From 5ef11d113a3ae98acb566736198622403c0615c7 Mon Sep 17 00:00:00 2001
From: Tomasz Grabiec <tgrabiec@cloudius-systems.com>
Date: Thu, 16 Apr 2015 13:15:07 +0200
Subject: [PATCH 1/2] types: Improve code readability

---
 keys.hh | 27 +++++++++++++++++++++------
 1 file changed, 21 insertions(+), 6 deletions(-)

diff --git a/keys.hh b/keys.hh
index 4ccab53e92..292bfbd673 100644
--- a/keys.hh
+++ b/keys.hh
@@ -264,8 +264,13 @@ public:
 public:
     using tuple = lw_shared_ptr<tuple_type<allow_prefixes::no>>;
 
-    static partition_key from_bytes(bytes b) { return partition_key(std::move(b)); }
-    static auto get_tuple_type(const schema& s) { return s.partition_key_type; }
+    static partition_key from_bytes(bytes b) {
+        return partition_key(std::move(b));
+    }
+
+    static const tuple& get_tuple_type(const schema& s) {
+        return s.partition_key_type;
+    }
 };
 
 class exploded_clustering_prefix {
@@ -294,8 +299,13 @@ public:
 public:
     using tuple = lw_shared_ptr<tuple_type<allow_prefixes::no>>;
 
-    static clustering_key from_bytes(bytes b) { return clustering_key(std::move(b)); }
-    static auto get_tuple_type(const schema& s) { return s.clustering_key_type; }
+    static clustering_key from_bytes(bytes b) {
+        return clustering_key(std::move(b));
+    }
+
+    static const tuple& get_tuple_type(const schema& s) {
+        return s.clustering_key_type;
+    }
 
     static clustering_key from_clustering_prefix(const schema& s, const exploded_clustering_prefix& prefix) {
         assert(prefix.is_full(s));
@@ -308,8 +318,13 @@ class clustering_key_prefix : public prefix_tuple_wrapper<clustering_key_prefix,
 public:
     using tuple = lw_shared_ptr<tuple_type<allow_prefixes::yes>>;
 
-    static clustering_key_prefix from_bytes(bytes b) { return clustering_key_prefix(std::move(b)); }
-    static auto get_tuple_type(const schema& s) { return s.clustering_key_prefix_type; }
+    static clustering_key_prefix from_bytes(bytes b) {
+        return clustering_key_prefix(std::move(b));
+    }
+
+    static const tuple& get_tuple_type(const schema& s) {
+        return s.clustering_key_prefix_type;
+    }
 
     static clustering_key_prefix from_clustering_prefix(const schema& s, const exploded_clustering_prefix& prefix) {
         return from_exploded(s, prefix.components());

From bacede04b2cc752fedd479eb7fda106bdf6b3342 Mon Sep 17 00:00:00 2001
From: Tomasz Grabiec <tgrabiec@cloudius-systems.com>
Date: Thu, 16 Apr 2015 13:15:30 +0200
Subject: [PATCH 2/2] types: Expose component iterators in tuple_wrapper

This automatically exposes them in partition_key and clustering_key too.

The iterators return bytes_view to components.

For example:

  schema s;
  partition_key k;

  for (bytes_view component : boost::make_iterator_range(key.begin(s), key.end(s))) {
     // ...
  }
---
 keys.hh                   | 10 ++++++++++
 tests/urchin/keys_test.cc | 29 +++++++++++++++++++++++++++++
 2 files changed, 39 insertions(+)

diff --git a/keys.hh b/keys.hh
index 292bfbd673..3c36749401 100644
--- a/keys.hh
+++ b/keys.hh
@@ -109,6 +109,16 @@ public:
     operator bytes_view() const {
         return _bytes;
     }
+
+    // begin() and end() return iterators over components of this tuple. The iterator yields a bytes_view to the component.
+    auto begin(const schema& s) const {
+        return get_tuple_type(s)->begin(_bytes);
+    }
+
+    // See begin()
+    auto end(const schema& s) const {
+        return get_tuple_type(s)->end(_bytes);
+    }
 };
 
 template <typename TopLevel, typename PrefixTopLevel>
diff --git a/tests/urchin/keys_test.cc b/tests/urchin/keys_test.cc
index d76ec3c945..2dc706efbc 100644
--- a/tests/urchin/keys_test.cc
+++ b/tests/urchin/keys_test.cc
@@ -25,3 +25,32 @@ BOOST_AUTO_TEST_CASE(test_key_is_prefixed_by) {
     BOOST_REQUIRE(!key.is_prefixed_by(s, clustering_key_prefix::from_exploded(s, {bytes("abc")})));
     BOOST_REQUIRE(!key.is_prefixed_by(s, clustering_key_prefix::from_exploded(s, {bytes("ab")})));
 }
+
+BOOST_AUTO_TEST_CASE(test_key_component_iterator) {
+    schema s({}, "", "",
+        {
+            {"c1", bytes_type}
+        }, {
+            {"c2", bytes_type}, {"c3", bytes_type}, {"c4", bytes_type}
+        },
+        {}, {}, utf8_type);
+
+    auto key = clustering_key::from_exploded(s, {bytes("a"), bytes("b"), bytes("c")});
+
+    auto i = key.begin(s);
+    auto end = key.end(s);
+
+    BOOST_REQUIRE(i != end);
+    BOOST_REQUIRE(*i == bytes_view(bytes("a")));
+    ++i;
+
+    BOOST_REQUIRE(i != end);
+    BOOST_REQUIRE(*i == bytes_view(bytes("b")));
+    ++i;
+
+    BOOST_REQUIRE(i != end);
+    BOOST_REQUIRE(*i == bytes_view(bytes("c")));
+    ++i;
+
+    BOOST_REQUIRE(i == end);
+}