From 80ce9b72a1e703a6cb2e1cd90961676da400d2f3 Mon Sep 17 00:00:00 2001
From: Piotr Sarna <sarna@scylladb.com>
Date: Wed, 11 Jul 2018 10:47:22 +0200
Subject: [PATCH] cql3: add value_for method

In order to extract value from a restriction for just one column,
value_for(column_name, options) method is implemented.
It's needed because once ALLOW FILTERING support was introduced,
index-related restrictions may contain more than 1 value.
---
 cql3/restrictions/restrictions.hh                           | 4 ++++
 cql3/restrictions/single_column_primary_key_restrictions.hh | 5 +++++
 cql3/restrictions/single_column_restrictions.hh             | 5 +++++
 cql3/restrictions/statement_restrictions.cc                 | 3 +++
 4 files changed, 17 insertions(+)

diff --git a/cql3/restrictions/restrictions.hh b/cql3/restrictions/restrictions.hh
index 111e182f6e..886ede07c3 100644
--- a/cql3/restrictions/restrictions.hh
+++ b/cql3/restrictions/restrictions.hh
@@ -68,6 +68,10 @@ public:
 
     virtual std::vector<bytes_opt> values(const query_options& options) const = 0;
 
+    virtual bytes_opt value_for(const column_definition& cdef, const query_options& options) const {
+        throw exceptions::invalid_request_exception("Single value can be obtained from single-column restrictions only");
+    }
+
     /**
      * Returns <code>true</code> if one of the restrictions use the specified function.
      *
diff --git a/cql3/restrictions/single_column_primary_key_restrictions.hh b/cql3/restrictions/single_column_primary_key_restrictions.hh
index d310f05211..5f6655ab4e 100644
--- a/cql3/restrictions/single_column_primary_key_restrictions.hh
+++ b/cql3/restrictions/single_column_primary_key_restrictions.hh
@@ -310,6 +310,11 @@ public:
         }
         return res;
     }
+
+    virtual bytes_opt value_for(const column_definition& cdef, const query_options& options) const override {
+        return _restrictions->value_for(cdef, options);
+    }
+
     std::vector<bytes_opt> bounds(statements::bound b, const query_options& options) const override {
         // TODO: if this proved to be required.
         fail(unimplemented::cause::LEGACY_COMPOSITE_KEYS); // not 100% correct...
diff --git a/cql3/restrictions/single_column_restrictions.hh b/cql3/restrictions/single_column_restrictions.hh
index 6408d53fee..63a97feb06 100644
--- a/cql3/restrictions/single_column_restrictions.hh
+++ b/cql3/restrictions/single_column_restrictions.hh
@@ -111,6 +111,11 @@ public:
         return r;
     }
 
+    virtual bytes_opt value_for(const column_definition& cdef, const query_options& options) const override {
+        auto it = _restrictions.find(std::addressof(cdef));
+        return (it != _restrictions.end()) ? it->second->value(options) : bytes_opt{};
+    }
+
     /**
      * Returns the restriction associated to the specified column.
      *
diff --git a/cql3/restrictions/statement_restrictions.cc b/cql3/restrictions/statement_restrictions.cc
index 8772bfc028..2ced16c4bf 100644
--- a/cql3/restrictions/statement_restrictions.cc
+++ b/cql3/restrictions/statement_restrictions.cc
@@ -72,6 +72,9 @@ public:
         // throw? should not reach?
         return {};
     }
+    bytes_opt value_for(const column_definition& cdef, const query_options& options) const override {
+        return {};
+    }
     std::vector<T> values_as_keys(const query_options& options) const override {
         // throw? should not reach?
         return {};