adb: win32: fix adb shell
28416d6d33267f92768116e269966d61eac01db9 broke adb shell on Windows
because it was calling unix_read() with a buffer size of 1 byte which
wasn't supported by unix_read()/_console_read().
This change makes _console_read() support such a small buffer by
maintaining an internal input buffer.
This lets us simplify the existing code that was already maintaining a
cached INPUT_RECORD.
Also eliminate some duplicate code in the big switch statement.
Change-Id: I8f0aed4fb9f6f2f5b9a6b68ce60d2e368fec81c7
Signed-off-by: Spencer Low <CompareAndSwap@gmail.com>
diff --git a/adb/sysdeps_win32.cpp b/adb/sysdeps_win32.cpp
index e325889..beaca16 100644
--- a/adb/sysdeps_win32.cpp
+++ b/adb/sysdeps_win32.cpp
@@ -2546,15 +2546,14 @@
return _get_console_handle(fd) ? 1 : 0;
}
-// Read an input record from the console; one that should be processed.
-static bool _get_interesting_input_record_uncached(const HANDLE console,
- INPUT_RECORD* const input_record) {
+// Get the next KEY_EVENT_RECORD that should be processed.
+static bool _get_key_event_record(const HANDLE console, INPUT_RECORD* const input_record) {
for (;;) {
DWORD read_count = 0;
memset(input_record, 0, sizeof(*input_record));
if (!ReadConsoleInputA(console, input_record, 1, &read_count)) {
- D("_get_interesting_input_record_uncached: ReadConsoleInputA() "
- "failed: %s\n", SystemErrorCodeToString(GetLastError()).c_str());
+ D("_get_key_event_record: ReadConsoleInputA() failed: %s\n",
+ SystemErrorCodeToString(GetLastError()).c_str());
errno = EIO;
return false;
}
@@ -2580,28 +2579,6 @@
}
}
-// Cached input record (in case _console_read() is passed a buffer that doesn't
-// have enough space to fit wRepeatCount number of key sequences). A non-zero
-// wRepeatCount indicates that a record is cached.
-static INPUT_RECORD _win32_input_record;
-
-// Get the next KEY_EVENT_RECORD that should be processed.
-static KEY_EVENT_RECORD* _get_key_event_record(const HANDLE console) {
- // If nothing cached, read directly from the console until we get an
- // interesting record.
- if (_win32_input_record.Event.KeyEvent.wRepeatCount == 0) {
- if (!_get_interesting_input_record_uncached(console,
- &_win32_input_record)) {
- // There was an error, so make sure wRepeatCount is zero because
- // that signifies no cached input record.
- _win32_input_record.Event.KeyEvent.wRepeatCount = 0;
- return NULL;
- }
- }
-
- return &_win32_input_record.Event.KeyEvent;
-}
-
static __inline__ bool _is_shift_pressed(const DWORD control_key_state) {
return (control_key_state & SHIFT_PRESSED) != 0;
}
@@ -2946,16 +2923,34 @@
return len + 1;
}
-// Writes to buffer buf (of length len), returning number of bytes written or
-// -1 on error. Never returns zero because Win32 consoles are never 'closed'
-// (as far as I can tell).
+// Internal buffer to satisfy future _console_read() calls.
+static std::vector<char> g_console_input_buffer;
+
+// Writes to buffer buf (of length len), returning number of bytes written or -1 on error. Never
+// returns zero on console closure because Win32 consoles are never 'closed' (as far as I can tell).
static int _console_read(const HANDLE console, void* buf, size_t len) {
for (;;) {
- KEY_EVENT_RECORD* const key_event = _get_key_event_record(console);
- if (key_event == NULL) {
+ // Read of zero bytes should not block waiting for something from the console.
+ if (len == 0) {
+ return 0;
+ }
+
+ // Flush as much as possible from input buffer.
+ if (!g_console_input_buffer.empty()) {
+ const int bytes_read = std::min(len, g_console_input_buffer.size());
+ memcpy(buf, g_console_input_buffer.data(), bytes_read);
+ const auto begin = g_console_input_buffer.begin();
+ g_console_input_buffer.erase(begin, begin + bytes_read);
+ return bytes_read;
+ }
+
+ // Read from the actual console. This may block until input.
+ INPUT_RECORD input_record;
+ if (!_get_key_event_record(console, &input_record)) {
return -1;
}
+ KEY_EVENT_RECORD* const key_event = &input_record.Event.KeyEvent;
const WORD vk = key_event->wVirtualKeyCode;
const CHAR ch = key_event->uChar.AsciiChar;
const DWORD control_key_state = _normalize_altgr_control_key_state(
@@ -3133,7 +3128,12 @@
break;
case 0x32: // 2
+ case 0x33: // 3
+ case 0x34: // 4
+ case 0x35: // 5
case 0x36: // 6
+ case 0x37: // 7
+ case 0x38: // 8
case VK_OEM_MINUS: // -_
{
seqbuflen = _get_control_character(seqbuf, key_event,
@@ -3149,25 +3149,6 @@
}
break;
- case 0x33: // 3
- case 0x34: // 4
- case 0x35: // 5
- case 0x37: // 7
- case 0x38: // 8
- {
- seqbuflen = _get_control_character(seqbuf, key_event,
- control_key_state);
-
- // If Alt is pressed and it isn't Ctrl-Alt-ShiftUp, then
- // prefix with escape.
- if (_is_alt_pressed(control_key_state) &&
- !(_is_ctrl_pressed(control_key_state) &&
- !_is_shift_pressed(control_key_state))) {
- seqbuflen = _escape_prefix(seqbuf, seqbuflen);
- }
- }
- break;
-
case 0x41: // a
case 0x42: // b
case 0x43: // c
@@ -3296,46 +3277,15 @@
// event.
D("_console_read: unknown virtual key code: %d, enhanced: %s",
vk, _is_enhanced_key(control_key_state) ? "true" : "false");
- key_event->wRepeatCount = 0;
continue;
}
- int bytesRead = 0;
-
- // put output wRepeatCount times into buf/len
- while (key_event->wRepeatCount > 0) {
- if (len >= outlen) {
- // Write to buf/len
- memcpy(buf, out, outlen);
- buf = (void*)((char*)buf + outlen);
- len -= outlen;
- bytesRead += outlen;
-
- // consume the input
- --key_event->wRepeatCount;
- } else {
- // Not enough space, so just leave it in _win32_input_record
- // for a subsequent retrieval.
- if (bytesRead == 0) {
- // We didn't write anything because there wasn't enough
- // space to even write one sequence. This should never
- // happen if the caller uses sensible buffer sizes
- // (i.e. >= maximum sequence length which is probably a
- // few bytes long).
- D("_console_read: no buffer space to write one sequence; "
- "buffer: %ld, sequence: %ld\n", (long)len,
- (long)outlen);
- errno = ENOMEM;
- return -1;
- } else {
- // Stop trying to write to buf/len, just return whatever
- // we wrote so far.
- break;
- }
- }
+ // put output wRepeatCount times into g_console_input_buffer
+ while (key_event->wRepeatCount-- > 0) {
+ g_console_input_buffer.insert(g_console_input_buffer.end(), out, out + outlen);
}
- return bytesRead;
+ // Loop around and try to flush g_console_input_buffer
}
}