上一篇文章已经粗略计划要讨论gsoap关于序列化/解析编程。
本文则阐述一下关于gsoap生成代码的一些重要特征方法及使用。如题,下我们从ONVIF生成的C码中,挑选简单的一个类型来试验一下与xsd__anyType之间的转换。这个试验如此重要,主要是因为,在之前我真的拿生成代码的相关结构的的一些__any字段没有办法。虽依据ONVIF文档,以及实际交互观测的XML结构中可知明明是已知的标准结构,却无奈生成被解析成any字段,主要是可能这部分字段可由厂商决定填充哪些扩展意义的结构。
本次试验选_trt__GetProfile结构作转换例程,主要理由是这个结构实在简单,只含有一个字段;书写初始化简单。
#soapStub.h
#ifndef SOAP_TYPE__trt__GetProfile #define SOAP_TYPE__trt__GetProfile (1365) /* trt:GetProfile */ struct _trt__GetProfile { char *ProfileToken; /* required element of type tt:ReferenceToken */ }; #endif
#include "inc.h" typedef struct soap *soap_pointer; #include "soap.nsmap" // anyType int anyType_ready(void) { return open("anyType.xml", O_RDWR|O_CREAT, S_IWUSR|S_IRUSR); } int FD_set(int* FD, int fd) { int ret = *FD; *FD = fd; return ret; }
注:inc.h是自组织的部分所需头依赖;
后面包含了soap.nsmap文件,你懂的,里面解开可以可以依次了解清楚包含与依赖关系;
soap.nsmap < soapH.h < soapStub.h < stdsoap2.h
static xsd__anyType* _trt__GetProfile2anyType(soap_pointer soap_, struct _trt__GetProfile* p_, xsd__anyType* _any); static struct _trt__GetProfile* _trt__GetProfile_from_anyType(soap_pointer soap_, struct _trt__GetProfile* _p, xsd__anyType* _any); int main(int argc, char const *argv[]) { /* code */ struct soap soap; soap_pointer soap_ = &soap; soap_init(soap_); struct _trt__GetProfile Data = {"Profile0"}; xsd__anyType Dom; soap_default_xsd__anyType(soap_, &Dom); if (_trt__GetProfile2anyType(soap_, &Data, &Dom)) { soap_default__trt__GetProfile(soap_, &Data); if (_trt__GetProfile_from_anyType(soap_, &Data, &Dom)) printf("Data >%s", Data.ProfileToken); } soap_end(soap_);soap_done(soap_); return 0; }
xsd__anyType* _trt__GetProfile2anyType( soap_pointer soap_, struct _trt__GetProfile* p_, xsd__anyType* _any ) { int fd = anyType_ready(); bool b = (fd == -1); if (b) return NULL; do { int* FD = &(soap_->sendfd); fd = FD_set(FD, fd); b = (soap_write__trt__GetProfile(soap_, p_) != SOAP_OK); fd = FD_set(FD, fd); b = b &&(lseek(fd, 0, SEEK_SET) == -1); if (b) break; FD = &(soap_->recvfd); fd = FD_set(FD, fd); b = (soap_read_xsd__anyType(soap_, _any) != SOAP_OK); fd = FD_set(FD, fd); } while(false); close(fd); if (b) return NULL; return _any; } struct _trt__GetProfile* _trt__GetProfile_from_anyType(soap_pointer soap_, struct _trt__GetProfile* _p, xsd__anyType* _any) { int fd = anyType_ready(); bool b = (fd == -1); if (b) return NULL; do { int* FD = &(soap_->sendfd); fd = FD_set(FD, fd); b = (soap_write_xsd__anyType(soap_, _any) != SOAP_OK); fd = FD_set(FD, fd); b = b &&(lseek(fd, 0, SEEK_SET) == -1); if (b) break; FD = &(soap_->recvfd); fd = FD_set(FD, fd); b = (soap_read__trt__GetProfile(soap_, _p) != SOAP_OK); fd = FD_set(FD, fd); } while(false); close(fd); if (b) return NULL; return _p; }
本次试验启发于gsoap指南
You can assign an output stream to soap.os or a le descriptor to soap.sendfd. For example
soap.sendfd = open(file, O_RDWR|O_CREAT, S_IWUSR|S_IRUSR); soap_serialize_PointerTons_Person(&soap, &p); soap_begin_send(&soap); soap_put_PointerTons_Person(&soap, &p, "ns:element-name", "ns:type-name"); soap_end_send(&soap);
The above can be abbreviated to
soap.sendfd = open(file, O_RDWR|O_CREAT, S_IWUSR|S_IRUSR); soap_write_PointerTons_Person(&soap, &p);
这是客户端的生成简单,soapClient.c 是soapStub.h的实现, soapC.c是soapH.h的实现,soap.nsmap是定义全局编译所需的xmlns集合namespaces[];
我们主要通过调用soapStub.h声明的方法来完成Service的访问,其中封装了交互过程;所有结构都定义在soapStub.h中有声明;
当然soapH.h则对应每一个结构都生成了相应的序列化/解析的方法,以及一些读写宏。
所有交互命令的调用及结构声明;
#ifndef SOAP_TYPE_xsd__duration #define SOAP_TYPE_xsd__duration (190) #endif SOAP_FMAC1 void SOAP_FMAC2 soap_default_xsd__duration(struct soap*, LONG64 *); SOAP_FMAC3S const char* SOAP_FMAC4S soap_xsd__duration2s(struct soap*, LONG64); SOAP_FMAC1 int SOAP_FMAC2 soap_out_xsd__duration(struct soap*, const char*, int, const LONG64 *, const char*); SOAP_FMAC3S int SOAP_FMAC4S soap_s2xsd__duration(struct soap*, const char*, LONG64 *); SOAP_FMAC1 LONG64 * SOAP_FMAC2 soap_in_xsd__duration(struct soap*, const char*, LONG64 *, const char*); SOAP_FMAC3 int SOAP_FMAC4 soap_put_xsd__duration(struct soap*, const LONG64 *, const char*, const char*); #ifndef soap_write_xsd__duration #define soap_write_xsd__duration(soap, data) ( soap_serialize_xsd__duration(soap, data), soap_begin_send(soap) || soap_put_xsd__duration(soap, data, "xsd:duration", NULL) || soap_end_send(soap), soap->error ) #endif SOAP_FMAC3 LONG64 * SOAP_FMAC4 soap_get_xsd__duration(struct soap*, LONG64 *, const char*, const char*); #ifndef soap_read_xsd__duration #define soap_read_xsd__duration(soap, data) ( soap_begin_recv(soap) || !soap_get_xsd__duration(soap, data, NULL, NULL) || soap_end_recv(soap), soap->error ) #endif
我们能见到大量类似这样规则的定义,每个方法的前置宏声明是有区别意义的。
SOAP_FMAC3S 这是序列化成字符串的方法修饰;这类方法主要是一类简单的基本类型到字符串的序列化转换, 比如ONVIF中有定义许多的枚举;
具体这么多修饰宏的意义可以参照stdsoap2.h中描述,在VC环境下使用助手的outline功夫查看文件代码结构是相当直观的。
另外我们还看见每一种类型都定义了soap_read/write_***的函式宏,本文试验主要就是通过这类读写来实现不同实现结构的转换的。
总之,为了工作简洁高效,日后可读可维护,我们尽量使用标准化的调用方式,而不走偏方,这才是本文针对各编程界提倡的建议。