IncludeFileSystem -> DefaultFileSystem (#677)

Improvements in 'singleton'ness of DefaultFileSystem
Made WrapFileSystem a stand alone type - to remove 'odd' aspects of deriving from DefaultFileSystem (such as inheriting getSingleton method/fixing ref counting)
Simplified CompileRequest::loadFile - becauce fileSystemExt is always available.

1 files changed, 110 insertions, 0 deletions

diff --git a/source/slang/default-file-system.cpp b/source/slang/default-file-system.cpp
new file mode 100644
index 000000000..be171d37c
--- /dev/null
+++ b/source/slang/default-file-system.cpp
@@ -0,0 +1,110 @@
+#include "default-file-system.h"
+
+#include "../../slang-com-ptr.h"
+#include "../core/slang-io.h"
+#include "compiler.h"
+
+namespace Slang
+{
+
+// Allocate static const storage for the various interface IDs that the Slang API needs to expose
+static const Guid IID_ISlangUnknown = SLANG_UUID_ISlangUnknown;
+static const Guid IID_ISlangFileSystem = SLANG_UUID_ISlangFileSystem;
+static const Guid IID_ISlangFileSystemExt = SLANG_UUID_ISlangFileSystemExt;
+
+/* !!!!!!!!!!!!!!!!!!!!!!!!!! IncludeFileSystem !!!!!!!!!!!!!!!!!!!!!!!!!!!!!!*/
+
+/* static */DefaultFileSystem DefaultFileSystem::s_singleton; 
+
+ISlangUnknown* DefaultFileSystem::getInterface(const Guid& guid)
+{
+    return (guid == IID_ISlangUnknown || guid == IID_ISlangFileSystem || guid == IID_ISlangFileSystemExt) ? static_cast<ISlangFileSystemExt*>(this) : nullptr;
+}
+
+SlangResult DefaultFileSystem::getCanoncialPath(const char* path, ISlangBlob** canonicalPathOut)
+{
+    String canonicalPath;
+    SLANG_RETURN_ON_FAIL(Path::GetCanonical(path, canonicalPath));
+    
+    *canonicalPathOut = createStringBlob(canonicalPath).detach();
+    return SLANG_OK;
+}
+
+SlangResult DefaultFileSystem::calcRelativePath(SlangPathType fromPathType, const char* fromPath, const char* path, ISlangBlob** pathOut)
+{
+    String relPath;
+    switch (fromPathType)
+    {
+        case SLANG_PATH_TYPE_FILE:
+        {
+            relPath = Path::Combine(Path::GetDirectoryName(fromPath), path);
+            break;
+        }
+        case SLANG_PATH_TYPE_DIRECTORY:
+        {
+            relPath = Path::Combine(fromPath, path);
+            break;
+        }
+    }
+
+    *pathOut = createStringBlob(relPath).detach();
+    return SLANG_OK;
+}
+
+SlangResult DefaultFileSystem::loadFile(char const* path, ISlangBlob** outBlob)
+{
+    // Default implementation that uses the `core`
+    // libraries facilities for talking to the OS filesystem.
+    //
+    // TODO: we might want to conditionally compile these in, so that
+    // a user could create a build of Slang that doesn't include any OS
+    // filesystem calls.
+
+    if (!File::Exists(path))
+    {
+        return SLANG_E_NOT_FOUND;
+    }
+
+    try
+    {
+        String sourceString = File::ReadAllText(path);
+        ComPtr<ISlangBlob> sourceBlob = createStringBlob(sourceString);
+        *outBlob = sourceBlob.detach();
+        return SLANG_OK;
+    }
+    catch (...)
+    {
+    }
+    return SLANG_E_CANNOT_OPEN;
+}
+
+/* !!!!!!!!!!!!!!!!!!!!!!!!!! WrapFileSystem !!!!!!!!!!!!!!!!!!!!!!!!!!!!!!*/
+
+ISlangUnknown* WrapFileSystem::getInterface(const Guid& guid)
+{
+    return (guid == IID_ISlangUnknown || guid == IID_ISlangFileSystem || guid == IID_ISlangFileSystemExt) ? static_cast<ISlangFileSystemExt*>(this) : nullptr;
+}
+
+SlangResult WrapFileSystem::loadFile(char const* path, ISlangBlob** outBlob)
+{
+    // Used the wrapped file system to do the loading
+    return m_fileSystem->loadFile(path, outBlob);
+}
+
+SlangResult WrapFileSystem::getCanoncialPath(const char* path, ISlangBlob** canonicalPathOut)
+{
+    // This isn't a very good 'canonical  path' because the same file might be referenced 
+    // multiple ways - for example by using relative paths. 
+    // But it's simple and matches slangs previous behavior. 
+    String canonicalPath(path);
+    *canonicalPathOut = createStringBlob(canonicalPath).detach();
+    return SLANG_OK;
+}
+
+SlangResult WrapFileSystem::calcRelativePath(SlangPathType fromPathType, const char* fromPath, const char* path, ISlangBlob** pathOut)
+{
+    // Just defer to the default implementation
+    return DefaultFileSystem::getSingleton()->calcRelativePath(fromPathType, fromPath, path, pathOut);
+}
+
+} 
\ No newline at end of file