Add CFileStream. Move ErrnoException.

4 files changed, 145 insertions, 10 deletions

diff --git a/src/common/CMakeLists.txt b/src/common/CMakeLists.txt
index fb2dd471..2c7f28e0 100644
--- a/src/common/CMakeLists.txt
+++ b/src/common/CMakeLists.txt
@@ -6,6 +6,7 @@ add_library(CruBase
 	String.cpp
 	StringToNumberConverter.cpp
 	StringUtil.cpp
+	io/CFileStream.cpp
 	io/Stream.cpp
 	io/Resource.cpp
 	io/MemoryStream.cpp
diff --git a/src/common/Exception.cpp b/src/common/Exception.cpp
index 86816720..b0053bac 100644
--- a/src/common/Exception.cpp
+++ b/src/common/Exception.cpp
@@ -1,5 +1,9 @@
 #include "cru/common/Exception.h"
 
+#include "cru/common/Format.h"
+
+#include <cerrno>
+
 namespace cru {
 Exception::Exception() {}
 
@@ -14,4 +18,11 @@ const char* Exception::what() const noexcept {
 
   return utf8_message_.c_str();
 }
+
+ErrnoException::ErrnoException(const String& message)
+    : ErrnoException(message, errno) {}
+
+ErrnoException::ErrnoException(const String& message, int errno_code)
+    : Exception(Format(u"{}. Errno is {}.", message, errno_code)),
+      errno_code_(errno_code) {}
 }  // namespace cru
diff --git a/src/common/io/CFileStream.cpp b/src/common/io/CFileStream.cpp
new file mode 100644
index 00000000..de195538
--- /dev/null
+++ b/src/common/io/CFileStream.cpp
@@ -0,0 +1,132 @@
+#include "cru/common/io/CFileStream.h"
+#include "cru/common/Exception.h"
+#include "cru/common/io/Stream.h"
+
+#include <cstdio>
+
+namespace cru::io {
+static bool ModeCanRead(const char* mode) {
+  for (const char* p = mode; *p != '\0'; p++) {
+    if (*p == 'r' || *p == '+') {
+      return true;
+    }
+  }
+  return false;
+}
+
+static bool ModeCanWrite(const char* mode) {
+  for (const char* p = mode; *p != '\0'; p++) {
+    if (*p == 'w' || *p == 'a' || *p == '+') {
+      return true;
+    }
+  }
+  return false;
+}
+
+CFileStream::CFileStream(const char* path, const char* mode)
+    : file_(std::fopen(path, mode)),
+      readable_(ModeCanRead(mode)),
+      writable_(ModeCanWrite(mode)),
+      auto_close_(true) {
+  if (file_ == nullptr) {
+    throw ErrnoException(u"Cannot open file.");
+  }
+}
+
+CFileStream::CFileStream(std::FILE* file, bool readable, bool writable,
+                         bool auto_close)
+    : file_(file),
+      readable_(readable),
+      writable_(writable),
+      auto_close_(auto_close) {
+  if (file_ == nullptr) {
+    throw Exception(u"File is NULL.");
+  }
+}
+
+CFileStream::~CFileStream() {
+  if (auto_close_ && file_ != nullptr) {
+    std::fclose(file_);
+  }
+}
+
+bool CFileStream::CanSeek() {
+  CheckClosed();
+  return true;
+}
+
+static int ConvertOriginFlag(Stream::SeekOrigin origin) {
+  switch (origin) {
+    case Stream::SeekOrigin::Begin:
+      return SEEK_SET;
+    case Stream::SeekOrigin::Current:
+      return SEEK_CUR;
+    case Stream::SeekOrigin::End:
+      return SEEK_END;
+    default:
+      throw Exception(u"Unknown seek origin.");
+  }
+}
+
+Index CFileStream::Seek(Index offset, SeekOrigin origin) {
+  CheckClosed();
+  if (std::fseek(file_, offset, ConvertOriginFlag(origin))) {
+    throw ErrnoException(u"Seek failed.");
+  }
+  return Tell();
+}
+
+Index CFileStream::Tell() {
+  CheckClosed();
+  long position = std::ftell(file_);
+  if (position == -1) {
+    throw ErrnoException(u"Tell failed.");
+  }
+  return position;
+}
+
+void CFileStream::Rewind() {
+  CheckClosed();
+  std::rewind(file_);
+}
+
+bool CFileStream::CanRead() {
+  CheckClosed();
+  return readable_;
+}
+
+Index CFileStream::Read(std::byte* buffer, Index offset, Index size) {
+  CheckClosed();
+  auto count = std::fread(buffer + offset, 1, size, file_);
+  return count;
+}
+
+bool CFileStream::CanWrite() {
+  CheckClosed();
+  return writable_;
+}
+
+Index CFileStream::Write(const std::byte* buffer, Index offset, Index size) {
+  CheckClosed();
+  auto count = std::fwrite(buffer + offset, 1, size, file_);
+  return count;
+}
+
+void CFileStream::Flush() {
+  CheckClosed();
+  std::fflush(file_);
+}
+
+void CFileStream::Close() {
+  if (file_ != nullptr) {
+    std::fclose(file_);
+    file_ = nullptr;
+  }
+}
+
+void CFileStream::CheckClosed() {
+  if (file_ == nullptr) {
+    throw StreamAlreadyClosedException(u"File is closed.");
+  }
+}
+}  // namespace cru::io
diff --git a/src/common/platform/unix/ErrnoException.cpp b/src/common/platform/unix/ErrnoException.cpp
index f2171943..06c42ff6 100644
--- a/src/common/platform/unix/ErrnoException.cpp
+++ b/src/common/platform/unix/ErrnoException.cpp
@@ -1,14 +1,5 @@
 #include "cru/common/platform/unix/ErrnoException.h"
 
-#include "cru/common/Format.h"
-
-#include <errno.h>
-
 namespace cru::platform::unix {
-ErrnoException::ErrnoException(const String& message)
-    : ErrnoException(message, errno) {}
-
-ErrnoException::ErrnoException(const String& message, int errno_code)
-    : PlatformException(Format(u"{}. Errno is {}.", message, errno_code)),
-      errno_code_(errno_code) {}
+// Moved to Exception.cpp
 }  // namespace cru::platform::unix