Refactor enumerating directory contents (#1478)

* Use m_style for OSFindFilesResult

* Refactor of FindFilesResult.

* Fixes on linux for FindFiles.

* Simplify FindFilesState, and linux support for pattern matching.

* Small fixes to linux FindFilesState

* Fix typo on linux FindFiles

* Fix typo in linux FindFiles.

* Renamed some variables, and improved comments on FindFiles.

* Improve comments on FildFiles

* Small improvements around FindFiles.

* Refactor FindFiles again.. into a visitor and function in Path.

* Fix some problems on linux.

* Fix linux typo.

* Renamed os -> find-file-util

* find-file-utl -> directory-util

Co-authored-by: Tim Foley <tfoleyNV@users.noreply.github.com>

2 files changed, 127 insertions, 0 deletions

diff --git a/source/core/slang-io.cpp b/source/core/slang-io.cpp
index 1717c8354..5cbe021a2 100644
--- a/source/core/slang-io.cpp
+++ b/source/core/slang-io.cpp
@@ -19,6 +19,11 @@
 
 #if defined(__linux__) || defined(__CYGWIN__) || SLANG_APPLE_FAMILY
 #   include <unistd.h>
+// For Path::find
+#   include <fnmatch.h>
+
+#   include <dirent.h>
+#   include <sys/stat.h>
 #endif
 
 #if SLANG_APPLE_FAMILY
@@ -552,6 +557,97 @@ namespace Slang
 #endif
     }
 
+#if defined(_WIN32)
+    /* static */SlangResult Path::find(const String& directoryPath, const char* pattern, Visitor* visitor)
+    {
+        pattern = pattern ? pattern : "*";
+        String searchPath = Path::combine(directoryPath, pattern);
+
+        WIN32_FIND_DATAW fileData;
+
+        HANDLE findHandle = FindFirstFileW(searchPath.toWString(), &fileData);
+        if (!findHandle)
+        {
+            return SLANG_E_NOT_FOUND;
+        }
+
+        do
+        {
+            if (!((wcscmp(fileData.cFileName, L".") == 0) ||
+                  (wcscmp(fileData.cFileName, L"..") == 0)))
+            {
+                const Type type = (fileData.dwFileAttributes & FILE_ATTRIBUTE_DIRECTORY) ? Type::Directory : Type::File;
+
+                String filename = String::fromWString(fileData.cFileName);
+                visitor->accept(type, filename.getUnownedSlice());
+            }
+        }
+        while (FindNextFileW(findHandle, &fileData) != 0);
+
+         ::FindClose(findHandle);
+         return SLANG_OK;
+    }
+#else
+    /* static */SlangResult Path::find(const String& directoryPath, const char* pattern, Visitor* visitor)
+    {
+        DIR* directory = opendir(directoryPath.getBuffer());
+        
+        if (!directory)
+        {
+            return SLANG_E_NOT_FOUND;
+        }
+
+        StringBuilder builder;
+        for (;;)
+        {
+            dirent* entry = readdir(directory);
+            if (entry == nullptr)
+            {
+                break;
+            }
+
+            if (strcmp(entry->d_name, ".") == 0 ||
+                strcmp(entry->d_name, "..") == 0)
+            {
+                continue;
+            }
+
+            // If there is a pattern, check if it matches, and if it doesn't ignore it
+            if (pattern && fnmatch(pattern, entry->d_name, 0) != 0)
+            {
+                continue;
+            }
+
+            const UnownedStringSlice filename(entry->d_name);
+
+            // Produce the full path, to do stat
+            Path::combineIntoBuilder(directoryPath.getUnownedSlice(), filename, builder);
+
+            //    fprintf(stderr, "stat(%s)\n", path.getBuffer());
+            struct stat fileInfo;
+            if (stat(builder.getBuffer(), &fileInfo) != 0)
+            {
+                continue;
+            }
+
+            Type type = Type::Unknown;
+            if (S_ISDIR(fileInfo.st_mode))
+            {
+                type = Type::Directory;
+            }
+            else if (S_ISREG(fileInfo.st_mode))
+            {
+                type = Type::File;
+            }
+
+            visitor->accept(type, filename);
+        }
+
+        closedir(directory);
+        return SLANG_OK;
+    }
+#endif
+
     /// Gets the path to the executable that was invoked that led to the current threads execution
     /// If run from a shared library/dll will be the path of the executable that loaded said library
     /// @param outPath Pointer to buffer to hold the path.
diff --git a/source/core/slang-io.h b/source/core/slang-io.h
index b3d03d9a4..492723602 100644
--- a/source/core/slang-io.h
+++ b/source/core/slang-io.h
@@ -25,8 +25,39 @@ namespace Slang
 	class Path
 	{
 	public:
+
+        enum class Type
+        {
+            Unknown,
+            File,
+            Directory,
+        };
+
+        typedef uint32_t TypeFlags;
+        struct TypeFlag
+        {
+            enum Enum : TypeFlags
+            {
+                Unknown = TypeFlags(1) << int(Type::Unknown),
+                File = TypeFlags(1) << int(Type::File),
+                Directory = TypeFlags(1) << int(Type::Directory),
+            };
+        };
+
+        class Visitor
+        {
+        public:
+            virtual void accept(Type type, const UnownedStringSlice& filename) = 0;
+        };
+
 		static const char kPathDelimiter = '/';
 
+            /// Finds all all the items in the specified directory, that matches the pattern.
+            ///
+            /// @param directoryPath The directory to do the search in. If the directory is not found, SLANG_E_NOT_FOUND is returned
+            /// @param pattern. The pattern to match against. The pattern matching is targtet specific (ie window matching is different to linux/unix). Passing nullptr means no matching.
+            /// @return is SLANG_E_NOT_FOUND if the directoryPath is not found
+        static SlangResult find(const String& directoryPath, const char* pattern, Visitor* visitor);
 
             /// Returns -1 if no separator is found
         static Index findLastSeparatorIndex(String const& path);