Refactor input module to use RStream class

1 files changed, 24 insertions, 129 deletions

diff --git a/src/os/input.c b/src/os/input.c
index 6f44df166f..dfbe5dcc05 100644
--- a/src/os/input.c
+++ b/src/os/input.c
@@ -6,6 +6,8 @@
 
 #include "os/input.h"
 #include "os/event.h"
+#include "os/rstream_defs.h"
+#include "os/rstream.h"
 #include "vim.h"
 #include "globals.h"
 #include "ui.h"
@@ -15,7 +17,7 @@
 #include "term.h"
 #include "misc2.h"
 
-#define READ_BUFFER_LENGTH 4096
+#define READ_BUFFER_SIZE 256
 
 typedef enum {
   kInputNone,
@@ -23,101 +25,41 @@ typedef enum {
   kInputEof
 } InbufPollResult;
 
-typedef struct {
-  uv_buf_t uvbuf;
-  uint32_t rpos, wpos, fpos;
-  char_u data[READ_BUFFER_LENGTH];
-  bool reading;
-} ReadBuffer;
-
-static ReadBuffer rbuffer;
-static uv_pipe_t read_stream;
-// Use an idle handle to make reading from the fs look like a normal libuv
-// event
-static uv_idle_t fread_idle;
-static uv_handle_type read_channel_type;
-static bool eof = false;
+static RStream *read_stream;
+static bool eof = false, started_reading = false;
 
 static InbufPollResult inbuf_poll(int32_t ms);
 static void stderr_switch(void);
-static void alloc_cb(uv_handle_t *, size_t, uv_buf_t *);
-static void read_cb(uv_stream_t *, ssize_t, const uv_buf_t *);
-static void fread_idle_cb(uv_idle_t *);
+static void read_cb(RStream *rstream, void *data, bool eof);
 
 void input_init()
 {
-  rbuffer.wpos = rbuffer.rpos = rbuffer.fpos = 0;
-#ifdef DEBUG
-  memset(&rbuffer.data, 0, READ_BUFFER_LENGTH);
-#endif
-
-  if ((read_channel_type = uv_guess_handle(read_cmd_fd)) == UV_FILE) {
-    uv_idle_init(uv_default_loop(), &fread_idle);
-  } else {
-    uv_pipe_init(uv_default_loop(), &read_stream, 0);
-    uv_pipe_open(&read_stream, read_cmd_fd);
-  }
+  read_stream = rstream_new(read_cb, READ_BUFFER_SIZE, NULL);
+  rstream_set_file(read_stream, read_cmd_fd);
 }
 
 // Check if there's pending input
 bool input_ready()
 {
-  return rbuffer.rpos < rbuffer.wpos || eof;
+  return rstream_available(read_stream) > 0 || eof;
 }
 
 // Listen for input
 void input_start()
 {
-  // Pin the buffer used by libuv
-  rbuffer.uvbuf.len = READ_BUFFER_LENGTH - rbuffer.wpos;
-  rbuffer.uvbuf.base = (char *)(rbuffer.data + rbuffer.wpos);
-
-  if (read_channel_type == UV_FILE) {
-    // Just invoke the `fread_idle_cb` as soon as the loop starts
-    uv_idle_start(&fread_idle, fread_idle_cb);
-  } else {
-    // Start reading
-    rbuffer.reading = false;
-    uv_read_start((uv_stream_t *)&read_stream, alloc_cb, read_cb);
-  }
+  rstream_start(read_stream);
 }
 
 // Stop listening for input
 void input_stop()
 {
-  if (read_channel_type == UV_FILE) {
-    uv_idle_stop(&fread_idle);
-  } else {
-    uv_read_stop((uv_stream_t *)&read_stream);
-  }
+  rstream_stop(read_stream);
 }
 
 // Copies (at most `count`) of was read from `read_cmd_fd` into `buf`
 uint32_t input_read(char *buf, uint32_t count)
 {
-  uint32_t read_count = rbuffer.wpos - rbuffer.rpos;
-
-  if (count < read_count) {
-    read_count = count;
-  }
-
-  if (read_count > 0) {
-    memcpy(buf, rbuffer.data + rbuffer.rpos, read_count);
-    rbuffer.rpos += read_count;
-  }
-
-  if (rbuffer.wpos == READ_BUFFER_LENGTH) {
-    // `wpos` is at the end of the buffer, so free some space by moving unread
-    // data...
-    memmove(
-        rbuffer.data,  // ...To the beginning of the buffer(rpos 0)
-        rbuffer.data + rbuffer.rpos,  // ...From the first unread position
-        rbuffer.wpos - rbuffer.rpos);  // ...By the number of unread bytes
-    rbuffer.wpos -= rbuffer.rpos;
-    rbuffer.rpos = 0;
-  }
-
-  return read_count;
+  return rstream_read(read_stream, buf, count);
 }
 
 
@@ -188,7 +130,9 @@ static InbufPollResult inbuf_poll(int32_t ms)
   }
 
   if (event_poll(ms)) {
-    return eof && rbuffer.rpos == rbuffer.wpos ? kInputEof : kInputAvail;
+    return eof && rstream_available(read_stream) == 0 ?
+      kInputEof :
+      kInputAvail;
   }
 
   return kInputNone;
@@ -201,69 +145,22 @@ static void stderr_switch()
   // cooked mode
   settmode(TMODE_COOK);
   // Stop the idle handle
-  uv_idle_stop(&fread_idle);
+  rstream_stop(read_stream);
   // Use stderr for stdin, also works for shell commands.
   read_cmd_fd = 2;
   // Initialize and start the input stream
-  uv_pipe_init(uv_default_loop(), &read_stream, 0);
-  uv_pipe_open(&read_stream, read_cmd_fd);
-  uv_read_start((uv_stream_t *)&read_stream, alloc_cb, read_cb);
-  rbuffer.reading = false;
+  rstream_set_file(read_stream, read_cmd_fd);
+  rstream_start(read_stream);
   // Set the mode back to what it was
   settmode(mode);
 }
 
-// Called by libuv to allocate memory for reading.
-static void alloc_cb(uv_handle_t *handle, size_t suggested, uv_buf_t *buf)
+static void read_cb(RStream *rstream, void *data, bool at_eof)
 {
-  if (rbuffer.reading) {
-    buf->len = 0;
-    return;
-  }
-
-  buf->base = rbuffer.uvbuf.base;
-  buf->len = rbuffer.uvbuf.len;
-  // Avoid `alloc_cb`, `alloc_cb` sequences on windows
-  rbuffer.reading = true;
-}
-
-// Callback invoked by libuv after it copies the data into the buffer provided
-// by `alloc_cb`. This is also called on EOF or when `alloc_cb` returns a
-// 0-length buffer.
-static void read_cb(uv_stream_t *stream, ssize_t cnt, const uv_buf_t *buf)
-{
-  if (cnt <= 0) {
-    if (cnt != UV_ENOBUFS) {
-      // Read error or EOF, either way vim must exit
-      eof = true;
-    }
-    return;
-  }
-
-  // Data was already written, so all we need is to update 'wpos' to reflect
-  // the space actually used in the buffer.
-  rbuffer.wpos += cnt;
-}
-
-// Called by the by the 'idle' handle to emulate a reading event
-static void fread_idle_cb(uv_idle_t *handle)
-{
-  uv_fs_t req;
-
-  // Synchronous read
-  uv_fs_read(
-      uv_default_loop(),
-      &req,
-      read_cmd_fd,
-      &rbuffer.uvbuf,
-      1,
-      rbuffer.fpos,
-      NULL);
-
-  uv_fs_req_cleanup(&req);
-
-  if (req.result <= 0) {
-    if (rbuffer.fpos == 0 && uv_guess_handle(2) == UV_TTY) {
+  if (at_eof) {
+    if (!started_reading
+        && rstream_is_regular_file(rstream)
+        && uv_guess_handle(2) == UV_TTY) {
       // Read error. Since stderr is a tty we switch to reading from it. This
       // is for handling for cases like "foo | xargs vim" because xargs
       // redirects stdin from /dev/null. Previously, this was done in ui.c
@@ -271,9 +168,7 @@ static void fread_idle_cb(uv_idle_t *handle)
     } else {
       eof = true;
     }
-    return;
   }
 
-  rbuffer.wpos += req.result;
-  rbuffer.fpos += req.result;
+  started_reading = true;
 }