ca provider skeleton

pvAccessApp/Makefile

@@ -85,6 +85,10 @@ SRC_DIRS += $(PVACCESS)/rpcClient
 INC += rpcClient.h
 LIBSRCS += rpcClient.cpp
 
+SRC_DIRS += $(PVACCESS)/ca
+INC += caProvider.h
+LIBSRCS += caProvider.cpp
+
 SRC_DIRS += $(PVACCESS)/mb
 INC += pvAccessMB.h
 LIBSRCS += pvAccessMB.cpp
@@ -92,5 +96,6 @@ LIBSRCS += pvAccessMB.cpp
 LIBRARY = pvAccess
 pvAccess_LIBS += Com
 pvAccess_LIBS += pvData
+pvAccess_LIBS += ca
 
 include $(TOP)/configure/RULES

pvAccessApp/ca/caProvider.cpp

@@ -0,0 +1,111 @@
+/**
+ * Copyright - See the COPYRIGHT that is included with this distribution.
+ * pvAccessCPP is distributed subject to a Software License Agreement found
+ * in file LICENSE that is included with this distribution.
+ */
+
+#include <pv/logger.h>
+#include <pv/caProvider.h>
+
+#include <cadef.h>
+
+using namespace epics::pvData;
+using namespace epics::pvAccess;
+
+#define EXCEPTION_GUARD(code) try { code; } \
+        catch (std::exception &e) { LOG(logLevelError, "Unhandled exception caught from client code at %s:%d: %s", __FILE__, __LINE__, e.what()); } \
+                catch (...) { LOG(logLevelError, "Unhandled exception caught from client code at %s:%d.", __FILE__, __LINE__); }
+
+CAChannelProvider::CAChannelProvider()
+{
+    initialize();
+}
+
+CAChannelProvider::~CAChannelProvider()
+{
+}
+
+epics::pvData::String CAChannelProvider::getProviderName()
+{
+    return "ca";
+}
+
+void CAChannelProvider::destroy()
+{
+    /* Shut down Channel Access */
+    ca_context_destroy();
+}
+
+ChannelFind::shared_pointer CAChannelProvider::channelFind(
+        epics::pvData::String const & channelName,
+        ChannelFindRequester::shared_pointer const & channelFindRequester)
+{
+    if (channelName.empty())
+        throw std::invalid_argument("empty channel name");
+
+    if (!channelFindRequester)
+        throw std::invalid_argument("null requester");
+
+    Status errorStatus(Status::STATUSTYPE_ERROR, "not implemented");
+    ChannelFind::shared_pointer nullChannelFind;
+    EXCEPTION_GUARD(channelFindRequester->channelFindResult(errorStatus, nullChannelFind, false));
+    return nullChannelFind;
+}
+
+Channel::shared_pointer CAChannelProvider::createChannel(
+        epics::pvData::String const & channelName,
+        ChannelRequester::shared_pointer const & channelRequester,
+        short priority)
+{
+    static String emptyString;
+    return createChannel(channelName, channelRequester, priority, emptyString);
+}
+
+Channel::shared_pointer CAChannelProvider::createChannel(
+        epics::pvData::String const & channelName,
+        ChannelRequester::shared_pointer const & channelRequester,
+        short priority,
+        epics::pvData::String const & address)
+{
+    if (!address.empty())
+        throw std::invalid_argument("CA does not support 'address' parameter");
+
+    // TODO
+    Status errorStatus(Status::STATUSTYPE_ERROR, "not implemented");
+    Channel::shared_pointer nullChannel;
+    EXCEPTION_GUARD(channelRequester->channelCreated(errorStatus, nullChannel));
+    return nullChannel;
+
+    // NOTE it's up to internal code to respond w/ error to requester and return 0 in case of errors
+}
+
+void CAChannelProvider::configure(epics::pvData::PVStructure::shared_pointer /*configuration*/)
+{
+}
+
+void CAChannelProvider::flush()
+{
+}
+
+void CAChannelProvider::poll()
+{
+}
+
+void CAChannelProvider::initialize()
+{
+    /* Create Channel Access */
+    int result = ca_context_create(ca_disable_preemptive_callback);
+    if (result != ECA_NORMAL) {
+        throw std::runtime_error(std::string("CA error %s occurred while trying "
+                "to start channel access:") + ca_message(result));
+    }
+
+    // TODO create a ca_poll thread
+}
+
+ChannelProvider::shared_pointer createCAChannelProvider()
+{
+    ChannelProvider::shared_pointer ptr(new CAChannelProvider());
+    return ptr;
+}
+

pvAccessApp/ca/caProvider.h

@@ -0,0 +1,57 @@
+/**
+ * Copyright - See the COPYRIGHT that is included with this distribution.
+ * pvAccessCPP is distributed subject to a Software License Agreement found
+ * in file LICENSE that is included with this distribution.
+ */
+
+#ifndef CAPROVIDER_H
+#define CAPROVIDER_H
+
+#include <pv/pvAccess.h>
+
+namespace epics {
+namespace pvAccess {
+
+class CAChannelProvider :
+        public ChannelProvider
+{
+public:
+
+    CAChannelProvider();
+    virtual ~CAChannelProvider();
+
+    virtual epics::pvData::String getProviderName();
+
+    virtual void destroy();
+
+    virtual ChannelFind::shared_pointer channelFind(
+            epics::pvData::String const & channelName,
+            ChannelFindRequester::shared_pointer const & channelFindRequester);
+
+
+    virtual Channel::shared_pointer createChannel(
+            epics::pvData::String const & channelName,
+            ChannelRequester::shared_pointer const & channelRequester,
+            short priority);
+
+    virtual Channel::shared_pointer createChannel(
+            epics::pvData::String const & channelName,
+            ChannelRequester::shared_pointer const & channelRequester,
+            short priority,
+            epics::pvData::String const & address);
+
+    virtual void configure(epics::pvData::PVStructure::shared_pointer configuration);
+    virtual void flush();
+    virtual void poll();
+
+private:
+
+    void initialize();
+};
+
+extern ChannelProvider::shared_pointer createCAChannelProvider();
+
+
+}}
+
+#endif  /* CAPROVIDER_H */

pvAccessCPP.files

@@ -187,3 +187,5 @@ README
 runTestServer
 TODO
 testApp/remote/pvinfo.cpp
+pvAccessApp/ca/caProvider.h
+pvAccessApp/ca/caProvider.cpp