唐新發(fā) 2012-02-18 12:25 發(fā)表評(píng)論
]]>手冊(cè)上有一段話初看讓人疑惑：
Protocol Buffers and O-O Design Protocol buffer classes are basically dumb data holders (like structs in C++); they don't make good first class citizens in an object model. If you want to add richer behaviour to a generated class, the best way to do this is to wrap the generated protocol buffer class in an application-specific class. Wrapping protocol buffers is also a good idea if you don't have control over the design of the
.proto file (if, say,
you're reusing one from another project). In that case, you can use the
wrapper class to craft an interface better suited to the unique
environment of your application: hiding some data and methods, exposing
convenience functions, etc. You should never add behaviour to the generated classes by inheriting from them. This will break internal mechanisms and is not good object-oriented practice anyway.
大意是不要從它生成的Message類進(jìn)行派生，以便加入一些行為函數(shù)，而應(yīng)該采用包裝（wrap）的方式，說(shuō)白了就是組合（在你的類中放一個(gè)生成的Message類成員變量）。通過(guò)查看郵件列表，載錄以下詳細(xì)解釋：
*如果進(jìn)行派生，那么你的類中會(huì)混入Protocol Buffer生成的一些方法，而這些方法將來(lái)還可能會(huì)變化，
這就意味著你的類將依賴Protocol Buffer的實(shí)現(xiàn)。用設(shè)計(jì)相關(guān)的術(shù)語(yǔ)就是：你繼承了實(shí)現(xiàn)，你把業(yè)務(wù)和數(shù)據(jù)混在了一起。
唐新發(fā) 2009-06-07 23:02 發(fā)表評(píng)論
]]>stub由client使用，skeleton由server在收到請(qǐng)求時(shí)自動(dòng)調(diào)用。
考慮最基本的通信：client->network->server
在network的兩個(gè)邊界分別就是stub和skeleton
gsoap通過(guò)生成stub和skeleton，讓我們的client只需調(diào)用一下stub函數(shù)，而server只需要實(shí)現(xiàn)skeleton函數(shù)內(nèi)部調(diào)用的對(duì)應(yīng)的處理函數(shù)。
唐新發(fā) 2009-03-30 10:37 發(fā)表評(píng)論
]]>- 簡(jiǎn)介
http://logging.apache.org/log4cxx/index.html
- 下載、編譯、安裝
cd ~/libs
wget http://mirror.bjtu.edu.cn/apache//apr/apr-1.4.4.tar.bz2
tar xjvf apr-1.4.4.tar.bz2
cd apr-1.4.4
./configure --prefix=${HOME}/libs && make && make install
cd ..
wget http://mirror.bjtu.edu.cn/apache//apr/apr-util-1.3.11.tar.bz2
tar xjvf apr-util-1.3.11.tar.bz2
cd apr-util-1.3.11
./configure --prefix=${HOME}/libs --with-apr=${HOME}/libs && make && make install
cd ..
wget http://apache.etoak.com//logging/log4cxx/0.10.0/apache-log4cxx-0.10.0.tar.gz
tar xzvf apache-log4cxx-0.10.0.tar.gz
cd apache-log4cxx-0.10.0
./configure --with-charset=utf-8 --prefix=${HOME}/libs --with-apr=${HOME}/libs --with-apr-util=${HOME}/libs && make && make install
- 使用例子
#include?"log4cxx/logger.h"
#include?"log4cxx/propertyconfigurator.h"
static?log4cxx::LoggerPtr?logger(log4cxx::Logger::getLogger("hello"));
int?main(int?argc,?char?*argv[])
{
????????log4cxx::PropertyConfigurator::configure("./log4cxx_hello.properties");
??????? LOG4CXX_INFO(logger,?"你好，log4cxx!");
????????return?0;
}
#include?"log4cxx/propertyconfigurator.h"
static?log4cxx::LoggerPtr?logger(log4cxx::Logger::getLogger("hello"));
int?main(int?argc,?char?*argv[])
{
????????log4cxx::PropertyConfigurator::configure("./log4cxx_hello.properties");
??????? LOG4CXX_INFO(logger,?"你好，log4cxx!");
????????return?0;
}
log4cxx_hello.properties:
log4j.rootLogger=debug,?R
log4j.appender.stdout=org.apache.log4j.ConsoleAppender
log4j.appender.stdout.layout=org.apache.log4j.PatternLayout
#?Pattern?to?output?the?caller's?file?name?and?line?number.
log4j.appender.stdout.layout.ConversionPattern=%5p?[%t]?(%F:%L)?-?%m%n
log4j.appender.R=org.apache.log4j.RollingFileAppender
log4j.appender.R.File=./hello.log
log4j.appender.R.MaxFileSize=100KB
#?Keep?one?backup?file
log4j.appender.R.MaxBackupIndex=10
log4j.appender.R.layout=org.apache.log4j.PatternLayout
log4j.appender.R.layout.ConversionPattern=%5p?%c?[%t]?(%F:%L)?-?%m%n
log4j.appender.stdout=org.apache.log4j.ConsoleAppender
log4j.appender.stdout.layout=org.apache.log4j.PatternLayout
#?Pattern?to?output?the?caller's?file?name?and?line?number.
log4j.appender.stdout.layout.ConversionPattern=%5p?[%t]?(%F:%L)?-?%m%n
log4j.appender.R=org.apache.log4j.RollingFileAppender
log4j.appender.R.File=./hello.log
log4j.appender.R.MaxFileSize=100KB
#?Keep?one?backup?file
log4j.appender.R.MaxBackupIndex=10
log4j.appender.R.layout=org.apache.log4j.PatternLayout
log4j.appender.R.layout.ConversionPattern=%5p?%c?[%t]?(%F:%L)?-?%m%n
g++ -o hello hello.cpp -I${HOME}/libs/include ${HOME}/libs/lib/liblog4cxx.a ${HOME}/libs/lib/libaprutil-1.a ${HOME}/libs/lib/libapr-1.a? -lexpat -lpthread
- 注意事項(xiàng)
這個(gè)限制避免性能問(wèn)題，可以通過(guò)設(shè)置大一點(diǎn)的MaxFileSize來(lái)保存更多日志，否則就要在編譯時(shí)改大一點(diǎn)了。
參考：http://objectmix.com/apache/684503-urgent-log4cxx-large-window-sizes-not-allowed.html
- 使用技巧
???? xml雖較property格式繁鎖，支持的配置面更全，而property格式的配置文件使用更簡(jiǎn)單，容易在網(wǎng)上找到現(xiàn)成的配置文件。
2，logger命名。
???? logger名稱反映了軟件模塊，如果有代表軟件模塊的類，則在類中包含以該類類名命名的logger對(duì)象，該模塊功能相關(guān)代碼通過(guò)該logger進(jìn)行日志記錄。
另外可將logger對(duì)象作為全局變量，方便使用，特別是當(dāng)軟件模塊較松散，并無(wú)對(duì)應(yīng)的封裝類時(shí)。
3，在代碼中適當(dāng)?shù)胤胖萌罩敬a。引用適當(dāng)?shù)娜罩緦?duì)象，對(duì)日志進(jìn)行適當(dāng)分級(jí)。
4，余下的工作就是修改配置文件，對(duì)日志進(jìn)行控制了。
使用配置文件的好處就是可以方便地配置日志而不需要修改源代碼，可以在配置文件中方便配置日志過(guò)濾、格式、日志目的地。
- 體驗(yàn)
唐新發(fā) 2008-06-17 10:01 發(fā)表評(píng)論
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