platform_system_core/adb/adb_io.cpp
Elliott Hughes aa24549190 adb sync cleanup.
We can double the speed of "adb sync" (on N9) if we increase SYNC_DATA_MAX
from 64KiB to 256KiB. This change doesn't do that, because I still haven't
managed to plumb through the information about whether we're a new adb/adbd
to file_sync_client.cpp and file_sync_service.cpp. But this is already a big
change with a lot of cleanup, so let's do the cleanup and worry about the
intended change another day...

This change does improve performance somewhat by halving the number of
lstat(2) calls made on the client side, and ensuring that most packets are
sent with a single write. This has the pleasing result of making the null
sync on an AOSP N9 go from just over 300ms to around 100ms, which means it
now seems instantaneous (https://en.wikipedia.org/wiki/Mental_chronometry).

Change-Id: If9f6d4c1f93ec752b95f71211bbbb1c513045166
2015-08-24 11:15:01 -07:00

143 lines
3.8 KiB
C++

/*
* 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.
*/
#define TRACE_TAG TRACE_RWX
#include "adb_io.h"
#include <unistd.h>
#include <base/stringprintf.h>
#include "adb_trace.h"
#include "adb_utils.h"
#include "sysdeps.h"
bool SendProtocolString(int fd, const std::string& s) {
int length = s.size();
if (length > 0xffff) {
length = 0xffff;
}
// The cost of sending two strings outweighs the cost of formatting.
// "adb sync" performance is affected by this.
return WriteFdFmt(fd, "%04x%.*s", length, length, s.c_str());
}
bool ReadProtocolString(int fd, std::string* s, std::string* error) {
char buf[5];
if (!ReadFdExactly(fd, buf, 4)) {
*error = perror_str("protocol fault (couldn't read status length)");
return false;
}
buf[4] = 0;
unsigned long len = strtoul(buf, 0, 16);
s->resize(len, '\0');
if (!ReadFdExactly(fd, &(*s)[0], len)) {
*error = perror_str("protocol fault (couldn't read status message)");
return false;
}
return true;
}
bool SendOkay(int fd) {
return WriteFdExactly(fd, "OKAY", 4);
}
bool SendFail(int fd, const std::string& reason) {
return WriteFdExactly(fd, "FAIL", 4) && SendProtocolString(fd, reason);
}
bool ReadFdExactly(int fd, void* buf, size_t len) {
char* p = reinterpret_cast<char*>(buf);
size_t len0 = len;
D("readx: fd=%d wanted=%zu\n", fd, len);
while (len > 0) {
int r = adb_read(fd, p, len);
if (r > 0) {
len -= r;
p += r;
} else if (r == -1) {
D("readx: fd=%d error %d: %s\n", fd, errno, strerror(errno));
return false;
} else {
D("readx: fd=%d disconnected\n", fd);
errno = 0;
return false;
}
}
D("readx: fd=%d wanted=%zu got=%zu\n", fd, len0, len0 - len);
if (ADB_TRACING) {
dump_hex(reinterpret_cast<const unsigned char*>(buf), len0);
}
return true;
}
bool WriteFdExactly(int fd, const void* buf, size_t len) {
const char* p = reinterpret_cast<const char*>(buf);
int r;
D("writex: fd=%d len=%d: ", fd, (int)len);
if (ADB_TRACING) {
dump_hex(reinterpret_cast<const unsigned char*>(buf), len);
}
while (len > 0) {
r = adb_write(fd, p, len);
if (r == -1) {
D("writex: fd=%d error %d: %s\n", fd, errno, strerror(errno));
if (errno == EAGAIN) {
adb_sleep_ms(1); // just yield some cpu time
continue;
} else if (errno == EPIPE) {
D("writex: fd=%d disconnected\n", fd);
errno = 0;
return false;
} else {
return false;
}
} else {
len -= r;
p += r;
}
}
return true;
}
bool WriteFdExactly(int fd, const char* str) {
return WriteFdExactly(fd, str, strlen(str));
}
bool WriteFdExactly(int fd, const std::string& str) {
return WriteFdExactly(fd, str.c_str(), str.size());
}
bool WriteFdFmt(int fd, const char* fmt, ...) {
std::string str;
va_list ap;
va_start(ap, fmt);
android::base::StringAppendV(&str, fmt, ap);
va_end(ap);
return WriteFdExactly(fd, str);
}