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* Copyright by the contributors to the Dafny Project
* SPDX-License-Identifier: MIT
*******************************************************************************/
namespace DafnyLibraries
{
using System;
using System.IO;
using Dafny;
public class FileIO
{
/// <summary>
/// Attempts to read all bytes from the file at the given path, and outputs the following values:
/// <list>
/// <item>
/// <term>isError</term>
/// <description>
/// true iff an exception was thrown during path string conversion or when reading the file
/// </description>
/// </item>
/// <item>
/// <term>bytesRead</term>
/// <description>
/// the sequence of bytes read from the file, or an empty sequence if <c>isError</c> is true
/// </description>
/// </item>
/// <item>
/// <term>errorMsg</term>
/// <description>
/// the error message of the thrown exception if <c>isError</c> is true, or an empty sequence otherwise
/// </description>
/// </item>
/// </list>
///
/// We output these values individually because Result is not defined in the runtime but instead in library code.
/// It is the responsibility of library code to construct an equivalent Result value.
/// </summary>
public static void INTERNAL_ReadBytesFromFile(ISequence<char> path, out bool isError, out ISequence<byte> bytesRead,
out ISequence<char> errorMsg)
{
isError = true;
bytesRead = Sequence<byte>.Empty;
errorMsg = Sequence<char>.Empty;
try
{
bytesRead = Helpers.SeqFromArray(File.ReadAllBytes(path?.ToString()));
isError = false;
}
catch (Exception e)
{
errorMsg = Helpers.SeqFromArray(e.ToString().ToCharArray());
}
}
/// <summary>
/// Attempts to write all given bytes to the file at the given path, creating nonexistent parent directories as necessary,
/// and outputs the following values:
/// <list>
/// <item>
/// <term>isError</term>
/// <description>
/// true iff an exception was thrown during path string conversion or when writing to the file
/// </description>
/// </item>
/// <item>
/// <term>errorMsg</term>
/// <description>
/// the error message of the thrown exception if <c>isError</c> is true, or an empty sequence otherwise
/// </description>
/// </item>
/// </list>
///
/// We output these values individually because Result is not defined in the runtime but instead in library code.
/// It is the responsibility of library code to construct an equivalent Result value.
/// </summary>
public static void INTERNAL_WriteBytesToFile(ISequence<char> path, ISequence<byte> bytes, out bool isError, out ISequence<char> errorMsg)
{
isError = true;
errorMsg = Sequence<char>.Empty;
try
{
string pathStr = path?.ToString();
CreateParentDirs(pathStr);
File.WriteAllBytes(pathStr, bytes.CloneAsArray());
isError = false;
}
catch (Exception e)
{
errorMsg = Helpers.SeqFromArray(e.ToString().ToCharArray());
}
}
/// <summary>
/// Creates the nonexistent parent directory(-ies) of the given path.
/// </summary>
private static void CreateParentDirs(string path)
{
string parentDir = Path.GetDirectoryName(Path.GetFullPath(path));
Directory.CreateDirectory(parentDir);
}
}
}
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