QPID-4710: [AMQP 1.0] Support for transactions in qpid::messaging C++ client.

Implements the "transactional retire and settle immediately" option for
transactions as specified in AMQP 1.0 in the qpid::messaging C++ client.

NOTE: Transactions over AMQP 1.0 require proton 0.9 or greater.  With older
versions, attempting a transactions over AMQP 1.0 will raise a link-detached
exception "Node not found: tx-transaction"

1. Added descriptor list to Variant with support in Encoder and PnData.

Required to support transactions, need to be able to create described lists.
Variant changes are source and binary compatible.

A Variant now has a Variant::List of descripors which can be numeric or string.
Nested descriptors are implemented by putting multiple descriptors in the list.

Other minor changes:
- Variant refactor: don't delete impl on every assignment.
- Add Variant constructors that take a string encoding.
  (new constructors, not defaulted arguments, so the change is binary and source compatible.)
- Growable buffer support for Encoder.
- Printing described Variant prints descriptors in form @descriptor value

2. Added transaction support to AMQP 1.0 client code

Added messaging/amqp/Transaction.h,cpp: transaction logic
- communicate with coordinator, send declare/dischange messages.
- add tx state info to transfers and acknowledgements.
- Sync session after discharge.
- A transactional session automatically acks any message retrieved by fetch/get
  to bring them into the transaction. This is consistent the 0-10 client.

Minor fixes to existing client code:
- Fix use of pn_drain API in C++ client to work with C++ and Java brokers.
- Make amqp::Exception derive from qpid::Exception

3. Fixes to existing broker code:

- Incoming.cpp fix: start async completion before processing message.
- Delay accept of dischage message till commit is complete.
- newSession - handle failover during session creation.

4. Added tests

interop_tests.py: transaction tests that can run against an external broker, see comments.

ha_tests.py: Enable transaction tests over AMQP 1.0.

Minor test fixes:
- brokertest.py don't set default logging if QPID_LOG env vars set.
- brokertest.py Pass kwargs to broker() create function.
- qpid-receive: capacity should never be larger than message count.
- Accept user:pass as well as user/pass in Url.
- brokertest.py: Always do a ready() check on all brokers.

If proton < 0.9 is used, transaction tests will be skipped or will downgrade to
the amqp0-10 protocol with a printed warning.

git-svn-id: https://svn.apache.org/repos/asf/qpid/trunk@1662743 13f79535-47bb-0310-9956-ffa450edef68

1 files changed, 42 insertions, 3 deletions

diff --git a/qpid/cpp/include/qpid/types/Variant.h b/qpid/cpp/include/qpid/types/Variant.h
index faba5fe9a4..843870e438 100644
--- a/qpid/cpp/include/qpid/types/Variant.h
+++ b/qpid/cpp/include/qpid/types/Variant.h
@@ -89,7 +89,9 @@ class QPID_TYPES_CLASS_EXTERN Variant
     QPID_TYPES_EXTERN Variant(float);
     QPID_TYPES_EXTERN Variant(double);
     QPID_TYPES_EXTERN Variant(const std::string&);
+    QPID_TYPES_EXTERN Variant(const std::string& value, const std::string& encoding);
     QPID_TYPES_EXTERN Variant(const char*);
+    QPID_TYPES_EXTERN Variant(const char* value, const char* encoding);
     QPID_TYPES_EXTERN Variant(const Map&);
     QPID_TYPES_EXTERN Variant(const List&);
     QPID_TYPES_EXTERN Variant(const Variant&);
@@ -156,9 +158,10 @@ class QPID_TYPES_CLASS_EXTERN Variant
     QPID_TYPES_EXTERN Map& asMap();
     QPID_TYPES_EXTERN const List& asList() const;
     QPID_TYPES_EXTERN List& asList();
+
     /**
-     * Unlike asString(), getString() will not do any conversions and
-     * will throw InvalidConversion if the type is not STRING.
+     * Unlike asString(), getString() will not do any conversions.
+     * @exception InvalidConversion if the type is not STRING.
      */
     QPID_TYPES_EXTERN const std::string& getString() const;
     QPID_TYPES_EXTERN std::string& getString();
@@ -168,9 +171,45 @@ class QPID_TYPES_CLASS_EXTERN Variant
 
     QPID_TYPES_EXTERN bool isEqualTo(const Variant& a) const;
 
+    /** Reset value to VOID, does not reset the descriptors. */
     QPID_TYPES_EXTERN void reset();
+
+    /** True if there is at least one descriptor associated with this variant. */
+    QPID_TYPES_EXTERN bool isDescribed() const;
+
+    /** Get the first descriptor associated with this variant.
+     *
+     * Normally there is at most one descriptor, when there are multiple
+     * descriptors use getDescriptors()
+     *
+     *@return The first descriptor or VOID if there is no descriptor.
+     *@see isDescribed, getDescriptors
+     */
+    QPID_TYPES_EXTERN Variant getDescriptor() const;
+
+    /** Set a single descriptor for this Variant. The descriptor must be a string or integer. */
+    QPID_TYPES_EXTERN void setDescriptor(const Variant& descriptor);
+
+    /** Return a modifiable list of descriptors for this Variant.
+     * Used in case where there are multiple descriptors, for a single descriptor use
+     * getDescriptor and setDescriptor.
+     */
+    QPID_TYPES_EXTERN List& getDescriptors();
+
+    /** Return the list of descriptors for this Variant.
+     * Used in case where there are multiple descriptors, for a single descriptor use
+     * getDescriptor and setDescriptor.
+     */
+    QPID_TYPES_EXTERN const List& getDescriptors() const;
+
+    /** Create a described value */
+    QPID_TYPES_EXTERN static Variant described(const Variant& descriptor, const Variant& value);
+
+    /** Create a described list, a common special case */
+    QPID_TYPES_EXTERN static Variant described(const Variant& descriptor, const List& value);
+
   private:
-    VariantImpl* impl;
+    mutable VariantImpl* impl;
 };
 
 #ifndef SWIG