[Spice-devel] [PATCH spice-streaming-agent 3/9] Implement an exception hierarchy for ReadError

[Lukáš Hrázký]

Introduces an exception hierarchy up to a ReadError class, which is
thrown from read_all().

Signed-off-by: Lukáš Hrázký <lhrazky at redhat.com>
---
 src/Makefile.am               |  2 ++
 src/error.cpp                 | 29 ++++++++++++++++++++++++++++
 src/error.hpp                 | 44 +++++++++++++++++++++++++++++++++++++++++++
 src/spice-streaming-agent.cpp |  2 +-
 src/stream-port.cpp           |  4 ++--
 5 files changed, 78 insertions(+), 3 deletions(-)
 create mode 100644 src/error.cpp
 create mode 100644 src/error.hpp

diff --git a/src/Makefile.am b/src/Makefile.am
index 604c1e5..18ed22c 100644
--- a/src/Makefile.am
+++ b/src/Makefile.am
@@ -52,6 +52,8 @@ spice_streaming_agent_SOURCES = \
 	spice-streaming-agent.cpp \
 	concrete-agent.cpp \
 	concrete-agent.hpp \
+	error.cpp \
+	error.hpp \
 	mjpeg-fallback.cpp \
 	mjpeg-fallback.hpp \
 	jpeg.cpp \
diff --git a/src/error.cpp b/src/error.cpp
new file mode 100644
index 0000000..1b76ea4
--- /dev/null
+++ b/src/error.cpp
@@ -0,0 +1,29 @@
+/* The errors module.
+ *
+ * \copyright
+ * Copyright 2018 Red Hat Inc. All rights reserved.
+ */
+
+#include "error.hpp"
+
+#include <string.h>
+#include <syslog.h>
+
+
+namespace spice {
+namespace streaming_agent {
+
+Error::Error(const std::string &message) : message(message) {}
+
+const char* Error::what() const noexcept
+{
+    return message.c_str();
+}
+
+IOError::IOError(const std::string &msg, int errno_) :
+    Error(msg + ": " + std::to_string(errno_) + " - " + strerror(errno_))
+{}
+
+ReadError::ReadError(const std::string &msg, int errno_) : IOError(msg, errno_) {}
+
+}} // namespace spice::streaming_agent
diff --git a/src/error.hpp b/src/error.hpp
new file mode 100644
index 0000000..de1cb83
--- /dev/null
+++ b/src/error.hpp
@@ -0,0 +1,44 @@
+/* The errors module.
+ *
+ * \copyright
+ * Copyright 2018 Red Hat Inc. All rights reserved.
+ */
+
+#ifndef SPICE_STREAMING_AGENT_ERROR_HPP
+#define SPICE_STREAMING_AGENT_ERROR_HPP
+
+#include <exception>
+#include <string>
+
+
+namespace spice {
+namespace streaming_agent {
+
+class Error : public std::exception
+{
+public:
+    Error(const std::string &message);
+    const char *what() const noexcept override final;
+
+protected:
+    const std::string message;
+};
+
+class IOError : public Error
+{
+public:
+    IOError(const std::string &msg, int errno_);
+
+protected:
+    int errno_;
+};
+
+class ReadError : public IOError
+{
+public:
+    ReadError(const std::string &msg, int errno_);
+};
+
+}} // namespace spice::streaming_agent
+
+#endif // SPICE_STREAMING_AGENT_ERROR_HPP
diff --git a/src/spice-streaming-agent.cpp b/src/spice-streaming-agent.cpp
index 7b166d3..2c0340d 100644
--- a/src/spice-streaming-agent.cpp
+++ b/src/spice-streaming-agent.cpp
@@ -535,7 +535,7 @@ int main(int argc, char* argv[])
     try {
         do_capture(streamport, f_log);
     }
-    catch (std::runtime_error &err) {
+    catch (std::exception &err) {
         syslog(LOG_ERR, "%s\n", err.what());
         ret = EXIT_FAILURE;
     }
diff --git a/src/stream-port.cpp b/src/stream-port.cpp
index 3699d92..f256698 100644
--- a/src/stream-port.cpp
+++ b/src/stream-port.cpp
@@ -5,6 +5,7 @@
  */
 
 #include "stream-port.hpp"
+#include "error.hpp"
 
 #include <errno.h>
 #include <string.h>
@@ -25,8 +26,7 @@ void read_all(int fd, void *msg, size_t len)
             if (errno == EINTR) {
                 continue;
             }
-            throw std::runtime_error("Reading message from device failed: " +
-                                     std::string(strerror(errno)));
+            throw ReadError("Reading message from device failed", errno);
         }
 
         len -= n;
-- 
2.16.2