Michael Davidsaver
113 lines
3.0 KiB
C++
113 lines
3.0 KiB
C++
/**
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* Copyright - See the COPYRIGHT that is included with this distribution.
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* pvxs is distributed subject to a Software License Agreement found
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* in file LICENSE that is included with this distribution.
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*/
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/** Meant to be run against the mailbox example.
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* eg. in one terminal run:
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*
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* ./mailbox some:pv:name
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*
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* And in another terminal run:
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*
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* ./client some:pv:name
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*/
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#include <iostream>
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#include <pvxs/client.h>
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#include <pvxs/log.h>
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using namespace pvxs;
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int main(int argc, char* argv[])
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{
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if(argc<2) {
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std::cerr<<"Usage: "<<argv[0]<<" <pvname>\n";
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return 1;
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}
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// Read $PVXS_LOG from process environment and update
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// logging configuration. eg.
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// export PVXS_LOG=*=DEBUG
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// makes a lot of noise.
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logger_config_env();
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// Create a client context
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client::Context ctxt(client::Config::fromEnv()
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.build());
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// Fetch current value
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int32_t current;
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{
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std::cout<<"Getting current value of '"<<argv[1]<<"'"<<std::endl;
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// Build and start network operation
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auto op = ctxt.get(argv[1])
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.exec();
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// wait for it to complete, for up to 5 seconds.
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Value result = op->wait(5.0);
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std::cout<<"Result is:\n"<<result<<std::endl;
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if(auto value = result["value"]) {
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// there is a .value field
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// as may still throw pvxs::NoConvert if its value can't
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// be converted to int32_t
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current = value.as<int32_t>();
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} else {
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// an example. won't happen with mailbox server
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std::cerr<<"Server type doesn't have .value field!\n";
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return 1;
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}
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}
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{
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// attempt to change.
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// uses simple builder form to assign .value
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ctxt.put(argv[1])
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.set("value", current+1)
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.exec()
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->wait(5.0);
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std::cout<<"First increment successful"<<std::endl;
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}
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{
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// change again.
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// use build() callback
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auto op = ctxt.put(argv[1])
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// provide present value to build() callback.
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.fetchPresent(true)
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.build([](Value&& current) -> Value {
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// allocate an empty container
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auto toput(current.cloneEmpty());
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// fill in .value.
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// Assignment implicitly marks .value as changed
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toput["value"] = current["value"].as<int32_t>() + 1;
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// return the container to be sent
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return toput;
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})
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.exec();
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op->wait(5.0);
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std::cout<<"Second increment successful"<<std::endl;
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}
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// fetch final value
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{
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std::cout<<"Getting current value of '"<<argv[1]<<"'"<<std::endl;
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// Build and start network operation
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auto result = ctxt.get(argv[1])
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.exec()
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->wait(5.0);
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std::cout<<"Result is:\n"<<result<<std::endl;
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}
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}
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