8 files changed, 638 insertions, 0 deletions
diff --git a/src/base/io/AutoReadStream.cpp b/src/base/io/AutoReadStream.cpp
new file mode 100644
index 00000000..c24f61d1
--- /dev/null
+++ b/src/base/io/AutoReadStream.cpp
@@ -0,0 +1,56 @@
+#include "cru/base/io/AutoReadStream.h"
+#include "cru/base/io/Stream.h"
+
+#include <thread>
+
+namespace cru::io {
+
+AutoReadStream::AutoReadStream(Stream* stream, bool auto_delete,
+                               const AutoReadStreamOptions& options)
+    : Stream(false, true, stream->CanSeek()) {
+  auto buffer_stream_options = options.GetBufferStreamOptions();
+  stream_ = stream;
+  size_per_read_ = buffer_stream_options.GetBlockSizeOrDefault();
+  buffer_stream_ = std::make_unique<BufferStream>(buffer_stream_options);
+  background_thread_ = std::thread(&AutoReadStream::BackgroundThreadRun, this);
+}
+
+AutoReadStream::~AutoReadStream() {
+  if (auto_delete_) {
+    delete stream_;
+  }
+}
+
+Index AutoReadStream::DoRead(std::byte* buffer, Index offset, Index size) {
+  std::unique_lock lock(buffer_stream_mutex_);
+  return buffer_stream_->Read(buffer, offset, size);
+}
+
+Index AutoReadStream::DoWrite(const std::byte* buffer, Index offset,
+                              Index size) {
+  return stream_->Write(buffer, offset, size);
+}
+
+void AutoReadStream::DoFlush() { stream_->Flush(); }
+
+void AutoReadStream::DoClose() {}
+
+void AutoReadStream::BackgroundThreadRun() {
+  std::vector<std::byte> buffer(size_per_read_);
+  while (true) {
+    try {
+      auto read = stream_->Read(buffer.data(), buffer.size());
+      if (read == 0) {
+        buffer_stream_->SetEof();
+        break;
+      } else {
+        buffer_stream_->Write(buffer.data(), read);
+      }
+    } catch (const StreamAlreadyClosedException& exception) {
+      buffer_stream_->SetEof();
+      break;
+    }
+  }
+}
+
+}  // namespace cru::io
diff --git a/src/base/io/BufferStream.cpp b/src/base/io/BufferStream.cpp
new file mode 100644
index 00000000..e81731e8
--- /dev/null
+++ b/src/base/io/BufferStream.cpp
@@ -0,0 +1,109 @@
+#include "cru/base/io/BufferStream.h"
+#include "cru/base/io/Stream.h"
+
+namespace cru::io {
+BufferStream::BufferStream(const BufferStreamOptions& options)
+    : Stream(false, true, true) {
+  block_size_ = options.GetBlockSizeOrDefault();
+  max_block_count_ = options.GetMaxBlockCount();
+
+  eof_ = false;
+}
+
+BufferStream::~BufferStream() { DoClose(); }
+
+Index BufferStream::DoRead(std::byte* buffer, Index offset, Index size) {
+  std::unique_lock lock(mutex_);
+
+  condition_variable_.wait(lock,
+                           [this] { return !buffer_list_.empty() || eof_; });
+
+  if (buffer_list_.empty() && eof_) {
+    return 0;
+  }
+
+  auto full = max_block_count_ > 0 && buffer_list_.size() == max_block_count_;
+
+  Index read = 0;
+
+  while (!buffer_list_.empty()) {
+    auto& stream_buffer = buffer_list_.front();
+    auto this_read =
+        stream_buffer.PopFront(buffer + offset + read, size - read);
+    if (stream_buffer.GetUsedSize() == 0) {
+      buffer_list_.pop_front();
+    }
+    read += this_read;
+    if (read == size) {
+      break;
+    }
+  }
+
+  if (full && buffer_list_.size() < max_block_count_) {
+    // By convention, there should be at most one producer waiting. So
+    // notify_one and notify_all should be the same.
+    condition_variable_.notify_one();
+  }
+
+  return read;
+}
+
+Index BufferStream::DoWrite(const std::byte* buffer, Index offset, Index size) {
+  std::unique_lock lock(mutex_);
+
+  if (eof_) {
+    throw WriteAfterEofException(
+        u"Stream has been set eof. Can't write to it any more.");
+  }
+
+  condition_variable_.wait(lock, [this] {
+    return max_block_count_ <= 0 || buffer_list_.size() < max_block_count_ ||
+           buffer_list_.back().GetBackFree() > 0;
+  });
+
+  auto empty = buffer_list_.empty();
+
+  Index written = 0;
+
+  if (empty) {
+    buffer_list_.push_back(Buffer(block_size_));
+  }
+
+  while (true) {
+    if (buffer_list_.back().GetBackFree() == 0) {
+      if (max_block_count_ > 0 && buffer_list_.size() == max_block_count_) {
+        break;
+      }
+      buffer_list_.push_back(Buffer(block_size_));
+    }
+    auto& stream_buffer = buffer_list_.back();
+    auto this_written =
+        stream_buffer.PushBack(buffer + offset + written, size - written);
+    written += this_written;
+    if (written == size) {
+      break;
+    }
+  }
+
+  if (empty) {
+    // By convention, there should be at most one consumer waiting. So
+    // notify_one and notify_all should be the same.
+    condition_variable_.notify_one();
+  }
+
+  return written;
+}
+
+void BufferStream::SetEof() {
+  std::unique_lock lock(mutex_);
+
+  eof_ = true;
+  if (buffer_list_.empty()) {
+    // By convention, there should be at most one consumer waiting. So
+    // notify_one and notify_all should be the same.
+    condition_variable_.notify_one();
+  }
+}
+
+void BufferStream::DoClose() { CRU_STREAM_BEGIN_CLOSE }
+}  // namespace cru::io
diff --git a/src/base/io/CFileStream.cpp b/src/base/io/CFileStream.cpp
new file mode 100644
index 00000000..d5acc707
--- /dev/null
+++ b/src/base/io/CFileStream.cpp
@@ -0,0 +1,96 @@
+#include "cru/base/io/CFileStream.h"
+#include "cru/base/Exception.h"
+#include "cru/base/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)
+    : Stream(true, ModeCanRead(mode), ModeCanWrite(mode)),
+      file_(std::fopen(path, 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)
+    : Stream(true, readable, writable), file_(file), auto_close_(auto_close) {
+  if (file_ == nullptr) {
+    throw Exception(u"File is NULL.");
+  }
+}
+
+CFileStream::~CFileStream() {
+  if (auto_close_ && file_ != nullptr) {
+    std::fclose(file_);
+  }
+}
+
+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::DoSeek(Index offset, SeekOrigin origin) {
+  if (std::fseek(file_, offset, ConvertOriginFlag(origin))) {
+    throw ErrnoException(u"Seek failed.");
+  }
+  return DoTell();
+}
+
+Index CFileStream::DoTell() {
+  long position = std::ftell(file_);
+  if (position == -1) {
+    throw ErrnoException(u"Tell failed.");
+  }
+  return position;
+}
+
+void CFileStream::DoRewind() { std::rewind(file_); }
+
+Index CFileStream::DoRead(std::byte* buffer, Index offset, Index size) {
+  auto count = std::fread(buffer + offset, 1, size, file_);
+  return count;
+}
+
+Index CFileStream::DoWrite(const std::byte* buffer, Index offset, Index size) {
+  auto count = std::fwrite(buffer + offset, 1, size, file_);
+  return count;
+}
+
+void CFileStream::DoFlush() { std::fflush(file_); }
+
+void CFileStream::DoClose() {
+  CRU_STREAM_BEGIN_CLOSE
+  std::fclose(file_);
+  file_ = nullptr;
+}
+}  // namespace cru::io
diff --git a/src/base/io/MemoryStream.cpp b/src/base/io/MemoryStream.cpp
new file mode 100644
index 00000000..4c650f3e
--- /dev/null
+++ b/src/base/io/MemoryStream.cpp
@@ -0,0 +1,74 @@
+#include "cru/base/io/MemoryStream.h"
+
+#include <cstring>
+#include "cru/base/Exception.h"
+#include "cru/base/io/Stream.h"
+
+namespace cru::io {
+MemoryStream::MemoryStream(
+    std::byte* buffer, Index size, bool read_only,
+    std::function<void(std::byte* buffer, Index size)> release_func)
+    : Stream(true, true, !read_only),
+      buffer_(buffer),
+      size_(size),
+      position_(0),
+      release_func_(std::move(release_func)) {
+  if (!buffer) {
+    throw Exception(u"Buffer is nullptr");
+  }
+  if (size <= 0) {
+    throw Exception(u"Size is 0 or negative.");
+  }
+}
+
+MemoryStream::~MemoryStream() {}
+
+void MemoryStream::Close() { DoClose(); }
+
+Index MemoryStream::DoSeek(Index offset, SeekOrigin origin) {
+  switch (origin) {
+    case SeekOrigin::Current:
+      position_ += offset;
+      break;
+    case SeekOrigin::Begin:
+      position_ = offset;
+      break;
+    case SeekOrigin::End:
+      position_ = size_ + offset;
+      break;
+  }
+  return position_;
+}
+
+Index MemoryStream::DoRead(std::byte* buffer, Index offset, Index size) {
+  if (position_ + size > size_) {
+    size = size_ - position_;
+  }
+  if (size <= 0) {
+    return 0;
+  }
+  std::memmove(buffer + offset, buffer_ + position_, size);
+  position_ += size;
+  return size;
+}
+
+Index MemoryStream::DoWrite(const std::byte* buffer, Index offset, Index size) {
+  if (position_ + size > size_) {
+    size = size_ - position_;
+  }
+  if (size <= 0) {
+    return 0;
+  }
+  std::memmove(buffer_ + position_, buffer + offset, size);
+  position_ += size;
+  return size;
+}
+
+void MemoryStream::DoClose() {
+  CRU_STREAM_BEGIN_CLOSE
+  release_func_(buffer_, size_);
+  buffer_ = nullptr;
+  release_func_ = {};
+}
+
+}  // namespace cru::io
diff --git a/src/base/io/OpenFileFlag.cpp b/src/base/io/OpenFileFlag.cpp
new file mode 100644
index 00000000..47069b29
--- /dev/null
+++ b/src/base/io/OpenFileFlag.cpp
@@ -0,0 +1,19 @@
+#include "cru/base/io/OpenFileFlag.h"
+
+namespace cru::io {
+bool CheckOpenFileFlag(OpenFileFlag flags) {
+  auto has = [flags](OpenFileFlag flag) { return flags & flag; };
+
+  if ((has(OpenFileFlags::Append) || has(OpenFileFlags::Truncate) ||
+       has(OpenFileFlags::Create)) &&
+      !has(OpenFileFlags::Write)) {
+    return false;
+  }
+
+  if (has(OpenFileFlags::Truncate) && has(OpenFileFlags::Append)) {
+    return false;
+  }
+
+  return true;
+}
+}  // namespace cru::io
diff --git a/src/base/io/ProxyStream.cpp b/src/base/io/ProxyStream.cpp
new file mode 100644
index 00000000..de66169e
--- /dev/null
+++ b/src/base/io/ProxyStream.cpp
@@ -0,0 +1,37 @@
+#include "cru/base/io/ProxyStream.h"
+#include "cru/base/io/Stream.h"
+
+namespace cru::io {
+ProxyStream::ProxyStream(ProxyStreamHandlers handlers)
+    : Stream(static_cast<bool>(handlers.seek), static_cast<bool>(handlers.read),
+             static_cast<bool>(handlers.write)),
+      handlers_(std::move(handlers)) {}
+
+ProxyStream::~ProxyStream() { DoClose(); }
+
+Index ProxyStream::DoSeek(Index offset, SeekOrigin origin) {
+  return handlers_.seek(offset, origin);
+}
+
+Index ProxyStream::DoRead(std::byte* buffer, Index offset, Index size) {
+  return handlers_.read(buffer, offset, size);
+}
+
+Index ProxyStream::DoWrite(const std::byte* buffer, Index offset, Index size) {
+  return handlers_.write(buffer, offset, size);
+}
+
+void ProxyStream::DoFlush() {
+  if (handlers_.flush) {
+    handlers_.flush();
+  }
+}
+
+void ProxyStream::DoClose() {
+  CRU_STREAM_BEGIN_CLOSE
+  if (handlers_.close) {
+    handlers_.close();
+  }
+  handlers_ = {};
+}
+}  // namespace cru::io
diff --git a/src/base/io/Resource.cpp b/src/base/io/Resource.cpp
new file mode 100644
index 00000000..d369b5f5
--- /dev/null
+++ b/src/base/io/Resource.cpp
@@ -0,0 +1,48 @@
+#include "cru/base/io/Resource.h"
+#include "cru/base/Exception.h"
+#include "cru/base/log/Logger.h"
+
+#if defined(CRU_PLATFORM_OSX)
+#include <CoreFoundation/CoreFoundation.h>
+#elif defined(CRU_PLATFORM_WINDOWS)
+#include <Windows.h>
+#endif
+
+#include <filesystem>
+
+namespace cru::io {
+std::filesystem::path GetResourceDir() {
+  constexpr auto kLogTag = u"GetResourceDir";
+
+#if defined(CRU_PLATFORM_OSX)
+  CFBundleRef main_bundle = CFBundleGetMainBundle();
+  CFURLRef bundle_url = CFBundleCopyBundleURL(main_bundle);
+  CFStringRef cf_string_ref =
+      CFURLCopyFileSystemPath(bundle_url, kCFURLPOSIXPathStyle);
+  std::filesystem::path bundle_path(
+      CFStringGetCStringPtr(cf_string_ref, kCFStringEncodingUTF8));
+
+  CFRelease(bundle_url);
+  CFRelease(cf_string_ref);
+
+  return bundle_path / "Contents/Resources";
+#elif defined(CRU_PLATFORM_WINDOWS)
+  wchar_t buffer[MAX_PATH];
+  DWORD size = ::GetModuleFileNameW(nullptr, buffer, MAX_PATH);
+  std::filesystem::path module_path(buffer, buffer + size);
+  auto p = module_path;
+  while (p.has_parent_path()) {
+    p = p.parent_path();
+    auto resource_dir_path = p / "assets";
+    if (std::filesystem::exists(resource_dir_path) &&
+        std::filesystem::is_directory(resource_dir_path)) {
+      return resource_dir_path;
+    }
+  }
+
+  throw Exception(u"Failed to find resource directory.");
+#else
+  throw Exception(u"Not implemented.");
+#endif
+}
+}  // namespace cru::io
diff --git a/src/base/io/Stream.cpp b/src/base/io/Stream.cpp
new file mode 100644
index 00000000..d65bac46
--- /dev/null
+++ b/src/base/io/Stream.cpp
@@ -0,0 +1,199 @@
+#include "cru/base/io/Stream.h"
+#include "cru/base/Exception.h"
+#include "cru/base/Format.h"
+
+#include <utility>
+
+namespace cru::io {
+StreamOperationNotSupportedException::StreamOperationNotSupportedException(
+    String operation)
+    : operation_(std::move(operation)) {
+  SetMessage(Format(u"Stream operation {} not supported.", operation_));
+}
+
+void StreamOperationNotSupportedException::CheckSeek(bool seekable) {
+  if (!seekable) throw StreamOperationNotSupportedException(u"seek");
+}
+
+void StreamOperationNotSupportedException::CheckRead(bool readable) {
+  if (!readable) throw StreamOperationNotSupportedException(u"read");
+}
+
+void StreamOperationNotSupportedException::CheckWrite(bool writable) {
+  if (!writable) throw StreamOperationNotSupportedException(u"write");
+}
+
+StreamAlreadyClosedException::StreamAlreadyClosedException()
+    : Exception(u"Stream is already closed.") {}
+
+void StreamAlreadyClosedException::Check(bool closed) {
+  if (closed) throw StreamAlreadyClosedException();
+}
+
+Stream::Stream(SupportedOperations supported_operations)
+    : supported_operations_(std::move(supported_operations)), closed_(false) {}
+
+Stream::Stream(std::optional<bool> can_seek, std::optional<bool> can_read,
+               std::optional<bool> can_write)
+    : Stream(SupportedOperations{can_seek, can_read, can_write}) {}
+
+bool Stream::CanSeek() {
+  CheckClosed();
+  return DoCanSeek();
+}
+
+Index Stream::Seek(Index offset, SeekOrigin origin) {
+  CheckClosed();
+  StreamOperationNotSupportedException::CheckSeek(DoCanSeek());
+  return DoSeek(offset, origin);
+}
+
+Index Stream::Tell() {
+  CheckClosed();
+  return DoTell();
+}
+
+void Stream::Rewind() {
+  CheckClosed();
+  return DoRewind();
+}
+
+Index Stream::GetSize() {
+  CheckClosed();
+  return DoGetSize();
+}
+
+bool Stream::CanRead() {
+  CheckClosed();
+  return DoCanRead();
+}
+
+Index Stream::Read(std::byte* buffer, Index offset, Index size) {
+  CheckClosed();
+  StreamOperationNotSupportedException::CheckRead(DoCanRead());
+  return DoRead(buffer, offset, size);
+}
+
+Index Stream::Read(std::byte* buffer, Index size) {
+  return Read(buffer, 0, size);
+}
+
+Index Stream::Read(char* buffer, Index offset, Index size) {
+  return Read(reinterpret_cast<std::byte*>(buffer), offset, size);
+}
+
+Index Stream::Read(char* buffer, Index size) {
+  return Read(reinterpret_cast<std::byte*>(buffer), 0, size);
+}
+
+bool Stream::CanWrite() {
+  CheckClosed();
+  return DoCanWrite();
+}
+
+Index Stream::Write(const std::byte* buffer, Index offset, Index size) {
+  CheckClosed();
+  StreamOperationNotSupportedException::CheckWrite(DoCanWrite());
+  return DoWrite(buffer, offset, size);
+}
+
+Index Stream::Write(const std::byte* buffer, Index size) {
+  return Write(buffer, 0, size);
+}
+
+Index Stream::Write(const char* buffer, Index offset, Index size) {
+  return Write(reinterpret_cast<const std::byte*>(buffer), offset, size);
+}
+
+Index Stream::Write(const char* buffer, Index size) {
+  return Write(reinterpret_cast<const std::byte*>(buffer), size);
+}
+
+void Stream::Flush() {
+  CheckClosed();
+  DoFlush();
+}
+
+bool Stream::DoCanSeek() {
+  if (supported_operations_->can_seek) {
+    return *supported_operations_->can_seek;
+  } else {
+    throw Exception(
+        u"Can seek is neither set in supported_operations nor implemeted in "
+        u"virtual function.");
+  }
+}
+
+bool Stream::DoCanRead() {
+  if (supported_operations_->can_read) {
+    return *supported_operations_->can_read;
+  } else {
+    throw Exception(
+        u"Can read is neither set in supported_operations nor implemeted in "
+        u"virtual function.");
+  }
+}
+
+bool Stream::DoCanWrite() {
+  if (supported_operations_->can_write) {
+    return *supported_operations_->can_write;
+  } else {
+    throw Exception(
+        u"Can write is neither set in supported_operations nor implemeted in "
+        u"virtual function.");
+  }
+}
+
+Index Stream::DoSeek(Index offset, SeekOrigin origin) {
+  throw Exception(u"Stream is seekable but DoSeek is not implemented.");
+}
+
+Index Stream::DoTell() {
+  StreamOperationNotSupportedException::CheckSeek(DoCanSeek());
+  return DoSeek(0, SeekOrigin::Current);
+}
+
+void Stream::DoRewind() {
+  StreamOperationNotSupportedException::CheckSeek(DoCanSeek());
+  DoSeek(0, SeekOrigin::Begin);
+}
+
+Index Stream::DoGetSize() {
+  StreamOperationNotSupportedException::CheckSeek(DoCanSeek());
+  Index current_position = DoTell();
+  Seek(0, SeekOrigin::End);
+  Index size = DoTell();
+  Seek(current_position, SeekOrigin::Begin);
+  return size;
+}
+
+Index Stream::DoRead(std::byte* buffer, Index offset, Index size) {
+  throw Exception(u"Stream is readable but DoSeek is not implemented.");
+}
+
+Index Stream::DoWrite(const std::byte* buffer, Index offset, Index size) {
+  throw Exception(u"Stream is writable but DoSeek is not implemented.");
+}
+
+void Stream::DoFlush() {}
+
+Buffer Stream::ReadToEnd(Index grow_size) {
+  Buffer buffer(grow_size);
+  while (true) {
+    auto read = Read(buffer.GetUsedEndPtr(), buffer.GetBackFree());
+    buffer.PushBackCount(read);
+    if (read == 0) {
+      break;
+    }
+    if (buffer.IsUsedReachEnd()) {
+      buffer.ResizeBuffer(buffer.GetBufferSize() + grow_size, true);
+    }
+  }
+  return buffer;
+}
+
+String Stream::ReadToEndAsUtf8String() {
+  auto buffer = ReadToEnd();
+  return String::FromUtf8(buffer);
+}
+}  // namespace cru::io