cmUVProcessChain: Add cmUVProcessChain

This class is ultimately intended as a replacement for cmsys::Process.
It spawns a series of processes using libuv, piping the output of each
command into the next.

Note: input support has not yet been implemented because write
support has not yet been implemented on cmUVStreambuf.

1 files changed, 100 insertions, 0 deletions

diff --git a/Source/cmUVProcessChain.h b/Source/cmUVProcessChain.h
new file mode 100644
index 0000000..2b33520
--- /dev/null
+++ b/Source/cmUVProcessChain.h
@@ -0,0 +1,100 @@
+/* Distributed under the OSI-approved BSD 3-Clause License.  See accompanying
+   file Copyright.txt or https://cmake.org/licensing for details.  */
+#ifndef cmUVProcessChain_h
+#define cmUVProcessChain_h
+
+#include "cm_uv.h"
+
+#include <array>
+#include <iosfwd>
+#include <memory> // IWYU pragma: keep
+#include <string>
+#include <vector>
+
+#include <stdint.h>
+
+class cmUVProcessChain;
+
+class cmUVProcessChainBuilder
+{
+public:
+  enum Stream
+  {
+    Stream_INPUT = 0,
+    Stream_OUTPUT = 1,
+    Stream_ERROR = 2,
+  };
+
+  cmUVProcessChainBuilder();
+
+  cmUVProcessChainBuilder& AddCommand(
+    const std::vector<std::string>& arguments);
+  cmUVProcessChainBuilder& SetNoStream(Stream stdio);
+  cmUVProcessChainBuilder& SetBuiltinStream(Stream stdio);
+  cmUVProcessChainBuilder& SetExternalStream(Stream stdio, int fd);
+
+  cmUVProcessChain Start() const;
+
+private:
+  enum StdioType
+  {
+    None,
+    Builtin,
+    External,
+  };
+
+  friend class cmUVProcessChain;
+
+  struct StdioConfiguration
+  {
+    StdioType Type;
+    int FileDescriptor;
+  };
+
+  struct ProcessConfiguration
+  {
+    std::vector<std::string> Arguments;
+  };
+
+  std::array<StdioConfiguration, 3> Stdio;
+  std::vector<ProcessConfiguration> Processes;
+};
+
+class cmUVProcessChain
+{
+public:
+  struct Status
+  {
+    int64_t ExitStatus;
+    int TermSignal;
+  };
+
+  cmUVProcessChain(const cmUVProcessChain& other) = delete;
+  cmUVProcessChain(cmUVProcessChain&& other) noexcept;
+
+  ~cmUVProcessChain();
+
+  cmUVProcessChain& operator=(const cmUVProcessChain& other) = delete;
+  cmUVProcessChain& operator=(cmUVProcessChain&& other) noexcept;
+
+  uv_loop_t& GetLoop();
+
+  // FIXME: Add stdin support
+  std::istream* OutputStream();
+  std::istream* ErrorStream();
+
+  bool Valid() const;
+  bool Wait(int64_t milliseconds = -1);
+  std::vector<const Status*> GetStatus() const;
+  const Status* GetStatus(std::size_t index) const;
+
+private:
+  friend class cmUVProcessChainBuilder;
+
+  cmUVProcessChain();
+
+  struct InternalData;
+  std::unique_ptr<InternalData> Data;
+};
+
+#endif