/// <summary>
/// Saves a tree to a file.
/// </summary>
///
/// <exception cref="System.ArgumentNullException">Thrown if `root` is null.</exception>
/// <exception cref="System.IO.IOException">Thrown if `overwrite` is false, and a tree called `name` already exists.</exception>
///
/// <param name="name">The name to give the tree.</param>
/// <param name="root">The root node of the tree.</param>
/// <param name="overwrite">
/// If True, then if a tree called 'name' already exists, it is overwritten.
/// If False, then an IOException is thrown if a tree called 'name' already exists.
/// </param>
public static void saveTree(string name, Node root, bool overwrite = true)
{
if (root == null)
{
throw new ArgumentNullException("root");
}
if (!overwrite && GameFiles.treeExists(name))
{
throw new IOException($"Unable to save tree {name} as it already exists, and overwrite is set to false.");
}
// Make sure the tree directory exists, then serialise `root` into a new tree file.
GameFiles.ensureDirectories();
using (var fs = new FileStream(GameFiles.makeTreePath(name), FileMode.Create))
{
using (var bw = new BinaryWriter(fs))
{
/*
* Format:
* [4 bytes, 'TREE']
* [1 byte, file version]
* [X bytes, serialised tree]
* */
bw.Write((char[])GameFiles._treeFileHeader.ToCharArray());
bw.Write((byte)GameFiles.treeFileVersion);
root.serialise(bw);
}
}
}
/// <summary>
/// Removes a tree with a specific name.
/// </summary>
///
/// <exception cref="System.IO.FileNotFoundException">Thrown if `shouldThrow` is true, and a tree called `name` does not exist.</exception>
///
/// <param name="name">The name of the tree to remove</param>
/// <param name="shouldThrow">If True, then this function will throw a FileError if the tree does not exist.</param>
public static void removeTree(string name, bool shouldThrow = false)
{
if (shouldThrow && !GameFiles.treeExists(name))
{
throw new FileNotFoundException("Could not remove tree as it does not exist.", GameFiles.makeTreePath(name));
}
File.Delete(GameFiles.makeTreePath(name));
}
/// <summary>
/// Loads a previously saved tree.
/// </summary>
///
/// <exception cref="System.IO.FileNotFoundException">Thrown if a tree called `name` doesn't exist.</exception>
/// <exception cref="System.IO.IOException">Thrown if the tree file is malformed in some way, and cannot be loaded.</exception>
///
/// <param name="name">The name of the tree to load.</param>
/// <param name="shouldThrow">If True, then an exception is thrown if 'name' doesn't exist.</param>
///
/// <returns>
/// The root node of the tree saved as 'name'.
/// Null is returned if 'shouldThrow' is False, and 'name' doesn't exist.
/// </returns>
public static Node loadTree(string name, bool shouldThrow = true)
{
try
{
if (!GameFiles.treeExists(name))
{
throw new FileNotFoundException($"Unable to load tree {name} as it does not exist.", GameFiles.makeTreePath(name));
}
using (var fs = new FileStream(GameFiles.makeTreePath(name), FileMode.Open))
{
using (var br = new BinaryReader(fs))
{
// Make sure the header is correct
string header = new string(br.ReadChars(GameFiles._treeFileHeader.Length));
if (header != GameFiles._treeFileHeader)
{
throw new IOException($"Unable to load tree {name} as it's header is incorrect: '{header}'");
}
// Then read in the version number, and make sure we can read it in.
byte version = br.ReadByte();
if (version > GameFiles.treeFileVersion)
{
throw new IOException($"Unable to load tree {name} as it uses a newer version of the TREE format.\n"
+ $"File version: {version} | Highest Supported version: {GameFiles.treeFileVersion}");
}
// Then unserialise the tree.
var root = Node.root;
root.deserialise(br, version);
return(root);
}
}
}
catch (Exception ex)
{
if (shouldThrow)
{
throw ex;
}
return(null);
}
}
/// <summary>
/// Determines whether a tree with a specific name exists.
/// </summary>
///
/// <param name="name">The name of the tree to search for.</param>
///
/// <returns>True if the tree exists. False otherwise.</returns>
public static bool treeExists(string name)
{
return(File.Exists(GameFiles.makeTreePath(name)));
}
