1/*
2 * Copyright (C) 2015 The Android Open Source Project
3 *
4 * Licensed under the Apache License, Version 2.0 (the "License");
5 * you may not use this file except in compliance with the License.
6 * You may obtain a copy of the License at
7 *
8 *      http://www.apache.org/licenses/LICENSE-2.0
9 *
10 * Unless required by applicable law or agreed to in writing, software
11 * distributed under the License is distributed on an "AS IS" BASIS,
12 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
13 * See the License for the specific language governing permissions and
14 * limitations under the License.
15 */
16
17#include "shell_service.h"
18
19#include <string.h>
20
21#include <algorithm>
22
23#include "adb_io.h"
24
25ShellProtocol::ShellProtocol(int fd) : fd_(fd) {
26    buffer_[0] = kIdInvalid;
27}
28
29ShellProtocol::~ShellProtocol() {
30}
31
32bool ShellProtocol::Read() {
33    // Only read a new header if we've finished the last packet.
34    if (!bytes_left_) {
35        if (!ReadFdExactly(fd_, buffer_, kHeaderSize)) {
36            return false;
37        }
38
39        length_t packet_length;
40        memcpy(&packet_length, &buffer_[1], sizeof(packet_length));
41        bytes_left_ = packet_length;
42        data_length_ = 0;
43    }
44
45    size_t read_length = std::min(bytes_left_, data_capacity());
46    if (read_length && !ReadFdExactly(fd_, data(), read_length)) {
47        return false;
48    }
49
50    bytes_left_ -= read_length;
51    data_length_ = read_length;
52
53    return true;
54}
55
56bool ShellProtocol::Write(Id id, size_t length) {
57    buffer_[0] = id;
58    length_t typed_length = length;
59    memcpy(&buffer_[1], &typed_length, sizeof(typed_length));
60
61    return WriteFdExactly(fd_, buffer_, kHeaderSize + length);
62}
63