编译hadoop-2.4.0之HDFS的64位C++库

C++库的源代码位于：

hadoop-2.4.0-src/hadoop-hdfs-project/hadoop-hdfs/src/main/native/libhdfs

这里提供一个直接对这些源文件进行编译的makefile，编译后将打包命名为libhdfs.a. makefile内容为：

CC            = gcc
DEFINES       = -DG_ARCH_X86_64


CFLAGS        += -fPIC -D_LARGEFILE_SOURCE -D_FILE_OFFSET_BITS=64 -pipe -O3 -D_REENTRANT $(DEFINES)
CXXFLAGS      += -pipe -O3 -D_REENTRANT $(DEFINES) -rdynamic

AR            = ar cqs
LFLAGS        = -rdynamic

OBJECTS       = exception.o expect.o hdfs.o jni_helper.o native_mini_dfs.o

TARGET        = libhdfs.a

#command, don't change
CHK_DIR_EXISTS= test -d
DEL_FILE      = rm -f


first: all
####### Implicit rules

.SUFFIXES: .o .c .cpp .cc .cxx .C .cu

.cpp.o:
	$(CXX) -c $(CXXFLAGS) $(INCPATH) -o "$@" "$<"

.cc.o:
	$(CXX) -c $(CXXFLAGS) $(INCPATH) -o "$@" "$<"

.cxx.o:
	$(CXX) -c $(CXXFLAGS) $(INCPATH) -o "$@" "$<"

.C.o:
	$(CXX) -c $(CXXFLAGS) $(INCPATH) -o "$@" "$<"

.c.o:
	$(CC) -c $(CFLAGS) $(INCPATH) -o "$@" "$<"
        
####### Build rules     
all: $(AR)

$(AR): $(TARGET)

$(TARGET):  $(OBJECTS)
	$(AR) $(TARGET) $(OBJECTS)

clean: 
	-$(DEL_FILE) $(OBJECTS) $(TARGET)

保存好后，直接make. 编译信息如下：

gcc -c -fPIC -D_LARGEFILE_SOURCE -D_FILE_OFFSET_BITS=64 -pipe -O3 -D_REENTRANT -DG_ARCH_X86_64  -o "exception.o" "exception.c"
gcc -c -fPIC -D_LARGEFILE_SOURCE -D_FILE_OFFSET_BITS=64 -pipe -O3 -D_REENTRANT -DG_ARCH_X86_64  -o "expect.o" "expect.c"
gcc -c -fPIC -D_LARGEFILE_SOURCE -D_FILE_OFFSET_BITS=64 -pipe -O3 -D_REENTRANT -DG_ARCH_X86_64  -o "hdfs.o" "hdfs.c"
gcc -c -fPIC -D_LARGEFILE_SOURCE -D_FILE_OFFSET_BITS=64 -pipe -O3 -D_REENTRANT -DG_ARCH_X86_64  -o "jni_helper.o" "jni_helper.c"
gcc -c -fPIC -D_LARGEFILE_SOURCE -D_FILE_OFFSET_BITS=64 -pipe -O3 -D_REENTRANT -DG_ARCH_X86_64  -o "native_mini_dfs.o" "native_mini_dfs.c"
ar cqs libhdfs.a exception.o expect.o hdfs.o jni_helper.o native_mini_dfs.o

接下来测试一下这个库能不能用。进入以下目录

hadoop-2.4.0-src/hadoop-hdfs-project/hadoop-hdfs/src/main/native/libhdfs/test

找到测试源代码，对该文件夹中所有测试代码进行编译.这里再提供一个简单的makefile，内容如下：

LIBS = -L$(JAVA_HOME)/jre/lib/amd64/server/ -ljvm  -L../ -lhdfs
INCPATH = -I$(JAVA_HOME)/include -I$(JAVA_HOME)/include/linux -I. -I..
all:
	gcc -o hdfs_ops test_libhdfs_ops.c $(INCPATH) $(LIBS)
	gcc -o hdfs_read test_libhdfs_read.c $(INCPATH) $(LIBS)
	gcc -o hdfs_write test_libhdfs_write.c $(INCPATH) $(LIBS)
	gcc -o hdfs_zerocopy test_libhdfs_zerocopy.c $(INCPATH) $(LIBS)

直接make,编译信息如下：

gcc -o hdfs_ops test_libhdfs_ops.c -I/d0/data/lichao/software/java/jdk1.7.0_55/include -I/d0/data/lichao/software/java/jdk1.7.0_55/include/linux -I. -I.. -L/d0/data/lichao/software/java/jdk1.7.0_55/jre/lib/amd64/server/ -ljvm  -L../ -lhdfs
gcc -o hdfs_read test_libhdfs_read.c -I/d0/data/lichao/software/java/jdk1.7.0_55/include -I/d0/data/lichao/software/java/jdk1.7.0_55/include/linux -I. -I.. -L/d0/data/lichao/software/java/jdk1.7.0_55/jre/lib/amd64/server/ -ljvm  -L../ -lhdfs
gcc -o hdfs_write test_libhdfs_write.c -I/d0/data/lichao/software/java/jdk1.7.0_55/include -I/d0/data/lichao/software/java/jdk1.7.0_55/include/linux -I. -I.. -L/d0/data/lichao/software/java/jdk1.7.0_55/jre/lib/amd64/server/ -ljvm  -L../ -lhdfs
gcc -o hdfs_zerocopy test_libhdfs_zerocopy.c -I/d0/data/lichao/software/java/jdk1.7.0_55/include -I/d0/data/lichao/software/java/jdk1.7.0_55/include/linux -I. -I.. -L/d0/data/lichao/software/java/jdk1.7.0_55/jre/lib/amd64/server/ -ljvm  -L../ -lhdfs

我们随便生成一个文件，包含1到10这10个数字，并加载到hdfs文件系统。

seq 1 10 >  tmpfile
hadoop fs -mkdir /data
hadoop fs -put tmpfile /data
hadoop fs -cat /data/tmpfile
1
2
3
4
5
6
7
8
9
10

ok。现在运行生成的hdfs_read程序，测试一下hdfs的64位C++接口：

./hdfs_read /data/tmpfile 21 32

运行信息如下：

log4j:WARN No appenders could be found for logger (org.apache.hadoop.metrics2.lib.MutableMetricsFactory).
log4j:WARN Please initialize the log4j system properly.
log4j:WARN See http://logging.apache.org/log4j/1.2/faq.html#noconfig for more info.
1
2
3
4
5
6
7
8
9
10