Process: support pipe redirection

5 files changed, 347 insertions, 12 deletions

diff --git a/src/file.cpp b/src/file.cpp
new file mode 100644
index 0000000..cb9be81
--- /dev/null
+++ b/src/file.cpp
@@ -0,0 +1,75 @@
+// Copyright (c) 2020 Egor Tensin <Egor.Tensin@gmail.com>
+// This file is part of the "winapi-common" project.
+// For details, see https://github.com/egor-tensin/winapi-common.
+// Distributed under the MIT License.
+
+#include <winapi/error.hpp>
+#include <winapi/file.hpp>
+#include <winapi/handle.hpp>
+#include <winapi/utf8.hpp>
+
+#include <cstring>
+#include <string>
+
+namespace winapi {
+namespace {
+
+struct CreateFileParams {
+    static CreateFileParams read() {
+        CreateFileParams params;
+        params.dwDesiredAccess = GENERIC_READ;
+        params.dwShareMode = FILE_SHARE_READ;
+        params.dwCreationDisposition = OPEN_EXISTING;
+        return params;
+    }
+
+    static CreateFileParams write() {
+        CreateFileParams params;
+        params.dwDesiredAccess = GENERIC_WRITE;
+        params.dwShareMode = FILE_SHARE_READ;
+        params.dwCreationDisposition = OPEN_ALWAYS;
+        return params;
+    }
+
+    DWORD dwDesiredAccess = 0;
+    DWORD dwShareMode = 0;
+    DWORD dwCreationDisposition = 0;
+
+private:
+    CreateFileParams() = default;
+};
+
+Handle open_file(const std::string& path, const CreateFileParams& params) {
+    const auto unicode_path = LR"(\\?\)" + widen(path);
+
+    SECURITY_ATTRIBUTES attributes;
+    std::memset(&attributes, 0, sizeof(attributes));
+    attributes.nLength = sizeof(attributes);
+    attributes.bInheritHandle = TRUE;
+
+    const auto handle = ::CreateFileW(unicode_path.c_str(),
+                                      params.dwDesiredAccess,
+                                      params.dwShareMode,
+                                      &attributes,
+                                      params.dwCreationDisposition,
+                                      FILE_ATTRIBUTE_NORMAL,
+                                      NULL);
+
+    if (handle == INVALID_HANDLE_VALUE) {
+        throw error::windows(GetLastError(), "CreateFileW");
+    }
+
+    return Handle{handle};
+}
+
+} // namespace
+
+Handle File::open_for_reading(const std::string& path) {
+    return open_file(path, CreateFileParams::read());
+}
+
+Handle File::open_for_writing(const std::string& path) {
+    return open_file(path, CreateFileParams::write());
+}
+
+} // namespace winapi
diff --git a/src/handle.cpp b/src/handle.cpp
new file mode 100644
index 0000000..a6ab3a5
--- /dev/null
+++ b/src/handle.cpp
@@ -0,0 +1,153 @@
+// Copyright (c) 2020 Egor Tensin <Egor.Tensin@gmail.com>
+// This file is part of the "winapi-common" project.
+// For details, see https://github.com/egor-tensin/winapi-common.
+// Distributed under the MIT License.
+
+#include <winapi/error.hpp>
+#include <winapi/handle.hpp>
+#include <winapi/workarounds.hpp>
+
+#include <boost/config.hpp>
+
+#include <windows.h>
+
+#include <cassert>
+#include <cstddef>
+#include <sstream>
+#include <stdexcept>
+
+namespace winapi {
+namespace {
+
+std::runtime_error write_file_incomplete(std::size_t expected, std::size_t actual) {
+    std::ostringstream oss;
+    oss << "WriteFile could only write " << actual << " bytes instead of " << expected;
+    return std::runtime_error{oss.str()};
+}
+
+bool is_invalid_handle(HANDLE handle) {
+    return handle == NULL || handle == INVALID_HANDLE_VALUE;
+}
+
+bool is_std_handle(HANDLE handle) {
+    return handle == ::GetStdHandle(STD_INPUT_HANDLE) ||
+           handle == ::GetStdHandle(STD_OUTPUT_HANDLE) ||
+           handle == ::GetStdHandle(STD_ERROR_HANDLE);
+}
+
+} // namespace
+
+Handle::Handle(HANDLE impl) : m_impl{impl} {}
+
+Handle::Handle(Handle&& other) BOOST_NOEXCEPT_OR_NOTHROW {
+    swap(other);
+}
+
+Handle& Handle::operator=(Handle other) BOOST_NOEXCEPT_OR_NOTHROW {
+    swap(other);
+    return *this;
+}
+
+void Handle::swap(Handle& other) BOOST_NOEXCEPT_OR_NOTHROW {
+    using std::swap;
+    swap(m_impl, other.m_impl);
+}
+
+bool Handle::is_invalid() const {
+    return !m_impl || is_invalid_handle(m_impl.get());
+}
+
+void Handle::close() {
+    m_impl.reset();
+}
+
+bool Handle::is_std() const {
+    return is_std_handle(m_impl.get());
+}
+
+Handle Handle::std_in() {
+    return Handle{::GetStdHandle(STD_INPUT_HANDLE)};
+}
+
+Handle Handle::std_out() {
+    return Handle{::GetStdHandle(STD_OUTPUT_HANDLE)};
+}
+
+Handle Handle::std_err() {
+    return Handle{::GetStdHandle(STD_ERROR_HANDLE)};
+}
+
+bool Handle::read_chunk(Buffer& buffer) const {
+    buffer.resize(max_chunk_size);
+    DWORD nb_read = 0;
+
+    const auto ret = ::ReadFile(m_impl.get(), buffer.data(), buffer.size(), &nb_read, NULL);
+
+    buffer.resize(nb_read);
+
+    if (ret) {
+        return nb_read != 0;
+    }
+
+    const auto ec = GetLastError();
+
+    switch (ec) {
+        case ERROR_BROKEN_PIPE:
+            // We've been reading from an anonymous pipe, and it's been closed.
+            return false;
+        default:
+            throw error::windows(ec, "ReadFile");
+    }
+}
+
+Handle::Buffer Handle::read() const {
+    Buffer buffer;
+    Buffer chunk;
+
+    while (true) {
+        const auto next = read_chunk(chunk);
+
+        buffer.reserve(buffer.size() + chunk.size());
+        buffer.insert(buffer.cend(), chunk.cbegin(), chunk.cend());
+
+        if (!next) {
+            break;
+        }
+    }
+
+    return buffer;
+}
+
+void Handle::write(const void* data, std::size_t nb) const {
+    DWORD nb_written = 0;
+
+    const auto ret = ::WriteFile(m_impl.get(), data, nb, &nb_written, NULL);
+
+    if (!ret) {
+        throw error::windows(GetLastError(), "WriteFile");
+    }
+
+    if (nb != nb_written) {
+        throw write_file_incomplete(nb, nb_written);
+    }
+}
+
+void Handle::write(const Buffer& buffer) const {
+    write(buffer.data(), buffer.size());
+}
+
+void Handle::inherit(bool yes) const {
+    if (!::SetHandleInformation(m_impl.get(), HANDLE_FLAG_INHERIT, yes ? 1 : 0)) {
+        throw error::windows(GetLastError(), "SetHandleInformation");
+    }
+}
+
+void Handle::Close::operator()(HANDLE impl) const {
+    if (is_invalid_handle(impl) || is_std_handle(impl))
+        return;
+    const auto ret = ::CloseHandle(impl);
+    assert(ret);
+    WINAPI_UNUSED_PARAMETER(ret);
+}
+
+} // namespace winapi
diff --git a/src/pipe.cpp b/src/pipe.cpp
new file mode 100644
index 0000000..a00a8f6
--- /dev/null
+++ b/src/pipe.cpp
@@ -0,0 +1,46 @@
+// Copyright (c) 2020 Egor Tensin <Egor.Tensin@gmail.com>
+// This file is part of the "winapi-common" project.
+// For details, see https://github.com/egor-tensin/winapi-common.
+// Distributed under the MIT License.
+
+#include <winapi/error.hpp>
+#include <winapi/handle.hpp>
+#include <winapi/pipe.hpp>
+
+#include <boost/config.hpp>
+
+#include <windows.h>
+
+#include <cstring>
+
+namespace winapi {
+namespace {
+
+void create_pipe(Handle& read_end, Handle& write_end) {
+    HANDLE h_read_end = INVALID_HANDLE_VALUE;
+    HANDLE h_write_end = INVALID_HANDLE_VALUE;
+
+    SECURITY_ATTRIBUTES attributes;
+    std::memset(&attributes, 0, sizeof(attributes));
+    attributes.nLength = sizeof(attributes);
+    attributes.bInheritHandle = TRUE;
+
+    BOOST_STATIC_CONSTEXPR DWORD buffer_size = 16 * 1024;
+
+    const auto ret = ::CreatePipe(&h_read_end, &h_write_end, &attributes, buffer_size);
+
+    if (!ret) {
+        throw error::windows(GetLastError(), "CreatePipe");
+    }
+
+    read_end = Handle{h_read_end};
+    write_end = Handle{h_write_end};
+}
+
+} // namespace
+
+Pipe::Pipe() {
+    create_pipe(m_read_end, m_write_end);
+}
+
+} // namespace winapi
diff --git a/src/process.cpp b/src/process.cpp
index 1771328..5887b05 100644
--- a/src/process.cpp
+++ b/src/process.cpp
@@ -21,42 +21,62 @@ namespace {
 
 typedef std::vector<wchar_t> EscapedCommandLine;
 
-Handle create_process(EscapedCommandLine cmd_line) {
-    BOOST_STATIC_CONSTEXPR DWORD flags = CREATE_NO_WINDOW | CREATE_UNICODE_ENVIRONMENT;
+Handle create_process(EscapedCommandLine cmd_line, Process::IO& io) {
+    BOOST_STATIC_CONSTEXPR DWORD flags = /*CREATE_NO_WINDOW | */ CREATE_UNICODE_ENVIRONMENT;
 
     STARTUPINFOW startup_info;
     std::memset(&startup_info, 0, sizeof(startup_info));
     startup_info.cb = sizeof(startup_info);
+    startup_info.dwFlags = STARTF_USESTDHANDLES;
+    startup_info.hStdInput = static_cast<HANDLE>(io.std_in.handle);
+    startup_info.hStdOutput = static_cast<HANDLE>(io.std_out.handle);
+    startup_info.hStdError = static_cast<HANDLE>(io.std_err.handle);
 
     PROCESS_INFORMATION child_info;
     std::memset(&child_info, 0, sizeof(child_info));
 
     const auto ret = ::CreateProcessW(
-        NULL, cmd_line.data(), NULL, NULL, FALSE, flags, NULL, NULL, &startup_info, &child_info);
+        NULL, cmd_line.data(), NULL, NULL, TRUE, flags, NULL, NULL, &startup_info, &child_info);
 
     if (!ret) {
         throw error::windows(GetLastError(), "CreateProcessW");
     }
 
-    Handle h_process{child_info.hProcess};
-    Handle h_thread{child_info.hThread};
+    io.close();
 
-    return std::move(h_process);
+    Handle process{child_info.hProcess};
+    Handle thread{child_info.hThread};
+
+    return std::move(process);
 }
 
 EscapedCommandLine escape_command_line(const CommandLine& cmd_line) {
-    const auto whole = widen(cmd_line.join());
-    return {whole.cbegin(), whole.cend()};
+    const auto unicode_cmd_line = widen(cmd_line.join());
+    EscapedCommandLine buffer;
+    buffer.reserve(unicode_cmd_line.size() + 1);
+    buffer.assign(unicode_cmd_line.cbegin(), unicode_cmd_line.cend());
+    buffer.emplace_back(L'\0');
+    return buffer;
 }
 
-Handle create_process(const CommandLine& cmd_line) {
-    return create_process(escape_command_line(cmd_line));
+Handle create_process(const CommandLine& cmd_line, Process::IO& io) {
+    return create_process(escape_command_line(cmd_line), io);
 }
 
 } // namespace
 
+void Process::IO::close() {
+    std_in.handle.close();
+    std_out.handle.close();
+    std_err.handle.close();
+}
+
 Process Process::create(const CommandLine& cmd_line) {
-    return Process{create_process(cmd_line)};
+    return create(cmd_line, {});
+}
+
+Process Process::create(const CommandLine& cmd_line, IO io) {
+    return Process{create_process(cmd_line, io)};
 }
 
 void Process::wait() {
@@ -64,7 +84,7 @@ void Process::wait() {
 
     switch (ret) {
         case WAIT_OBJECT_0:
-            m_handle = Handle{};
+            m_handle.close();
             return;
         case WAIT_FAILED:
             throw error::windows(GetLastError(), "WaitForSingleObject");
diff --git a/src/stream.cpp b/src/stream.cpp
new file mode 100644
index 0000000..b31635e
--- /dev/null
+++ b/src/stream.cpp
@@ -0,0 +1,41 @@
+// Copyright (c) 2020 Egor Tensin <Egor.Tensin@gmail.com>
+// This file is part of the "winapi-common" project.
+// For details, see https://github.com/egor-tensin/winapi-common.
+// Distributed under the MIT License.
+
+#include <winapi/file.hpp>
+#include <winapi/handle.hpp>
+#include <winapi/stream.hpp>
+
+#include <string>
+#include <utility>
+
+namespace winapi {
+namespace process {
+
+Stdin::Stdin() : Stream{Handle::std_in()} {}
+
+Stdout::Stdout() : Stream{Handle::std_out()} {}
+
+Stderr::Stderr() : Stream{Handle::std_err()} {}
+
+Stdin::Stdin(const std::string& path) : Stream{File::open_for_reading(path)} {}
+
+Stdout::Stdout(const std::string& path) : Stream{File::open_for_writing(path)} {}
+
+Stderr::Stderr(const std::string& path) : Stream{File::open_for_writing(path)} {}
+
+Stdin::Stdin(Pipe& pipe) : Stream{std::move(pipe.read_end())} {
+    pipe.write_end().dont_inherit();
+}
+
+Stdout::Stdout(Pipe& pipe) : Stream{std::move(pipe.write_end())} {
+    pipe.read_end().dont_inherit();
+}
+
+Stderr::Stderr(Pipe& pipe) : Stream{std::move(pipe.write_end())} {
+    pipe.read_end().dont_inherit();
+}
+
+} // namespace process
+} // namespace winapi