0] == '\\' && outputBuilder[1] == '\\'; - rootDifference = PrependDevicePathChars(ref outputBuilder, isDosUnc, ref inputBuilder); - } - - rootLength += rootDifference; - int inputLength = inputBuilder.Length; - - bool success = false; - int foundIndex = inputBuilder.Length - 1; - - while (!success) - { - uint result = Interop.Kernel32.GetLongPathNameW( - ref inputBuilder.GetPinnableReference(terminate: true), ref outputBuilder.GetPinnableReference(), (uint)outputBuilder.Capacity); - - // Replace any temporary null we added - if (inputBuilder[foundIndex] == '\0') inputBuilder[foundIndex] = '\\'; - - if (result == 0) - { - // Look to see if we couldn't find the file - int error = Marshal.GetLastWin32Error(); - if (error != Interop.Errors.ERROR_FILE_NOT_FOUND && error != Interop.Errors.ERROR_PATH_NOT_FOUND) - { - // Some other failure, give up - break; - } - - // We couldn't find the path at the given index, start looking further back in the string. - foundIndex--; - - for (; foundIndex > rootLength && inputBuilder[foundIndex] != '\\'; foundIndex--) ; - if (foundIndex == rootLength) - { - // Can't trim the path back any further - break; - } - else - { - // Temporarily set a null in the string to get Windows to look further up the path - inputBuilder[foundIndex] = '\0'; - } - } - else if (result > outputBuilder.Capacity) - { - // Not enough space. The result count for this API does not include the null terminator. - outputBuilder.EnsureCapacity(checked((int)result)); - } - else - { - // Found the path - success = true; - outputBuilder.Length = checked((int)result); - if (foundIndex < inputLength - 1) - { - // It was a partial find, put the non-existent part of the path back - outputBuilder.Append(inputBuilder.AsSpan(foundIndex, inputBuilder.Length - foundIndex)); - } - } - } - - // If we were able to expand the path, use it, otherwise use the original full path result - ref ValueStringBuilder builderToUse = ref (success ? ref outputBuilder : ref inputBuilder); - - // Switch back from \\?\ to \\.\ if necessary - if (wasDotDevice) - builderToUse[2] = '.'; - - // Change from \\?\UNC\ to \\?\UN\\ if needed - if (isDosUnc) - builderToUse[PathInternal.UncExtendedPrefixLength - PathInternal.UncPrefixLength] = '\\'; - - // Strip out any added characters at the front of the string - ReadOnlySpan<char> output = builderToUse.AsSpan(rootDifference); - - string returnValue = ((originalPath != null) && output.Equals(originalPath.AsSpan(), StringComparison.Ordinal)) - ? originalPath : output.ToString(); - - inputBuilder.Dispose(); - return returnValue; - } - } -} |