adb: create shell protocol class (take 2).
Adds a new class ShellProtocol to help read and write data with
`adb shell`. This will allow splitting streams and sending out-of-band
data such as exit codes.
Nothing uses the new class yet except the unit tests.
This is the second attempt at this CL, the first is at
http://r.android.com/169600. The problems was using sighandler_t
which is not available on mac. sig_t is used instead which is available
due to _GNU_SOURCE being defined in Android.mk, which causes
_BSD_SOURCE -> __USE_BSD -> sig_t to be defined. Nothing else has been
changed from the original CL.
Bug: http://b/23030641
Change-Id: I7bd7f5a82ad811fbca7a3eee1236d2c55ae57c48
diff --git a/shell_service_protocol.cpp b/shell_service_protocol.cpp
new file mode 100644
index 0000000..623629c
--- /dev/null
+++ b/shell_service_protocol.cpp
@@ -0,0 +1,62 @@
+/*
+ * Copyright (C) 2015 The Android Open Source Project
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ * http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+#include "shell_service.h"
+
+#include <string.h>
+
+#include <algorithm>
+
+#include "adb_io.h"
+
+ShellProtocol::ShellProtocol(int fd) : fd_(fd) {
+ buffer_[0] = kIdInvalid;
+}
+
+ShellProtocol::~ShellProtocol() {
+}
+
+bool ShellProtocol::Read() {
+ // Only read a new header if we've finished the last packet.
+ if (!bytes_left_) {
+ if (!ReadFdExactly(fd_, buffer_, kHeaderSize)) {
+ return false;
+ }
+
+ length_t packet_length;
+ memcpy(&packet_length, &buffer_[1], sizeof(packet_length));
+ bytes_left_ = packet_length;
+ data_length_ = 0;
+ }
+
+ size_t read_length = std::min(bytes_left_, data_capacity());
+ if (read_length && !ReadFdExactly(fd_, data(), read_length)) {
+ return false;
+ }
+
+ bytes_left_ -= read_length;
+ data_length_ = read_length;
+
+ return true;
+}
+
+bool ShellProtocol::Write(Id id, size_t length) {
+ buffer_[0] = id;
+ length_t typed_length = length;
+ memcpy(&buffer_[1], &typed_length, sizeof(typed_length));
+
+ return WriteFdExactly(fd_, buffer_, kHeaderSize + length);
+}