private readonly PackedResourceLoader _loader;

private readonly IDictionary<string, PackedResourceInfo> _unpackedLibrary;

private readonly IDictionary<string, PackedResourceInfo[]> _unpackedModules;

private readonly string _unpackingError;

private static readonly Dictionary<string, ModuleCodeType> SearchOrder;

[Flags]

private enum ModuleCodeType {

Source = 0,

//ByteCode,

Package,

}

static ResourceMetaPathImporter() {

// we currently don't support bytecode, so just include the source versions.

SearchOrder = new Dictionary<string, ModuleCodeType> {

{

Path.DirectorySeparatorChar + "__init__.py",

ModuleCodeType.Package |

ModuleCodeType.Source

},

{".py", ModuleCodeType.Source},

};

}

/// <summary>

/// Instantiates a new meta_path importer using an embedded ZIP resource file.

/// </summary>

/// <param name="fromAssembly"></param>

/// <param name="resourceName"></param>

public ResourceMetaPathImporter(Assembly fromAssembly, string resourceName) {

_loader = new PackedResourceLoader(fromAssembly, resourceName);

if (_loader.LoadZipDirectory(out _unpackedLibrary, out _unpackedModules,

out _unpackingError))

return;

_unpackedLibrary = new Dictionary<string, PackedResourceInfo>();

_unpackedModules = new Dictionary<string, PackedResourceInfo[]>();

if (!String.IsNullOrEmpty(_unpackingError))

throw MakeError("meta_path importer initialization error: {0}", _unpackingError);

}

[Documentation(

@"find_module(fullname, path=None) -> self or None.

)]

public object find_module(CodeContext /*!*/ context, string fullname, params object[] args) {

var packedName = MakeFilename(fullname);

foreach (var entry in SearchOrder) {

var temp = packedName + entry.Key;

if (_unpackedLibrary.ContainsKey(temp))

return this;

}

return null;

}

[Documentation(

@"load_module(fullname) -> module.

)]

public object load_module(CodeContext /*!*/ context, string fullname) {

var modules = context.LanguageContext.SystemStateModules;

if (modules.TryGetValue(fullname, out var module))

return module;

bool ispackage;

string modpath;

var code = GetModuleCode(context, fullname, out ispackage, out modpath);

if (code == null)

return null;

var pythonContext = context.LanguageContext;

ScriptCode script;

var mod = pythonContext.CompileModule(modpath, fullname,

new SourceUnit(pythonContext,

new MemoryStreamContentProvider(pythonContext, code, modpath),

modpath, SourceCodeKind.File),

ModuleOptions.None, out script);

var dict = mod.__dict__;

// we do these here because we don't want CompileModule to initialize the module until we've set

// up some additional stuff

dict.Add("__name__", fullname);

dict.Add("__loader__", this);

// ReSharper disable AssignNullToNotNullAttribute

dict.Add("__package__", null);

// ReSharper restore AssignNullToNotNullAttribute

dict.Add("__file__", "<resource>");

if (ispackage) {

//// add __path__ to the module *before* the code

//// gets executed

//var subname = GetSubName(fullname);

//var fullpath = string.Format("{0}{1}",

// Path.DirectorySeparatorChar,

// subname);

//var pkgpath = PythonOps.MakeList(fullpath);

var pkgpath = new PythonList();

dict.Add("__path__", pkgpath);

}

modules.Add(fullname, mod);

try {

script.Run(mod.Scope);

}

catch (Exception) {

modules.Remove(fullname);

throw;

}

return mod;

}

private byte[] GetModuleCode(CodeContext /*!*/ context, string fullname, out bool ispackage,

out string modpath) {

var path = MakeFilename(fullname);

ispackage = false;

modpath = string.Empty;

if (String.IsNullOrEmpty(path))

return null;

foreach (var entry in SearchOrder) {

var temp = path + entry.Key;

if (!_unpackedLibrary.ContainsKey(temp))

continue;

var tocEntry = _unpackedLibrary[temp];

ispackage = (entry.Value & ModuleCodeType.Package) == ModuleCodeType.Package;

// we currently don't support bytecode modules, so we don't check

// the time of the bytecode file vs. the time of the source file.

byte[] code = GetCodeFromData(context, false, tocEntry);

if (code == null) {

continue;

}

modpath = tocEntry.FullName;

return code;

}

throw MakeError("can't find module '{0}'", fullname);

}

private byte[] GetCodeFromData(CodeContext /*!*/ context, bool isbytecode, PackedResourceInfo tocEntry) {

byte[] data = GetData(tocEntry);

byte[] code = null;

if (data != null) {

if (isbytecode) {

// would put in code to unmarshal the bytecode here...

}

else {

code = data;

}

}

return code;

}

private byte[] GetData(PackedResourceInfo tocEntry) {

string unpackingError;

byte[] result;

if (!_loader.GetData(tocEntry, out result, out unpackingError))

throw MakeError(unpackingError);

return result;

}

private static Exception MakeError(params object[] args) {

return IronPython.Runtime.Operations.PythonOps.CreateThrowable(PythonExceptions.ImportError, args);

}

private static string MakeFilename(string name) {

return name.Replace('.', Path.DirectorySeparatorChar);

}

private struct PackedResourceInfo {

private int _fileSize;

public string FullName;

public int Compress;

public int DataSize;

public int FileOffset;

public static PackedResourceInfo Create(string fullName, int compress,

int dataSize, int fileSize, int fileOffset) {

PackedResourceInfo result;

result.FullName = fullName;

result.Compress = compress;

result.DataSize = dataSize;

result._fileSize = fileSize;

result.FileOffset = fileOffset;

return result;

}

#if DEBUG

public override string ToString() {

var sizeDesc = String.Format("{0} bytes", _fileSize);

if (Convert.ToDouble(_fileSize)/1024.0 > 1.0)

sizeDesc = String.Format("{0} KB", Math.Round(Convert.ToDouble(_fileSize)/1024.0, 1));

return String.Format("{0} ({1})", FullName, sizeDesc);

}

#endif

}

private class PackedResourceLoader {

private readonly Assembly _fromAssembly;

private readonly string _resourceNameBase;

private const int MaxPathLen = 256;

public PackedResourceLoader(Assembly fromAssembly, string resourceName) {

_fromAssembly = fromAssembly;

_resourceNameBase = resourceName;

}

public bool LoadZipDirectory(

out IDictionary<string, PackedResourceInfo> files,

out IDictionary<string, PackedResourceInfo[]> modules,

out string unpackingError) {

if (!ReadZipDirectory(out files, out unpackingError)) {

modules = null;

return false;

}

try {

var parsedSources =

from entry in files.Values

let isPyFile = entry.FullName.EndsWith(".py", StringComparison.OrdinalIgnoreCase)

where isPyFile

let name = entry.FullName.Substring(0, entry.FullName.Length - 3)

let dottedName = name.Replace('\\', '.').Replace('/', '.')

let lineage = dottedName.Split('.')

let fileName = lineage.Last()

let path = lineage.Take(lineage.Length - 1).ToArray()

orderby fileName

select new {

name = fileName,

path,

dottedPath = String.Join(".", path),

entry

};

var moduleContents =

from source in parsedSources

orderby source.dottedPath

group source by source.dottedPath

into moduleGroup

select new {

moduleGroup.Key,

Items = moduleGroup.Select(item => item.entry).ToArray()

};

modules = moduleContents.ToDictionary(

moduleGroup => moduleGroup.Key,

moduleGroup => moduleGroup.Items);

return true;

}

catch (Exception exception) {

files = null;

modules = null;

unpackingError = String.Format("{0}: {1}", exception.GetType().Name, exception.Message);

return false;

}

}

private Stream GetZipArchive() {

var fullResourceName = _fromAssembly.GetManifestResourceNames().Where(name => name.EndsWith(_resourceNameBase, StringComparison.OrdinalIgnoreCase)).FirstOrDefault();

return string.IsNullOrEmpty(fullResourceName) ? null : _fromAssembly.GetManifestResourceStream(fullResourceName);

}

private bool ReadZipDirectory(out IDictionary<string, PackedResourceInfo> result,

out string unpackingError) {

unpackingError = null;

result = null;

try {

var stream = GetZipArchive();

if (stream == null) {

unpackingError = "Resource not found.";

return false;

}

using (var reader = new BinaryReader(stream)) {

if (reader.BaseStream.Length < 2) {

unpackingError = "Can't read ZIP resource: Empty Resource.";

return false;

}

var endofCentralDir = new byte[22];

reader.BaseStream.Seek(-22, SeekOrigin.End);

var headerPosition = (int) reader.BaseStream.Position;

if (reader.Read(endofCentralDir, 0, 22) != 22) {

unpackingError = "Can't read ZIP resource: Invalid ZIP Directory.";

return false;

}

if (BitConverter.ToUInt32(endofCentralDir, 0) != 0x06054B50) {

// Bad: End of Central Dir signature

unpackingError = "Can't read ZIP resource: Not a ZIP file.";

return false;

}

var headerSize = BitConverter.ToInt32(endofCentralDir, 12);

var headerOffset = BitConverter.ToInt32(endofCentralDir, 16);

var arcOffset = headerPosition - headerOffset - headerSize;

headerOffset += arcOffset;

var directoryEntries = ReadZipDirectory(reader, headerOffset, arcOffset);

result = directoryEntries

.OrderBy(entry => entry.FullName)

.ToDictionary(entry => entry.FullName);

return true;

}

}

catch (Exception exception) {

unpackingError = String.Format("{0}: {1}", exception.GetType().Name, exception.Message);

return false;

}

}

private static IEnumerable<PackedResourceInfo> ReadZipDirectory(BinaryReader reader, int headerOffset,

int arcoffset) {

while (true) {

var name = string.Empty;

reader.BaseStream.Seek(headerOffset, SeekOrigin.Begin); // Start of file header

int l = reader.ReadInt32();

if (l != 0x02014B50) {

break; // Bad: Central Dir File Header

}

reader.BaseStream.Seek(headerOffset + 10, SeekOrigin.Begin);

var compress = reader.ReadInt16();

/*var time =*/

reader.ReadInt16();

/*var date =*/

reader.ReadInt16();

/*var crc =*/

reader.ReadInt32();

var dataSize = reader.ReadInt32();

var fileSize = reader.ReadInt32();

var nameSize = reader.ReadInt16();

var headerSize = 46 + nameSize +

reader.ReadInt16() +

reader.ReadInt16();

reader.BaseStream.Seek(headerOffset + 42, SeekOrigin.Begin);

var fileOffset = reader.ReadInt32() + arcoffset;

if (nameSize > MaxPathLen)

nameSize = MaxPathLen;

for (int i = 0; i < nameSize; i++) {

char c = reader.ReadChar();

if (c == '/')

c = Path.DirectorySeparatorChar;

name += c;

}

headerOffset += headerSize;

yield return

PackedResourceInfo.Create(name, compress, dataSize, fileSize, fileOffset);

}

}

public bool GetData(PackedResourceInfo tocEntry, out byte[] result, out string unpackingError) {

unpackingError = null;

result = null;

var fileOffset = tocEntry.FileOffset;

var dataSize = tocEntry.DataSize;

var compress = tocEntry.Compress;

try {

var stream = GetZipArchive();

if (stream == null) {

unpackingError = "Resource not found.";

return false;

}

using (var reader = new BinaryReader(stream)) {

// Check to make sure the local file header is correct

reader.BaseStream.Seek(fileOffset, SeekOrigin.Begin);

var l = reader.ReadInt32();

if (l != 0x04034B50) {

// Bad: Local File Header

unpackingError = "Bad local file header in ZIP resource.";

return false;

}

reader.BaseStream.Seek(fileOffset + 26, SeekOrigin.Begin);

l = 30 + reader.ReadInt16() + reader.ReadInt16(); // local header size

fileOffset += l; // start of file data

reader.BaseStream.Seek(fileOffset, SeekOrigin.Begin);

byte[] rawData;

try {

rawData = reader.ReadBytes(compress == 0 ? dataSize : dataSize + 1);

}

catch {

unpackingError = "Can't read data";

return false;

}

if (compress != 0) {

rawData[dataSize] = (byte) 'Z';

}

result = compress == 0 ? rawData : ZlibModule.Decompress(rawData, -15);

return true;

}

}

catch (Exception exception) {

unpackingError = String.Format("{0}: {1}", exception.GetType().Name, exception.Message);

return false;

}

}

}