中文文档 | Introduction

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Glog: General Log

Glog is a high-performance, cross-platform mobile logging component. Use mmap I/O, support synchronous/asynchronous write mode, format log with custom binary format, SDK user can choose whatever mechanism you like(eg. JSON, Protobuf). The underlaying file format is flexible, high-performance and fault-tolerant. Glog support log compression, encryption and cleanup, also includes reading module written by C++

I. WHY CHOOSE

Most of the logging component takes over the data serialization process, convert data object to binary data by JSON or other mechanism, then write binary data to file. The advantage of this is easy to use, but lack of flexible. Glog decouple the serialization process with underlaying log, remain high performance and reliable.

Technical implementation

• mmap I/O
• Customized binary file format, store each log with binary data, upper layer is responsible for serialization(Protobuf is recommended).Add sync mark to the end of each log to support fault-tolerant.
• Stream compression to reduce CPU usage
• Encrypt each log by AES CFB-128 and ECDH
• Support synchronous/asynchronous write mode, asynchronous mode implemented by message queue written by C++
• Support incremental archive(per day) and full archive(per file)
• Build-in read module

Benchmark

Phone model	Log SDK	10K write	100K write
Samsung Galaxy S10+ Android 11	glog	21 ms	182 ms
	glog+pb	54 ms	335 ms
	xlog	207 ms	1961 ms
	logan	250 ms	6469 ms
Huawei Honor Magic 2 Android 10	glog	38 ms	286 ms
	glog+pb	84 ms	505 ms
	xlog	263 ms	2165 ms
	logan	242 ms	3643 ms
Xiaomi 10 Android 11	glog	27 ms	244 ms
	xlog	198 ms	1863 ms
	logan	210 ms	4238 ms
Huawei Mate 40 pro HarmonyOS 2.0.0	glog	30 ms	257 ms
	xlog	275 ms	2484 ms
	logan	260 ms	4020 ms
OPPO R11 Android 8.1.0	glog	63 ms	324 ms
	glog+pb	234 ms	1611 ms
	xlog	464 ms	3625 ms
	logan	430 ms	5355 ms
iPhone 12 128G iOS 14.8	glog	7 ms	29 ms
	xlog	152 ms	1079 ms
	logan	162 ms	12821 ms
iPhone 8 64G iOS 13.7	glog	12 ms	50 ms
	xlog	242 ms	2106 ms
	logan	251 ms	38312 ms

II. HOW TO USE

Android

IMPORT

The latest release is available on Maven Central.

allprojects {
    repositories {
        mavenCentral()
    }
}

dependencies {
    implementation "cn.huolala.glog.android:glog-android-static:1.0.0"
    // implementation "cn.huolala.glog.android:glog-android-shared:1.0.0"
}

QUIC START

public class SampleApp extends Application {
    private Glog glog;

    @Override
    public void onCreate() {
        super.onCreate();
        // Global initialization, setup internal log level for debug
        Glog.initialize(BuildConfig.DEBUG ? InternalLogLevelDebug : InternalLogLevelInfo);
        setup();
    }

    // initialize instance
    private void setup() {
        glog = new Glog.Builder(getApplicationContext())
                .protoName("glog_identify")         // instance identity, instance with same identity will create only once
                .encryptMode(Glog.EncryptMode.AES)  // Encryption mode
                .key("")                            // ECDH Server public key
                .incrementalArchive(true)           // Incremental archive，log within a day write to same file
                .build();
    }

    // write log
    private void write() {
        byte[] data = serialize();                  // serizlize data
        glog.write(data);                           // write binary data
    } 

    // read log
    private void read() {
        ArrayList<String> logFiles = new ArrayList<>();
        glog.getArchiveSnapshot(logFiles, 10, 100 * 1024); // get snapshot of log files list, flush cache if log num >= 10 or log size >= 100KB in cache
        byte[] inBuffer = new byte[Glog.getSingleLogMaxLength()];
        for (String logFile : logFiles) {
            try (Glog.Reader reader = glog.openReader(logFile)) {
                while (true) {
                    int n = reader.read(inBuffer);
                    if (n < 0) {
                        break;
                    } else if (n == 0) { // fault-tolerant
                        continue;
                    }
                    byte[] outBuffer = new byte[n];
                    System.arraycopy(inBuffer, 0, outBuffer, 0, n);
                    deserialize(outBuffer); // deserialize binary data
                }
            } catch (IOException e) {
                e.printStackTrace();
            }
        }
    }

}

iOS

IMPORT

    pod 'Huolala-Glog'

QUIC START

    // initialize default instance
    Glog *glog = [Glog defaultGlog];
    // write data
    glog.write(data);
    // get snapshot of log files list, flush cache if log num >= 10 or log size >= 100KB in cache
    NSArray *logFiles = [self.glog getArchiveSnapshot:true minLogNum:10 totalLogSize:100 * 1024];
    NSMutableArray *dataArr = [NSMutableArray new];
    for (NSString *item in logFiles) {
        GlogReader *reader = [self.glog openReader:item];
        NSInteger length = 0;
        NSData *data;
        do {
            length = [reader read:16 * 1024 data:&data];
            if (length == 0) { // fault-tolerant
                continue;
            } else if (length < 0){
                break;
            }
            if (data) {
                NSString *dataString = [[NSString alloc] initWithData:data encoding:NSASCIIStringEncoding];
                [dataArr addObject:dataString];
            }
        } while (YES);
        NSLog(@"all the data: %@",dataArr);
        [self.glog closeReader:reader];
    }
    

III. TOOLS

• Misc/Reader
• Misc/generate-ecc-key.py

IV. AUTHOR

HuolalaTech

V. LICENSE

---

Copyright 2022 Huolala, Inc.

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.