input: use libwaio for pipe input on Windows

Use libwaio to read from pipes (stdin or named pipes) on Windows. This
liberates us from nasty issues, such as pipes (as created by most
programs) not being possible to read in a non-blocking or event-driven
way. Although it would be possible to do that in a somewhat sane way
on Vista+, it's still not easy, and on XP it's especially hard. libwaio
handles these things for us.

Move pipe.c to pipe-unix.c, and remove Windows specific things. Also
adjust the input.c code to make this work cleanly.

1 files changed, 91 insertions, 0 deletions

diff --git a/input/pipe-win32.c b/input/pipe-win32.c
new file mode 100644
index 0000000000..816bdcffed
--- /dev/null
+++ b/input/pipe-win32.c
@@ -0,0 +1,91 @@
+#include <pthread.h>
+#include <stdio.h>
+#include <windows.h>
+#include <io.h>
+
+#include <stdint.h>
+#include <waio/waio.h>
+
+#include "common/msg.h"
+#include "osdep/io.h"
+#include "input.h"
+
+static void request_cancel(struct mp_input_src *src)
+{
+    HANDLE terminate = src->priv;
+
+    MP_VERBOSE(src, "Exiting...\n");
+    SetEvent(terminate);
+}
+
+static void uninit(struct mp_input_src *src)
+{
+    HANDLE terminate = src->priv;
+
+    CloseHandle(terminate);
+    MP_VERBOSE(src, "Exited.\n");
+}
+
+static void read_pipe_thread(struct mp_input_src *src, void *param)
+{
+    char *filename = talloc_strdup(src, param);
+
+    struct waio_cx_interface *waio = NULL;
+    int mode = O_RDONLY;
+    int fd = -1;
+    bool close_fd = true;
+    if (strcmp(filename, "/dev/stdin") == 0) { // for symmetry with unix
+        fd = STDIN_FILENO;
+        close_fd = false;
+    }
+    if (fd < 0)
+        fd = open(filename, mode);
+    if (fd < 0) {
+        MP_ERR(src, "Can't open %s.\n", filename);
+        goto done;
+    }
+
+    waio = waio_alloc((void *)_get_osfhandle(fd), 0, NULL, NULL);
+    if (!waio) {
+        MP_ERR(src, "Can't initialize win32 file reader.\n");
+        goto done;
+    }
+
+    HANDLE terminate = CreateEvent(NULL, TRUE, FALSE, NULL);
+    if (!terminate)
+        goto done;
+
+    src->priv = terminate;
+    src->cancel = request_cancel;
+    src->uninit = uninit;
+    mp_input_src_init_done(src);
+
+    char buffer[128];
+    struct waio_aiocb cb = {
+        .aio_buf = buffer,
+        .aio_nbytes = sizeof(buffer),
+        .hsignal = terminate,
+    };
+    while (1) {
+        if (waio_read(waio, &cb)) {
+            MP_ERR(src, "Read operation failed.\n");
+            break;
+        }
+        if (waio_suspend(waio, (const struct waio_aiocb *[]){&cb}, 1, NULL))
+            break;
+        ssize_t r = waio_return(waio, &cb);
+        if (r <= 0)
+            break; // EOF or error
+        mp_input_src_feed_cmd_text(src, buffer, r);
+    }
+
+done:
+    waio_free(waio);
+    if (close_fd)
+        close(fd);
+}
+
+void mp_input_pipe_add(struct input_ctx *ictx, const char *filename)
+{
+    mp_input_add_thread_src(ictx, (void *)filename, read_pipe_thread);
+}