3 files changed, 159 insertions, 0 deletions
diff --git a/include/cru/base/platform/unix/PosixSpawnSubProcess.h b/include/cru/base/platform/unix/PosixSpawnSubProcess.h
new file mode 100644
index 00000000..ee4e912a
--- /dev/null
+++ b/include/cru/base/platform/unix/PosixSpawnSubProcess.h
@@ -0,0 +1,50 @@
+#pragma once
+
+#include "../../PreConfig.h"
+
+#ifndef CRU_PLATFORM_UNIX
+#error "This file can only be included on unix."
+#endif
+
+#include "../../Base.h"
+#include "../../SubProcess.h"
+#include "../../io/AutoReadStream.h"
+
+#include "UnixFileStream.h"
+#include "UnixPipe.h"
+
+#include <spawn.h>
+
+namespace cru::platform::unix {
+class PosixSpawnSubProcessImpl : public Object,
+                                 public virtual IPlatformSubProcessImpl {
+  CRU_DEFINE_CLASS_LOG_TAG(u"PosixSpawnSubProcess")
+
+ public:
+  explicit PosixSpawnSubProcessImpl();
+  ~PosixSpawnSubProcessImpl();
+
+  void PlatformCreateProcess(const SubProcessStartInfo& start_info) override;
+  SubProcessExitResult PlatformWaitForProcess() override;
+  void PlatformKillProcess() override;
+
+  io::Stream* GetStdinStream() override;
+  io::Stream* GetStdoutStream() override;
+  io::Stream* GetStderrStream() override;
+
+ private:
+  pid_t pid_;
+  int exit_code_;
+
+  UnixPipe stdin_pipe_;
+  UnixPipe stdout_pipe_;
+  UnixPipe stderr_pipe_;
+
+  std::unique_ptr<UnixFileStream> stdin_stream_;
+  std::unique_ptr<UnixFileStream> stdout_stream_;
+  std::unique_ptr<UnixFileStream> stderr_stream_;
+
+  std::unique_ptr<io::AutoReadStream> stdout_buffer_stream_;
+  std::unique_ptr<io::AutoReadStream> stderr_buffer_stream_;
+};
+}  // namespace cru::platform::unix
diff --git a/include/cru/base/platform/unix/UnixFileStream.h b/include/cru/base/platform/unix/UnixFileStream.h
new file mode 100644
index 00000000..8021f21a
--- /dev/null
+++ b/include/cru/base/platform/unix/UnixFileStream.h
@@ -0,0 +1,39 @@
+#pragma once
+
+#include "../../PreConfig.h"
+
+#ifndef CRU_PLATFORM_UNIX
+#error "This file can only be included on unix."
+#endif
+
+#include "../../io/Stream.h"
+
+namespace cru::platform::unix {
+class UnixFileStream : public io::Stream {
+ private:
+  static constexpr auto kLogTag = u"cru::platform::unix::UnixFileStream";
+
+ public:
+  UnixFileStream(const char* path, int oflag, mode_t mode = 0660);
+  UnixFileStream(int fd, bool can_seek, bool can_read, bool can_write,
+                 bool auto_close);
+  ~UnixFileStream() override;
+
+ public:
+  CRU_STREAM_IMPLEMENT_CLOSE_BY_DO_CLOSE
+
+  int GetFileDescriptor() const { return file_descriptor_; }
+
+ protected:
+  Index DoSeek(Index offset, SeekOrigin origin = SeekOrigin::Current) override;
+  Index DoRead(std::byte* buffer, Index offset, Index size) override;
+  Index DoWrite(const std::byte* buffer, Index offset, Index size) override;
+
+ private:
+  void DoClose();
+
+ private:
+  int file_descriptor_;  // -1 for no file descriptor
+  bool auto_close_;
+};
+}  // namespace cru::platform::unix
diff --git a/include/cru/base/platform/unix/UnixPipe.h b/include/cru/base/platform/unix/UnixPipe.h
new file mode 100644
index 00000000..cf35fb11
--- /dev/null
+++ b/include/cru/base/platform/unix/UnixPipe.h
@@ -0,0 +1,70 @@
+#pragma once
+
+#include "../../PreConfig.h"
+
+#ifndef CRU_PLATFORM_UNIX
+#error "This file can only be included on unix."
+#endif
+
+#include "../../Base.h"
+#include "../../Bitmask.h"
+
+namespace cru::platform::unix {
+namespace details {
+struct UnixPipeFlagTag;
+}
+using UnixPipeFlag = Bitmask<details::UnixPipeFlagTag>;
+struct UnixPipeFlags {
+  constexpr static auto NonBlock = UnixPipeFlag::FromOffset(1);
+};
+
+/**
+ * @brief an unix pipe, commonly for communication of parent process and child
+ * process.
+ *
+ * There are two types of pipes sorted by its usage. For stdin, parent process
+ * SEND data to child process. For stdout and stderr, parent process RECEIVE
+ * data from child process. Each pipe has two ends, one for read and the other
+ * for write. But for send and receive, they are reversed. It is a little
+ * confused to consider which end should be used by parent and which end should
+ * be used by child. So this class help you make it clear. You specify SEND or
+ * RECEIVE, and this class give you a parent used end and a child used end.
+ *
+ * This class will only close the end used by parent when it is destructed. It
+ * is the user's duty to close the one used by child.
+ */
+class UnixPipe : public Object {
+ private:
+  constexpr static auto kLogTag = u"cru::platform::unix::UnixPipe";
+
+ public:
+  enum class Usage {
+    Send,
+    Receive,
+  };
+
+  explicit UnixPipe(Usage usage, bool auto_close, UnixPipeFlag flags = {});
+
+  CRU_DELETE_COPY(UnixPipe)
+  CRU_DELETE_MOVE(UnixPipe)
+
+  ~UnixPipe();
+
+  /**
+   * @brief aka, the one used by parent process.
+   */
+  int GetSelfFileDescriptor();
+
+  /**
+   * @brief aka, the one used by child process.
+   */
+  int GetOtherFileDescriptor();
+
+ private:
+  Usage usage_;
+  bool auto_close_;
+  UnixPipeFlag flags_;
+  int read_fd_;
+  int write_fd_;
+};
+}  // namespace cru::platform::unix